Lateralized ictal dystonia of upper and lower limbs in patients with temporal lobe epilepsy

To perform a retrospective study to determine the incidence and lateralizing value of ictal dystonia in patients with temporal lobe epilepsy.

The study included 142 patients (76 males, 66 females) with temporal lobe epilepsy, aged from 19 to 58 years with an average age of 33.1 +/- 8.7 years. Overall, 454 seizures were analysed. The seizure onset zone was mesial in 112 patients (78.8%), and "non-mesial" in 30 patients (21.2%).

Ictal dystonia was present in 68 of the 142 patients (47.9%), and in 186 of 454 total seizures (40.9%). Upper limb dystonia was present in 94 seizures (50.5%) of 32 patients; hemidystonia in 84 seizures (45.2%) of 30 patients; and lower limb dystonia in eight seizures (4.3%) of six patients. For all cases, all types of ictal dystonia were contralateral to the seizure onset zone. Ictal dystonia was significantly more frequent in patients with a mesial seizure onset zone than in "non-mesial" patients (58.1% vs 7.7%; p < 0.001). Within the mesial group, ictal dystonia was significantly more frequent in patients with hippocampal sclerosis than in those patients with other lesions (66.1% vs 41.1%; p = 0.023).

Ictal dystonia in temporal lobe epilepsy is a reliable lateralizing ictal sign. During almost half of the seizures studied, ictal dystonia was present in the form of hemidystonia, and isolated involvement of the lower limbs also occurred. Combined data obtained from both noninvasive and invasive EEG showed that ictal dystonia tended to occur more often in mesial onset temporal lobe epilepsy, especially when hippocampal sclerosis was the epileptogenic lesion.