Idiopathic generalized epilepsies with pure grand mal: clinical data and genetics

Objective: To analyze the clinical features and family history of patients with idiopathic generalized epilepsy (IGE), with pure grand mal (GM), divid ed into epilepsies with GM occurring exclusively on awakening (GMA) and ran dom GM (RGM). Methods: We studied retrospectively 98 patients from a large epilepsy outpatient clinic. All patients had a full clinical examination an d computed cerebral tomography scans (CCT) or magnetic resonance imaging (M RI) when feasible. We analyzed seizure type, seizure frequency, provocative factors, prognosis, electroencephalography (EEG) findings and family histo ry. Results: Sixty-eight patients had GMA and 30 had RGM. The mean age at s eizure onset was 16.6 years (+/- 6.3 S.D., range: 5-41) and 16.7 years in t hose with RGM (+/- 7.5 S.D., range: 4-42, NSD). Patients with GMA had a lon ger course of active epilepsy (median 8.5 years) compared to RGM (median 2 years). Seizure-provoking factors, especially sleep deprivation, were signi ficantly (P = 0.001) more common in patients with GMA (52/68, 77%) than in the group with RGM (13/30, 43%). Of all patients, 23% (23/98) reported firs t degree relatives with seizures or epilepsy. Pure GM was found in 41% (12/ 29) of affected first degree relatives, other idiopathic generalized epilep sy syndromes were less frequently observed (4/29, 14%). The concordance rat e was high within the syndrome - none of the patients with RGM had an affec ted relative with GMA and vice versa only two of affected relatives of GMA patients had RGM. Conclusion: GMA seems to be associated with a longer dura tion of active epilepsy, a higher relapse rate and a stronger tendency to b e precipitated by seizure provoking factors. The different concordance rate s between the syndromes suggest a genetically different background. (C) 200 1 Elsevier Science B.V. All rights reserved.