MOTOR AND SENSORY MAPPING OF THE FRONTAL AND OCCIPITAL LOBES

In patients with intractable epilepsy, surgical resections are perform ed with the primary goal of improving seizure control. The risk is tha t the resections may also remove tissues crucial for normal activities . The goal of surgical planning is therefore to determine as accuratel y as possible the regions of seizure onset and the regions controlling important functions, so that one can determine what to remove and wha t to leave in place. Clinical functional localization has been perform ed using cortical stimulation for over half a century, using both intr aoperative and extraoperative methods. Signal averaging also has been widely used. More recently, techniques based on analysis of EEG in the frequency domain have shown promise. The methods appear to accurately indicate the function of the region assessed but do not necessarily p redict functional consequences of resection. We review these methods, their indications, and the results obtained by their use.