8 Multiple Sclerosis Flashcards
MS Etiology
2.3 million people worldwide
Women 2-3x more likely than men
Most commonly diagnosed 25-35 y/o
Strong correlation between MS prevalence and distance from equator- vit D may be a factor
Factors that may cause MS
Lower risk closer to equator
Smoking increases risk
Higher risk if parent or sibling has it
Human herpes virus-6, Epstein-Barr, chlamydia pneumoniae bacteria, canine distemper, measles
Pathology of MS
Acute demyelination of axons- recovery with axonal plasticity/re-myelination early on, but permanent axonal damage later on
McDonald criteria overview
Dissemination in time- 2 or more distinct attacks
Dissemination in space- 2 or more lesions in CNS
Exclusion of other diagnoses
McDonald criteria for diagnosis
2 attacks + 2 lesions = no additional info needed
2 attacks + 1 lesion = need diss in space
1 attack + 2 lesions = need diss in time
1 attack + 1 lesion = need both
Progressive course over 1 year- need diss in space by two of: MRI brain, MRI SC, CSF fluid oligoclonal bands
MRI types
T1- detects active inflammation
T2- detects old and new lesions
FLAIR (fluid attenuated inversion recovery)- subtle changes
Evoked potentials
Sensory- impulses to arm or leg
Brainstem auditory- listen for series of clicks in each ear
Visual- observe alternating checkerboard pattern, identifies pathologic transmission along optic nerve pathway, only type proven useful in MS diagnosis
CSF analysis
Obtained via lumbar puncture
Findings- IgG, oligoclonal bands, certain proteins common with myelin breakdown (immune-related markers)
Not specific to MS
Sensory and pain symptoms
Paresthesias (most commonly begin distally)
Loss of proprioception and vibratory sense
Dyesthetic pain (pain not provoked by stimulus)
Visual symptoms
Optic neuritis- blurred vision, change in color perception, visual field deficit = most common
Nystagmus
Oscillopsia
Intranuclear opthalmaplegia (disconjucate eye movements)
Optic disc pallor
Heat intolerance symptoms
Sensitivity to changes in core body temperature
Uhthoff phenomenon- increase in body temp causes increased in neurologic symptoms
Neuroblockade hypothesis- increased temp decreases nerve conduction in partially demyelinated fibers (greater demyelination –> greater conduction loss)
Primary MS fatigue
Central fatigue- demyelination leads to failure of motor pathways during rapid activity
Decreased efficiency of motor unit activation- dec oxidative capacity, slow muscle contractile properties, decrease number of slow-twitch fibers, lower tetanic and twitch tension in muscles
Cerebellar symptoms
Ataxia, incoordination, dizziness, imbalance
Urinary symptoms
Incontinence, incomplete emptying, increased frequency
Can get UTIs
Cognitive symptoms
Emotional lability, depression, anxiety, decreased executive functioning
Krutzke expanded disability status scale (EDSS)
0 (no disability) to 10 (death)
0-4.5 can walk independently
5.0-9.5 impairments in ambulation
Functional systems- pyramidal (motor function), cerebellar, brainstem, sensory, bowel and bladder, visual, cerebral or mental, other
FS scored 0 (low level of problems) to 5 (high level)
EDSS cutoffs
- 0- minimal disability in one FS (one S grade 2, others 0 or 1)
- 0- ambulates without aid or rest 200 m, disability severe enough to impair ADLs
- 0- essentially restricted to bed or chair but may be out of bed much of day. Retains many self-care functions
Relapsing-remitting
Most common 80%
Temp relapses lasting 1-3 months, complete or partial recovery between
Secondary-progressive
Second phase of RRMS if not treated
Progressive worsening, may or may not have relapses and remissions
Primary progressive
Steady worsening, no relapses or remissions
Progressive-relapsing
Steady worsening with intermittent acute flare-ups
Malignant MS
Rapid and progressive
Prognostic factors
Positive- RRMS, one symptom at onset
Negative- PPMS, older age at onset, male, African-American, early cerebellar or pyramidal signs, smoking, low vit D
Relapse/exacerbation management meds
Corticosteroids- IV or oral, high dose, short duration
