A new syndrome of familial temporal lobe epilepsy is described in 38 subjects from 13 unrelated families and was first identified in 5 concordant monozygotic twin pairs at the Australian National Health and Medical Research Council Twin Registry, University of Melbourne, Parkville, Australia. Seizure types were simple partial seizures with psychic or autonomic symptoms, infrequent complex partial seizures, and rare secondarily generalized seizures. EEGs showed focal temporal interictal epileptiform discharges in 22%. MRIs were normal. Autosomal dominant inheritance with age-dependent penetrance was likely. Some family members were affected with only mild and subtle seizure manifestations. 
COMMENT. Onset of familial temporal lobe epilepsy (TLE) is typically in adolescence or early adult life, whereas TLE with hippocampal sclerosis (HS) usually begins in childhood. Febrile seizures, often preceding the TLE of HS, were not increased in frequency in family members of familial TLE subjects. The mild and subtle nature of familial TLE may explain the previous infrequent reports of similar syndromes. Bray PF and Wiser WC have described the hereditary characteristics of familial temporo-central focal epilepsy, and the above authors suggest that some of their cases persisting into adulthood might represent examples of familial TLE.