The invention relates to a device for the early detection of cortical electrical anomalies during surgical procedures involving direct cortical stimulation. The inventive device comprises a handpiece supporting: electric stimulating means for stimulating an area of the cerebral cortex； means for detecting the electrical activity in this area, and； means for transmitting electrical signals received and emitted by said area. In practice, a stimulating electrode and an electrode for collecting the signal area arranged in such a manner as to realize, on a same area of the cerebral cortex, the stimulation and the monitoring of the cortical electrical activity. The inventive device is integrated in an instrument, serving to emit and process the signals and to assure the automated monitoring of the cortical electrical activity. The device and the integrated instrument are primarily used during the preoperative mapping of functional areas of the cerebral cortex of a patient for the early detection of hypersynchronous paroxysmal discharges that indicate an epileptic seizure.
