EEG in childhood absence epilepsy.
We performed a longitudinal clinico-electroencephalographic study of 23 children who were diagnosed as having absence epilepsy on their initial visits to our facility and we analysed those factors which lead to an unfavourable prognosis.


METHODS
We divided the 23 patients into three groups according to their clinical courses: Group A: eight patients who responded well to the therapy and became seizure free without relapse of epileptic discharges on EEGs; Group B: thirteen patients who suffered from relapse of epileptic discharges on EEGs despite clinical seizure cessation; Group C: two patients who continued to suffer from seizures.


RESULTS
(1) Fifty-six percent of all patients had focal epileptic discharges, including a surprising 63% of patients in Group A. (2) "Lead in" in the ictal EEGs and automatisms during seizures were most commonly observed in patients in Group B, although there were no significant differences between the three groups. (3) The epilepsy of one patient in Group C evolved into complex partial seizures or absence status during her clinical course. She seemed to suffer from so-called "frontal absence", despite the fact that her initial EEG did not show any focal abnormalities. (4) Patients in Group B were treated with lower AED dosages than those in Group A. In addition, one patient in Group C was treated irregularly.


CONCLUSIONS
We conclude that it is not uncommon for patients with absence epilepsy to show focal abnormalities on EEGs and clinical ictal automatisms. Thus, the existence of clinical ictal automatisms and focal signs in electroencephalographic features are not sufficient indicators of the final outcome. Furthermore, it appears that regular and adequate drug therapy is important for a favourable prognosis.
Yoshinaga
Harumi
H
Department of Child Neurology, Okayama University Medical School, Shikatacho 2-5-1, Okayama 700-8558, Japan. magenta@md.okayama-u.ac.jp
Ohtsuka
Yoko
Y
Tamai
Kei
K
Tamura
Ibuki
I
Ito
Minako
M
Ohmori
Iori
I
Oka
Eiji
E
D000927:Anticonvulsants / Q000627:therapeutic use; D001332:Automatism / Q000209:etiology; D002648:Child; D002675:Child, Preschool; D004305:Dose-Response Relationship, Drug; D004569:Electroencephalography; D004828:Epilepsies, Partial; D004832:Epilepsy, Absence / Q000175:diagnosis* / Q000188:drug therapy / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic; D011237:Predictive Value of Tests; D011379:Prognosis; D014635:Valproic Acid / Q000627:therapeutic use
D000927:Anticonvulsants; D014635:Valproic Acid