Temporal lobe epilepsy of adult age of possible idiopathic nature

OBJECTIVE To verify the existence of sporadic cases of temporal lobe epilepsy (TLE) of possible idiopathic nature with onset in adult life and to define their characteristics. BACKGROUND Currently, the existence of these forms is not fully recognized. In the last few years, familial cases of TLE of the early adult age have been described. Besides, sporadic cases of TLE characterized by both onset in adulthood and high prevalence of familial history of epilepsy have also been reported. METHOD All subjects with TLE, defined according to the ILAE criteria (1989), with onset in adult age, followed at our Centre from 1990 to 1998, were re-examined to find out the cases with possible idiopathic origin of seizures. RESULTS Among 159 subjects with a diagnosis of TLE, 14 subjects (8.8%) were so identified (Group 1), and compared with the remaining 145 subjects (Group 2). High familial incidence for epilepsy, prevalence of autonomic seizures, low seizure frequency, and good prognosis are the main characteristics of the group 1. The difference between the two groups is statistically significant for family history for epilepsy (chi square test: P< 0.01) and for freedom from seizures after medication (chi square test: P< 0.05). CONCLUSION The distinctive features of the subjects identified suggest that at least some of these patients may have familial TLE. Whether this disorder may be present in sporadic form remains a matter of debate which must await the identification of the gene(s) responsible of this disorder. Till then, it is worthwhile to underline the better prognosis of these patients compared to those that did not meet these criteria.