Neuro - MS

Question 1

What is the pathophysiology of MS?

Answer 1

• Chronic and progressive inflammatory condition which causes the demyelination of myelinated neurones in CNS (affects oligodendrocytes).
• In early disease, re-myelination can occur
• In later disease, re-myelination is incomplete and symptoms gradually become more permanent
• MS lesions are disseminated in ‘time and space’ - different nerves are affected and sx change over time

Question 2

What are some causative/risk factors linked to MS?

Answer 2

• Multiple genes
• Ebstein-Barr virus
• Low vitamin D
• Smoking
• Obesity

Question 3

What are some important signs and symptoms of MS?

Answer 3

• Optic neuritis
• Eye movement abnormalities
• Focal weakness
• Focal sensory symptoms
• Spinal cord lesions (myelopathy)
• Ataxia

Question 4

What is optic neuritis?

Answer 4

Presents with unilateral reduced vision developing over hours to days

Key features:

• Central scotoma (enlarged blind spot)
• Pain on eye movement
• Impaired colour vision (test with a red pin - red colour changes as it is brought centrally)
• Relative afferent pupillary reflex defect: less pupillary constriction (bilat) when light is shined in affected eye but normal (bilat) pupillary constriction when light is shined in unaffected eye

Question 5

What are other causes of optic neuritis?

Answer 5

• Sarcoidosis
• SLE
• Diabetes
• Syphilis
• Measles
• Mumps
• Lyme disease

Question 6

What should you do if a patient presents with optic neuritis?

Answer 6

• Must be seen urgently by an ophthalmologist for assessment
• Treatment with steroids
• 50% of patients with single episode of optic neuritis will develop MS over next 15 years

Question 7

Describe some eye abnormalities found in MS

Answer 7

• Diplopia caused by 6th nerve palsy
• unilateral internuclear opththalmoplegia of 6th nerve causes a conjugate lateral gaze disorder (when looking laterally in direction of affected eye, the affected eye will not be able to abduct)

Question 8

What focal weakness can you find in a patient with MS?

Answer 8

• Bells palsy
• Horner’s syndrome
• Limb paralysis (spinal cord lesions or also known as myelopathy are very common, lead to a spastic paralysis)
• Incontinence: recent onset nocturnal, increased urinary frequency

Question 9

What focal sensory symptoms can you find in a patient with MS?

Answer 9

• Trigeminal neuralgia
• Numbness
• Paraesthesia
• Lhermitte sign: electric shock sensation travels down the spine and into the limbs when flexing the neck indicates disease in cervical spinal cord in the dorsal column - caused by stretching of demyelination dorsal column

Question 10

What types of ataxia can you see in a patient with MS?

Answer 10

• Sensory: damage to proprioceptive sense (eg inability to sense joint position) - will have positive Romberg’s test
• Cerebellar ataxia: result of problem with cerebellum coordinating movement - suggestive of cerebellar lesions

Question 11

What disease patterns are found in MS?

Answer 11

• Clinically isolated syndrome: 1st episode of demyelination and neurological signs and symptoms - cannot diagnose MS after 1 episode.
• Relapsing-remitting: most common pattern at initial diagnosis. Characterised by episodes of disease and neurological symptoms followed by recovery. Can be active (new sx and lesions) or non active (no new sx or lesions) and worsening (overall worsening of disability) or not worsening
• Secondary progressive: were MS was relapsing-remitting at first but now there is progressive worsening with incomplete remission - sx are more permanent. Can be active/worsening as above
• Primary progressive: worsening of disease and neurological symptoms from the point of diagnosis, without initial relapses + remissions.

Question 12

How is MS diagnosed?

Answer 12

• Clinical diagnosis made by a neurologist - must have a clinical picture of lesions that change of time
• Symptoms must be progressive for 1 year to be labelled as primary progressive MS

Investigations:

• MRI: can look at lesions and plaque load (low load = better prognosis)
• LP: check for unmatched (ie not in blood) oligoclonal bands
• B12 levels

Question 13

How is MS managed? What is the treatment for chronic vs relapses?

Answer 13

• MDT: neurologist, MS neuroses, PT, OT
• Careful patient education
• Use disease modifying drugs (beta interferon) and biologic therapy - the aim is to induce long term remission with no evidence of disease activity
• Relapses: methylprednisolone (500mg PO OD for 5/7 or 1g IV for 3-5/7 if PO treatment has failed previously or if it is a severe relapse)

Question 14

What other medication/treatment should you consider apart form steroids/disease modifying drugs

Answer 14

• Exercise: maintain activity and strength
• Neuropathic pain: Gabapentin/amitriptyline
• Depression: SSRI
• Urge incontinence: anticholinergics medication (tolterodine/oxybutynin but can cause/worsen cognitive impairment)
• Spasticity: baclofen, gabapentin and PT