P16.14BRAIN LOCATIONS INVOLVED IN COGNITIVE ALTERATIONS AFTER RESECTIVE BRAIN SURGERY IDENTIFIED BY RESECTION PROBABILITY MAPS

INTRODUCTION: Cognition is at risk in patients with brain tumors. Cognitive alterations, improvement or decline, may result from brain tumor surgery, as well as from other factors such as direct tumor effects, radiotherapy, chemotherapy, anti-epileptic drugs, and steroids. In this study, cognitive alterations after brain tumor surgery are quantified and correlated with brain location using resection probability maps, which is a new approach. METHODS: Adult patients were included, who had (1) a brain tumor, (2) resective surgery between 2006 and 2011, (3) baseline and postoperative (9-12 months) neuropsychological assessment in seven cognitive domains, and (4) pre- and postoperative MRI available. Resective surgery was performed with intraoperative stimulation mapping until functional boundaries were met. Resection probability maps quantify the likelihood of resection throughout the brain in 3D at 1 mm resolution in standard brain space. We compared resection probability maps of patients with and without cognitive alterations. Considerations for spatial dependence and multiple comparisons were taken into account. PRELIMINARY RESULTS: Seventy-four patients were so far included. The cognitive domains with most frequent and most extensive alterations after surgery were attentional function and working memory capacity. Results on the correlation between these cognitive changes and brain location are pending, but will be available in October 2014. CONCLUSION: Brain locations involved in cognitive improvement as well as decline in relation to resective surgery can be identified using resection probability maps. Brain tumors which are located in regions to be identified are associated with alterations in attention and verbal working memory.