Nerve bits:

Question 1

What is MS?

Answer 1

Multiple sclerosis. Inflammatory demyelinating autoimmune disease of the CNS. Charactersied by multiple plaques of demyelination present in the brain and spinal cord. Plaques disseminated in time and space

Question 2

Where do plaques typically present?

Answer 2

• Periventricular region
• Brainstem/cerebellum
• Cervical cord
• Optic nerves

Question 3

Outline the different types of progression of MS:

Answer 3

Relapsing remitting (85-90%):
- Clearly defined relapses with full recovery or with some deficit upon recovery

Secondary progressive:
- What the disease starts with a relapsing remitting picture, but eventually recovery from each successive relapse becomes less complete

Primary progressive (10-20%):
- Gradually gets worse

Question 4

What are the symptoms related to MS?

Answer 4

Symptoms and signs relate to the areas of demyelination.

Eyes (optic neuritis -> optic atrophy):

• Unilateral vision loss
• Painful eye movement
• reduced colour vision

Recovery is normally over a few weeks

Question 5

What motor, sensory and cerebellar features can be present in MS?

Answer 5

Motor:
- weakness, clumsiness, tonic spasms

Sensory:

• Numbness, tingling, Lhermittes pneomenon
• Altered temperature sensation

Cerebellar (DANISH):

• D - Dysdiodochokinesia
• A - Ataxia
• N - Nystagmus
• I - Intention Tremor
• S - Slurred speech
• H - Hypotonia

Question 6

What is Lhermittes phenomenon?

Answer 6

On flexion of neck - brief electric shock like sensation down the limbs.

Question 7

What investigations are performed in those with suspected MS?

Answer 7

• MRI + gadolinium contrast (plaques) - definitive
• Visual evoked potential (delayed conduction)
• CSF electrophoresis - oligoclonal bands of IgG

Question 8

What is the diagnosis of MS based on?

Answer 8

McDonald Criteria

Question 9

What is the treatment of MS?

Answer 9

• No cure
• Acute - IV methylprednisolone
• Chronic: Immunomodulation - beta-interferon

Question 10

What is Myasthenia Gravis?

Answer 10

Disorder of the neuromuscular junction. Results due to autoimmune destruction of Ach receptors at the neuromuscular junction (NMJ). This interferes with neuromuscular transmission via depletion of working post-synaptic receptor sites

Question 11

What is Myasthenia Gravis associated with?

Answer 11

Thymoma/thymic hyperplasia in 70% of patients.

others autoimmune disorders

Question 12

What are the clinical features of Myasthenia Gravis?

Answer 12

Fatiguability - ocular, bulbar, face, neck, limb girdle

• Ptosis - eyelid droops after looking up for 1-2 mins
• Diplopia
• Myathenic snarl/dysarthria
• Voice fades when counting to 50

Tendon reflexes normal, but fatigue on repeat testing

Sensory examination normal

Question 13

What investigations should be performed in someone with suspected Myasthenia Gravis?

Answer 13

• Antibodies - Anti-AChR, MuSK
• CT thorax - thymus
• Ice test
• Tensilon (edrophonium) test

Question 14

What is the tensilon test?

Answer 14

(used in myasthenia Gravis)

• Very short actng anti-acetylcholinesterase given
• +ve result shows improvement in muscular strength following administration

(performed less frequently due to risk of life threatening bradycardia)

Question 15

What is the treatment for Myasthenia Gravis?

Answer 15

• Acetycholinesterase inhibitor: Pyridostigmine
• Immunosuppressants for relapse: Prednisolone
• Thymectomy

Question 16

What is a myathenic crisis?

Answer 16

Weakness of respiratory muscles. May need intubation and ventilation.

Rx - IV Ig
- treat cause (infection/meds/post-op)

Question 17

What is the management of delirium?

Answer 17

General:

• Optimise sensory acuity
• Orientation aids
• Calm consistent nursing staff

Specific:

• Treat cause
• Haloperidol if pose risk to self