Neuro Pathologies Flashcards
Osmotic Demyelination Syndrome (Central pontine Myelinolysis)
Demyelination due to osmotic changes- specifically rapid correction of HYPOnatremia
Results in demyelination of PONTINE white matter –> loss of consciousness, acute paralysis, dysarthria, dysphagia, diplopia –> locked in syndrome
Contrast - HYPERNATREMIA CORRECTION –> cerebral edema/herniation
Huntingtons disease
Pathogenesis:
- Caused by CAG trinucleotide repeats
- Neuronal cell death via NMDA-R and glutamate toxicity
- Gain of function mutation of huntingtin protein: deacetylation of histones
- dec. GABA, dec Ach, Inc Dopamine
- Caudate atrophy with ex vaco dilitation of frontal horns
Loss of motor control (choriform movements)–> loss of memory, affect changes (aggression and depression),personality changes–> full blown dementia and
Autosomal Dominate
anticipation: increase number of repeats during spermatogenesis
Charcot Bouchard Micro aneurysms
aneurysm of the small vessels- basal ganglia and lenticulostriate
Associated with HTN
Charcot Bouchard Micro aneurysms
aneurysm of the small vessels- basal ganglia and lenticulostriate
Associated with chronic HTN
Central post stroke Pain syndrome
Stroke affect thalamus –> parasthesias for a few weeks –> allodynia and dysesthesias.
Anencephaly
Failure of closure of the anterior neural tube- no forebrain and open calvarium
Area cerebrovasculosa: disorganized brain tissue, ependymal cells, and choroid
No cranium
Posterior Fossa intact
AFP inc
Polyhydraminos- no swallowing center
Assoicated
with maternal Type 1 diabetes and folate deficiency
Holoprosencephaly
Failure of the left and right hemispheres to separate
- may be association with FAS, or Patau syndrome (trisomy chromosome 13) with failure of SHH
- Most severe form: cyclopia
- Less severe: cleft palate, cleft lip, failure of CNI, can’t smell
Communicating Hydrocephalus
Due to granulations failure to absorp ** post meningitis arachnoid scarring Inc. ICP uncal hemorrhage HA
Non-communicating Hydrocephalus
Blockage- as with a chiari 2 malformation (compression of the aqueduct) Inc. ICP papilledema HA CN 3 palsy- eye down and out lethargy and personality change
Normal Pressure Hydrocephalus
Old people
Idiopathic
No inc. in subarachnoid Volume
No inc ICP
Inc in ventricle dilation becuase of inc. fluid –> distort the Internal capsule (corona radiata)
–> incontinence, ataxia, REVERSIBLE dementia
(wet, wobbly, wacky)
Hydrocephalus in infant Sx
- Poor feeding
- Hypertonicity
- Hyperreflexia
- due to stretching of the paraventricular CST (pyramidal)
Multiple Sclerosis
Inflammation and Autoimmune destruction of olgiodentroctyes (myelin) in the CNS
Sx:
- Marcus Gunn Pupil due to optic neuritis (periorbital pain and pain with eye motion)
- loss of sensory and muscle control
- incontinence
- scanning speech
- internuclear opthalmoplegia
- intention tremor
- waxing and waning symptoms- get progressively worse)
(SIINS- charcot “triad”)
- affects optic nerve and chiasm, brain stem and spinal cord, cerebellum
Dx:
CT:
1. Asymmetric periventricular lesions or white matter lesions - most commonly located at the ventricle angles (demyelination and reactive gliosis)
2. CSF: inc in protein, Ig light chain in CSF, olgioclonal bands are diagnostic
Pathogenesis:
TH1 CD4 cell activation to myelin self antigens –> Macrophages –> macrophages and released cytokines responsible for macrophage destruction
Alzheimer’s Disease
Most common cause of dementia (loss of memory, change in behavior, and functioning, but INTACT consciousness)
Sx
Loss of memory –> loss of language, mathematical skills, and learned motor skills —> mute, incontinence, unable to walk–> die of pneumonia
Can be familial or sporadic
Familial:
- Chromosome 21- APP mutation- inc. AB protein
- Chromosome 1 missense or splicing mutation- Presenilin 2- inc. production of AB
- Chromosome 14 missense mutation- Presenilin 1- inc production of AB
- APOE4- dec. age of onset
Neurofibrillary Tangles: hypophosphorylated tau protein- insoluble (correlates with severity of dementia)
Amyloid Plaques- APP cleaved into Amyloid B, AB surrounded by enlarged dilated tortuous neurites
Vascular amyloidopathy- due to inc. in amyloid plaques
Dec Acetyl choline transferase activity - dec Ach
Corticol atrophy- degradation of gyri widening of sulci, hydrocephalus ex vaco
Acute Disseminated Encephalomyelitis
Periventricular inflammation and demyelination due to infections:
- MEASLES
- VZV
- POX virus
- RABIES
Charcot Marie Tooth
HMSN Pathogenesis: dec production of proteins needed for structure and function of peripheral nerves and myelin Sx: Calf atrophy Hypertrophic nerves- palpable Onion skin segmental demylination
Autosomal dominant
Progressive
Related to scoliosis and foot issues (high arch)
Krabbe Disease
Defect in enzyme galactocerebriase –> accumulation of galatocerebride and psychosine–> degradation of myelin sheath
Peripheral neuropathy, optic nerve atrophy, developmental delay, globoid cells
Metachromatic Leukodystrophy
Defect in arly-sulftidase –> inc. in sulfatides –> dec production and destruction of peripheral and central myelin sheath
ataxia, dementia
peripheral and central demyelination
Progressive multifocal Leukoencephalopathy
Demyelination of CNS due to JC virus in AIDs pts
Rapidly progressive and fatal
