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

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.

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.

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.

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.