Time course of neurological deficits after surgery for primary brain tumours

BACKGROUND: The postoperative course after surgery for primary brain tumours can be difficult to predict. We examined the time course of postoperative neurological deficits and analysed possible predisposing factors. METHOD: Hundred adults with a radiological suspicion of low- or high-grade glioma were prospectively included and the postoperative course analysed. Possible predictors of postoperative neurological deterioration were evaluated. RESULTS: New postoperative neurologic deficits occurred in 37% of the patients, and in 4%, there were worsening of a preoperative deficit. In 78%, the deficits occurred directly after surgery. The probable cause of deterioration was EEG-verified seizures in 7, ischemic lesion in 5 and both in 1, resection of eloquent tissue in 6, resection close to eloquent tissue including SMA in 11 and postoperative haematoma in 1 patient. Seizures were the main cause of delayed neurological deterioration. Two-thirds of patients with postoperative deterioration showed complete regression of the deficits, and in 6% of all patients, there was a slight disturbance of the function after 3 months. Remaining deficits were found in 6% and only in patients with preoperative neurological deficits and high-grade tumours with mainly eloquent locations. Eloquent tumour location was a predictor of postoperative neurological deterioration and preoperative neurological deficits of remaining deficits. CONCLUSIONS: Postoperative neurological deficits occurred in 41% and remained in 6% of patients. Remaining deficits were found in patients with preoperative neurological deficits and high-grade tumours with mainly eloquent locations. Eloquent tumour location was a predictor of neurological deterioration and preoperative neurological deficits of remaining deficits. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s00701-020-04425-3) contains supplementary material, which is available to authorized users.