Information about specific seizures in seniors varies among studies. Partial seizures, particularly if defined as in the International League Against Epilepsy classification to include secondarily generalized seizures, are much more common than primarily generalized seizures, which usually have their onset in childhood or adolescence and often remit with maturity.
Complex partial seizures are the most common seizure type in seniors. In some cases, these represent the continuation into old age of refractory mesial temporal lobe epilepsy (TLE) that began in childhood, adolescence, or early adulthood. The prevalence of “typical” mesial TLE in seniors is uncertain.21 Similar limbic seizures can certainly begin late in life as a result of appropriately placed lesions.
Retrospective studies have been inconsistent in their identification or classification of secondarily generalized seizures and have considered only one-third to two-thirds to be partial.21-24 Electroencephalographic (EEG) data, when available, frequently show focal abnormalities.24,25
Anecdotally, manifestations of partial seizures in seniors are more varied than those in younger adults. In seniors, partial seizures largely follow vascular and neoplastic insults, which can occur in many areas of the brain. In young adults, on the other hand, most partial seizures are of mesial temporal origin.
Partial seizures with prominent motor manifestations, reflecting the low threshold of motor cortex to seizure generation,26 are often seen after stroke, although it is not clear that these seizures are more common in older than in younger persons.27 Reporting bias may affect these data because motor seizures are more likely to be recognized and diagnosed in patients who may have diminished communicative skills than are seizures with only subjective manifestations. Visceral, visual, and somatosensory auras preceding complex partial or secondarily generalized seizures are probably not rare but must be carefully sought.27,28
Classification of epilepsy syndromes in seniors leans strongly toward the localization-related, symptomatic group. Idiopathic syndromes would represent long-standing cases that have not remitted. Juvenile myoclonic epilepsy, for example, typically persists into adulthood. Since it is often misdiagnosed, it may occasionally “present” in old age. Since most of these idiopathic syndromes are defined in part by age of onset, however, their identification may be obscured in atypically older patients.21
Reviewed and revised June 2004 by Steven C. Schachter, MD, epilepsy.com Editorial Board.
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