Electroclinical features of idiopathic generalized epilepsies in the elderly: a geriatric hospital-based study.

Purpose: Idiopathic generalized epilepsies (IGE) are age-related epileptic syndromes mainly described in children and adolescence. Our aim is to describe their electroclinical features in the elderly.

Methods: Patients aged 70 years or more were prospectively selected in a geriatric EEG laboratory on the basis of rhythmic generalized spikes and waves discharges. Their clinical data were then examined to ascertain the syndromic diagnosis.

Results: Among 1181 geriatric patients referred for EEG over a 30-month period, IGE were identified in 10 cases. Eight patients began seizures in childhood or adulthood (3 childhood absence epilepsies, 2 juvenile/adult myoclonic epilepsies and 3 epilepsies with-generalized-tonic-clonic-seizures alone (EGTCS)) and 2 very late in life with EGTCS. The early-onset IGE cases had usually experienced a quiescent long period in adulthood before relapsing late in life. This relapse, mostly severe, consisted of absence status, myoclonic status or repeated generalized tonic clonic seizures and was often not-situation related. Absence status and myoclonic status were stopped by Clonazepam. The two late-onset IGE cases had familial history of epilepsy. Inappropriate antiepileptic drugs (AED) previously given in four patients with two worsenings were corrected.

Conclusions: In this study, the non-negligible number of elderly cases observed over a short period of time suggests that IGE are frequent in the elderly but underestimated until recently. IGE may be lifelong with late severe exacerbations. A few very late-onset IGE cases exist. EEG remains useful in contributing to diagnose IGE and AED adjustment continues to be beneficial at extreme age.