Multiple Sclerosis Flashcards
what is MS?
- progressive autoimmune disease characterized by inflammation, selective demyelination, and gliosis
- demyelinating lesions (plaques) impair neural transmission, causing nerve fibres to fatigue rapidly
- characterized by replase, remission, progression
- unpredictable course
describe the pathophysiology of MS
is white matter or gray matter more affected?
- abnormal immuno-mediated response attacks myelin, oligodendrocytes, and the axons themselves throughout the CNS
- activation of immune cells that cross BBB, enter CNS, and initate damaging inflammatory cascade of events
- acute inflammatory attack, gradually subsides (REMISSION)
- remyelination often incomplete
- with time, anti-inflammatory response/remyelination cannot keep up
- demyelination areas undergo gliosis
- white matter > gray matter
epidemiology of MS
- Most common cause of disability in young and middle-aged adults
- >900,000 cases in US
- 362 per 100,000
- average age of onset between 15-50 years
describe the etiology/cause of MS
an autoimmune disorder without a clear origin
thought to be viral/infectious
several different triggers
Predisposing factors for MS
- Women > Men (3:1)
- Population genetics
- Caucasian of Nordic origin
- Higher income countries
- Temperature zones (genes and geography)
- western europe and north america
- inconsistent latitude effect
- low vitamin D exposure during childhood and teenage years
- exposure to Epstein-Barr virus
how is MS diagnosed?
- Clinical presentation
- MRI
- dissemination in space
- dissemination in time
- Additional lab tests
- visual evoked potentials
- lumbar puncture
- elevated IgG index, pressure of oligoclonal bands, or both
what is dissemination in space? Where are the most common areas this occurs in?
refers to plaque build up in different areas of the CNS, most common in MS:
- periventricular
- juxtacortical
- infratentorial
- spinal cord
T/F: early detection of MS doesn’t change much
FALSE
significant decline in number of attacks, lesion sites, and disability in pts that participate in early drug treatment protocols
what is a CIS?
- clinically isolated syndrome
- first clinical episode of a disease that shows characteristics of inflammatory demyelination that could be MS but has yet to fulfill criteria of dissemination in time
- can be monofocal or multifocal
common sites for CIS
- optic nerve
- brainstem
- spinal cord
initial treatment for CIS
- high-dose glucocorticoids for acute symptoms
risk factors for conversion of CIS to MS
- polysymptomatic presentation
- >/= T2 MRI lesions
- Oligoclonal bands present in CSF, not in serum
relationship between CIS and MRI findings
- CIS + MRI findings indicative of early event = confirmed MS diagnosis
- CIS + MRI findings = 60-80% chance of MS developing
- CIS without MRI findings = 20% chance of MS developing
S/S of optic neuritis resulting from CIS
- unilateral reduced visual acuity
- Orbital pain particularly with eye movement
- reduced color vision
- afferent pupillary defect
- retrobulbar or mild disc swelling
S/S of brainstem CIS (8)
- bilateral internuclear opthalmoplegia
- ataxia and gaze evoked nystagmus
- 6th nerve palsy
- multi-focal symptoms
- facial sensory loss
- vertigo
- ataxia
- dysarthria
S/S of spinal cord CIS
- incomplete transverse myelitis
- (+) Lhermitte’s sign
- sphincter symptoms
- asymmetric limb weakness
- symptom progression between 4 hours and 21 days
MS Clinical Signs and Symptoms
- Motor function deficits
- Sensory function deficits
- Visual deficits
- Cognitive function
- Poor tolerance for temperature increases
- Fatigue
- Pain
- sleep disorders
- speech and swallow impairments
- dizziness
- bowel and bladder dysfunction
- sexual dysfunction
motor function deficits MS (3)
- weakness
- spasticity
- coordination (cerebellar)
sensory function deficits MS
- complete loss of sensation rare
- numbness
- paresthesia
- proprioceptive/kinesthetic deficits
cognitive function deficts MS
- Hallmark → slowed information processing speed
- Attention deficits (divided, sustained)
types of pain present in MS (5)
- trigeminal neuralgia
- paroxysmal limb pain
- headache
- chronic neuropathic pain
MS and heat insensitivity
What does Uhthoff mean?
- 80% of pts with MS are sensitive to increases in core body temp
- Uhthoff symptom
- increase in presence of neurological symptoms in response to heating condition
- pseudo-exacerbation
describe the neuroblockade hypothesis
hypothesis for heat insensitivity in MS pts
- demyelinated neurons ability to conduct APs decrease as temp increases
- Internal vs External sources
- internal = vigorous exercise, high fevers
- external = environmental temp, bathing or swimming in hot water
MS and Fatigue
- Up to 80% experience some type of acute or chronic fatigue
- 75% of which report fatigue as severe
- 50-60% report fatigue as most troublesome symptom
- # 1 cause of unemployment
- tends to worsen as day progresses
- exacerbated by heat, exercise
- primary, secondary fatigue
- central, peripheral, psychological factors
- can often lead to fear of fatigue → decreased physical activity → disuse → worsening disability