Epilepsy or paroxysmal kinesigenic choreoathetosis?

Epileptic seizures induced by sudden movement and paroxysmal kinesigenic choreoathetosis (PKC) have often been confused in the past, owing to the close similarity of the attacks, the equally good response to anticonvulsants, and the frequent occurrence of epilepsy and PKC in the same family, or even in the same patient. The pathophysiology of PKC is still unclear and its relationship with epilepsy open to discussion. The sparing of consciousness and the lack of postictal phenomena are constant features of PKC, thus differentiating this syndrome from epilepsy. We report the case of an 8-year-old boy with frequent brief tonic attacks, without loss of consciousness, triggered by sudden movement. The neurologic examination, EEG and MRI did not help to differentiate between epilepsy and PKC. Only the occurrence of a longer seizure with clouding of consciousness and the recording of the postictal abnormalities on the EEG supported a diagnosis of reflex epilepsy induced by movement.