Neuro Pathology Flashcards
What are the two different neuro issues with B1 (Thiamine) deficiency?
Wernicke Encephalopathy: Damage to mammillary bodies mainly. Confusion, opthalmoplegia, ataxia. Acute and reversible.
Korsakoff Syndrome: Damage to mammillary bodies and thalamus. Memory disturbances, confabulation. Prolonged and mostly irreversible.
*Usually associated with chronic alcoholism because they get a big portion of calories from alcohol, at the expense of B1.
What are the effects of B12 (Cobalamin) deficiency in the brain?
Anemia, which is reversible with B12 administration
Subacute combined degeneration of spinal cord:
Lower extremity numbness, ataxia, weakness. Reversible UNTIL paraplegia occurs from swelling of myelin layers. Ascending and descending tracts involved.
What are the effects of hypoglycemia on the brain?
Large pyramidal neurons of cortex are very vulnerable “pseudo laminar necrosis”..hippocampus and cerebellum also vulnerable.
What are the effects of hyperglycemia on the brain?
Dehydration, confusion, stupor, coma. Can be associated with either ketoacidosis or hyperosmolar coma. Most commonly seen in diabetes mellitus.
What are the effects of carbon monoxide on the brain?
Injury is due to hypoxia. Recall that CO displaces oxygen on Hb. May see demyelination of white matter tracts. In autopsy, person appears pink and healthy from CO-Hb complex.
What are the effects of methanol on the brain?
Very toxic. 30 mL can kill, 10 mL can blind. Preferentially affects retina. Degeneration of ganglion cells.
What are the effects of ethanol on the brain?
Acute effects reversible, chronic not. Preferentially affects cerebellum. Truncal ataxia, unsteady gait, nystagmus. Cerebellar atrophy, loss of granule cells, loss of purkinje cells, Bergmann gliosis (astrocytes accumulating between granular and molecular layer).
Tay-Sachs
Missing Hexosaminidase A. Buildup of gangliosides.
Krabbe Disease
Missing galactosylceramidase. Buildup of galactocerebroside which is converted to the toxic [to oligodendrocytes] galactosylsphingosine.
Neuronal ceroid lipofuscinoses
Deficiency in enzymes involved in protein modification and degradation. Leads to lipofuscin accumulation.
Key Guillain-Barre points.
Acute inflammatory demyelinating polyradiculoneuropathy. Idiopathic flu-like illness followed by symmetric ascending paralysis starting at the feet caused by macrophages engulfing myelin. Usually stops at waist, if goes higher, need respiratory support. Resolves on it’s own and remyelination usually happens.
What is leprosy caused by?
Mycobacterium leprae. Need acid fast stain. About 95% of world is immune to this. Hits some people harder than others. Hard for body to kill so it forms granulomas.
What are the two forms of leprosy?
Tuberculoid leprosy: less sever, localized. Dry scaly skin lesions. Nerve degeneration. Nice T-cell response with nice granuloma formation.
Lepromatous leprosy: more severe, widespread. Affects areas that are ~91 degrees, everywhere but deep body structures. Patients immune system doesn’t respond. Deformities arise. Leonine facies (lion face).
What is pathologically characteristic of a herpes zoster stain?
Multinucleated giant cell.
Characteristics of Hereditary Motor and Sensory Neuropathy Type I (Charcot-Marie-Tooth disease).
Repetitive demyelination and remyelination. Muscle loss, loss of sensation but pain intact. Childhood or early adulthood. Key features: High arches, hammer toes, muscle atrophy. Normal life span.
