0828 Autoimmune disorders of the CNS Flashcards
Define multiple sclerosis.
A multiphasic immune disorder against myelin in the CNS where the episodes of demyelination are separated by space and time.
What is the believed pathogenesis in multiple sclerosis?
- auto-reactive myelin specific Th1&17 cells are normally controlled by Tregs, however this fails when Th1&17 cells are stimulated by antigens that allow them the express adhesion molecules to cross the BBB.
- Th1&17 secrete IFNy and IL-17 respectively, activating microglia and PMN cells and immune response against myelin.
List the four classifications of MS.
benign relapsing remitting MS (10%),
primary progressive MS (20%),
relapsing remitting MS, into secondary progressive MS (70%)
List some presenting clinical features of MS.
optic neuritis, sensory loss, motor deficits, cerebellar dysfunction, fatigue.
How is MS diagnosed?
Evidence of lesions separated in time and space (often through MRI, individual lesions are small).
Preveiosly CSF studies to look for oligoclonal bands for proteins.
What is used to treat MS?
Disease modifying drugs, for example Natalizumab - T cell adhesion molecule
What is acute disseminated encephalomyelitis (ADEM)?
a monophasic illness associated with systemic viral illness or vaccination, where T cells react to CNS myelin for a short period following antigen exposure but disease eventually wanes. Treatment with high dose methylprednisolone.
What is neuromyelitis optica (NMO)
an auto-immune disease against aquaporin 4, that typically affects spinal cord and optic nerves and causes long spinal lesions that span across >3 vertebral levels.
How can NMO be distinguished from MS?
NMO spinal lesions typically span >3 vertebral levels, MS spinal lesions are small.
What is Guillain-Barre syndrome?
An acute post-infectious autoimmune peripheral neuropathy due to molecular mimicry between infectious agent and PNS glycoproteins.
Progresses for under 4 weeks then plateaus with slow recovery. Take care to monitor respiration and prevent PE
