title: Clinical features of late-onset partial cryptogenic epilepsy: toward an idiopathic temporal epilepsy?
abstract: Adult-onset epilepsy is commonly thought to be secondary to a brain lesion. However, the etiology of adult-onset epilepsy remains unknown in approximately 25% of patients, despite progress in medical and diagnostic tools. In the present study, we investigated whether late-onset partial cryptogenic epilepsies could be subgrouped based on seizure semiology and clinical characteristics. A total of 41 patients with late-onset cryptogenic epilepsy were included, and the corresponding clinical and electrophysiological data were analyzed. The following three clinical subgroups were identified: 1) a group that fulfilled the diagnostic criteria of transient epileptic amnesia (TEA); 2) a group with late-onset cryptogenic epilepsies with a temporal seizure semiology; and 3) a cryptogenic extratemporal group, which was consistent with the categorization of cryptogenic epilepsies, i.e., epilepsies involving unknown lesions. The temporal group showed homogeneous clinical characteristics, especially a rapid evolution and a greater tendency toward generalization and pharmacoresistance compared with the other two groups. Transient epileptic amnesia was associated with a higher frequency of sleep disorders than either of the other groups. Our findings argue for the clinical identification of a subgroup of late-onset temporal epilepsy that might constitute an idiopathic form. The association between TEA and sleep disorders would suggest a possible pathophysiological role of sleep apnea syndromes in TEA.
authors.affiliation: Service de Neurophysiologie Clinique, Centre Hospitalier Universitaire Pellegrin, Bordeaux, France. vlambrecq@hotmail.fr
authors.forename: Virginie
authors.initials: V
authors.lastname: Lambrecq
authors.forename: Cécile
authors.initials: C
authors.lastname: Marchal
authors.forename: Véronique
authors.initials: V
authors.lastname: Michel
authors.forename: Dominique
authors.initials: D
authors.lastname: Guehl
authors.forename: Pierre
authors.initials: P
authors.lastname: Burbaud
authors.forename: Alain
authors.initials: A
authors.lastname: Rougier
mesh_terms: D000328:Adult; D017668:Age of Onset; D000647:Amnesia / Q000150:complications*; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis* / Q000209:etiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D014741:Video Recording