Abstracts

A variety of techniques are utilized to localize epileptic seizure onset in patients with complex partial seizures in order to co-register non-neurophysiologic parameters with ictal EEG findings. Some techniques such as positron emission computerized tomography (SPECT) are based on detecting an increase in regional blood flow in the area of seizure onset. Very little is known about changes in larger diameter blood vessels during seizures. Such changes in cerebral blood flow were investigated utilizing ictal transcranial doppler (TCD). Transcranial doppler was recorded during EEG-video monitoring in 2 adult patients undergoing evaluation for anterior temporal lobectomy. Bilateral TCD sensors were held in place over the temporal regions utlizing a fixed halo. Standard EEG-video monitoring protocols utlizing scalp electrodes were not altered from clinical practice for this study. One seizure each was recorded from each patient. For each, there was an increase in mean blood flow velocities on the side ipsilateral to the seizure onset as determined by ictal EEG. This preliminary data suggests that blood flow changes during TCD monitoring during complex partial seizures may correlate to the side of seizure onset. This may provide another tool in the evaluation of candidates for epilepsy surgery allowing another non-neurophysiologic method for co-registration of functional data. In addition, since TCD reflects changes in blood flow velocities in larger diameter blood vessels, this technique may provide further insight into blood flow patterns in larger blood vessels during partial seizures. (Supported in part by the Peter Kellaway Research Endowment, Baylor College of Medicine and National Service Award Training Grant T32 NS07399, National Institutes of Neurological Disorders and Stroke, NIH.)