Demyelinating Disease Flashcards
Multiple Sclerosis
Pathology
Selective demyelination of CNS (plaques scattered throughout white matter)
Classic location of plaques = at angles of lateral ventricles
Multiple Sclerosis
Commonly involved tracts
- Pyramidal and cerebellar pathways
- Medial longitudinal fasciculus
- Optic nerve
- Posterior columns
Multiple Sclerosis
Clinical features
- Transient sensory deficits (decreased sensation or paresthesias in upper or lower limbs)
- Fatigue
- Motor sx–mainly weakness/spasticity
- Caused by pyramidal tract involvement (UMN)
- Visual disturbances
-
Optic neuritis
- Monocular visual loss
- Pain EOM
- Central scotoma (black spot in center of vision)
- Decreased pupillary rxn to light
-
Internuclear ophthalmoplegia
- Lesion in MLF –> ipsilateral MR palsy on attempted lateral gaze (adduction defect) and horizontal nystagmus of abducting eye (contralateral to side of lesion)
-
Optic neuritis
- Cerebellar involvement – ataxia, intention tremor, dysarthria
- Loss of bladder control (UMN)
- Autonomic involvement (impotence and/or constipation)
- Cerebral involvement (advanced… personality change, anxiety, depression)
- Neuropathic pain. (hyperesthesias, trigem neuralgia)
Multiple Sclerosis
How old are most patients at initial px?
20-30 y/o
Multiple Sclerosis
Dx (helpful hints)
-
MRI = most sensitive test –> ID demyelinating lesions in CNS
- Abnormal in 90% of MS pts
-
Lumbar puncture
- No lab tests are specific for MS, but oligoclonal bands of IgG present in 90% of MS pts
- Evoked potential = suggest demyelination of certain areas by measuring. speed of nerve conduction within the brain… newly remyelinated nerves will conduct sensory impulses more slowly
Multiple Sclerosis
Tx
- Acute attacks*
- Disease-modifying therapy*
- Symptomatic tx*
NO CURE
- Acute attacks:*
- High-dose. IV corticosteroids
Disease-Modifying therapy:
- Recombinant IFN-B, and glatiramer acetate
Symptomatic tx:
- Baclofen or dantrolene for muscle spasticity
- Carbamazepine or gabapentin for neuropathic pain
- Tx depression if indicated
GBS
Pathology
Inflammatory demyelinating polyneuropathy that affects MOTOR NEURONS
Usually preceded by viral or mycoplasmal infection of upper respiratory or GI tract
Common infections: C. jejuni, CMV, hepatitis, HIV
GBS
Clinical features
ABRUPT onset with rapidly ascending weakness/paralysis of all four. extremities
If generalized paralysis is present –> respiratory arrest
Sphincter control and mentation spared
GBS
Dx:
CSF. analysis –> elevated protein, but normal cell count
Electrodiagnostic. studies –> decreased motor nerve conduction velocity
GBS
Tx
Monitor pulmonary function
IV immunoglobulin –> plasmapheresis
do NOT give steroids (usually harmful)
