23. Multiple sclerosis

Question 1

Definition of MS

Answer 1

Chronic, progressive, autoimmune, inflammatory disease of the CNS resulting in demyelination of nerves

Question 2

Epidemiology of MS

Answer 2

30-40s
Female:Male 2:1

Question 3

Etiology of MS

Answer 3

Unknown, but has a few risk factors:
- Genetic: HLA, fam. history
- Environmental: Virus, geographics (more towards the poles), vitamin D def.

Question 4

Pathology of MS

Answer 4

T-cells (CD8+) activated in the periphery leads to apoptosis of oligodendrocytes (usually producing myelin) and secondary axon degeneration in the CNS. This leads to neurodegeneration of white- and grey matter –> brain atrophy

Question 5

What are the demyelinated regions in MS called?

Answer 5

Plaques

Question 6

Characteristics of active plaques in MS

Answer 6

• BBB dysfunction
• Perivascular infiltration of lymphocytes and plasma cells
• Segmental demyelination

Question 7

Characteristics of chronic plaques in MS

Answer 7

Scar tissue formation (sclerosis) due to astrocyte proliferation

Question 8

Clinical signs of MS

Answer 8

• Optic neuritis
• Sensory: parasthasia, numbness
• Motor: paresis
• Cerebellar: limb/trunk ataxia, dysarthria, nystagmus, tremor, coordination/balance problems
• Brainstem: gaze palsy, trigeminal pain
• Internuclear ophthalmoplegia
• Demyelination of spinal cord tracts
• Autonomic dysfunction
• Cranial nerve palsies

Question 9

Characteristics of optic neuritis

Answer 9

• Often first symptom of MS
• Impaired vision
• Painful
• Unilateral
• Colour blindness

Question 10

Characteristics of Internuclear ophthalmoplegia

Answer 10

Gaze abnormality characterized by impaired horizontal eye movements with weak and slow adduction of the affected eye, and abduction nystagmus of the contralateral eye

Question 11

Signs of demyelination of spinal cord tracts

Answer 11

Lhermitte sign: a shooting electric sensation traveling down the spine upon flexion of the neck.

Pyramidal tract lesion: upper motor neuron weakness, spasticity, hyperreflexia, positive Babinski sign, impaired gait

Dorsal spinal column lesion: loss of vibration and fine-touch sensation, numbness, paresthesias, sensory ataxia usually involving the trunk or one or more limbs

Neuropathic pain

Absent abdominal reflex

Question 12

Diagnosis criteria for MS is called

Answer 12

Mc donald criteria

Question 13

What is diagnostic criteria of MS based on

Answer 13

1. How many attacks (0 - 2 or more)
2. How many lesions (0 - 2 or more)
3. Additional criteria (needed when attacks and lesions are low in number. based on dissemination on MR)

Question 14

Diagnostic tools in MS

Answer 14

• MR
• CSF examination
• Evoked potentials
• Serology (ddx.)

Question 15

Treatment of MS

Answer 15

• Acute attacks = high dose glucocorticoids + plasmapheresis
• Autologous stem cell transplant
• Disease-modifying drugs (slow progression); interferon beta, glatiramer acetate, teriflunomide

Question 16

Characteristics of MS progression

Answer 16

Most people with MS have a relapsing-remitting disease course. They experience periods of new symptoms or relapses that develop over days or weeks and usually improve partially or completely. These relapses are followed by quiet periods of disease remission that can last months or even years.