Block 1 Metabloic Diseases Flashcards
What are symptoms of neuronal storage diseases?
Loss of cognitive function and epilepsy
What are the two Neuronal storage diseases?
Neural ceroid lipofuscinoses
Tay-Sachs disease
What are symptoms of neuronal ceroid lipofuscinoses?
Blindness, mental and motor deterioration, seizures
When is the onset for neuronal ceroid lipofuscinoses?
Ranges from children to adults
What accumulates in neuronal ceroid lipofuscinoses?
Lipofuscin within the neurons
What enzyme is deficient on Tay-Sachs disease and what accumulates?
Hexosaminidase A is the enzyme that is missing leaving ganglioside 2 to accumulate in all tissues in the lysosomes
What is the inheritance pattern of Tay-Sachs and what population is it more common in?
Autosomal recessive
More common in Ashkenazi Jews
When does Tay-Sachs usually begins?
Early infantcy
What are symptoms of Tay-Sachs?
Developmental delay, then paralysis and loss of neurological function.
Death within several years (4)
Infant just doesn’t reach milestones.
What is nearly diagnosis of Tay-Sachs?
Cherry red spot in the retina
The cells around the macula turn white because of the accumulation of ganglioside.
What are the two genetic metabolic brain diseases discussed?
Neuronal storage diseases
Leukodystrophies
What are leukodystrophies and what are they characterized by?
Characterized by myelin abnormalities
Most are autosomal recessive
Involve lysosomal or peroxisomal enzymes
Deterioration of motor skills, spasticity, hypotonia, ataxia
What is krabbe disease?
A leukodystrophy with the deficient enzyme being galactosylceramidase.
Because of the missing enzyme galactocerebroside accumulates and is converted to galactosylsphingosine which is toxic to Oligodendrocytes.
What happens in krabbe disease?
Loss of myelin and Oligodendrocytes in the CNS and peripheral nerves
What cells form in the brain in krabbe disease?
globoid cells (fat macrophages) in the brain
When is the onset of krabbe disease?
3-6months
What are the symptoms of krabbe disease?
Rapidly progressive muscle stiffness, weakness
Fingers get a curved look with hand paralysis
What are the names for B1 (thiamine) deficiency?
Wernicke encephalopathy first and if lasting
Korsakoff’s syndrome
Associated with chronic alcoholism
What characterizes wernicke’s syndrome?
CONFUSION, OPHTHALMOPLEGIA, ATAXIA
Hemorrhage and necrosis in mammillary bodies and walls of the third and fourth ventricles
Acute and reversible
What is Korsakoff’s syndrome?
Progression of wernicke’s syndrome of b1 def
Still have confusion, ophthalmoplegia, and ataxia
In addition have memory disturbances, confabulation, cystic spaces in mammillary bodies, thalamic cysts
Prolonged mostly irreversible
People will make up stories they actually believe.
What happens with vitamin b12 deficiency? (Cobalamin)
Reversible anemia
Subacute combined depredation of the spinal cord
Reversible until paraplegia appears
Swelling in myelin layers
Both ascending and descending tracts involved
What happens with Carbon monoxide poisoning?
Injury is due to hypoxia
Particularly vulnerable areas are:
Cortex, hippocampus, purkinje cells
May see demyelination of white matter
What does methanol poisoning affect?
Preferentially the retina
Degradation of ganglion cells
10ml causes blindness
30-100ml is fatal
Ewhat does ethanol affect?
Cerebellum
Get truncal ataxia, unsteady gait, nystagmus.
Chronically get loss of granule cells, purkinje cells, and Bergmann cells
