Epileptic apnea in a trisomy 18 infant.

Trisomy 18 is frequently associated with neurologic abnormalities, including hypotonia in infancy, mental retardation, central apnea, and epilepsy. Although central apnea and epilepsy are common complications in children with trisomy 18, epileptic apnea in these children was not previously reported. We describe an infant with trisomy 18 who developed epileptic apnea. Her apneic episodes began at age 10 months, occurring in clusters over several days each month. According to ictal electroencephalogram, interictal [(11)C] flumazenil-positron emission tomography, and [(18)F] fluorodeoxyglucose-positron emission tomography, the apneic episodes represented complex partial seizures (autonomic seizures), probably originating in the left frontotemporal area, probably related to cortical microdysgenesis. The condition was successfully treated with zonisamide. In infants with trisomy 18, differentiation of epileptic apnea from central apnea is crucial, because medications used to treat central apnea, including caffeine and theophylline, can be harmful to children with epileptic apnea.