Multiple Sclerosis Flashcards
hey are cells in the peripheral nervous system (PNS) that produce the myelin sheath around neuronal axons.
schwann (neurilemma) cells
They are cells in the central nervous system (CNS) that produce the myelin sheath around neuronal axons
oligodendrocytes
- acquired conditions characterized by preferential damage to previously normal myelin.
- commonly result from immune-mediated injury.
- drugs and other toxic agents.
Demyelinating diseases
*Once normal myelin, then it’s damaged
- myelin is not formed properly or has abnormal turnover kinetics.
- associated with mutations affecting the proteins required for formation of normal myelin or in mutations that affect the synthesis or degradation of myelin lipids.
- the other general term for these diseases is leukodystrophy.
Dysmyelinating diseases
*The myelin itself is abnormal (Genetic/familial)
multiple sclerosis (MS) is an autoimmune demyelinating disorder characterized by (1), separated in time, attributable to (2) that are separated in space
- neurologic deficits
- white matter lesions
MS is common (demyelinating/dysmyelinating) disorder
demyelinating
MS is predominantly a disease of young adults with a mean age of onset around ()
30 years old (15-45 years old)
types of MS
- relapsing remitting (RR-MS)
- primary progessive (PP-MS)
- relapsing progressive (RP-MS)
- secondary progressive (SP-MS)
type of MS wherein:
* there is clinical exacerbation of neurological symptoms, followed by periods during which the person fully or partially recovers from the acquired neurological deficits.
* Most common (80% of MS patients)
relapsing remitting (RR-MS)
type of MS wherein:
* Gradual progression of the disease from onset, no overlapping relapse or remission.
* 10-20% of cases.
primary progessive (PP-MS)
type of MS wherein:
* Initially presents as PP-MS
* During the course of the disease, individuals develop true neurologic deficit exacerbations.
* Steady progression of clinical neurological damage with superimposed relapses and remissions.
Relapsing progressive (RP-MS)
type of MS wherein:
* Steady progression of neurological damage with or without superimposed relapses and minor remissions.
* Patients will have experienced a period of RR-MS before which may have lasted 2-40 years.
* Relapses and remissions fade over time.
* 50% of RR-MS will eventually develop this.
Secondary progressive (SP-MS)
list some risk factors for ALS
- genetics (sex, family history, race, polymorphism)
- environmental (infections, Vit. D deficiency, smoking, obesity)
- A clinical attack is considered if the symptoms are present for at least (1) and is preceded by more than (2) of clinical stability.
- 24 hours
- 30 days
when determining if patient has clinical attack of MS, we must first rule out ()
psuedorelapse
Examples of psuedorelapse: metabolic stress, infections that worsens the symptoms. or if the symptoms last for LESS than 24 hours. (in a relapse the symptoms have to occur for MORE than 24 hours.)
Clinical exacerbation of neurological symptoms
relapse
person fully or partially recovers from the acquired neurological deficits
remission
some common patterns of neurological symptoms in MS
- unilateral visual impairment
- spinal cord lesions
Unilateral visual impairment occurring over the course of a few days is frequent initial manifestation of MS due to involvement of the ()
optic nerve “ optic neuritis “
() give rise to motor and sensory impairment of trunk and limbs, spasticity, and difficulties with the voluntary control of bladder function .
spinal cord lesions
In any individual patient MS is hard to predict when the next relapse will occur ; most current treatments aid to () rather than recovering lost function .
decrease the rate and severity of relapses
The pathologic hallmark of MSis multiple focal areas of ()
myelin loss within the CNS (plaques or lesions).
MS selectively affects (white/gray) matter of CNS
white
Classical location of plaques are at the periventricular regions of the (1), (2), and the (3).
- brain
- optic nerves
- spinal cord
() occurring in early MS lesions contribute to the relapse related disability observed predominantly during the disease’s inflammatory phase
Acute axonal injury
() will cause axonal loss or sclerosis resulting in permanent deficits.d
Chronic axonal injury
which immune cells are involved in the neuroinflammation associated with MS
(CD8+) cytotoxic T-lymphocytes, (CD4+) T-lymphocytes and B cells
Why don’t we classify MS as an autoimmune disease?
Direct proof of an autoimmune response is lacking, no specific autoantibody or autoreactive T cells
- Mc Donald’s MS diagnostic criteria (2017)
: Diagnosis of “Clinically definite MS” needs demonstration of ()
dissemination of space and time.
Indications for treatment of a relapse include (1) symptoms with objective evidence of (2).
- functionally disabling
- neurologic impairment
what is the main idea behind experimental autoimmune encephalomyelitis (EAE)
researchers inject the animals with proteins that are normally found in the myelin sheath. These proteins trick the animal’s immune system into thinking these proteins are dangerous, causing it to attack the myelin, similar to what happens in MS.
