Paroxysmal electroencephalographic abnormalities genetically transmitted: one family description.

A 10-year-old girl came to our observation since a general rule-out electroencephalogram (EEG) had showed, in absence of any clinical manifestation, generalized and symmetrical 3 c/s spike-and-wave bursts, whose duration was longer than 3 s. The subject, only daughter born from her mother's first marriage, had no family history of neurological diseases; her physical and neuropsychological examinations were normal. A polysomnographic recording showed, during sleep, the same abnormalities observed during wakefulness. Also on this occasion, there were no related clinical manifestations. Subsequent recordings were performed on her 33-year-old mother and on two siblings, 3 and 2 years old, respectively, born from their mother's second marriage, all normal by physical and neuropsychological examinations, with no referral about clinical seizures. Among them, the 3-year-old sister showed asymptomatic left rolandic spikes, while the 2-year-old boy, whose EEG was firstly normal, displayed, 1 year later, a burst of generalized 3 c/s spike-and-wave paroxysmal activity on a 4-7 c/s background activity. The possible unitary genetic transmission of paroxysmal EEG abnormalities is discussed.