Dr.Rochet 35 Flashcards
What is MS
MS or multiple sclerosis is an immune mediated disorder that involved destruction of the myelin sheath that surrounds neurinal axons
What are the symptoms of multiple sclerosis
Visual problems, numbness, fatigue, pain, difficulty walking, spasticity, dizziness, sexual dysfunction, bladder problems, emotional or cognitive changes/ depression
what are the risk factors of MS
Age, increased risk with decreased 25-hydroxyvitamin D levels, viral infection, environmental insults, cigarette smoking, genetic factors
explain how genetics play a role in increased risk of MS
Individuals with a particular HLA phenotype have an increased risk of developing MS when they also have anti-EBNA ANTIBODIES (EBNA ANTIBODIES are epstein barr nuclear antigen)
What is relapsing remitting MS (RRMS)
RRMS is relapses of neurological dysfunction lasting weeks or months that affect the brain, optic nerves, and/or spinal cord
Patients have symptoms then they disappear and reappear and as the disease progress the remission in between flairs gets shorter and shorter
RRMS eventually turns into SPMS
What is secondary progressive MS (SPMS)
SPMS is less inflammation than RRMS and is slow progressive neurological decline and CNS damage
patients do not have the relapses of symptoms like seen in RRMS
What is primary progressive MS (PPMS)
resembles SPMS at initial stage of disease
Mean age of oneset is later than RRMS
it appears right away and does not have the relapse symptoms
what is clinically isolated syndrome (CIS)
CIS is initial episodes of neurologic symptoms lasting more than 24 hours
Progressive phase involves cytodegeneration and occurs with a similar rate in the different forms of MS
Clinical presentation includes degredation and immune reaction
What is the autoimmune phase in MS
- Dendritic cells that present CNS antigens activate Tcell responses in the peripheral lymphoid tissue
- these now active T and B cells bind to alpha 4 and penetrate the BBB to reach the CNS
- once inside the CNS B cells mature to plasma cells and release IgG antibodies that target neurons.
- Once inside the CNS activated T cells release cytokines and stimulate macrophages which leads to myelin sheath damage
What is the degenerative phase in MS
CNS damage is triggered by the activated T and B cells or by infection or stroke.
Antigens release from damaged sites in the CNS and they prime immune cells in the periphery and start a vicious cycle of degredation
What are the effects of demyelination on axon conductive potential
Action potentials travel faster in myelinated regions of axons
- action potential is slowed down in demyelinated regions
How does remyelination work?
