Lecture 5: MS Flashcards
Demyelination
disruption of myelin that coats neurons; makes the AP transmit slower
Multiple sclerosis definition
an idiopathic inflammatory demyelinating dz of CNS ; caused by an autoimmune attack on oligodendrocytes
Hallmark of MS
multiple scarred foci (plaques) with in the white matter of CNS and perivenular inflammation
-lesions primarily in white matter
MS Pathophysiology:
under inflammatory cndtns T cells, B cells, macrophages, granulocytes cross BBB and enter CNS; once inside target self antigens on oligodendrocytes, decreasing myelin production
Demographics of MS
- age preference: 15-55
- gender preference: females = 2:1
- Genetics
- Environment: born in northern states: 3x higher likelihood
Sx’s of MS: Episodic relapses
- occur during different periods, but are short lived
- progress over hrs to days
- improve over days to weeks
Chronic Sx’s of MS
heat sensitivity; bowel/bladder/sexual dysfxn; fatigue; mood disorders; cognitive dysfxn; gait impairment
Most common Sx’s of MS
Limb sensory loss
Visual Loss: optic neuritis
Other: subacute weakness, diplopia, gait disturbance; balance probs; acute weakness
Transverse myelitis
- sensory loss in one or both limbs
- L’hermitte’s phenomenon: when flex neck have sharp shooting tingling down length of spinal cord
- MS hug: feeling of tightness around chest
Optic neuritis
- eye pain; decrease acuity
- optic disc edema
Dx of MS: 2 things must have
1) dissemination in space
2) dissemination in time
MS MRI
- diagnostic test of choice
- T2/Flair: lesions are hyper intense; found periventricularly, juxtacortical, infratentorial or spinal cord
Dissemination in time
at least 2 lesions in locations typical for MS
Dissemination in space
either clinically or on
MRI: T2/Flair: hyperintense lesions with simultaneous enhancing lesions or see hyper intense lesions or enhancing lesions on F/U
Other diagnostic tools
- LP
- Evoked Potentials
MS on LP
- see oligoclonal bands in CSF: represents increased synthesis of ABs with limited # of responsible antigens in CSF
- also see IgG in CSF
MS Evoked Potentials
visual stimulation are presented and electrical impulse over primary visual cortex are recorded
-VEp will show increased latency suggesting signal thru optic nerve is slowed = optic neuritis
Types of MS
1) Benign
2) Relapsing-Remitting
3) Primary progressive
4) Secondary progressive
5) Progressive Relapsing
Relapsing-Remitting MS
- multiple episodes of transient neuro dysfxn which may or may not completely resolve
- But NO progressions btwn attacks = whatever disability had prior to attacks remains the same
Primary Progressive
dz progresses relentlessly from onset
steady increase in disability w/out attacks
Secondary Progressive
pts with relapsing remitting start to have progression btwn attacks; usually occurs after 17 yrs
Progressive Relapsing
usually have relentless progression from onset but may have rare clinical relapses
Clinically Isolate MS
First attack of MS
-2 common clinically isolated syndromes: optic neuritis and transverse myelitis
Acute Relapse Tx of MS
IV methylprednisone
Plasma Exchange
