<prompt> All of the following are features of absence seizures exceptUsually seen in childhood3-Hz spike wave in EEGPostictal confusionPreciptation by hyperventilation  <response>: Harrisons textbook of internal medicine 17th edition . Absence seizurespreviously petit malusually sta in childhood 4-8yrsor 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 . 