Toxic Metabolites Flashcards
What are the symptoms of Wernicke’s encephalopathy?
Acute ophthalmoplegia
Ataxia
Confusion
What are the symptoms of Karsakoff’s psychosis?
Permanent memory deficit
Confabulation (memory disturbance)
Which areas are degenerated in Wernicke-Korsakoff Syndrome?
Mammillary bodies
Periventricular areas
What can cause Cobalamin (B12) deficiency?
Genetic deficiency of intrinsic factor (required for absorbtion of B12)
Vegetarians
What is the result of Cobalamin (B12) deficiency?
Megaloblastic anemia
Subacute combined degeneration of spinal cord (myelin vacuolization in dorsal and lateral columns)
May mimick dementia with memory problems
What is used histologically to identify hepatic encephalopathy?
Caused by chronic liver failure (cirrhosis)
Alzheimer Type II glia (correlated with high blood ammonium levels)
What metabolic cause can lead to similar effect of hypoxia/ischemia?
Hypoxic/ischemic damage = Red neurons
Can be caused by hypoglycemia
What areas of the brain are most sensitive to hypoglycemia?
CA1 (Sommer’s sector) of hippocampus
Cortical layers III, IV, and V
Purkinje cells
What symptoms are associated with hyperglycemia?
Confusion
Stupor
Coma
What is the mechanism by which hyperglycemia causes cellular damage?
Cellular dehydration due to hyperosmolar state (too much glucose in blood) –> cells shrivel up and die
Must be corrected slowly to avoid cerebral edema
What results from methanol ingestion?
Degeneration of retinal ganglion cells (blindness)
Bilateral putamen necrosis
Focal white matter necrosis
What resutls from arsenic poisoning?
Peripheral neuropathy
What results from lead poisoning in children?
IQ and attention deficits
What drugs can cause peripheral neuropathy and necrotizing myelitis?
Isoniazid
Vincristine
Others
What can methotrexate cause?
White matter necrosis
