Multiple Sclerosis || all solved.
Multiple Sclerosis: General correct answers Chronic neurological disorder
Demyelination, gliosis, and neuronal loss in the central nervous system
Recurrent symptom episodes or progressive neurological decline, or both, reflect involvement of
brain, eye, and spinal cord
Usually seen in young to middle age adults, esp. women
MS Facts correct answers 50% require assistance at 15 years
Cerebral atrophy and some degree of cognitive impairment seen in 50 to 60%
Slight decreased life expectancy in the past
Increasing survival shown with some newer drugs
Disease characterized by demyelination correct answers Multiple sclerosis = CNS, MS is
prototype
Guillian-Barre syndrome = autoimmune demyelination of the PNS, areflexia is the hallmark
Pathogenesis of MS correct answers Inflammation (T cells and macrophages)
BBB disruption
Some B cell involvement with autoantibodies on degenerating myelin sheets (source of potential
treatment)
Gliosis
Some remyelination
**Partial or total axonal destruction
Pathophysiology of MS correct answers Myelin destruction and loss leads a "bare" axon and
exposure of voltage gated K+ channels with initial lack of Na channels (Tx implications)
AP not propagated across bare axon = conduction block
, Eventually Na channels redistribute leading to improved but not normal conduction (conduction
may be affected by temperature and metabolic conditions)
Epidemiology of MS correct answers Peak incidence between 20-30 years
70% between 21 to 40
Range 3 to 67 years (very rare <10 or >60)
Women 2-3x as likely as men
Much more common in higher latitudes
But rare in Lapps Americas/Alaska Natives, and equitorial Africa; uncommon in Japan, China,
and South America
Increased risk with move from low to high risk area before puberty
Environmental triggers in MS correct answers UVB exposure
Ebstein-Barr virus exposure
Migrant studies (before puberty)
Acute triggers for relapse (possible viral)
Genetic predisposition in MS correct answers MHC on chromosome 6 - DRB1*15:01:
homozygote=9x risk, heterozygote=3x risk
33% concordance in monozygotic twins, 6% in dizygotic twins
Autoimmune contribution in MS correct answers Activated myelin basic protein - reactive T
cells found in blood, CSF, and within MS lesions
Clonally expanded B-cells, auto-antibodies, oligoclonal bands in CSF
Typical presentation in MS correct answers 34 yo women experiences sudden loss of vision in
the left eye that lasts 2 mo. with spontaneous resolution. Three years later she notices numbness
ascending to the waistline that partially resolves after 6 weeks
Multiple Sclerosis: General correct answers Chronic neurological disorder
Demyelination, gliosis, and neuronal loss in the central nervous system
Recurrent symptom episodes or progressive neurological decline, or both, reflect involvement of
brain, eye, and spinal cord
Usually seen in young to middle age adults, esp. women
MS Facts correct answers 50% require assistance at 15 years
Cerebral atrophy and some degree of cognitive impairment seen in 50 to 60%
Slight decreased life expectancy in the past
Increasing survival shown with some newer drugs
Disease characterized by demyelination correct answers Multiple sclerosis = CNS, MS is
prototype
Guillian-Barre syndrome = autoimmune demyelination of the PNS, areflexia is the hallmark
Pathogenesis of MS correct answers Inflammation (T cells and macrophages)
BBB disruption
Some B cell involvement with autoantibodies on degenerating myelin sheets (source of potential
treatment)
Gliosis
Some remyelination
**Partial or total axonal destruction
Pathophysiology of MS correct answers Myelin destruction and loss leads a "bare" axon and
exposure of voltage gated K+ channels with initial lack of Na channels (Tx implications)
AP not propagated across bare axon = conduction block
, Eventually Na channels redistribute leading to improved but not normal conduction (conduction
may be affected by temperature and metabolic conditions)
Epidemiology of MS correct answers Peak incidence between 20-30 years
70% between 21 to 40
Range 3 to 67 years (very rare <10 or >60)
Women 2-3x as likely as men
Much more common in higher latitudes
But rare in Lapps Americas/Alaska Natives, and equitorial Africa; uncommon in Japan, China,
and South America
Increased risk with move from low to high risk area before puberty
Environmental triggers in MS correct answers UVB exposure
Ebstein-Barr virus exposure
Migrant studies (before puberty)
Acute triggers for relapse (possible viral)
Genetic predisposition in MS correct answers MHC on chromosome 6 - DRB1*15:01:
homozygote=9x risk, heterozygote=3x risk
33% concordance in monozygotic twins, 6% in dizygotic twins
Autoimmune contribution in MS correct answers Activated myelin basic protein - reactive T
cells found in blood, CSF, and within MS lesions
Clonally expanded B-cells, auto-antibodies, oligoclonal bands in CSF
Typical presentation in MS correct answers 34 yo women experiences sudden loss of vision in
the left eye that lasts 2 mo. with spontaneous resolution. Three years later she notices numbness
ascending to the waistline that partially resolves after 6 weeks
