External ophthalmoplegia, alpha and spindle coma in imipramine overdose: case report and review of the literature.

A 13-year-old boy with imipramine overdose developed seizures, respiratory arrest, and coma. Abnormalities of oculovestibular reflexes, electroencephalograms, and brainstem auditory evoked potentials were monitored in relation to measurements of drug levels. An alpha-coma electroencephalographic pattern evolved into one evidencing spindle coma and eventually into a normal pattern. Prolonged brainstem auditory evoked potentials also normalized as coma and oculocephalic reflex abnormalities resolved. In spite of the history that suggested hypoxic damage, the absence of reflex eye movements in a comatose patient and the presence of alpha- and spindle-coma electroencephalographic patterns, even with prolonged brainstem auditory evoked potentials, are not reliable prognostic indicators in tricyclic drug overdose.