Brain Functions: Eloquent Areas – Motor and Somatosensory

Intraoperative monitoring and mapping may allow real-time risk stratification and intraoperative guidance of the surgical strategy. During surgery under general anesthesia, diverse monitoring and mapping techniques have been developed, which will be discussed in the following chapter. Transcranial and direct cortical stimulation for monitoring motor evoked potentials helps to assess the functional integrity of the primary motor system and allows predicting motor functional outcome of the patients. Cortical mapping identifies eloquent areas and helps to define safe entry sites to resect tumors. Subcortical mapping is essential to preserve white matter tracts such as the corticospinal tract. Besides the classical intermittent mapping techniques, recently, continuous dynamic mapping approaches via surgical instruments have evolved.