5.1 Alex.

Transcription

1 5.1 Alex

2 Alex is a 20-year-old full-time national serviceman. His only past medical history is asthma, presents to A&E with a 4-day history of bilateral finger weakness and numbness, change in voice, and nasal congestion. He was diagnosed with sinusitis and discharged with clarithromycin. Two days later, he comes back with additional symptoms of breathlessness, lethargy, difficulty swallowing, and diplopia. These symptoms had developed over the last two days. His temperature was 38.5 degrees, blood pressure was 145/75, pulse 114, and oxygen saturations 97% on room air. On examination, he was alert and orientated. First and second heart sounds were heard, lungs were clear, and the abdomen was soft. He was able to walk, with power at least 4+ in all limbs. Cranial nerve examination was remarkable for bilateral abduction impairment and pooling of saliva in the mouth. Other cranial nerves were intact.

3 On examination, he was alert and orientated. First and second heart sounds were heard, lungs were clear, and the abdomen was soft. He was able to walk, with power at least 4+ in all limbs. Cranial nerve examination was remarkable for bilateral abduction impairment and pooling of saliva in the mouth. Other cranial nerves were intact. Reflexes were normal. He was admitted to GW. Q1. Which of the following differential diagnoses is the LEAST plausible? a) Cerebral infarction b) Meningitis c) Miller-Fischer syndrome d) Multiple sclerosis e) Myasthenia Gravis

4 On examination, he was alert and orientated. First and second heart sounds were heard, lungs were clear, and the abdomen was soft. He was able to walk, with power at least 4+ in all limbs. Cranial nerve examination was remarkable for bilateral abduction impairment and pooling of saliva in the mouth. Other cranial nerves were intact. Reflexes were normal. He was admitted to GW. Q1. Which of the following differential diagnoses is the LEAST plausible? a) Cerebral infarction Factors against stroke b) Meningitis Subacute onset c) Miller-Fischer syndrome Bilateral?brainstem deficits d) Multiple sclerosis with preserved consciousness e) Myasthenia Gravis

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6 A full blood count, electrolytes, and CRP was unremarkable. A CT brain was unremarkable except for sinusitis. The ENT surgeon oncall performed nasoendoscopy, which was normal. CXR is shown:

7 A full blood count, electrolytes, and CRP was unremarkable. A CT brain was unremarkable except for sinusitis. The ENT surgeon oncall performed nasoendoscopy, which was normal. Q2. Which of the following initial management is the MOST crucial? a) 4-hourly monitoring of negative inspiratory force and forced vital capacity b) 4-hourly monitoring of Glasgow coma score c) Dilated fundoscopic examination. d) Intravenous broad-spectrum antibiotics. e) Insertion of nasogastric tube

8 A chest X-ray was normal. A full blood count, electrolytes, and CRP was unremarkable. A CT brain was unremarkable except for sinusitis. The ENT surgeon on-call performed nasoendoscopy, which was normal. Q2. Which of the following initial management is the MOST crucial? a) 4-hourly monitoring of negative inspiratory force (keep more than -30) and forced vital capacity (keep more than 20ml/kg) b) 4-hourly monitoring of Glasgow coma score c) Dilated fundoscopic examination. d) Intravenous broad-spectrum antibiotics. e) Insertion of nasogastric tube

9 He was admitted to the general ward. The next morning, he was found in respiratory distress. On examination, power was 1-2/5 in both upper limbs, with a weak cough reflex. Arterial blood gas on a non-rebreather mask showed ph 7.4, po2 100, pco2 29, HCO3 21. Q3. Which is the most appropriate management? a) Electrocardiogram b) Endotracheal intubation c) Neurology referral d) Urgent CT brain e) Urgent MRI spine

10 He was admitted to the general ward. The next morning, he was found in respiratory distress. On examination, power was 1-2/5 in both upper limbs, with a weak cough reflex. Arterial blood gas on a non-rebreather mask showed ph 7.4, po2 100, pco2 29, HCO3 21. Q3. Which is the most appropriate management? a) Electrocardiogram b) Endotracheal intubation c) Neurology referral d) Urgent CT brain e) Urgent MRI spine ¼ of all GBS patients require intubation. Watch: NIF, FVC, neck flexion <3

11 He was intubated and transferred to the medical ICU. Further examination showed: - Eyes: bilateral ptosis, abduction and depression deficit - Neck flexion 3/5 - Power in upper and lower limbs: 2-3 proximally, 4 distally - Absent ankle jerks - Decreased pinprick sensation below the ankles A diagnosis of Miller-Fischer / Guillain-Barre syndrome was made.

12 A diagnosis of Miller-Fischer / Guillain-Barre syndrome was made. Q4. Which of the following additional features, if present, would cast DOUBT on the diagnosis of guillain-barre syndrome? (Choose 2 of 7) a) Bilateral facial droop b) Bladder or bowel dysfunction c) Labile blood pressure and/or heart rate d) Normal sensation e) Pain f) Relatively symmetrical weakness g) Sensory level

13 A diagnosis of Miller-Fischer / Guillain-Barre syndrome was made. Q4. Which of the following additional features, if present, would cast DOUBT on the diagnosis of guillain-barre syndrome? (Choose 2 of 7) a) Bilateral facial droop b) Bladder or bowel dysfunction c) Labile blood pressure and/or heart rate d) Normal sensation e) Pain f) Relatively symmetrical weakness g) Sensory level

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15 Variants of GBS

16 Q5. Which of the following investigation(s) is/are necessary for the diagnosis of Miller-Fischer / Guillain-Barre syndrome? a) Lumbar puncture b) Nerve conduction studies c) Serum autoantibodies d) MRI brain e) None of the above

17 Q5. Which of the following investigation(s) is/are necessary for the diagnosis of Miller-Fischer / Guillain-Barre syndrome? a) Lumbar puncture may show albuminocytologic dissociation b) Nerve conduction studies evidence of demyelination or axonopathy c) Serum autoantibodies - GQ1B in MFS d) MRI brain e) None of the above

18 Lumbar puncture showed no cells and albumin of Serum GQ1B was sent and eventually came back positive. Nerve conduction studies were scheduled to be performed at a later date. Q6. The following therapies are beneficial EXCEPT a) Analgesia. b) High-dose pulsed steroids c) Intravenous immunoglobulin d) Plasmapheresis e) DVT prophylaxis

19 Q6. The following therapies are beneficial EXCEPT a) Analgesia. b) High-dose pulsed steroids c) Intravenous immunoglobulin d) Plasmapheresis e) Short-acting beta-blockers for hypertension Disease modifying treatment - IVIg - Plasmapheresis Supportive care Respiratory support Management of autonomic dysfunction Pain control DVT prophylaxis Rehabilitation

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21 He received intravenous immunoglobulin over 5 days. He was extubated 6 days later, and discharged on day 10 of admission. At discharge, he was able to walk independently. He went on to make a complete recovery. Q7. Which of the following advice would you give to the patient? a) The chance of relapse is low b) Long term immunosuppression is required c) He should not receive any immunizations in future d) He is at risk of developing Chronic Inflammatory Demyelinating Polyneuropathy

22 He received intravenous immunoglobulin over 5 days. He was extubated 6 days later, and discharged on day 10 of admission. At discharge, he was able to walk independently. He went on to make a complete recovery. Q7. Which of the following advice would you give to the patient? a) The chance of relapse is low b) Long term immunosuppression is required c) He should not receive any immunizations in future d) He is at risk of developing Chronic Inflammatory Demyelinating Polyneuropathy

23 Key lessons for Neuromuscular Diseases What is the lesion time course Hyperacute onset weakness think stroke Subacute onset weakness think GBS, MG, cervical cord. Where is the lesion Multiple cranial nerve palsy think brainstem, clubs, base of skull, nerve and muscle. Watch for respiratory compromise (NIF > -30, FVC < 20ml/kg) Specific treatment: - IVIg / plasmapheresis for both GBS and myasthenia gravis.

24 Additional concerns in myasthenia gravis Principles of diagnosis and supportive management same as in other neuromuscular disease (GBS) Rapid immunotherapy: IVIg or phasmapheresis Chronic treatment: pyridostigmine, steroids, steroid-sparing agents take time to work. Look for a thymoma Some drugs may exacerbate myasthenia Antibiotics: aminoglycoside, fluoroquinolones Neuromuscular blocking agents may lead to prolonged weakness Magnesium

25 Neurologic localization Limbs Cranial nerves Cerebellar Extrapyramidal

26 Know your neuroaxis Pyramidal Brain Brainstem Spinal cord AHC Root / plexus Peripheral nerve NMJ Muscle Extrapyramidal Cerebellar

27 UMN: Brain, brain-stem, spinal cord LMN: root, plexus, peripheral nerve 2 LMN: NMJ or muscle Atrophy Less marked May be severe Variable 3 Fasciculation None May be present None Tone Increased 1 Decreased Usually normal 3 Clonus 3 beats 1 3 beats 3 beats Reflexes Increased 1 Decreased Usually normal 3 Plantars Upgoing 1 Downgoing Downgoing

28 Right brain lesion Right brainstem lesion Cervical spinal cord lesion

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30 Prototypical disorder Anterior horn cell Spinal muscular atrophy Peripheral nerve Diabetic neuropathy Specific nerve, root, or plexus Disk prolapse NMJ Myasthenia gravis Muscle Dermatomyositis Sensation Normal Impaired Impaired Normal Normal Distribution of Symmetrical Symmetrical Patchy Symmetrical Symmetrical weakness proximal distal proximal proximal Reflexes Diminished Diminished Diminished Normal Usually normal Additional characteristics Exceptions to the rules Fasciculations Eye muscles usually spared Weakness may be distal and asymmetrical. Reflexes may be brisk in motor neuron diseases. Pure motor neuropathies have normal sensation. Fatigability There are distal myopathies. Depressed reflexes may occur in severe myopathy

31 SMA: spinal muscular atrophy, PMA: progressive muscular atrophy, MG: myasthenia gravis LEMS: Lambert-Eaton myasthenic syndrome, MMN: multifocal motor neuropathy AMAN: acute motor axonal neuropathy, NCS: nerve conduction study, EMG: electromyography GBS: Guillain-Barre syndrome, CIDP: chronic inflammatory demyelinating polyneuropathy CMT: Charcot-Marie-tooth

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36 UMN Isolated unilateral LMN Bells palsy CN VII Ramsay-Hunt syndrome Mastoid disorders Parotid disorders Bilateral Myasthenia gravis Myotonic dystrophy Complex Miller-Fischer syndrome Other causes: mononeuritis multiplex, sarcoidosis, etc.

37 Short Case Where is the lesion What is the lesion