CNS Metabolic disease

Question 1

Two main types of metabolic disease in the brain:

Answer 1

Genetic

• neuronal storage disease
• leukodystrophies
• usually present in childhood after normal birth

Toxic and acquired metabolic diseases

• vitamin deficiencies
• metabolic and toxic disturbances

Question 2

Accumulation of LIPOFUSCIN within neurons from deficiency of enzymes involved in protein degradation/modification

Answer 2

Neuronal Ceroid Lipofuscinoses

Question 3

Deficiency of hexosaminidase A
accumulation of gangliosides in all tissues
autosomal recessive (more common in Ashkenazi Jews)
onset early infancy
Developmental delays
***Cherry red spot in retina

Answer 3

Tay-Sachs

Question 4

Group of disorders characterized by myelin abnormalities:

Characterized by deterioration of motor skills, spacticity, hypotonia, ataxia

Answer 4

Leukodystrophies

Question 5

Deficiency of galactosylceramidase

• accumiulation of galactocerebroside gets converted to galactosylsphingosine (toxic to oligodendrocytes)
• loss of myelin in CNS and PNS

**“Globoid cells”–fat macrophages in brain

• onset 3-6 mo
• rapidly progressive muscle stiffness

Answer 5

Krabbe Disease

Question 6

Vit B1–Thyamine deficiency associated with poor diet usually resulting from chronic alchoholism
-hemmorhage and necrosis of mammilary bodies

Answer 6

Wernicke encephalopathy (reversible)

progresses to

Korsakoff syndrome (not reversible)

Question 7

Vit B12 (cobalamin) deficiency associated with:

• LE numbness, ataxia, weakness
• reversible until paraplegia occurs
• swelling of myelin layers
• ASCENDING and DESCENDING tracts involved
• vacuolization of white matter

Answer 7

Subacute combined degeneration of spinal cord

Question 8

Mechanism of injury for CO poisoning:

Why?

Answer 8

Hypoxia

• CO has much higher affinity for Hgb than O2
• vulnerable areas include cortex, hippocampus, Purkinje cells

Question 9

Toxic injury prefferentially affecting RETINA

• degeneration of ganglion cells
• may cause BLINDNESS

Answer 9

Methanol

-crosses BBB very rapidly, doesn’t take much to kill

Question 10

Toxic injury preferentially affecting cerebellum:
Acute- truncal ataxia, unsteady gait, nystagmus
Chronic- cerebral atrophy, loss of granule cells, Purkinje cells, and Bergman gliosis (proliiferation of astrocytes)

Answer 10

Ethanol