Abstracts

Cortical stimulation is commonly used for seizure localization and cortical mapping in the operating room (OR) and in the seizure monitoring unit (SMU). The Canadian Society of Clinical Neurophysiology has published guidelines on minimal standards for EEG, EMG and Evoked Potentials but not for intracranial cortical stimulation. Our aim was to assess current practice patterns in Canadian epilepsy surgery centers., A questionnaire was sent to 11 major epilepsy surgery centers in all Canadian provinces. Centres were asked if they had a cortical stimulation protocol, which equipment was used for cortical stimulation, specific stimulation parameters (monopolar or bipolar, polarity of pulses, frequency and duration of stimulation and current intensities). We also inquired about who performed cognitive testing during stimulation, and about recording parameters (EEG recorded in conjunction with stimulation, EEG filter settings, criteria to stop stimulation, and if and when replication of results was required)., Eight centres responded (five adult and three children). Most centers performed cortical stimulation in the OR, the SMU or in both. Only three centres had a protocol for cortical stimulation and EEG recording parameters. Most centers used Ojemann stimulators and handheld bipolar stimulators were used in the operating room. Centres use a combination of grids, strips and cortical arrays as recording electrodes. There was much variation in the stimulation parameters used, but similar recording parameters were used (table). The criteria for discontinuing stimulation was similar in all centers., Many Canadian laboratories perform cortical stimulation and most lack protocols or guidelines for performing successful and safe stimulation. Stimulation parameters used in Canadian centers vary significantly. Limited research exists to support appropriate safe and effective parameters for cortical stimulation. We propose that Canadian epilepsy centres examine the ACNS guidelines and adopt minimum standard guidelines for cortical stimulation.[table1],