PITFALLS IN JUVENILE ABSENCE EPILEPSY

Objectives: Although juvenile absence epilepsy (JAE) is a benign condition, it is a lifelong disorder and needs special attention regarding diagnosis. Spanioleptic typical absence seizures, rare generalized tonico clonic (GTC) fits may be misinterpreted as focal epilepsy. The aim of this paper is to describe 6 patients with JAE who had peculiar clinical presentation.

Methods: Four patients with JAE who were seen in a secondary care hospital and two in a tertiary center of the University of São Paulo, Brazil are presented. All had normal neurological and neuroimaging examination and were submitted to routine sleep deprived EEG with hyperventilation (HV) and photostimulation.

Results: Age of first evaluation ranged from to 11 to 14 yr. and sex distribution was 1:1. First symptoms were single GTCS in two, absence in one, suspected partial seizure (head version) on arousal in two, and headache in one. Our initial EEG was abnormal in all patients, showing generalized spike-and-wave complex (SWC) discharges, but only in 4 absence seizures were registered. Regional abnormal EEG activity predominance were seen in 4 (right frontal in three and bilateral posterior in one). Photosensitivity was not observed in any patient. The two patients with single GTCS presented also absences that were not realized by the family, one documented by EEG and the other retrieved by history. Another patient had episodes of lack of reactivity since the age of three yr. twice a year and during HV she could count and obey simple commands during prolonged SWC. Two patients with suspected partial seizure on arousal, one had absence seizures during HV only in the third tracing, and the other had had several previous reported normal EEG, and after a sleep deprived tracing, had an absence seizure on arousal; these latter children presented absences in EEG only after receiving antiepileptic drugs, Clobazam and Phenobarbital, respectively. One patient with headache presented prolonged SWC associated to impairment in calculating, with normal counting and repetition. All patients were controlled with AED, 5 with VPA and one with LTG, and attend appropriate age academic level.

Conclusion: It is very important that benign but lifelong forms of idiopatic epilepsy such juvenile absence epilepsy is suspected during a first neurological evaluation. Because of the spanioleptic presentation of absence seizures and lack of familiarity of EEG pitfalls, juvenile absence epilepsy may be much more prevalent than previously thought.