Two forms of hemitonic seizure in patients with infantile hemiplegia and epilepsy

Two forms of unilateral tonic (hemitonic) seizure were observed in two adult epileptic patients with infantile hemiplegia. Their ictal EEGs showed diffuse bilaterally synchronous spike bursts without focal features. In one case, a 31-year-old male, the VTR/EEG recording clearly demonstrated hemitonic seizure which simultaneously involved his paretic limbs and body and were associated with loss of consciousness and autonomic signs. In the other case, a 33-year-old male, partial seizures with secondary unilateral generalization were demonstrated by VTR/EEG recording. The reason why these cases do not exhibit motor seizure activity on the unaffected side despite diffuse bilateral EEG changes, a lower motor threshold in the paretic limbs and inhibitory effect in the brain-stem on undamaged side are postulated. These two cases suggest that hemitonic seizures include heterogeneous characteristics of partial and generalized epilepsy. In patients with diffuse brain damage, such as those with infantile hemiplegia, seizures appear to exhibit complicated patterns, with characteristics of partial and generalized seizures. There is a gradiation of expression of unilateral seizure, range from clearly partial seizures to those with mostly features of generalized seizures, except for an asymmetry of motor expression.