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Brain ultrastructure in Reye's syndrome
Insights
Severe Reye's syndrome causes brain cell swelling and mitochondrial damage, but recovery is possible. This study details reversible organelle changes in a child's brain biopsy.
Area of Science:
- Neurology
- Pathology
- Cell Biology
Background:
- Reye's syndrome is a severe condition affecting children, characterized by encephalopathy and liver damage.
- Understanding the cerebral organelle pathology is crucial for diagnosing and treating Reye's syndrome.
Observation:
- Electron microscopy of cerebral biopsies from a child with severe Reye's syndrome.
- Biopsies were taken 48 and 72 hours after encephalopathy onset.
- The child survived and recovered, indicating the observed pathology was reversible.
Findings:
- Key ultrastructural changes include astrocyte swelling, partial deglycogenation, and myelin bleb formation.
- Neurons exhibited universal mitochondrial injury with matrix disruption and moderate swelling.
- Endoplasmic reticulum dilation and nuclear changes were observed in neurons with severe mitochondrial alterations.
Implications:
- The observed brain pathology in Reye's syndrome differs from hepatic encephalopathy and ammonia intoxication.
- Cerebral mitochondrial ultrastructure uniquely resembles that seen in the liver parenchyma in Reye's syndrome.
- Findings suggest a specific pattern of reversible organelle injury in the brain during Reye's syndrome.
Abstract:
Cerebral biopsies were obtained for electron microscopy 48 and 72 hours after the onset of encephalopathy from a child with severe Reye's syndrome. Gravely ill at the time of craniectomy to relieve cerebral hypertension, the child survived and recovered good brain function; therefore, the biopsy findings appear to reflect the organelle pathology of the brain at a severe yet reversible stage in the disease process. The cardinal ultrastructural changes in the brain in Reye's syndrome are astrocyte swelling and partial deglycogenation, myelin bleb formation and universal injury of neuron mitochondria. The mitochondrial injury consists of matrix disruption with moderate but not massive swelling. Dilatation of rough endoplasmic reticulum and nuclear changes occurred only in neurons with severely altered mitochondria. The organelle pathology of the brain in this case did not resemble the organelle pathology of the brain in human "hepatic encephalopathy" or in experimental ammonia intoxication in primates. The mitochondrial ultrastructure of the cerebral neurons resembled the unique mitochondrial ultrastructural changes seen in the liver parenchyma in Reye's syndrome.