“…Over a period of 15 months, we included 137 patients in our study, of which 118 patients underwent surgery in the semi-sitting position and 19 in the supine position. Lindroos et al have gained extensive experience by having used the semi-sitting position for almost 20 years (14,17,26,31). The semi-sitting position optimizes the operation situation for the surgeon in that it causes a drainage of liquor and blood from the surgical eld by gravity, decreases intracranial pressure and enables the monitoring of the motoric response of patients to cranial nerve stimulation (14,17,26,32).…”