Lecture 4-MS/MG Flashcards
a slowly progressive demyelinating disorder og the CNS
MS
patho of MS
- attack of myelin sheath
- CNS WHITE MATTER LESIONS SEPARATED BY TIME AND SPACE
area primarily affected in MS
white matter of cervical and dorsal region of lateral and posterior columns
-also optic nerves and periventricular areas
characteristics of MS
visual changes
- dizziness
- numbness
- incoordination
- dysdiadochokinesia (difficulty with RAMs)
avg age of onset of MS
30
most common neurologic disability beginning in early to middle adulthood
MS
most frequent presentations of MS
- fatigue
- paresthesias of extrem.
- clumsiness or weakness
- visual disturbances
signs of MS
internuclear ophthalmoplegia, lhermitte’s sx, optic neuritis, pyramidal tract involvement results (hyperreflexia, clonus), cerebellar involvement, posterior column involvement (reduced vibration and proprioception)
what is internuclear ophthalmoplegia
lesion in mlf
-paresis of medial rectus muscle on lateral conjugate gaze, but not on convergence
what is lhermitte’s sx
neck flexion sends sensation of elevtrical shock down back to legs
what is optic neuritis
decreased visual acuity, defective pupillary reaction to light
what is marcus gunn pupil
afferent pupillary defect
relapsing-remitting MS
- most common
- attacks of sxs that come on over 1-2 weeks and resolve in 4-8 weeks
secondary progressive MS
relapsing-remitting at first, then evolves to relapsing progressive
primary progressive MS
gradual preogression
most common form of MS in pts who develop ds after age 40
primary progressive MS
lab studies for MS
- CSF analysis
- MRI
csf findings for MS
elevated total IgG
-presence of oligoclonal bands
best radiographic test and most sensitive overall test for MS
MRI
MRI findings of MS
periventricular plaques (bright signals)
tx of MS
- acute attacks-high dose steroids
- ongoing disease-interferon beta-1a and beta-1b; glatiramer (synthetic analog of myelin basic protein
- +/- immunosuppressants
sx management of MS
- spasticity: baclofen, tizanidine, clonazepam
- ataxia: no effective tx
- temperature sensitivity: cool pools and cooling suit
- contractures: surgical release
- incontinence: anticholinergics
- sexual dysfunction: sildenafil
- pain: TCAs, baclofen, clonazepam, gapapentin
- fatigue: amantadine, pemoline
- depression: counseling, antidepressants
- assist devices: canes, walkers, etc
an autoimmune disorder og the NMJ
myasthenia gravis
patho of MG
circulating antibodies attack and destroy AChRs
this is abnormal is 75% of cases of MG
thymus
additional defect a/w MG
postsynaptic folds are flattened
signs and sxs of MG
- muscle weakness/fatgiue that is worse with continued activity and improves with rest
- eyelid weakness and EOM weakness
- normal DTRs
dx tests of MG
- repetitive exercises to reproduce sxs
- tensilon test (edrophonium): results in temporary improvement of muscle strength
- acetylcholine receptor antibody test (+ test is diagnostic, - test does not r/o)
- EMG: decremental response (aka fatigability)
- CT or MRI to check for thymoma
lambert-eaton myasthenic syndrome
- presynaptic disorder
- incremental responses on repetitive nerve stim
- depressed or absent DTRs
- small cell CA of lung most common malignancy a/w LE
tx of MG
- anticholinesterase drugs (pyridostigmine)
- thymectomy
- immunosuppresive drugs (prednisone, azathioprine, cyclosporine)
- plasmapheresis
- IV Ig
