title: Temporal lobe epilepsy caused by mesial temporal sclerosis and temporal neocortical lesions. A clinical and electroencephalographic study of 46 pathologically proven cases.
abstract: This study aims to determine whether there are important clinico-electrical differences between patients with temporal lobe epilepsy (TLE) secondary to mesial temporal sclerosis (MTS) and those with TLE secondary to a discrete temporal neocortical lesion (NL). The case histories, interictal EEG, seizure semiology, ictal EEG and postoperative outcome of 46 pathologically proven patients (31 MTS and 15 NL) were compared. A history of febrile convulsions (FC) was more common in MTS patients (58% versus 26%, P < 0.05), as was a history of a significant cerebral event at < 4 years of age (22% versus 0%, P < 0.05). There were no statistically significant differences in the incidence or nature of auras. No statistically significant differences between the groups were found in the interictal-EEG. With ictal semiology dystonic posturing occurred more frequently in MTS patients (mean 52% versus 26%, P < 0.05). Facial grimacing/ twitching occurred earlier in the seizures of NL patients (median 19 s versus 35 s, P < 0.05). There was an increased frequency of fast rhythmic sharp waves (> 4 Hz) in the ictal-EEG of MTS patients (mean 81% versus 60%, P = 0.05). The patients with NL developed bilateral ictal EEG changes more often (mean 55% versus 26%, P < 0.05) and more rapidly (mean 23 s versus 74 s, P < 0.005). The onset of ictal EEG seizure activity was bilateral more often in patients with NL (20% versus 4%, P < 0.005). There were no significant differences between the two groups for any of the video-EEG features, in terms of whether or not the feature occurred at least once in an individual patients. There was a tendency for MTS patients to have a higher seizure-free postsurgical outcome (87% versus 60%, P = 0.057). However, all the NL patients who were not free of seizures had had an incomplete lesion resection. We conclude that there are a number of clinico-electrical differences between patients with mesial TLE (MTLE) and patients with neocortical TLE (NCTLE), but that none of these are sufficient to allow a distinction to be made in an individual patient.
authors.affiliation: Royal Melbourne Hospital, Australia.
authors.forename: T J
authors.initials: TJ
authors.lastname: O'Brien
authors.forename: C
authors.initials: C
authors.lastname: Kilpatrick
authors.forename: V
authors.initials: V
authors.lastname: Murrie
authors.forename: S
authors.initials: S
authors.lastname: Vogrin
authors.forename: K
authors.initials: K
authors.lastname: Morris
authors.forename: M J
authors.initials: MJ
authors.lastname: Cook
mesh_terms: D000293:Adolescent; D000328:Adult; D001927:Brain Diseases / Q000150:complications* / Q000503:physiopathology*; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000209:etiology* / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006212:Hallucinations / Q000209:etiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012598:Sclerosis; D013702:Temporal Lobe / Q000473:pathology* / Q000503:physiopathology*