[Intraoperative assessment of cognitive and executive functions in patients with brain tumors]

The aim of this paper was to evaluate the usefulness of selected methods of intraoperative neuropsychological assessment. In order to investigate the influence of the direct cortical stimulation and tumor resection on the patients' intraoperative performance, we examined selected areas of cerebral cortex involved in cognitive activity in patients undergoing awake craniotomy for brain tumors.

The analyzed group consisted of 21 patients (11 men, 10 women) with tumors located in eloquent areas of the left hemisphere. All patients had intact understanding of speech and relatively minor neurological deficits. We applied both experimental methods as well as certain standardized tests (WAIS-R, AVLT) for the investigation of verbal and nonverbal functions. The tests were performed during direct cortical stimulation and tumor resection, and also before and one week after the operation.

Verbal areas were identified in 10 patients, sensorimotor strip in 3, whereas both of them in 3. Even though in 5 out of 21 subjects we were unable to identify the eloquent cortex, there was no difference between pre- and postoperative assessment in these patients. Similarly, there was no statistically significant difference in pre- and postoperative tests among patients with successful cortical mapping.

We showed that the presented methods of intraoperative assessment of cognitive activity were useful and appropriate for the identification of the eloquent areas of the brain.