Neuropathy, Radiculopathy & Myelopathy. Jean D. Francois, MD Neurology & Neurophysiology

Transcription

1 Neuropathy, Radiculopathy & Myelopathy Jean D. Francois, MD Neurology & Neurophysiology

2 Purpose and Objectives PURPOSE Avoid Confusing Certain Key Neurologic Concepts OBJECTIVES Objective 1: Define & Identify certain types of Neuropathies Objective 2: Define & Identify Radiculopathy & its causes Objective 3: Define & Identify Myelopathy FINANCIAL DISCLOSURE NONE

3 Basics

4 What is Neuropathy? The term 'neuropathy' is used to describe a problem with the nerves, usually the 'peripheral nerves' as opposed to the 'central nervous system' (the brain and spinal cord). It refers to Peripheral neuropathy It covers a wide area and many nerves, but the problem it causes depends on the type of nerves that are affected: Sensory nerves (the nerves that control sensation>skin) causing cause tingling, pain, numbness, or weakness in the feet and hands Motor nerves (the nerves that allow power and movement>muscles) causing weakness in the feet and hands Autonomic nerves (the nerves that control the systems of the body eg gut, bladder>internal organs) causing changes in the heart rate and blood pressure or sweating It May produce Numbness, tingling,(loss of sensation) along with weakness. It can also cause pain. It can affect a single nerve (mononeuropathy) or multiple nerves (polyneuropathy)

5 Neuropathy Symptoms usually start in the longest nerves in the body: Feet & later on the hands ( Stocking-glove pattern) Symptoms usually spread slowly and evenly up the legs and arms. Other body parts may also be affected. Peripheral Neuropathy can affect people of any age. But mostly people over age 55 CAUSES: Neuropathy has a variety of forms and causes. (an injury systemic illness, an infection, an inherited disorder) some of the causes are still unknown. Most common cause: Diabetes. Other causes: alcohol abuse, poor nutrition, autoimmune processes (where the body s own immune system attacks parts of the nerves) and genes. Exposure to certain drugs or toxins can lead to neuropathy. Direct pressure or compression of a single nerve, like in CTS, may cause it to malfunction

6 Diabetic Peripheral Neuropathy Sensory - Numbness as if wearing gloves or socks - Loss of balance, especially with the eyes closed - Painless injuries due to loss of sensation + Burning, prickling pain, tingling, electric shock like feelings, aching, or hypersensitivity to touch Motor UE: fine hand coordination (difficulty with opening jars or turning keys) LE: Foot slapping, toe scuffing, frequent tripping may be early symptoms of foot weakness. Proximal limb weakness: difficulty climbing up and down stairs, difficulty getting up from a seated or supine position, falls due to the knees giving way, and difficulty raising the arms above the shoulders Autonomic GI: Gastroparesis, Dysphagia, Abdominal pain, Diarrhea, Constipation : Persistent sinus tachycardia, Orthostatic hypotension Bladder: Poor urinary stream, incomplete emptying, Straining Sudomotor: sweating of head, neck, and trunk with anhidrosis of lower trunk and extremities

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8 Neuropathic Pain Diagnosis: Clinical presentations / characteristic symptoms Investigative steps: medical conditions, medications taken, neurologic examination, Blood count, ESR, Blood sugar, Liver and renal function tests, Serum vitamin B 12, Paraprotein levels, Thyroid function tests, Vasculitis profile, electromyography and nerve conduction studies final cause may not be identified Treatment Options: For most types of neuropathy> no treatment is available to cure or modify condition. Treatments are therefore aimed at addressing certain symptoms. Physical therapy, TENS unit (a portable device that sends an electrical current to electrodes attached to the skin), assistive devices, addressing the root cause of condition, identified treatable associated medical cause exercise, Diet Living with PN: Lifestyle change, review habits(smoking, sleeping hours, smoking, alcohol intake, healthy diet, review meds taken including the so-called natural / OTC meds (excess B6 ), Support group

9 In polyneuropathy, the sensory deficits generally follow a length-dependent stocking-glove pattern. By the time sensory disturbances of the longest nerves in the body (lower limbs) have reached the level of the knees, paresthesias are noted in the secondlongest nerves (upper limbs) at the tips of the fingers. When sensory impairment reaches the mid-thigh, involvement of the thirdlongest nerves, the anterior intercostal and lumbar segmental nerves, leads to a tent-shaped area of hypoesthesia on the anterior chest and abdomen. At this point, the recurrent laryngeal nerves may be affected, resulting in hoarseness. Motor weakness is greater in extensor foot muscles than in corresponding flexors. For example, heel walking is affected earlier than toe walking. ILLUSTRATION

10 Charcot Marie Tooth Disease CMT1 Starts at y/o Distal legs: slow progressive weakness, muscle wasting, sensory Foot deformities, difficulties in running or walking resulting from symmetrical weakness and wasting in the intrinsic foot, peroneal, and anterior tibial muscles ankle reflexes are universal frequently knee and upper limb reflexes In 2/3 pts, upper limbs involved later in life CMT2 Begins later 20+, middle age+ Foot and spinal deformities less prominent peripheral nerves are not enlarged, and upper limb involvement, tremor, and general areflexia occur less frequently

11 Causes of Radiculopathies Radiculopathy is caused by compression or irritation of the nerves as they exit the spine. This can be due to mechanical compression of the nerve by a disc herniation, a bone spur (osteophytes) from osteoarthritis, or from thickening of surrounding ligaments. Other less common causes of mechanical compression of the nerves are from a tumor or infection. Either of these can reduce the amount of space in the spinal canal and compress the exiting nerve. Scoliosis can cause the nerves on one side of the spine to become compressed by the abnormal curve of the spine. Inflammation from trauma or degeneration can lead to radiculopathy from direct irritation of the nerves Radiculopathy is one of (if not )the most common cause of disability in people under M people in US seek treatment annually for back pain. 6-8 M with permanent disability

12 Radiculopathies Radix = root, Pathos = suffering or disease > Nerve root disorder Radiculopathy is a condition due to a compressed nerve in the spine that can cause pain, numbness, tingling, or weakness along the course of the nerve. Radiculopathy can occur in any part of the spine, but it is most common in the lower back (lumbar radiculopathy) and in the neck (cervical radiculopathy). It is less commonly found in the middle portion of the spine (thoracic radiculopathy). Lesions of a single nerve root are easier to recognize. Radicular pain and paresthesias (tingling, pins & needles) Sensory loss in the dermatome (skin innervated by a nerve root) Weakness in the myotome (muscles innervated by a spinal cord segment and its nerve root) Diminished deep tendon reflex activity at a segmental level However, with multiple roots involved (polyradiculopathy) clinically may resemble: Disorder of the peripheral nerves polyneuropathy? Disorder of the anterior horn cells - progressive muscular atrophy form of ALS? Supporting evidence for radiculopathy: CSF ( protein, WBCs), paraspinal muscle needle EMG (positive sharp waves and fibrillation potentials), spinal cord MRI (compromise or contrast enhancement of the nerve roots)

13 Causes of Radiculopathies continued Symptoms of RADICULOPATHY: The symptoms of radiculopathy depend on which nerves are affected. The nerves exiting from the neck (cervical spine) control the muscles of the neck and arms and supply sensation there (most common radiculopathies in arms: C5-C6). The nerves from the middle portion of the back (thoracic spine) control the muscles of the chest and abdomen and supply sensation there. The nerves from the lower back (lumbar spine) control the muscles of the buttocks and legs and supply sensation there(most common radiculopathies in legs affect L5 & S1 roots). The most common symptoms of radiculopathy are pain, numbness, and tingling in the arms or legs. It is common for patients to also have localized neck or back pain as well. Lumbar radiculopathy that causes pain that radiates down a lower extremity is commonly referred to as sciatica. Thoracic radiculopathy causes pain from the middle back that travels around to the chest. It is often mistaken for shingles. Some patients develop a hypersensitivity to light touch that feels painful in the area involved. Less commonly, patients can develop weakness in the muscles controlled by the affected nerves. This can indicate nerve damage.

14 Risk factors for Radiculopathy Radiculopathy Risk factors include: activities that place an excessive or repetitive load on the spine. Patients involved in heavy labor or contact sports are more prone to develop radiculopathy than those with a more sedentary lifestyle. A family history of radiculopathy or other spine disorders also increases the risk of developing radiculopathy. DIAGNOSIS: The diagnosis of radiculopathy requires a medical history and physical examination by the physician. (patient will describe the type and location of symptoms, how long they have been present, what makes them better and worse, and what other medical problems present. By knowing the exact location of the patient's symptoms, one can help localize the nerve that is responsible. The physical examination will focus on the extremity involved. It is important to check the patient's muscle strength, sensation, and reflexes to see if there are any abnormalities. Then, obtain imaging studies to look for a source of the radiculopathy. Plain X-rays are often obtained first. These can often identify the presence of trauma or osteoarthritis and early signs of tumor or infection. An MRI scan may then be obtained. This study provides the best look at the soft tissues around the spine including the nerves, the disc and the ligaments. If the patient is unable to obtain an MRI, they may obtain a CT scan instead to explore possible compression of the nerves. Based on condition and clinical indication, the neurologist may do a nerve conduction study (NCS) or electromyogram (EMG). These studies look at the electrical activity along the nerve and can show if there is damage to the nerve

15 Treatment for Radiculopathy Generally, most people can obtain good relief of their symptoms of radiculopathy with conservative treatment such as: anti-inflammatory medications, physical therapy or chiropractic treatment, Acupuncture, and avoiding activity that strains the neck or back. The majority of radiculopathy patients respond well to this conservative treatment, and symptoms often improve within 6 weeks to 3 months. (bear in mind that pain and discomfort has a subjective part) If patients do not improve with the treatments listed above they may benefit from an epidural steroid injection. With the help of an X-ray machine, a physician injects steroid medication between the bones of the spine adjacent to the involved nerves. This can help to rapidly reduce the inflammation and irritation of the nerve and help reduce the symptoms of radiculopathy. In some cases the symptoms continue despite all of the above treatment options. If this occurs and the symptoms are severe, surgery may be an option. The goal of the surgery is to remove the compression from the affected nerve. Depending on the cause of the radiculopathy, this can be done by a laminectomy or a discectomy. A laminectomy removes a small portion of the bone covering the nerve to allow it to have additional space. A discectomy removes the portion of the disc that has herniated out and is compressing a nerve. Overall, The outlook for radiculopathy is good. The majority of patients respond well to conservative treatment options. Those patients that need surgical procedures typically obtain good results as well with no long-term restrictions. Radiculopathy is caused by compression or irritation of a nerve as it exits the spinal column. Most patients with radiculopathy respond well to conservative treatment including medications, physical therapy, or chiropractic treatment. Radiculopathy may resolve within 6 weeks to 3 months. Condition must be individualized

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22 Needle EMG into cervical paraspinal muscles (at rest) the posterior primary ramus (first branch of the spinal nerve) arises just beyond the DRG and proximal to the brachial plexus EMG shows cervical paraspinal fibrillation potentials (abnormal) = root avulsion Status of the (posterior) root may remain uncertain if paraspinal fibrillation potentials are not found

23 Diagnosis: Plain radiography, CT myelography, MRI; Needle EMG Sensory conduction studies are useful because SNAPs are typically normal because the lesion is proximal to the DRG in the intervertebral foramina (In contrast to plexopathy and peripheral nerve trunk lesions, where SNAPs are reduced or absent) L5 radiculopathy: if severe enough, compression of the L5 DRG may lead to loss of the superficial peroneal nerve SNAP Appropriate physical therapy > bed rest Epidural corticosteroid injection may help relieve pain, but does not improve neurological function or reduce the need for surgery

24 Myelopathy Defined as a neurological deficit in relation to the spinal cord. Myelopathy Traumatic (Acute spinal Cord injury) Traumatic brown sequard syndrome Inflammation (myelitis) Transverse myelitis Vascular (vascular myelopathy) Degenerative joint disease (spinal stenosis) Lumbar stenosis and cervical stenosis

25 Myelopathy Myelopathy is a broad term that refers to spinal cord involvement of multiple etiologies. Spinal cord diseases often have devastating consequences, ranging from quadriplegia and paraplegia to severe sensory deficits due to its confinement in a very small area. Many of these diseases are potentially reversible if they are recognized on time, hence the importance of recognizing the significance of magnetic resonance imaging when approaching a multifactorial disease considered as one of the most critical neurological emergencies, where prognosis depends on an early and accurate diagnosis. However, although MR scanning has become the key investigation in establishing the diagnosis for most patients presenting with a spinal cord syndrome, myelopathy with normal spinal imaging remains a common clinical conundrum: MR normal myelopathy. This is to underscore the challenges presented by such condition that may require urgent intervention. The term Myelopathy describes pathologic conditions that cause spinal cord, meningeal or perimeningeal space damage or dysfunction. It is a common neurologic finding and presentations may vary widely.

26 Myelopathy continued Traumatic injuries, vascular diseases, infections and inflammatory or autoimmune processes may affect the spinal cord. Myelopathy s clinical signs entail a broad spectrum of different etiologies and pathogeneses that may be responsible for such a condition. Whether it is structural, genetic, metabolic, or nutritional in nature, it is critical for the clinician to maintain and investigate a broad differential diagnosis to arrive at the correct diagnosis and provide appropriate treatment and intervention. Correct diagnosis leads to appropriate treatment that may be medical, surgical, or supportive.

27 Myelopathy Cervical = having to do with the spine in the neck Lumbar = lower back Spondylotic = having to do with spinal degeneration Myelopathy = damage to the spinal cord Spinal stenosis, a narrowing of the spinal canal, can damage the spinal cord and cause myelopathy. Degenerative disc disorders or other conditions that affect the spinal column, such as osteoporosis, can result in myelopathy. A tumor associated with the spinal column can cause myelopathy. Myelopathy may occur as the result of another disease, such as multiple sclerosis. Symptoms of Myelopathy: Numbness, clumsiness of the hands arm and/or hand weakness leg stiffness ( walking like a robot ),loss of balance, urinary urgency, neck & low back pain may be present but does not have to be a significant complaint People with myelopathy may have trouble with activities that require some degree of coordination, such as tying shoes or walking downstairs. It is not uncommon to have problems with balance, walking, or muscle weakness. These symptoms may be mild at first and go unnoticed or at least not be a cause of concern. They may notice: Changes in coordination, Sudden muscle weakness, Inability to control Their body, particularly hand-eye coordination, in ways they used to be able to do.,,,this Indicates urgent necessity to see a physician or even a visit in the emergency room.

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29 MYELOPATHY Work Up: Plain films, Computed tomography, Magnetic resonance imaging Electrodiagnostic studies TREATMENT Since these patients seem to have a typical natural history, there are some particular indications for the surgical management. Thus, patients with gradual neurological deficits and those older than 60 years obtain significant benefits from the surgical treatment. These advantages are clearer in disabled patients, although patients with mild neurological deficits have greater tendency to have their deficits deteriorated when non-operative management is chosen. Non-surgical patients (CSM mild forms) may be treated with cervical immobilization, analgesics, anti-inflammatory and Physiotherapy. In cases associated with cervical radiculopathies, drugs such as Tricyclic antidepressants, anticonvulsants or even antagonists of drugs N-methyl -D-aspartate receptors as riluzole may be used. Myelopathy and spinal cord injuries are serious and complex medical problems. In some cases, compression or pressure on the spinal cord will put pressure on nerves. This may cause pain, weakness, or a lack of control. If patients develop muscle weakness and pain, They may be asked to consider surgery in order to relieve the pressure on the nerves. Over time, pressure on a nerve can permanently damage it. While many cells in the body have the ability to repair themselves, nerve cells can, in some instances, be irreversibly damaged. Typical cervical spine magnetic resonance imaging in cervical spondylotic myelopathy showing severe spinal cord compression in different levels.

30 Brown Sequard Syndrome Hemisection of the spinal cord usually due to traumatic injury. Symptoms Ipsilateral distal UMN dysfunction symptoms Ipsilateral LMN dysfunction AT level of lesion*** Ipsilateral proprioception, light touch and vibration sense lost below lesion Contralateral sensory loss of pain and temperature two levels below lesion due to input at various levels of spinal cord. Diagnosis Physical exam and MRI of spine Treatment Stabilize patient from any trauma that has occurred Expectant management neurological sequelae

31 Radiculopathy vs Myelopathy Any pathological condition involving spinal nerve root Spinal nerve root contains a segment of LMN that comes out of the spinal cord segment. Any pathological condition involving spinal cord Spinal Cord contains many UMN segments and a motor cell body at that level resulting in a few LMN symptoms (help in localization of lesion)

32 Myelopathy, Radiculopathy, Myopathy What You Should Remember about Myelopathy Myelopathy affects the entire spinal cord. It is not like other types of back problems where pain is localized to a specific area of the back, neck, or legs. Myelopathy can be challenging to diagnose. Myelopathy is a serious condition that requires prompt and expert medical attention. Myelopathy Versus Radiculopathy Myelopathy may sometimes be accompanied by radiculopathy. Radiculopathy is the term used to describe pinching of the nerve roots as they exit the spinal cord or cross the intervertebral disc, rather than the compression of the cord itself (myelopathy). Myelopathy Versus Myopathy Myopathy is a muscular disorder and should not be confused with myelopathy, which has to do with nerve damage inside the spinal cord.

33 Myopathy Neuromuscular disorder in which the primary symptom is muscle weakness due to dysfunction of muscle fiber. Etiologies: Congenital or inherited, Idiopathic, infectious, Metabolic, Inflammatory, Endocrine, Drug induced, Toxic Causes: Inflammatory Myopathies, Muscular dystrophies, Congenital Myopathies, Metabolic myopathies, Myotonic Syndromes, Endocrine myopathies, Drug Induced/toxic Types: Congenital, Metabolic, Inflammatory, Atrophic, Myotonic Differential Diagnoses : Motor neuron disease, Neuromuscular junction disorders, Tick-Borne Diseases, Myelopathy/ spinal stenosis, Parkinson s, Guillain-Barre Syndrome Treatment: Based on etiologies...

34 Overall Pearls from Above Presentation Most common disease affecting the peripheral nerve: Diabetes, Alcohol, Nutritional, Guillain-Barré syndrome, Trauma, Hereditary, environmental toxins and drugs, Rheumatic (collagen vascular), Amyloid, Paraneoplastic, Infections, Systemic disease and tumors. Most neuropathies begin distally. They are often asymmetric& accompanied by atrophy & fasciculations. They have Sensory Changes. However, a few may begin proximally: a) Sensory neuropathies: porphyria & rare cases of CMT and Tangier disease b) Motor neuropathies: GBS, Chronic inflammatory demyelinating neuropathy (CIDP), diabetes and idiopathic acute brachial plexus neuropathy. Neuropathies that are predominantly motor: Guillain-Barré syndrome, Diphteric neuropathy, dapsone-induced neuropathy and porphyria. If clinical findings and electrodiagnostic test results are inconclusive, do a biopsy (nerve biopsy for suspected large-fiber neuropathy or skin punch biopsy for suspected small-fiber neuropathy). If all limbs are affected, consider MRI to rule out cervical spinal cord compression. Peripheral neuropathy exam: distal, often asymmetric weakness, atrophy, fasciculations & sensory loss, Muscle tone is decreaced or normal. Reflexes are usually diminished, There may be changes in skin texture,some swelling, temperature dysregulation and loss of hair or nails. 34

35 Overall Pearls from Above Presentation continued RADICULOPATHIES: Hallmark is pain, that is usually described as sharp, stabbing, hot and electric. It typically shoots or radiates down the limb. Otherwise may resemble Peripheral neuropathy (asymmetric weakness, atrophy, fasciculations & sensory loss). Weakness may be proximal or distal depending upon which roots are involved. EXAMINATION: also may find asymmetric muscle weakness with atrophy, & fasciculations. Sensory loss occurs in a dermatomal distribution. Muscle tone is normal or decreased. Reflexes in the involved muscles are diminished or absent. Any maneuvers that tend to stretch the root often such as straight leg raising, or neck rotation- aggravate the pain. MYELOPATHY: patient with Spinal cord disease usually reveals a triad of symptoms: sensory level, Distal symmetric, spastic weakness, Bowel and bladder problems (exam: no significant atrophy or fasciculations, positive Babinski signs, increased reflexes / clonus, increased tone, greater distal weakness than proximal, greater weakness of extensors / antigravity muscles than flexors 35

36 Summary Neuropathy Symptoms most commonly appear distal to lesion. Lesion is in the periphery. Usually gives rise to sensory, motor, or automonic symptoms that do not exactly correlate with dermatomes and reflex locations Results in LMN motor symptoms Radiculopathy Symptoms most commonly involve a dermatomal pattern. Lesion is at the level of the nerve roots Often gives rise to sensory and motor abnormalities Results in LMN motor symptoms Can occur with myelopathy Myelopathy Symptoms most commonly are indicative of UMN lesion LMN symptoms present at level of pathology. (lost reflexes help with localization) Can occur with radiculopathy as well.

37 Contact Information Jean D. Francois, MD Neurologist & Neurophysiologist The Brookdale University Hospital and Medical Center Kingsbrook Jewish Medical Center VARIOUS SOURCES: WebMD newsletter Up-to-date Medicine net Merck Manuals American Academy of Neurology Archives PubMed ETC