Demyelinating Disease Flashcards
Where are the lesions typically distributed in MS?
Perivenous white matter
What is the pathology of acute lesions in MS?
Myelin destruction with relative axon sparing
Mononuclear cell and lymphocyte infiltration with interstitial oedema
Breakdown of the BBB
How do acute lesions progress in MS after initial inflammation?
Astrocyte proliferation
Old lesions are acellular, clearly demarcated and bare axons surrounded by astrocytes; increasing axonal loss accounts for increasing disability
Is there a prodrome to MS?
Sometimes - vague, non-specific e.g. Headaches, lethargy, aches
What should be considered the underlying diagnosis in a young adult presenting with paroxysmal facial pain?
Trigeminal neuralgia - MS presentation
What is Lhermitte’s sign?
Shock-like sensation in limbs on neck flexion due to cervical posterior column/spinothalamic plaques
What does loss of all sensory modalities at a given spinal level in MS suggest about the location of the lesion?
Dorsal root entry zone
What are the most common motor presentation distributions in MS?
Monoparesis or paraparesis
Much less commonly hemiparesis or quadraparesis
What reflex is lost in UMNL?
Abdominal reflex
What would a plaque of demyelination at the anterior horn cell root cause?
A mixed UMNL and LMNL picture
What are the symptoms of optic neuritis?
Visual loss with central scotoma
Pain on eye movement may occur due to irritation of dural membrane surrounding optic nerve
What might a mild optic neuritis cause isolated loss of?
Colour vision
What does bilateral optic neuritis suggest in terms of differential diagnosis?
MS less likely
Neuromyelitis optica
Leber’s hereditary optic neuropathy (mitochondrial)
What is Uhthoff’s phenomenon?
Visual Sx of MS (or demyelinating disease generally) worsening following hot bath or exercise
What does fundoscopy show in optic neuritis?
Papillitis
2 investigations for optic neuritis?
HRCT/MRI - exclude optic nerve tumour and possibly identify plaques
Delayed VERs/VEPs
What does an optic disc with previous optic neuritis look like?
Atrophic with a pale, punched out temporal margin
What is internuclear ophthalmoplegia? Where is the lesion?
Medial longitudinal fasciculus lesion pathognomonic of MS in young people
Causes a failure of adduction on the affected side and a side-by-side diplopia
When does primary progressive MS more commonly occur?
If it presents after that age of 45 or so
What process do unmatched oligoclonal CSF bands indicate?
Intrathecal antibody production
What MRI modality best highlights demyelination?
T2 - demyelination shows increased signal
What MRI modality is best for showing acute demyelinating lesions?
GAD
What does GAD highlight in demyelinating disease?
Acute lesions
What criteria is used to diagnose MS with a single clinical episode?
McDonald Criteria
