Dissociative Head and Eye Movement during Seizure: A Case Report

Introduction: Deviation of the eyes may occur with seizures involving any cerebral lobe. Most notably, a lesion of the FEF that causes excess neural activity, like a focal seizure, or spreading of ictal discharges to the FEF will drive the eyes contralaterally during the period of the seizure. The head also may turn contralateral to the seizure focus during the ictus. In the post-ictal state, when there may be lingering hypoactivity of the FEF neurons, the eyes may deviate ipsilateral to the side of the lesion because of a relative increase in the input from the unaffected FEF on the opposite side of the brain. Methods: A ۱۴- year old right handed boy with refractory epilepsy was admitted for video EEG monitoring in an attempt to better define his seizures and to evaluate him for possible epilepsy surgery. He had thirteen clinical seizures with different semiology. In one of these, he had disconjugated head and eye movement that is an unusual finding. In this investigation, we noted his brain MRI with and without contrast that reported focal signal abnormality in the right prerolandic region indicative of AV malformation and also abnormal intraaxial infratentorial cystic mass located in the left cerebellar peduncle. Results: In the present case, disconjugated head and eye movement occurred during the seizure, probably; due to brain stem cystic lesion that is mainly located in mesencephalic area that may interrupt the connections between FEF and superior colliculus. Conclusion: The patient studied in the present study experienced Rt. Side (ipsilateral) eye gaze with dis-conjugated left sided (contralateral) head version during his seizure. While long term video-EEG monitoring and imaging studies pointed to epileptogenic zone of right centroparietal region. This is probably due to a cystic lesion located in the mesencephalic region mainly in the left cerebellar peduncle.