Abstracts

RATIONALE: To determine whether there are clinical predictors of secondarily generalized convulsions (GTCs) in mesial temporal lobe epilepsy (MTLE) and analyze semiology and lateralizing signs of GTCs. METHODS: Of 43 patients with documented MTLE 17 had GTCs, 26 had not. Demographic and standardized videotape analysis (two reviewers) of 207 seizures (31 GTCs) was undertaken. RESULTS: No particular risk factor (febrile convulsions, perinatal complications or CNS infections) was associated with the occurrence of GTCs. Age of habitual seizures onset (mean +GTC 13.4 years,- GTC 13.1 years), duration of epilepsy (+ GTC 22 years, -GTC 23.9 years), type of first seizure and history of status epilepticus was not predictive of GTCs (p<0.05). Asymmetric tonic arm extension combined with tonic arm flexion on the other side was noted in 10 patients (60%), tonic abduction and elevation of one arm with versive head turning in 7 patients (41%), versive head turning without arm abduction in 6 patients (35%), symmetric tonic arm extension in 10 patients (60%), symmetric tonic arm flexion in 5 patients (29%), vocalization in 10 patients (60%), forced eye-deviation in 7 patients (41%), asymmetric clonic face in 3 patients (18%) and asymmetric tonic face in 5 patients (29%). These clinical signs were seen in various combinations during individual GTCs. Asymmetric tonic arm extension was contralateral to the seizure focus, except in one patient who had alternating tonic extension. Head deviation, arm abduction and asymmetric face movements were always contralateral. Only 10 patients (60%) showed the typical sequence of a tonic phase, superimposed tremulousness and a clonic phase. Four patients were tonic and clonic simultaneously, four patients underwent two tonic phases with relaxation in between and one patient had no tonic phase. When patients had more than one GTC the individual patterns were stereotyped with two exceptions. CONCLUSIONS: There are no clinical predictors of GTCs in MTLE. Patterns of generalization are not uniform and suggest multiple electrical propagation patterns. Lateralized tonic or clonic signs at the onset of generalization have lateralizing value.