Degenerative Demyelinating Disease Flashcards
What is demyelination?
Acquired (axons spared)
- MS
- Viral infections
- PML: JC
- Metabolic
- Guillian-Barre syndrome
- Toxic: CO, Radiation, Chemotherapy, Alcohol
What is dysmyelination?
Inherited (axons degenerate)
- Leukodystrophies
What is multiple sclerosis?
Demyelinating, inflammatory
Aquired, episodic neuro defecits
White matter lesions that are separated by space
Most common in Young Women
Genetic Factors sigificant: HLA-DR2, DR4, DR15, DQ6
May be environmental
What is the pathogenesis of MS?
CD4 Th mediated attack on oligodendrocytes (CNS)
Against MOG (myeline oligo glycoprotein), myeline basic protein
Clonal expansion of B cells from CD4 cells: ANTIBODIES (IgG)
- Macrophages come in (produce ROS, NOS, Proteolytic enzymes, cytokines
- Complement is activated
- CD8 T cells come in and attack also
What are demyelinated areas in MS called?
Plaques
White matter of periventricular region
Active: Loss of myeline
- Myelin-laden Macros
- Center of plaque has perivascular TCs
- Retention of Axons
Inactive Plaques
- Axons degenerate, leave astrocytes to repair (GLIOSIS)
Shadow Plaque: Remyelination slowly
- LFB stain pale, new myelin seen
What are MS variants?
Acute Marburg
Neuromyeltis Optica: Spinal Cord andn optic nerves
-Aquaporin 4 abnormal, BBB integrity
Schilder’s disease: Children, Fulminant reponds to steroids
Concentric Sclerosis: RARE
What is central pontine myelinolysis?
Toxic disorder
Too rapid overcorrection of hyponatremia
Also occurs with low Mg
Due to swelling of myelin sheath
Rapid confusion, limb weakness, conjugate palsy, dysarthria, dysphagia, hypotension
Patients succumb within weeks
What is GBS?
Infectious
Guillian barre syndrome
Due to molecular mimcry to immune recog myelin proteins
Rapid onset of ASCENDING paralysis
Few go on to develop MS
Chronic: CIDP (Deyelinating polyradiculopathy)
What is Acute Disseminated Encephalomyelitis (ADEM)?
Few weeks after viral infection
T cell mediated reaction
HA, Vomiting, Rapid onset of weakness, sensory loss, ataxia, visual impairment, supor, LOC, Seizures
20% succumb to disease
5-10% have relapses
What is FAS?
Fetal alcohol syndrome due to utero exposure
Craniofacial defects to learning disabilities
Cardiac Defects
Trauma and alco poisoning most frequent in young adult
What is seen with severe necrotizing encelapathy of mamillary bodies?
Thiamine deficiency (B1)
Wernickes encephalopathy (ataxia+gaze palsy+ AMS
Treatment: Replace thiamine
If goes to thalmaus become Korsakoff syndrome (amnesia+confabulation)
What happens in B12 def?
Get both macrocytic anemia (folate def) and Subacute combine degeneration of Spinal COrd (SpC)
- Ataxia, numbness, paresthesias
What causes cerebellar atrophy?
Chronic alch exposure
Toxic to internal granular layer resuling in vermis atrophy
What is Marchiavava-Bignami Disease?
It is seen in Italian men who drank raw red wine
Toxic demyleination of Corpus callosum
What occurs to the CNS in lead toxicity?
Anemia due to heme alteration (stippled basoophila RBC)
Delayed cogn and intel development
Retarded growth
Learnin difficulties and behavioral changes
Peripheral neuropathy irreversible
