Demyelinating disorders Flashcards
What are the symptoms of MS?
- Acute optic neuritis (painful unilateral vision loss associated w. Marcus Gunn pupil)
- Brain stem/cerebellar symptoms (diplopia, ataxia, scanning speech, intention tremor, nystagmus/INO [bilateral.unilateral]
- Pyramidal tract demyelination (weakness, spasticity)
- Spinal cord syndromes (electric shock like sensation along cervical spine and neck flexion, neurogenic bladder, parapesis, sensory manifestations affecting the trunk or more than one extremity)
In what temperatures may MS be exacerbated?
Increased (hot bath, exercise)
What is the most common clinical course of MS?
Relapsing remitting
Who is most often afected by MS?
- Females 20-30
- Low sunlight populations (low vit D exposure)
What will be seen on MRi with MS?
- Oligoclonal bands
- Periventricular plaques (areas of oligodendrocyte loss and reactive gliosis)
- Multiple white matter lesions disseminated in space and time
What is the treatement of MS (in terms of disease modifying)?
- Beta-interferon
- Glatiramer
- Natalizumab
- IV steroids for falre ups
What drugs are given for neurogenic bladder MS?
- Muscarinic antagonists
- Also catheterisation
What drugs can be given for spasticity in MS?
- Baclofen
- GABAB receptor agonists
What can be given for pain in MS?
- TCAs
- Anticonvulsants
What can osmotic demyelination syndrome also be known as?
Central pontine myelinosis
- Axonal dymelination in pontine white matter
What is osmotic dymelination due to?
- Rapid osmotic changes (correction of hyponatremia most commonly)
- Could be shifts in other osmolytes (e.g. glucose)
What are the symptoms of osmotic dymelination syndrome?
- Acute paralysis
- Dysarthria
- Dysphagia
- Diplopia
- Loss of consciousness
- May cause “locked in syndrome”
Correcting Hyponatremia (serum Na+) too fast will cause what?
Osmotic dymelination syndrome (pons white matter)
Correcting Hypernatremia too quickly can cause what?
Cerebral oedema / herniation
What is the most common subtype of GBS?
Acute inflammatory Demyelinating Polyneuropathy
What cells are mainly destroyed in GBS / Acute inflammatory Demyelinating Polyneuropathy?
Schwann cells
What is the mechanism behind GBS which induces autoimmunity?
Molecular mimicry
What is the main symptom of GBS / Acute inflammatory Demyelinating Polyneuropathy?
- Symmetric ascending paralysis / muscle weakness (depressed/absent DTRs in lower extremities)
- Facial paralysis
- Resp failure
- Autonomic dysregulation (cardiac, hyper/hypotension) + sensory abnormalities may also be seen
What is the treatment of acute inflammatory dymelinating polyneuropathy?
What class of drugs should NOT be given?
- Plasma exchange
- IV immunoglobulins
- Resp support
NO STEROIDS
What does Acute disseminated (postinfectious) encephalomyelitis present with?
Rapidly progressive multifocal neurologic symptoms, altered mental status
What is Acute disseminated (postinfectious) encephalomyelitis caused by?
Infection or vaccine
What gene deformaity causes Charcot-Marie-Tooth [subtype CMT1A]?
How is it inherited?
Aut dominant
- PMP22 gene duplication
What is the pathology behind CMT disease?
Hereditary nerve disease due to defective production of proteins involved in the structure and function of peripheral nerves of the myelin sheath
What are the symptoms of CMT disease?
- Foot deformaties (eg pevus cavus, hammer toe)
- Lower extremity weakness (eg foot drop)
- Sensory deficits (can’t move toes)
What is Progressive multifocal leukoencephalopathy caused by?
Describe the pathophysiology
Reactivation of JC virus
- Destroys oligodendrocytes -> Dymelination of CNS
What is Progressive multifocal leukoencephalopathy associated with?
- Severe immunosuppression (AIDS, organ transplant, lymphoma leukemia)
- Natalizumab and rituximab
What areas of the brain are primarily affected in Progressive multifocal leukoencephalopathy?
- Parietal and occipital areas, visual symptoms common
What are the outcomes like for Progressive multifocal leukoencephalopathy patients?
Rapidly progressive, usually fatal
