1. MULTIPLE SCLEROSIS high risk zone 30-80/100,000 popln - west europe/uk North USA South Canada medium risk zone 5-15/100,000 popln - Southern Europe Southern USA Australia low risk zone 5/100,000 popln - Asia and Africa

2. MS - Cause -- not established 1. Genetic susceptibility - ethnic variation in incidence higher in relatives of MS Concordance in M twins 20-30% HLA - A3, B7, DW2 2. Environment - altitude high immigration away before age fifiteen - changes risk

3. Bitish troops in farce island - suden increase in MS more in the affluent Viral hypothesis - prolonged progressive illness non specific incrase in measles Ab no virus isolated

4. 3. Auto immunity - ? In the genetically predisposed Ag is myelin or oligodendrocyte increased IgM, IgG, IgA in CSF increased IgG in margins of MS plaque subsets if T-cells specific - detected

5. MS - Pathology plaques greyish areas with sharp outline around ventricles in white matter optic n, chiasma, brain stem, spinal chord

6. microscopy plaque - end stage - no myeline early - fragments of myeline Axons - preserved no ologodendroglial cells Reactive increase astrocytes perivesicular cuff with lympho, phagocytes and glial cells

7. MS - clinical young adults - starts 20-40yrs dessiminated remissions and relapses mainly related with white matter and not gray matter not peripheral nerves onset - acute/subacute depends on area involved eye, spinal chord, brain stem, cerebellum

8. a> acute optic neuritis -commonest blurring pain central scotoma - red/green test retro bulbar - disc lock normal near disc - papillitis seen b> diplodia - midbrain plaque adducting muscles affected

9. MS - clinical cerebellum dysarthria - scanning speech nystagmus intension tremor virtigo, imbalance cranial nerves deafness - rare trigeminal - (5) - sensory impairment on phase 9th and 10th - pseudobulbar palsy

10. spinal cord monoplegia, para plegia, hemiplegia, pyramidal - spasticity, hyperreflexia, plantor extensor