PROVIDED ON BEHALF OF THE DEPARTMENT FOR WORK AND PENSIONS. Training & Development Assessment of Neurological Conditions for Registered Nurses

Transcription

1 MEDICAL SERVICES PROVIDED ON BEHALF OF THE DEPARTMENT FOR WORK AND PENSIONS Training & Development Assessment of Neurological Conditions for Registered Nurses (Pre Course Reading) MED-RNEXNEURO~001(a) Version: 20 November 2012

2

3 Foreword This pre-course reading document has been produced as part of a training programme for registered nurses approved by the Department for Work and Pensions Chief Medical Adviser to carry out medical assessments in Employment and Support Allowance (ESA). All registered nurses undertaking medical assessments must be registered practitioners who in addition, have undergone training in disability assessment medicine and specific training in ESA. The training includes theory training in a classroom setting, supervised practical training, and a demonstration of understanding as assessed by quality audit. This pre-course reading document must be read with the understanding that, as experienced Health Care Professionals and disability analysts, the registered nurses will have detailed knowledge of the principles and practice of diagnostic techniques, and therefore such information is not contained in this pre-course reading document. In addition, the pre-course reading document is not a stand-alone document, and forms only a part of the training and written documentation that a Health Care Professional receives. As disability assessment is a practical occupation, much of the guidance also involves verbal information and coaching. Thus, although the pre-course reading document may be of interest to non-medical readers, it must be remembered that some of the information may not be readily understood without background medical knowledge and an awareness of the other training given to Health Care Professionals. Office of the Chief Medical Adviser November 2012 MED-RNEXNEURO~001(a) Page 2

4

5 Document control Superseded documents Version history Version Date Comments 3 Final 6 July 2011 Final sign of by CMMS 4a draft 26 July 2012 Schedule 28 review 4b draft 09 August 2012 Revised post internal QA comments 4c draft 17 August 2012 Further revisions post internal QA comments 4d draft 3 October 2012 Further revisions post internal QA comments 20 November 2012 Signed off by HWD and CMMS Changes since last version P6 Trainer event changed to trainer-led course P19 & 29 Tricep supinator reflex root value clarification P39 & 44 Evidence based protocols version 2 updated to latest version P40 Straight leg raise clarification about testing lying vs. sitting. P41 Plantar reflexion corrected to plantar flexion Outstanding issues and omissions Updates to Standards incorporated Issue control Author: Owner and approver: Signature: Distribution: Medical Training and Development Team National Clinical Manager (Performance) Date: MED-RNEXNEURO~001(a) Page 3

6

7 Contents Introduction 6 A guide to using this pack 7 Section One Instructions for the MCQ Test 9 Section Two Neuroanatomy and Neurophysiology 10 Objectives 10 Materials 10 Duration 10 Cells, Neurons and Neuromuscular Junctions 11 Central Nervous System 12 Peripheral Nervous System 14 Autonomic Nervous System 17 Reflexes 19 Upper Motor Neuron versus Lower Motor Neuron Lesions 21 Section Three - Neurological Examination 24 Objectives 24 Materials 24 Duration 24 History 25 Observation 25 Examination 26 Section Four - Specific Conditions 38 Objectives 38 Materials 38 Duration 38 Prolapsed Intervertebral Disc / Sciatica 39 Cause 39 Symptoms and Signs 40 Treatment 41 Functional impact 41 MED-RNEXNEURO~001(a) Page 4

8 Cervical spondylosis 44 Cause 44 Symptoms and Signs 44 Treatment 45 Functional impact 46 Peripheral neuropathy 48 Cause 48 Symptoms and Signs 49 Treatment 50 Functional impact 51 Nerve Compression Syndromes / Focal Neuropathy 53 Median nerve (carpal tunnel syndrome) 53 Ulnar Nerve 55 Radial Nerve 57 Common Peroneal Nerve 58 Lateral Cutaneous Nerve of the Thigh 59 Brachial Plexus Injuries 60 Thoracic Outlet Syndrome 61 Raynaud s Phenomenon, Hand Arm Vibration Syndrome (HAVS) and Vibration White Finger (VWF) 64 Raynaud s Phenomenon 64 Hand-Arm Vibration Syndrome (HAVS) 65 Vibration White Finger (VWF) 65 Functional Impact 65 Glossary 67 Observation form 72 MED-RNEXNEURO~001(a) Page 5

9 Introduction Welcome to your pre-course reading for the neurological examination training course for Registered General Nurses (RGNs) who are already trained in Revised Work Capability Assessment (RWCA) Examinations. Following completion of this reading you will progress to a facilitated trainer led training event Neurological symptoms and conditions are common; approximately 10% of GP consultations are about a neurological symptom. In our role as Disability Analysts, roughly 20% of WCA cases examined have a neurological symptom or problem. The nervous system is the most elaborate bodily system. The field of neurology is correspondingly vast and complex. Neurological conditions can range from the simple to the highly complicated. The neurological system is therefore one of the most difficult systems to fully examine. The focus for this training will be on simple neurological conditions that are seen commonly within our work as disability analysts. Cases will continue to be sifted at the Pre Board Check (PBC) /scrutiny stage to determine whether the claimant should be assessed by a RGN or registered physiotherapist or by a medical practitioner. There may also be times, within the examination setting, when cases still need to be handed over to a medical practitioner. However following this training this is likely to be an infrequent event. RGNs within the company will have differing levels of knowledge depending on their prior experience. Some of you may be familiar with the some or all of the information contained within this document and for others it will be completely new. This document will cover the following topics: Basic Neurophysiology and Neuroanatomy Neuro-terminology Neurological Examination Specific Neurological Conditions Within each section there are several questions with text boxes to assist self reflection and aid learning. You should make a note of your answers and bring them along to the trainer led event. A text box has also been provided at the end of the document for you to record any issues or questions raised. You may want to discuss these with colleagues or raise them at the trainer led event. MED-RNEXNEURO~001(a) Page 6

10 After each small part of the pre-course reading has been completed, you should complete the online Multiple Choice Questions (MCQ). You are allowed access to your reading material at all times; the tests are all open book tests. Further instructions are provided in Section One of this document. This pre-course reading must be read and the online MCQ completed and passed prior to attending the trainer led event. If the MCQ is not completed, or a satisfactory score in the MCQ is not reached, then the participant will not be able to progress to the trainer-led course. This trainer led course will not cover the majority of the topics in the pre-course reading again, but will build on the knowledge within this document to develop the skills necessary to assess claimants with specific neurological conditions. It is anticipated that this pre-course reading and associated questions will take you about 3.5 hours in total. You may find it easier to break the reading into smaller amounts. There is a document called the Neurological Condition List by Practitioner Type - MED-NEURODA~001 which contains a list of which conditions can be seen by RGNs who have completed the neurology training and physiotherapists and those conditions which must be seen by a doctor. The list is not comprehensive and is added to regularly as additional conditions are identified. The most up to date version is held on LiveLink. Please familiarise yourself with the document prior to attending the face to face training course. A guide to using this pack The following symbols are used to assist you in completing the learning activities included in this folder. Indicates a time for reading. Indicates you should record / write your views and comments. Advises you of the materials that are provided and/or needed. Duration Suggests the approximate time needed to complete any particular learning activity There is a glossary at end of this pre-course reading which you may find useful. It MED-RNEXNEURO~001(a) Page 7

11 contains definitions of neurological and medical terms used within this document. Pre-course Reading Objectives Through completion of this pre-course reading you should: Understand basic concepts of neurophysiology and neuroanatomy Understand neurological examination required in the context of disability assessments Be aware of specific neurological conditions MED-RNEXNEURO~001(a) Page 8

12 Section One Instructions for the MCQ Test Once you have completed reading each small part of this pre-course reading document, you will need to complete the MCQ following that particular part. This is an on-line test. This test must be completed and passed before attending the trainer led event. Shortly you will receive, in your work inbox, an automatic from THE TEST FACTORY containing the link to access the on-line MCQ. If you do not receive this please contact your training coordinator in your Medical Service Centre (MSC). When you receive this , click on the link and follow the instructions. The relevant questions, for each part of the pre-course reading, will follow that particular part of the pre-course reading. There are 53 questions in total. Once you have completed all the parts of the MCQ test, your score will be automatically displayed. A score of 84% (45 questions correct) or above indicates a pass. If you fail the MCQ you will be allowed to re-sit the test once. You will need to contact your training coordinator to arrange re-assignment of the test. Once the test has been re-assigned to you, you will receive a further from the Test Factory with the link to access the on-line re-sit. You should however re-read the pre course reading before attempting the re-sit of the test. MED-RNEXNEURO~001(a) Page 9

13 Section Two Neuroanatomy and Neurophysiology This section contains an overview of the principles of basic neurophysiology and neuroanatomy. The site of a lesion or problem within the neuromuscular system will often lead to a characteristic set of signs and symptoms. Therefore knowledge of these principles will assist you assessing neurological cases in your role as a disability analyst. Please spend some time considering the dermatome chart, especially the upper and lower limbs, and the myotomes described within this section, as these will be the subject of discussion at the trainer led event. Objectives By the end of this section you will be aware of: basic neurophysiology concepts basic neuroanatomy concepts dermatomes and myotomes the difference between the terms upper motor neuron and lower motor neuron Materials This booklet Pen / Pencil Duration The learning activities during this section should take approximately 70 minutes to complete. MED-RNEXNEURO~001(a) Page 10

14 Cells, Neurons and Neuromuscular Junctions The neuron (nerve cell) is the anatomic and functional building block of the nervous system. There are many millions of neurons in the nervous system and they vary in size shape and functional characteristics. Nevertheless in general they are composed of a cell body, dendrites (processes leading towards the cell body) and axons (processes leading away from the cell body). A neuron. The nervous system contains other cells which play important support roles including astrocytes, oligodendrocytes and microglial cells. The neuron conducts electrical impulses. Many neurons have myelin sheaths (myelinated neurons). Myelin sheaths are composed of specialised cells called Schwann cells, which wrap around the axon acting as insulation and so assisting in the conduction of the electrical impulses. A Schwann cell wrapping around an axon MED-RNEXNEURO~001(a) Page 11

15 A myelinated neuron The electrical impulses travel along nerve cells until they reach their destination, which may be a nerve cell or another type of cell (e.g. muscle). Synapses are contacts between 2 cells that allow transmission of signals from one nerve cell to another nerve cell or from a nerve cell to another type of cell e.g. muscle or gland cell. In general synapses use chemicals known as neurotransmitters to communicate between the cells. Examples of neurotransmitters include dopamine and serotonin. Some synapses are excitatory (making a nerve cell more likely to produce and carry an impulse); some are inhibitory (making a nerve cell less likely to produce and carry an impulse). Communication from a neuron to a voluntary (skeletal) muscle cell occurs at the motor end plate (also known as myoneural junction). One motor neuron usually supplies a number of muscles cells (known as a motor unit). Central Nervous System The central nervous system (CNS) consists of the brain and the spinal cord. The brain is made up of the cerebrum, cerebellum and brain stem. MED-RNEXNEURO~001(a) Page 12

16 The cerebrum consists of the right and left cerebral hemispheres. It is concerned with cognition, the higher (voluntary) control of movement, perception of sensation (touch, pain, pressure and temperature), vision and hearing. The cerebellum operates at an unconscious level. It controls muscle tone and posture and the co-ordination of movement. The brainstem contains centres controlling vital functions including respiration, the cardiovascular system and level of consciousness. It is also the origin of many of the cranial nerves. The spinal cord occupies the vertebral canal enclosed within the vertebral bodies. It is continuous with the brainstem. It provides sensory, motor and autonomic innervation for the trunk and limbs. Within the spinal cord and brainstem, nerves sharing common functions often follow the same course, known as tracts. There are ascending sensory tracts going to the brain from the periphery and descending motor tracts going away from the brain to the periphery. Broadly speaking, most of the sensory and motor tracts within the CNS cross to the other side. This is known as decussation. Therefore the left cerebral hemisphere perceives sensations and controls movement of the right side of the body and the right cerebral hemisphere perceives sensations and controls movement of the left side of the body. Different nerve tracts decussate at different levels of the CNS. The main motor tracts decussate in the brainstem, therefore lesions in the brain and higher brain stem will cause problems on the opposite side of the body. Lesions of the motor tracts in the spinal cord will cause problems on the same side of the body. Lesions of the spinal cord may produce two effects, firstly by causing loss of function at a local (segmental) level and secondly by damaging descending motor or ascending sensory tracts. MED-RNEXNEURO~001(a) Page 13

17 Peripheral Nervous System The peripheral nervous system is made up of the cranial and spinal nerves. There are 12 paired cranial nerves. As none of the conditions that RGNs will assess involve the cranial nerves, cranial nerves will not be further discussed in this document. There are 31 paired spinal nerves (8 cervical, 12 thoracic, 5 lumbar, 5 sacral and 1 coccygeal). Each segment of the spine gives off a ventral and dorsal root bilaterally. These unite in the intervertebral foramen to form a spinal nerve. The spinal cord ends at the level of the first lumbar vertebrae (L1). At this level the cord separates into the separate lumbar and sacral spinal nerves, known as the cauda equina ( horses tail ), that continue down the vertebral canal to their exit points. MED-RNEXNEURO~001(a) Page 14

18 Each spinal nerve contains sensory innervation for part of the body surface. This area of skin is known as a dermatome. Dermatome chart Note these areas are approximate only as adjacent spinal nerves do overlap (you may find minor variations between dermatome charts from different sources). All areas of the skin receive fibres from more than one spinal nerve, therefore damage to a single spinal nerve may cause little or no sensory loss. MED-RNEXNEURO~001(a) Page 15

19 In the region of the upper limbs and lower limbs the spinal nerves become redistributed within a nerve plexus to create peripheral nerves. Therefore the distribution of peripheral nerves is different from spinal nerves. The upper limb plexus is the brachial plexus which is located bilaterally in the axilla and neck. The lower limb plexus is the lumbosacral plexus which is located bilaterally within the pelvis. Peripheral nerves can become compressed and this leads to specific symptoms and signs based on the nerve involved. The group of skeletal muscles innervated by a spinal nerve is known as a myotome. These muscles are responsible for specific patterns of movement. The following illustrations demonstrate the segmental innervation of the main limb movements. MED-RNEXNEURO~001(a) Page 16

20 The sensory system is concerned with the sensations of pain, touch, temperature and proprioception. There are different receptors within the skin for pain, temperature, light touch, discriminative touch and vibration. Referred pain is pain felt at a site distant from the tissues causing the pain. It can be referred to the surface or deep within the body. It is often associated with pain from internal organs and may be felt at a site of the body which is far removed from its source (e.g. diaphragmatic pain can be felt in the tip of the shoulder or cardiac pain in the left shoulder). Referred pain from the ligaments and muscles of the spinal column can also be felt at remote sites in the upper and lower limbs. Autonomic Nervous System The autonomic nervous system (ANS) contains neurons within both the CNS and peripheral nervous system that control the internal (visceral) organs, smooth and cardiac muscle and the glands of the body. It is primarily concerned with the control of internal environment and functions at a subconscious level. The neurons of the autonomic nervous system are divided into 2 functional groups; sympathetic nerves and parasympathetic nerves. Most structures that are innervated by the autonomic nervous system are innervated by both types of nerves which exert opposite effects on that structure. Stimulation of the sympathetic system produces the fight and flight response which includes the following effects; tachycardia, decreased salivation, decreased bowel motility, increased sweating, inhibition of micturition and dilatation of bronchi. Stimulation of the parasympathetic system produces generally opposite effects including bradycardia, increased bowel motility, initiation of micturition and constriction of the bronchi. MED-RNEXNEURO~001(a) Page 17

21 Question Block A Please now use the on-line MCQ to answer the questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 18

22 Reflexes A reflex is an involuntary pattern of response following a stimulus. Deep tendon reflexes are stretch reflexes. When a muscle is stretched it responds by contracting. It is the simplest of reflexes and mediated by a monosynaptic reflex arc. This simply means that the pathways of the reflex consist of only afferent sensory neurons carrying impulses from the muscle stretch and efferent motor neurons carrying impulses back to the stretched muscle, as well as an inhibitory effect to the antagonistic muscle. Monosynaptic reflex arc Each of the commonly tested reflexes is subserved by specific spinal cord segments: Supinator (brachioradialis reflex) C6 Triceps C7 Biceps C5/C6 Knee (quadriceps) L3/L4 Ankle (achilles tendon) S1/S2 A plantar reflex (also known as Babinski reflex) is a superficial reflex rather than a deep tendon reflex. This has a much more complex pathway but in summary it provides information about the motor pathways to the lower limb. There will be more about reflexes within the neurological examination section. MED-RNEXNEURO~001(a) Page 19

23 Question Block B Please now use the on-line MCQ to answer some questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 20

24 Upper Motor Neuron versus Lower Motor Neuron Lesions Neurological conditions will often be described as an upper motor neuron condition or a lower motor neuron condition. Lower motor neurons are those that directly innervate skeletal muscle. They are the final common pathway by which the nervous system controls movement. Upper motor neurons are located in descending tracts, which control the activity of the lower motor neurons. Upper motor neuron lesions can occur in the brain or spinal cord. Lower motor neuron lesions can occur in the nerve roots or peripheral nerves. An upper motor neuron syndrome is usually characterised by the following symptoms and signs: weakness or paralysis of specific movements (e.g. extension of upper limbs) also known as pyramidal weakness no focal wasting of muscles increased resistance to passive stretching of muscles (spasticity) extensor (upwards) plantar reflex (if present, is a definite sign of an upper motor neuron condition) hyperactivity of deep tendon reflexes (hyperreflexia) A lower motor neuron syndrome is usually characterised by the following symptoms and signs: wasting of muscles weakness (paresis) or paralysis (plegia) of individual muscles fasciculations (a brief flickering contraction seen in the belly of the muscle) reduced resistance to passive stretching (hypotonia) decreased or lost deep tendon reflexes (hyporeflexia) MED-RNEXNEURO~001(a) Page 21

25 Consider the following questions What makes up the central nervous system? What makes up the peripheral nervous system? What makes up the autonomic nervous system? What signs would you expect to see in an upper motor neuron lesion? What signs would you expect to see in a lower motor neuron lesion? MED-RNEXNEURO~001(a) Page 22

26 Question Block C Please now use the on-line MCQ to answer some questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 23

27 Section Three - Neurological Examination The focus of this section will be on examination of the neurological system. However it will also cover history and observed behaviour. In your role as a disability analyst assessing neurological cases, the importance of careful and focused history taking, recording of observed behaviour and specific neurological examination cannot be overstated. It is always important to consider all pieces of evidence obtained in the light of what is medically reasonable. Your opinion must be fully justified and supported by evidence and any inconsistencies between pieces of evidence must always be addressed. Objectives By the end of this section you will be aware of: history taking in neurological cases observed behaviour in neurological cases principles of focused neurological examination Materials This booklet Pen / Pencil Duration The learning activities during this section should take approximately 70 minutes to complete. MED-RNEXNEURO~001(a) Page 24

28 History The history of the condition provides evidence which is important in the formulation of your opinion. You should ask about the following; Onset of the condition or problem What symptoms the claimant experiences Investigation and treatment received so far Progress with treatment With neurological symptoms it is very important to ask about the location of the symptoms experienced by the claimant. Depending on the medical condition reported it may be appropriate to ask whether the claimant has other symptoms which they have not mentioned such as paraesthesiae, numbness, weakness and problems with micturition or continence. Observation Observed behaviour remains a cornerstone of disability analysis. As always it is important to observe and record relevant informal observed behaviour such as sitting, standing, rising, use of arms, walking and getting on to and off the couch. Neurological conditions can, of course, affect any or all of these activities. Gait and balance are commonly affected. When assessing gait the following should be considered: Is the gait symmetrical or asymmetrical? Is the size of steps normal, small or large? Posture, is it upright (normal) or stooped? Do the arms swing normally or is this reduced or increased? What is the lateral distance between the feet, is it normal or increased? What is the position of the knees, are they being raised higher than normal? What about the movement of the pelvis and shoulders, are they normal or reduced / exaggerated? MED-RNEXNEURO~001(a) Page 25

29 A normal gait is symmetrical, with normal sized steps and an upright posture. The distance between the feet is normal and the knees are raised to a normal height Examples of abnormal gaits include: Hemiplegic, asymmetrical gait, with one leg swinging to the side. Seen in upper motor neuron lesions, such as stroke and multiple sclerosis. Parkinsonian, symmetrical small stepped shuffling gait, stooped, difficulty starting and stopping. There are many causes including Parkinson s disease, and as an effect of antipsychotic medication. Scissoring, symmetrical, feet cross over each other with toes dragging. Is an indication of spastic paresis and is seen in cord compression, cerebral palsy. High stepping, may be symmetrical or asymmetrical. Knee is raised higher than normal. Seen in bilateral or unilateral foot drop. Waddling, symmetrical, with excessive rotation of pelvis and shoulders. Is as a result of weak proximal muscles, causes include proximal myopathies, bilateral congenital dislocation of the hip. Antalgic, asymmetrical, claimant in pain, heavily reliant on non painful side, favouring non painful side. Orthopaedic, asymmetrical, associated with bony defects, such as a shortened limb. Ataxic, symmetrical wide based gait with irregular stride length, seen in cerebellar conditions and can be seen in peripheral neuropathy where joint position sense has been lost. Functional, may be symmetrical or asymmetrical, does not fit any recognised pattern, may get worse when known to be observed, not consistent with examination findings. Examination Before reading the following section you may find it helpful to re-read your physical skills pre-course reading document from your initial training course. It contains a description of general anatomical concepts and terms. Inspection As part of a regional neurological examination you should look for muscle wasting, ulceration, fasciculation (flickering contractions in belly of the muscle, which don t produce movement at a joint), trophic changes including ulceration, swelling of joints, malformation and signs of injury or surgery MED-RNEXNEURO~001(a) Page 26

30 Testing the Motor System Tone When testing tone it is important that the claimant is relaxed. This can be difficult to ensure especially as telling the claimant to relax may make them tense up. It can help to distract the claimant by talking generally about irrelevancies or asking them to count back from 100. Be aware when testing tone in limbs with painful joints, check with the claimant before moving the limb. In the upper limb, tone can be tested by taking the claimant s hand and initially pronating the hand then flexing the elbow, followed by flexing and extending the wrist. In the lower limb, tone can be tested by gently rotating the limb from side to side, then flexing knee and ankle joints. With normal tone there will be slight resistance throughout the whole range of movements. When tone is decreased there is a loss of the slight resistance. If there is significant loss of tone the limb will be flaccid. When tone is increased there is increased resistance. This can be of several types: Lead pipe rigidity where resistance is increased through out the entire range of movement Cogwheel rigidity where resistance breaks intermittently throughout whole range Clasp knife rigidity where after initial resistance to movement there is sudden reduction in tone and the limb moves freely throughout the rest of the range of the particular movement Reduced tone is seen in lower motor neuron lesions, cerebellar lesions and myopathies. Clasp knife rigidity is seen in upper motor neuron lesions where spasticity is present. Lead pipe rigidity and cogwheel rigidity is seen in extra pyramidal syndromes (see glossary). Power When examining power, consider what myotomes / spinal nerves / peripheral nerves you are actually testing for each movement. Conventional grading of power uses the Medical Research Council (MRC) scale. When grading power, the maximal power attained should be used, even if this is only sustained for a brief time. 5 normal power 4 movement against resistance MED-RNEXNEURO~001(a) Page 27

31 3 moves against gravity but not resistance 2 moves with gravity eliminated 1 flicker of movement can be seen in body of the muscle 0 no movement It is very important that any muscle weakness elicited during the examination is evaluated with other pieces of evidence. Is the weakness in an area that is consistent with the history? Are there corresponding changes in reflexes or tone? Can you consistently elicit the weakness or is it erratic? Is there a difference between the observed behaviour and formal examination findings? A claimant who is able to rise from a chair without difficulty, walks normally and is able to get on and off the couch without difficulty is unlikely to have significant weakness in the lower limb. Reflexes When testing reflexes it is important that the claimant is relaxed. Examination of reflexes cannot be performed unless the claimant is relaxed. As with tone, you may need to try to distract the claimant with conversation etc. Reflexes can be graded using the following scale: absent present but reduced normal increased (brisk) clonus Deep tendon reflexes are increased (brisk) in upper motor neuron lesions and reduced or absent in nerve root or peripheral nerve lesions and myopathies. Clonus is repetitive reflex contractions, most often seen in legs. Sudden dorsiflexion of the ankle joint will result in repetitive contractions. One or two beats of clonus can be normal, any more than 2 beats of clonus is always abnormal, and indicates substantially increased tone. If reflexes are absent, before they can be confirmed as absent, reinforcement manoeuvres may be carried out. These include: clenching teeth together (in upper limbs) hands clenched together across chest with claimant attempting to pull them apart (in lower limbs) MED-RNEXNEURO~001(a) Page 28

32 Isolated absent tendon reflexes may be a normal finding, but is uncommon in young people. When using a tendon hammer, you should ensure it is held correctly and swung rather than being used in a stabbing motion. This will be demonstrated at the trainer led event and you will be able to practice examining reflexes at this time. Biceps reflex This reflex tests the C5 and C6 nerve roots. You will need to expose the upper arm so that the biceps muscle is visible. With the claimant sitting ask them to place their hand in their lap, or if they are lying, ask them to place their hand palm down on their abdomen. Lay your index finger or thumb on the biceps tendon and hit your finger with the tendon hammer. Laying your finger on the biceps tendon ensures the stimulus is adequately transferred to the tendon. You should see a visible and feel a palpable contraction of biceps muscle. Triceps reflex This reflex tests the C7 nerve root.(some texts may also state C6 or C8 as contributors to this reflex, however C7 is the more consistent contributor.) You will need to expose the upper arm so that the triceps muscle is visible. Ask the claimant to bring their arm across their chest. Hold the wrist so that the elbow is held at 90 degrees. Hit the triceps tendon with the tendon hammer. MED-RNEXNEURO~001(a) Page 29

33 You should see visible contraction in the triceps muscle. Supinator reflex (also known as Brachioradialis) This reflex tests the C6 nerve root. You will need to expose the lower arm so that the brachioradialis muscle is visible. With claimant sitting ask them to place their hand in their lap, or if they are lying, place their hand palm down on their abdomen. Lay your finger on the brachoradialis tendon 3-5cm above the wrist joint and strike your finger with the tendon hammer. MED-RNEXNEURO~001(a) Page 30

34 You should see a visible and feel a palpable contraction of brachioradialis muscle. Knee reflex This reflex tests the L3 and L4 nerve roots. With the claimant lying down, place your arm under their knee drawing it up so that the knee is flexed to 90 degrees, with your arm supporting the weight of the leg. It is important that the claimant is relaxed. Strike the knee below the patella on the infrapatellar tendon with the tendon hammer. This can also be performed with the claimant sitting on the side of the couch, with knees at 90 degrees and lower legs dangling. You should see a visible contraction of the quadriceps muscle, causing a jerk of the lower leg. Ankle Reflex This reflex tests S1 and S2 nerve roots. It may be performed in several ways: With the claimant lying down, externally rotate foot bending the knee slightly, then dorsiflex the foot gently to 90 degrees and strike achilles tendon with the tendon hammer Or MED-RNEXNEURO~001(a) Page 31

35 With the claimant lying down with their legs out straight, place your hand on the ball of the foot with the ankles at 90 degrees, strike your hand with the tendon hammer. Or Ask claimant to kneel on a chair so that his ankles are hanging over the edge and strike the achilles tendon directly with tendon hammer. You should see a visible contraction of the calf muscle. This reflex may be absent in people over 65, however it is often absent because tendon is not hit correctly or claimant is holding their foot rigidly in dorsiflexion. Plantar reflex (Included for information only. RGNs will NOT be doing this test) To test a plantar reflex ask the claimant to remove their footwear including socks. They must be lying down and relaxed. You must explain to the claimant that you are about to stroke the bottom part of their foot, as it can be an unpleasant sensation. Using the end of the tendon hammer, gently draw it up the lateral border of the foot and across the ball of the foot. MED-RNEXNEURO~001(a) Page 32

36 Watch for movement of big toe and adduction (spreading) of the other toes. Downwards movement (plantarflexion) of the big toe is normal and upwards movement (dorsiflexion) is abnormal. It does not test a segmental level, but if abnormal, it may be a reflection of problems with lower limb motor pathways. An extensor plantar response must be distinguished from withdrawal (the claimant may actively pull their foot away as the sensation is unpleasant). If there is no movement of the big toe, check that the metatarsophalangeal joint has not been arthrodesed (fused). Testing the Sensory system The following sensory modalities are tested because they are easy to test and provide information that can help identify the site of neuropathology. In the CNS vibration, joint position and touch afferent fibres travel in a tract in the posterior spinal cord. With spinal cord lesions these sensory modalities may be lost individually, totally, or in certain combinations, depending on the site of the lesion, where as sensory loss from interruption of a peripheral nerve or posterior spinal root affects all modalities. When testing sensation it is important that you explain to the claimant what the test involves and what they are expected to do. They must understand the instructions to produce accurate consistent results. You may need to check their understanding before performing the test. Sensory signs are less objective than motor or reflex signs. The following sections describe testing of the different sensory modalities. They will all be demonstrated at the trainer led event and you will have an opportunity to practise and ask questions if anything is unclear. Vibration Vibration sense is tested using a tuning fork. First explain to the claimant that they are being asked whether they feel vibration. Demonstrate initially by striking the tuning fork and placing it on their chin or sternum whilst vibrating and whilst still. Do ensure they understand that it is the vibration they are feeling not just the contact on the skin of the tuning fork. Then ask the claimant to close their eyes. Strike the tuning fork and place it on the most distal joint of the limb, and ask the claimant if they feel any vibration. If is not felt then move to the next more proximal joint and so on until buzzing is felt. In the lower limb start with the tip of the big toe, then the first metatarsophalangeal joint, then medial malleolus at the ankle, the tibial tuberosity just below the knee and the anterior superior iliac spine just above the hip (these points will be demonstrated at the trainer led event). In the upper limb begin with the tip of the index finger, then in ascending order each interphalangeal joint of the index finger, the second metacarpophalangeal joint, the ulnar styloid at the wrist, the medial epicondyle of the elbow and the tip of the acromium at the shoulder (again these points will be demonstrated at the trainer led event). MED-RNEXNEURO~001(a) Page 33

37 Joint position (proprioception) Again it is very important to explain to the claimant exactly how the test will be performed and what is expected of them. This is best done by initially demonstrating the test with the claimant being able to view the joint. Holding the sides of the distal part of the joint (so that they are not simply feeling the pressure of your touch), move it down and up, telling the claimant which direction the movement is in. Once they understand ask them to close their eyes. Start distally and if there is abnormal position sense move proximally. If the most distal joint tested is normal, then it will be normal proximally. In the lower limb check the metatarsophalangeal joints. In the upper limb examine the interphalangeal joints and metacarpophalangeal joints. Normally people are able to detect minimal movement at a joint. Where there is a loss of position sense they may be unable to feel any movement, or they may be unable to state the direction (i.e. they may think that movement has been up when in fact it has been down). Romberg s test is a test of joint position sense. It cannot be performed if a claimant is unable to stand unaided or is unable to remain standing steadily with their eyes open. Ask claimant to stand with their feet together. After a few seconds, if there is no problem standing, ask them to close their eyes. The claimant may fall during the performance of this test. Advise the claimant that you are ready to steady them and prevent their falling (and be ready to do so). Note that it takes some moments to develop with increasing amplitude of slow swaying, until claimant can no longer remain upright. Claimants who immediately fall in one direction after closing their eyes, do not have a positive Romberg s test. Light touch This is usually performed lightly touching the skin using a piece of cotton wool or tissue, although it can be done using your fingertip. It is important to try to avoid a predictable stimulus. If using a fingertip don t drag your finger across the skin. Demonstrate what is required. Ask claimant to say yes each time they feel a touch. Once the claimant understands perform the test with their eyes closed. Start distally and move proximally. Check both sides. Do it randomly at different time intervals. If there is an abnormal result then starting at this point, check outwards to delineate the area of abnormal sensation. Sacral sensation is not checked in disability assessment. It may be abnormal in people with bladder and bowel symptoms, bilateral leg weakness or sensory loss. MED-RNEXNEURO~001(a) Page 34

38 However this would be regarded as an intimate assessment and therefore should not be performed in this setting. Pin prick Examination of pinprick sensation is not performed within our disability assessments. Temperature Examination of temperature sensation is not performed within our disability assessments. Two Point Discrimination Examination of two point discrimination sensation is not considered here, as it is unlikely to add any significant functional information to the tests outlined above. Coordination Coordination of movement requires integration of the sensory and motor systems. Problems with coordination are mainly seen with cerebellar disease but are also seen when there is abnormality of joint position sensation (loss of proprioception). Upper limb coordination can be tested with the finger nose test. Hold your finger out at arms length from claimant and ask the claimant to touch their finger tip to yours, then to their nose, then back to your finger etc, moving your finger to different positions. When it has been done correctly ask them to repeat it faster (the claimants arm has to be stretched out fully to examiner s finger for the test to be sensitive). Look for accuracy and smoothness of movement. Be aware claimants may have difficulty performing this test if they have limb weakness or arthropathy. Difficulty performing this test indicates cerebellar disease or sensory ataxia which is loss of proprioceptive feedback. In the lower limb coordination can be tested with the heel - shin test. With the claimant laying down on the couch, ask them to lift their leg and place the heel on the knee of the opposite leg, then run it down the sharp border of the calf. It may be necessary to demonstrate what is required. Again watch for accuracy and smoothness of movement. Be aware claimants may have difficulty performing this test if they have limb weakness or arthropathy. Abnormal movements Involuntary abnormal movements can be seen in neurological conditions. They are included here for completeness however if abnormal movements are seen in a claimant it is possible that cases may need to be assessed by a medical practitioner. This will be further discussed at the trainer led event. Abnormal movements that may be seen in the disability assessment setting include: MED-RNEXNEURO~001(a) Page 35

39 Tremor; repetitive rhythmical movement of the body or part of the body Chorea; constant rapid complex body movements that appear pseudo-purposeful but are involuntary. Tardive dyskinesia; characterized by repetitive, purposeless movements which are involuntary and include grimacing, tongue protrusion, lip smacking, puckering and pursing, and rapid eye blinking. Rapid movements of the arms, legs, and trunk may also be seen. This is often seen as a side effect of long term use of the older anti-psychotic medications. Dystonia; prolonged muscle contraction, resulting in twisting body motions, abnormal posture. May involve the whole body or specific parts. Myoclonic jerk; very brief contraction of a muscle group, causing involuntary jerk of limb. It occurs normally sometimes as people are dropping off to sleep. In summary this section has covered the basics of history, observed behaviour and examination of claimants with neurological conditions or symptoms. The importance of applying logical reasoning to all of the pieces of evidence obtained during the assessment cannot be overstated. As always, your justification should address any inconsistencies between various pieces of evidence. Consider the following questions What needs to be examined when examining the motor system? What needs to be examined when examining the sensory system? MED-RNEXNEURO~001(a) Page 36

40 What spinal segments do the following reflexes subserve? Biceps Triceps Supinator Knee Ankle Plantar Question Block D Please now use the on-line MCQ to answer some questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 37

41 Section Four - Specific Conditions This section provides information about some of the specific neurological conditions which are commonly seen within the setting of disability assessment that you will be expected to assess. It is not a comprehensive list of conditions. Objectives By the end of this section you will be aware of the following conditions: prolapsed intervertebral disc / sciatica cervical spondylosis peripheral neuropathy focal nerve compression syndromes Raynaud s phenomenon, hand arm vibration syndrome and vibration white finger Materials This booklet Pen / Pencil Duration The learning activities during this section should take approximately 70 minutes to complete. MED-RNEXNEURO~001(a) Page 38

42 Prolapsed Intervertebral Disc / Sciatica Before you read this section you may wish to review the section on back pain within the Evidence Based Protocols for the Disability Analyst (latest issue). You will have received a CD containing these protocols at your initial training course. Cause The spine is made up of vertebrae enclosing the vertebral (spinal) canal, which is occupied by the spinal cord. In between the vertebrae are intervertebral discs. They allow movement between the vertebral bodies and also function as shock absorbers. Intervertebral discs are composed of a tough fibrous outer coating; annulus fibrosis and an inner gel like substance; nucleus pulposis. A prolapsed intervertebral disc is caused by protrusion of the nucleus pulposis leading to impingement of adjacent nerve roots and nerves. It often occurs suddenly in association with bending or lifting heavy weights. However there is almost always underlying disc degeneration which is associated with normal wear and tear. Degeneration of the disc often begins to be seen in the 3rd decade and is often asymptomatic. You may see the term prolapsed intervertebral disc being shortened to PID. This MED-RNEXNEURO~001(a) Page 39

43 is to be discouraged since it is confusing as other terms are also shortened to this acronym including pelvic inflammatory disease. Prolapsed intervertebral discs most commonly occur regions of the spine. They may be central or lateral. in the cervical and lumbar A central disc prolapse occurs into the central spinal canal, compressing the spinal cord in the cervical region and cauda equina in the lumbar region. Compression of the cauda equina causes bilateral leg weakness often with severe bilateral sciatic pain, reduced sacral sensation and altered bladder control. This is a neurosurgical emergency requiring urgent MRI for diagnosis and urgent neurosurgical decompression. A lateral disc prolapse will affect the nerve roots entering and leaving the intervertebral foramen. Lateral disc prolapses most commonly affect the L5/S1 disc (compressing the S1 root) or the L4/L5 disc (compressing the L5 root). Less often the C5/C6 (compressing the C6 root) and C6/C7 (compressing the C7 root) are affected. A prolapsed disc can be confirmed by MRI scan. You may see references to the term spinal stenosis. Spinal stenosis is caused by a combination of a protruding intervertebral disc, spondylolithesis (slippage between adjacent vertebrae), hypertrophy of intraspinal ligaments and spondylitic protrusions from vertebral bones leading to narrowing of the vertebral canal. It is characterised by numbness, discomfort and weakness of the legs which develop whilst walking or during prolonged standing. The symptoms do not occur when exercising with spine flexed, such as in cycling. They are relieved by sitting down. There may be intermittent cauda equina compression with pain and altered bladder control. Again it can be confirmed on MRI scan. Treatment is usually surgery (laminectomy) often with good results. Symptoms and Signs A prolapsed intervertebral disc may be associated with local pain, produced by the annular tear and protective lumbar muscle spasm, with restriction of spinal movement. There maybe loss of the normal lumbar lordosis due to muscle spasm. Impulse symptoms are common, where sneezing or coughing cause a worsening of the pain. Sciatica is severe pain beginning in the lumbar region and radiating down the back of the leg to the knee, ankle or foot, depending on what nerve root is involved. It is exacerbated by stretching the nerve. Straight leg raising (SLR) may be restricted, with pain radiating down the leg. True sciatic pain on straight leg raising will be reduced by bending the knee and exacerbated by dorsiflexing the foot. Remember that testing straight leg raising in our assessments should never involve you passively moving the leg. The SLR can be performed with the claimant supine or sitting. Studies have shown that the test is more reliable when the claimant is supine, therefore this should be the examination method of choice. Neurological disturbance, if present, is dependent on the level of the prolapsed MED-RNEXNEURO~001(a) Page 40

44 disc. There may be focal muscle wasting, focal sensory impairment or loss and diminished or absent reflexes. Treatment The majority of people with symptoms from a prolapsed disc will get better with conservative treatment such as pain relief and initial rest. Anti-inflammatory medication, physiotherapy, and muscle relaxants may also help. Whilst rest may initially be of benefit, current opinion is that prolonged rest is of no benefit and may in fact be detrimental. Epidural treatment, where local anaesthetic or nerve roots, may help. steroids are injected around the If the symptoms do not improve or there are significant neurological symptoms and signs, surgery may be required. Surgical treatment includes laminectomy, discectomy and microdiscectomy. Surgery often relieves the pain immediately, but the neurological symptoms and signs, such as numbness and weakness, can take longer to improve and may not return completely to normal. There is a risk of recurrence. Functional impact There may be no functional impact. The pain associated with the prolapsed disc may lead to restrictions of sitting, standing, walking, heaving lifting (of objects from the floor) and bending. Where there is neurological involvement any associated impairment will depend on the site of the prolapsed disc. Examples include: Foot drop (L5 root) may cause the claimant to catch their toe whilst walking. Plantar flexion weakness (S1 root) may take the spring out of the claimant s stride causing problems with walking. Weak elbow extension (C7 root) may make it difficult to push open doors or find 3rd gear whilst driving. Weak elbow flexion (C6 root) may make it difficult to lift objects. MED-RNEXNEURO~001(a) Page 41

45 Consider the following examples. Think about what you have learnt in the neuroanatomy section. A claimant says that have a L4/5 disc prolapse. What symptoms might they have? What signs would be expected on examination? Consider a claimant with a L5/S1 disc prolapse. What symptoms might they complain of? MED-RNEXNEURO~001(a) Page 42

46 What signs would be expected on examination? Question Block E Please now use the on-line MCQ to answer some questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 43

47 Cervical spondylosis Before you read this section you may wish to review the section on neck pain within the Evidence Based Protocols for the Disability Analyst (latest issue). You will have received a CD containing these protocols at your initial training course. Cause Cervical Spondylosis is a degenerative condition, also known as cervical osteoarthritis, although the term is sometimes inappropriately applied to all non specific neck pain. With increasing age the cervical intervertebral discs shrink, becoming tougher and less flexible. This is associated with the growth of small bony spurs (osteophytes) and degenerative changes of the posterior facet joints. Cervical spondylosis tends to be most marked at C4/5, C5/6 and C6/7. Cervical spondylosis may be associated with a nerve root compression or myelopathy. Cervical nerve root compression may lead to dysfunction of that nerve root. You may see this sometimes referred to as cervical radiculopathy. C7 (60%) and C6 (25%) are the most commonly affected in nerve root compression. A myelopathy relates to a problem with the spinal cord. Cervical myelopathy is compression of the spinal cord in the neck. Single or multiple levels of the spinal cord may be compressed between 3rd and 7th cervical vertebra. It is an uncommon complication. You may see the term spondylitic radiculo-myelopathy, this simply means there is both myelopathy and nerve root compression. About 50% of the population develop cervical spondylosis by the age of 50, increasing to 70% by the age of 60. It affects men and women equally but men tend to develop it earlier. As many asymptomatic people over the age of 30 show similar changes in x-rays, the boundary of normal aging and disease is difficult to delineate. A previous neck injury can pre-dispose to the development of cervical spondylosis. The diagnosis of cervical spondylosis is made on clinical grounds alone, cervical x-rays can show degenerative changes but as these can be found in asymptomatic people, the changes correlate poorly with symptoms. An MRI scan is usually performed when neurological pathology is suspected. Symptoms and Signs Cervical spondylosis is associated with neck stiffness and pain worsened by movement. The pain may radiate to the base of skull, shoulders, arms hands and MED-RNEXNEURO~001(a) Page 44

48 fingers. There may also be complaints of retro-orbital (behind the eye) or temporal pain, dizziness, poor balance and rarely syncope, or triggering of migraine. Neurological signs may be the initial presenting feature or may develop in already established disease. Symptoms of nerve root compression may occur after some unusual strain or may occur spontaneously and usually come on over a few days. There may be complaints of pain, numbness, tingling or weakness in upper limbs. Symptoms of cervical myelopathy depend on the level of compression: Higher compressive neuropathy (C3-C5) can cause a syndrome of clumsy and numb hands with difficulty writing, loss of manual dexterity, diffuse nonspecific weakness and abnormal sensations. Lower compressive neuropathy (C6-C7) usually present with weakness, stiffness and proprioceptive loss in the legs. There are often signs of spasticity. Urinary control may be affected, although urinary incontinence is rare. Urinary urgency, frequency or hesitancy may be reported. Examination may show poorly localised tenderness and loss of cervical movement. There may be signs of nerve root compression (which may be poorly localized). Pain is often complained of proximally whilst paraesthesiae occur distally. With cervical myelopathy there will be signs of upper motor neuron dysfunction: hyperactive deep tendon reflexes spasticity of upper limbs +/- spastic gait extensor (up going) plantar reflex incoordination of limbs There may be wasting in triceps and intrinsic hand muscles (wasting of the intrinsic muscles of the hand is classic finding). Proximal muscle weakness is common, distal weakness is less common. Loss of vibratory sense and proprioception can occur in extremities, especially the feet. Treatment Treatment of cervical spondylosis is usually conservative including NSAIDS, physiotherapy and lifestyle modifications. Cervical nerve root entrapment symptoms often resolve with conservative measures (in up to 75% of cases). Surgery is generally advised for cervical nerve MED-RNEXNEURO~001(a) Page 45

49 root entrapment where there is intractable pain, progressive symptoms or weakness that fails to improve with conservative treatment. Surgical treatment for cervical myelopathy remains controversial, but is generally recommended for moderate to severe myelopathy. Mechanical relief of cord compression does not always lead to improvement because ischaemia of the cord is thought to be an additional factor. Functional impact There may be no functional impairment. Pain in the neck alone does not commonly produce significant loss of function in upper limbs. Lifting and carrying should not be affected by neck pain alone. Where there is a neurological deficit it may be associated with some loss of function. C6/7 nerve root compression may affect reaching (but not lifting) and sensory impairment of index and middle fingers may affect pinch grip function Myelopathy with cord compression at C3-5 may cause a problem with manual dexterity. Compression of spinal cord at a lower level C5-8 may affect gait and walking. Consider the following example. A claimant tells you they have cervical spondylosis. What symptoms might they complain of? You noticed that on walking to the examination room their gait was not normal. What specific neurological examination would you perform? MED-RNEXNEURO~001(a) Page 46

50 Question Block F Please now use the on-line MCQ to answer some questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 47

51 Peripheral neuropathy Peripheral neuropathies can be broadly divided into 2 groups; generalised and focal. In generalised peripheral neuropathy all nerve fibres are affected equally, irrespective of the peripheral nerve from which they are derived, leading to a generalised and symmetrical abnormality. Focal peripheral neuropathy affects individual peripheral nerves, either singly or multiply, therefore signs and symptoms are restricted to the territory of the affected nerves. This section deals with generalised neuropathy. Focal peripheral neuropathies will be addressed in the following section. Cause Generalised peripheral neuropathy can either be due to axonal degeneration of the nerve fibres or to demyelination of the nerve fibres. Axonal degeneration affects all axons (both myelinated and unmyelinated). With regard to the sensory neurons; joint position, vibration sense, pain, light touch, pinprick and temperature sensation are all affected. The degeneration of the nerve fibres can result in denervation of muscles supplied by these nerves, resulting in weakness and wasting. The longest axons to the feet are affected first and most severely. Demyelinating peripheral neuropathy only affects myelinated neurons. It causes impairment of joint position and vibration (however temperature and pinprick sensation normally remain intact). It usually causes more severe muscle weakness, including proximal muscles, because proximal nerve segments (sometimes including nerve roots) are affected. There is muscle weakness because of blockage of impulse conduction at demyelinated portion of nerve. However muscle wasting is less because the nerve fibres remain in continuity with the muscle. There are multiple causes of generalized peripheral neuropathy. The most common causes that you will see in your role as a disability analyst are diabetes and alcohol misuse. Diabetes Diabetic peripheral neuropathy involves both axonal degeneration and demyelination. It is a complication of diabetes, although it occurs relatively early in course of disease. It is most often seen where there is poor diabetic control. It is common, affecting around 30% of people with diabetes. It can affect sensory, motor and autonomic nerves. Most commonly seen is a symmetrical sensory peripheral neuropathy. It causes paraesthesiae and numbness, mainly in the feet, although it can also affect the hands. Neuropathic pain in the lower limbs is often reported (aching/piercing, worse at night, felt in the anterior of the legs), as are burning sensations in the soles of the feet. There is often hyperaesthesia. MED-RNEXNEURO~001(a) Page 48

52 On examination absent tendon reflexes and decreased vibration sense are early signs. There is often glove and stocking impairment of all modalities of sensation. There may be an abnormal wide-based gait. In advanced cases there may be muscle weakness and wasting. People with diabetes may less commonly develop a motor diabetic neuropathy (also known as diabetic amyotrophy). This is generally an asymmetrical peripheral neuropathy. It presents as severe and progressive weakness and wasting of the proximal muscles of mainly the lower limb (although it can occur in upper limb as well). Often there is severe pain felt on the anterior aspect of leg. Paraesthesia and hyperaesthesia are common. It may be associated with a significant loss of weight. It is thought to result from acute infarction of the lower motor neurons of the lumbosacral plexus. Management is supportive and recovery usually occurs over 12 months. Alcohol misuse Peripheral neuropathy occurs in up to 15 percent of people with chronic alcohol misuse. It is probably due to a combination of thiamine deficiency and direct toxic effects of ethanol. It causes bilateral numbness and paraesthesiae which is more pronounced distally. It is also associated with neuropathic pain which may be severe. Treatment is abstinence with thiamine replacement. Thiamine replacement may lead to some improvement in the condition. Specific treatment may be required for the painful neuropathy. There are many other causes of peripheral neuropathy. Guillain-Barré syndrome is an example of a demyelinating peripheral neuropathy. Vincristine, cisplatin, isoniazid, nitrofurantoin are examples of drugs that can cause peripheral neuropathies. Glue solvents, arsenic, lead, mercury, thallium and organophosphates are examples of chemically induced peripheral neuropathies. Some genetic conditions which cause peripheral neuropathies include Charcot- Marie-Tooth disease or hereditary sensory or motor neuropathy. Renal failure, liver failure and vitamin deficiencies, such as B12 and E are also causes. Symptoms and Signs Peripheral neuropathy generally begins with tingling or numbness in feet and fingers. The claimant may complain of weakness and clumsiness. Examination often shows loss of pinprick and touch sensation in a glove and stocking distribution. MED-RNEXNEURO~001(a) Page 49

53 Distribution of glove and stocking sensory loss. There may be impaired joint position sensation on direct testing, with finger-nose ataxia, an abnormal heel-shin test and a positive Romberg s sign. There may be weakness and wasting of muscles. Tendon reflexes are usually lost in the affected area. Nerve conduction tests will confirm the presence of a peripheral neuropathy. Charcot joints may be present. These are joints that have been damaged because the claimant is unable to feel pain, leading to progressive destruction bone and joint. Most commonly affected joints are the knee and ankle. Treatment Treatment involves treating the cause of the peripheral neuropathy. Where there are metabolic abnormalities or toxic causes, they should be corrected or removed. Where there is another cause, for example a genetic disorder, no specific treatment is available and management is supportive only. Peripheral nerves do have some ability to regenerate. The amount of recovery depends on the severity of the neuropathy and the distance over which regeneration is required. Unfortunately with axonal degeneration it rarely recovers well even if the cause is removed. In peripheral neuropathies where the cause is demyelination, with treatment of the cause, there is likely to be a good recovery over weeks to months. MED-RNEXNEURO~001(a) Page 50

54 Functional impact The claimant may describe difficulty with activities that involve walking. They may also describe difficulties with activities involving manual dexterity and coordination. Neuropathic pain may impact on their sleep and on their concentration thereby affecting their ability to carry out daily living activities. They may also report falls. Consider the following example. A claimant with alcohol misuse tells you that they have fallen several times recently. What would you ask about the history of condition? What examination would you perform in this case? What might you expect to find on examination? MED-RNEXNEURO~001(a) Page 51

55 Question Block G Please now use the on-line MCQ to answer some questions about the material you have just read. You will then return to this material to read the next part of this pre-course reading. MED-RNEXNEURO~001(a) Page 52

56 Nerve Compression Syndromes / Focal Neuropathy Focal neuropathy reflects a lesion of an individual peripheral nerve. Causes of focal peripheral neuropathy include: Compression Trauma / Laceration Vasculitis causing ischaemic damage Irradiation Nerve sheath tumours Tumour infiltration Diabetes Regeneration of a transected nerve can occur if the ends of the neural sheath are opposed. However it occurs very slowly and is often incomplete. Recovery time following compression will depend on the degree of damage to the nerve fibres. The following conditions are the most common focal nerve neuropathies that we see: Median nerve (carpal tunnel syndrome) Carpal tunnel syndrome is the commonest peripheral nerve problem in UK. It results from compression of the median nerve as it passes under the transverse carpal ligament (flexor retinaculum) at the wrist. MED-RNEXNEURO~001(a) Page 53

57 There is increased pressure within the carpal tunnel, impairing the blood supply of the nerve, causing demyelination of axons eventually resulting in axonal loss. Pressure is increased by wrist flexion and extension and finger flexion. There is a strong genetic predisposition, other risk factors are pregnancy and obesity. Middle-aged women are most commonly affected. It can be associated with hypothyroidism, acromegaly, Cushing s disease, rheumatoid arthritis, and repetitive use of vibrating tools. Symptoms and Signs Symptoms of carpal tunnel syndrome include painful tingling in thumb, index, middle and ring fingers. However claimants may find it difficult to correctly identify which fingers are involved. The symptoms classically occur at night and may wake the claimant up. They are also provoked by manual tasks such as writing and sewing. They may describe weakness or clumsiness of the hand. Claimants often describe improvement in the symptoms by changing hand posture or by shaking the hand. There are often no physical signs when the claimant is examined. There may be sensory loss in median nerve distribution (lateral palm and thumb, index middle and lateral half of ring finger). Skin supplied by median nerve in the hand The exact demarcation however is variable and the whole ring finger may be supplied by the median nerve. Weakness and wasting of abductor brevis muscle (thenar eminence ball of thumb) only occurs in advanced cases. In this situation there will be weakness of thumb opposition. A positive Tinel s sign may be found in carpal tunnel syndrome. The median nerve is tapped repetitively just proximal to the distal radius. If positive, tingling is felt in the appropriate median nerve distribution. MED-RNEXNEURO~001(a) Page 54

58 A positive Phalen s test may be found in carpal tunnel syndrome. This test is performed with the elbow resting on the desk and the forearm vertical. The wrist is then flexed with it being actively held (by the claimant) in that position. Another way would be asking the claimant to place the backs of both hands together to form right angles and hold the position. The test is considered positive if tingling or numbness is felt in the appropriate median nerve distribution within 60 seconds. However neither test is particularly sensitive nor specific for carpal tunnel syndrome. Both tests are less reliable in advanced disease. Both tests will be demonstrated at the trainer led event. Nerve conduction studies are recommended when the diagnosis is uncertain but do have a small false negative rate. The median nerve can be transected or compressed at a more proximal level than the wrist, although this is less common. If it is affected at the shoulder or elbow, in addition to the above symptoms and signs, there maybe pain in the forearm, medial (ulnar) deviation of the wrist when it is extended (due to paralysis of the lateral (radial) wrist flexor), inability to flex the terminal phalanx of the thumb and index finger, as well as some weakness of flexion of the terminal phalanx of the remaining fingers. Treatment Treatment involves treating a contributing cause if there is one present. For claimants with mild to moderate symptoms the condition may be managed conservatively with splinting of the wrists at night, activity modification and steroid injection at the wrist. The definitive treatment is surgical release of the carpal ligament to decompress the carpal tunnel. Surgery is generally offered to those in whom conservative measures have failed or those who present with severe disease, and is generally very successful. Functional impact There may be no functional impact. The claimant may describe difficulty handling small objects. There may be difficulty with writing or performing repetitive manual dexterity tasks, or tasks where there are sustained hand or arm positions. Ulnar Nerve The nerve runs behind the humerus at the elbow. It is at this site where it can be damaged (by fracture/dislocation or trauma) or compressed. The ulnar nerve supplies muscles that have the following actions; flexion of the wrist (medial (ulnar) side), flexion of little fingers at interphalangeal joint and metacarpophalangeal joint, partial flexion of ring finger, abduction of little finger, MED-RNEXNEURO~001(a) Page 55

59 abduction and adduction of fingers, extension of terminal phalanges of fingers. It supplies the skin of the medial palm, little finger and the medial half of the ring finger. Skin supplied by ulnar nerve in the hand Symptoms and Signs Tingling, numbness and pain in little and ring fingers and medial (ulnar) border of hand are the earliest symptoms. Over time weakness and wasting of the muscles supplied by the ulnar nerve will develop. Examination may demonstrate sensory loss in the medial palm, little finger and medial ring finger. There may be weakness and wasting of the small hand muscles. Longstanding ulnar nerve neuropathy results in a claw hand where there is hyperextension at the metacarpophalangeal joints and flexion at the interphalangeal joints. Treatment Treatment for ulnar nerve compression may involve splinting of the elbow, surgery to decompress the cubital tunnel or transpose the nerve anteriorly. Functional impact There may be no functional impact. The claimant may describe difficulty handling small objects and difficulty with tasks that require manual dexterity. MED-RNEXNEURO~001(a) Page 56

60 Radial Nerve The radial nerve supplies the triceps muscle, which extends the elbow, and muscles that extend the wrist and the fingers. Most radial nerve neuropathies are due to compression. It can be precipitated by sleeping in abnormal position, often when intoxicated, with the arm over the back of a chair (known as 'Saturday night palsy'). In the past it was seen with use of under the shoulder crutches which lead to compression of the nerve in the axilla, however with the use of elbow crutches this is seen less often nowadays. It may also be seen after surgery when the anaesthetised patient s arm is allowed to hang over the edge of the operating theatre table. Its course winds around the shaft of the humerus, where it is vulnerable to damage by humeral fracture, and rarely it can be damaged by dislocation of the elbow. Symptoms and Signs The principle findings are of weakness of finger and wrist extension and a small area of sensory loss on the dorsum of the thumb. The clinical features of radial nerve neuropathy depend upon the site of the injury. Lesions in or above the axilla result in paresis and wasting of all the muscles supplied by the radial nerve. Clinically, this is manifest as weakness of forearm extension and flexion, wrist drop and finger drop, weakness of the long thumb abductor and extensor muscles and sensory loss on the dorsum of hand and forearm. Skin supplied by radial nerve in the hand Lesions around the humerus often do not affect the extension of the elbow and may also spare wrist extension. MED-RNEXNEURO~001(a) Page 57

61 Lesions around the elbow lead to weakness of finger extension, and of thumb extension and abduction. There is little or no wrist drop, and usually, no sensory loss. Treatment Treatment is usually supportive, allowing the nerve time to recover over weeks or months. Splinting of the wrist to assist wrist drop may improve function. Functional impact There may be no functional impact. Depending of the level of the lesion, the claimant may have difficulty with lifting, and tasks requiring manual dexterity. Common Peroneal Nerve The common peroneal nerve is a branch of the sciatic nerve. It supplies the muscles that dorsiflex the feet and toes and everts the foot. It is often damaged where it crosses the fibular head. There may be compression where the nerve passes over head of the fibula (lateral to and just below the knee) or it may be damaged by fractures or penetrating wounds at the upper end of the fibula. A plaster or splint can cause compression at this site. Symptoms and Signs The claimant may have foot drop and sensory loss over dorsum of foot and lateral shin. Skin supplied by common peroneal nerve MED-RNEXNEURO~001(a) Page 58