III. METABOLIC DISORDERS
A. Acquired Disorders
Acquired disorders associated with hypoxia are the most common. Anoxic
poisons (carbon monoxide, cyanide, carbon disulfide), hypoglycemia and ischemia
produce similar pathology in the nervous system.
1. Hypoxic Encephalopathy
- Hypoxic encephalopathy is characterized by necrosis of neurons in selectively
vulnerable deep layers of cerebral cortex (laminar necrosis), Purkinje
cells of cerebellum, hippocampal pyramidal cells and globus pallidus neurons.
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Laminar necrosis in cortex is apparent in this section. |
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This microscopic section from the cerebullar cortex shows loss of many Purbinyc
cells & hypoxic change in the two present. |
2. Metabolic Encephalopathies
- Metabolic derangements secondary to renal or liver disease cause coma
and relatively nonspecific morphologic changes in the neurons and/or glia.
3. Diabetes Mellitus
- Infants of diabetic mothers have huge hyperfunctioning Islets of Langerhans
which overproduce insulin, and cause hypoglycemia and seizure. Diabetics
may develop any of a wide gamut of neurological signs and neuropathological
changes. Lesions at any level of central and peripheral nervous systems
and muscle are probably secondary to vasa nervora as well as larger vessel
disease. Secondary degeneration then occurs in peripheral somatic and visceral
nerves and CNS, respectively.
