A nonuniform decrease in several mitochondrial residual enzyme activities in the liver and brain of a 42 year old woman who died with Reye’s syndrome is reported from the Departments of Neurology and Pediatrics, Columbia Presbyterian Medical Center, New York, NY. Pyruvate carboxylase activity was negligible whereas subunits II and IV of cytochrome c oxidase were in normal quantities. There was no evidence for a specific insult to mitochondrial DNA or intramitochondrial protein synthesis. The trigger that precipitates the initial disturbance in the chemical micro environment of the mitochondrial matrix remains unknown. Restoration of mitochondrial ATP concentration repairs the disturbance of intramitrochondrial enzyme processing and is followed by recovery of organ function. 
COMMENT. In a review of the literature the authors found 26 additional cases of adult onset Reye’s syndrome. Viral studies showed influenza A or B in 11, varicella in 1, dengue in 1, and not reported in 14. 12 recovered.
The incidence of Reye’s syndrome has decreased since 1981 and in 1988 there were only 20 cases reported. The relationship between Reye’s syndrome and aspirin is debated  and the choice of alternative antipyretic management of fever is discussed in an editorial (Lancet Oct 26, 1991; 338:1049). Chronic paracetamol poisoning is reported in Australia and ibuprofen is suggested as an alternative.