gms | German Medical Science

Objective: Intraoperative neuromonitoring (IONM) including direct cortical/subcortical monopolar stimulation is widely used for elective resection of eloquent located cerebral lesions in order to increase safety and extent of resection. Due to the demand of special trained external personnel, sophisticated technical setup and time limitations, standard IONM is usually not taken for emergency situations. We here report the use of a device for monopolar brain mapping that can be quickly operated by the surgeon autonomously in emergency situations.

Methods: We here report three patients with residual neurologic function, in whom emergency surgery on eloquently located lesions (2 tumours, 1 intracerebral bleeding) was performed. To preserve residual motor function monopolar motor mapping using C2Xplore was performed. For monopolar cortical/subcortical stimulation a standard monopolar probe was connected to the device enabling EMG real-time tracking of 8 muscles. EMG signals were screened in real-time on the device monitor. Preoperative set up as well as intraoperative handling of the device were performed by the surgeons independently.

Results: In all patients cortical M1 mapping was performed (thresholds 4, 14 and 5mA). Subcortically the corticospinal tract (CTS) could be identified with 0.3, 2 and 5mA. Because of the eloquent tumor location and positive mapping, complete resection could not be achieved (residual tumor volume <2ml and 4.2ml). All patients fully recovered postoperatively with no new neurological deficits.

Conclusion: We could demonstrate feasibility of monopolar stimulation in patients undergoing emergency surgeries using a device autonomously operated by the surgeon. Due to fast set up and non-demanding handling monopolar stimulation could be used during emergency surgery under preservation of neurological function in all cases.