Multiple Sclerosis Flashcards
Mean age of onset of multiple sclerosis?
30 years
Majority of people between 20 - 40 years when diagnosed
What is the pathophysiology of MS?
It is an immune mediated inflammatory disease that attacks myelinated axons in the CNS
What sort of disease progression does MS tend to follow?
A relapse-remitting pattern
Onset of symptoms over days, stabilises over days - weeks, gradually resolves (not always completely), then relapses in a few months/years
What are some common ways in which MS relapses?
- Optic neuritis
- Sensory loss
- Limb weakness
- Brainstem issues (diplopia/ataxia)
- Spinal cord issues (bilateral motor & sensory symptoms, bladder involvement)
What is optic neuritis? Symptoms?
- Inflammation of the optic nerve
- Subacute visual loss
- Pain moving eye
- Colour vision disturbed
Common clinical sign of optic neuritis?
- Abnormal pupillary reflex in one eye
- Usually only one eye affected, so do pupillary constriction test and one eye will only cause partial constriction of the pupils compared to the other
Ways in which brainstem relapse of MS can present?
- Cranial nerve issues
- Pons: internuclear ophthalmoplegia (affected eye can’t adduct)
- Cerebellum: vertigo, nystagmus, ataxia
- UMN signs in limbs
- Sensory loss
What is nystagmus?
- Normally when the head moves the semicircular canals of the ears sense this movement and tell the brain to rotate the eyes the opposite way so that gaze can be fixated on an object
- Nystagmus occurs when the semicircular canals are being activated when the head is not moving, causing the eyes to “dance about.” Can cause visual issues
What is myelitis and what are some symptoms it can cause?
- Myelitis is inflammation of the spinal cord, can be transverse (both sides of a section of SC) or partial
- Band of hyperaesthesia (excessive sensitivity) at sensory level
- Weakness/UMN changes below level of demyelination
- Bladder & bowel involvement
Pathophysiology of the demyelination process?
- Autoimmune: activated T cells cross BBB
- Loss of function, repair, recovery of all/some function
- Post inflammatory gliosis (glial cell proliferation)
- Appears as plaques/lesions on MRI
What can cause MS relapse?
- Underlying infection in 25-30%
- Fewer relapses in pregnancy, increased risk in first 3 months post-partum
What causes persistent disability in MS? How is this diagnosed?
- Axonal loss causes persistent disability
- Seen as black holes on MRI and later as cerebral atrophy
What happens during the progressive phase of MS?
Accumulation of symptoms and signs, body can’t recover before onset of the next attack
What are some clinical signs to look for in examination of MS patient?
- Afferent pupillary defect
- Nystagmus or abnormal eye movement
- Cerebellar signs
- Sensory signs
- Weakness
- Spasticity
- Hyperreflexia
- Plantars extensor (+ Babinski - toe up when foot brushed w blunt object)
What are the three types of MS and description of their progression?
- Relapsing-remitting (85%): Symptoms, then resolution, then relapse a while later. Continuous
- Secondary progressive: Begins like RR, then one relapse initiates progressive disease that doesn’t resolve
- Primary progressive: progressive from onset
