[Detection of diphenhydramine in autolytic brain tissue in poison-induced brain death syndrome]

A case of accidental monointoxication caused by diphenhydramine is reported. Having taken 12 dragées of Neo-Emedyl (50 mg diphenhydramine), an 18-month-old girl showed the following symptoms: generalized erythema, dyspnoea, vomiting, hyperpyrexia, tremor, convulsions, coma, respiratory arrest and absence of reflexes. Computed tomography (CT) suggested a massive cerebral oedema. Her electroencephalogram was abnormally diffused at first; later on, it flattened significantly and became isoelectric between the 14th day and the final stoppage of circulation (after 5 weeks). Autopsy revealed total necrosis of the brain, with the venous cerebral blood vessels being thrombosed (the morphological basis for dissociated cerebral death). In autolysed brain tissue, diphenhydramine was detected at a concentration of 30 ng/g by GC/MS (gas chromatography, mass spectrometry); the concentration of the substance was less than 10 ng/g in the liver. The relatively high concentration in the brain was due to the previous blocking of the circulation. Cerebral death syndrome caused by intoxication offers the chance of detecting measurable amounts of the unchanged drug in autolysed brain tissue.