All of the following are features of absence seizures except

Harrison's textbook of internal medicine 17th edition . *Absence seizures(previously petit mal)usually sta in childhood (4-8yrs)or early adolescence *Electrophysiological hallmark is generalized,symmetrical ,3Hz spike-and-wave discharge that begins and ends suddenly,superimposed on normalEEG *Hyperventilation tend to provoke these electroencephalographic discharges *Seizure lasts only for seconds and there is no postictal confusion .