Multiple Sclerosis (MS)

Question 1

Definition of Multiple Sclerosis?

Answer 1

An inflammatory demyelinating disease of the CNS

Question 2

What are the types of MS?

Answer 2

• Relapsing-Remitting MS
• Clinically isolated syndrome
• Primary progressive MS
• Marburg variant

Question 3

Describe Relapsing-Remitting MS.

Answer 3

COMMONEST form of MS

Clinical attacks of demyelination with complete recovery in between attacks

Question 4

Describe clinically isolated syndrome.

Answer 4

Single clinical attack of demyelination

The attack in itself does NOT count as MS

10-50% progress to develop MS

Question 5

Describe Primary Progressive MS.

Answer 5

Steady accumulation of disability with NO relapsing-remitting pattern

Question 6

Describe the Marburg Variant.

Answer 6

Severe fulminant variant of MS leading to advanced disability or death within weeks

Question 7

Explain the aetiology and risk factors involved with MS.

Answer 7

• Unknown aetiology
• Autoimmune basis with potential environmental triggers in genetically susceptible individuals
• Immune-mediated damage to myelin sheaths results in impaired axonal conduction

Risk factors: EBV exposure + Prenatal vitamin D levels

Question 8

What is the epidemiology of MS?

Answer 8

UK prevalence: 1/1000

2 x as common in FEMALES

Age of presentation: 20-40 yrs

Question 9

What are the presenting symptoms of MS?

Answer 9

Varies depending on the site of inflammation

• Optic Neuritis (most common): unilateral deterioration of visual acuity and colour perception + pain on eye movement
• Sensory: Pins and needles, numbness and burning
• Motor: Limb weakness, spasms, stiffness and heaviness
• Autonomic: Urinary urgency, hesitancy, incontinence and impotence
• Psychological: Depression and psychosis

Question 10

What is the are the two signs associated with MS?

Answer 10

Uhthoff’s Sign - worsening of neurological symptoms as the body gets overheated from hot weather, exercise, saunas, hot tubs etc.

Lhermitte’s Sign - an electrical sensation that runs down the back and into the limbs when the neck is flexed

Question 11

Signs of MS on physical exam?

Answer 11

Optic Neuritis

• Signs on visual field testing
• Relative Afferent Pupillary Defect (RAPD)
• Internuclear Ophthalmoplegia

Sensory, Motor and Cerebellar signs

Question 12

What are the signs of optic neuritis?

Answer 12

Impaired visual acuity (MOST COMMON)

Loss of coloured vision

Question 13

What are the signs seen during visual field testing in a patient with MS?

Answer 13

Central scotoma (if optic nerve is affected)

Scotoma = a blind spot in the normal visual field

Field defects (if optic radiations are affected)

Question 14

What does internuclear opthalmoplegia involve in MS?

Answer 14

Lateral horizontal gaze causes failure of adduction of the contralateral eye

Indicates lesion of the contralateral medial longitudinal fasciculus

Question 15

What are the sensory, motor and cerebellar signs in MS?

Answer 15

• Sensory: Parasthesia
• Motor: UMN signs

- Cerebellar:
Limb ataxia (intention tremor, past-pointing, dysmetria) 
Dysdiadochokinesia 
Ataxic wide-based gait  
Scanning speech

Question 16

What are the appropriate investigations for MS?

Answer 16

• McDonald Criteria: Diagnosis is based on finding of 2 or more CNS lesions with corresponding symptoms seperated in time / space
• Lumbar puncture:
  Microsocopy - to exclude infection/ inflammatory causes
  CSF electrophoresis shows unmatched oligoclonal bands
• MRI Brain, cervical and thoracic spine:
  Plaques can be identified
  Gadolinium enhancement shows active lesions
• Evoked potentials:
  Visual, auditory and somatosensory evoked potentials may show delayed conduction velocity.