Cognitive effects of tumour and surgical treatment in glioma patients

Abstract

Quality of life in brain tumour patients is an emerging issue and has prompted neurosurgeons to reconsider the need for cognitive assessment in the course of treatment. In particular, to date there has been a lack of comprehensive neuropsychological assessment performed preoperatively and in the acute postoperative period. We examined 29 patients with glioma, analysing several functional domains-intelligence, executive functions, memory, language, praxis, gnosis and mood state-in order to establish the effect of tumour and surgery on cognition. At baseline, using test- and domain-based criteria, 79% and 38% of patients, respectively, were impaired, the former related to tumour factors such as oedema (P < 0.05), larger size (P < 0.05) and higher grade (P = 0.001). Verbal memory, visuospatial memory and word fluency were the most frequently affected functions, partly associated with depression. Postoperatively, again using test- and domain-based criteria, 38% and 55% of patients, respectively, were unchanged, 24% and 21% improved, and 38% and 24% worsened; 24% and 62% of patients were intact, respectively. The extent of removal did not influence the outcome. Improvement involved previously impaired functions and was correlated with high-grade tumours. Worsening regarded executive functions was related to tumour size and was partly explained by radiological findings on postoperative magnetic resonance imaging (MRI). This preliminary study, focussing on the effects of tumour and surgery, showed that tumour significantly affects cognitive functions, mainly due to the mass effect and higher grading. Surgical treatment improved the functions most frequently affected preoperatively and caused worsening of executive functions soon after operation, leaving the overall cognitive burden unchanged and capable of improvement prospectively.

Competing for patients: an ethical framework for recruiting patients with brain tumors into clinical trials

“…Brain tumor patients are a particularly vulnerable population, in which clinicians need to be aware of challenges of informed consent due to their underlying diseaserelated impairment [17]. One study found that subjects frequently consent to treatment with only modest appreciation of the risks involved, with 23.9% of subjects reporting no risks despite being explicitly informed otherwise [18].…”

“…One study found that subjects frequently consent to treatment with only modest appreciation of the risks involved, with 23.9% of subjects reporting no risks despite being explicitly informed otherwise [18]. Specifically, patients with brain tumors may have altered cognition and may lack the capacity to understand a rigorous informed consent process that covers several concurrent trials [17]. In other vulnerable populations, patients with a thought disorder, willingness to participate in trials was correlated with higher education and lower cognitive impairment [19].…”

Intraoperative cortical mapping of visuospatial functions in parietal low-grade tumors: changing perspectives of neurophysiological mapping

“…They both underwent a preliminary multidisciplinary interview as well as a battery of psychological and neuropsychological tests (Table 1) before and after surgery. 12,14,15 In addition to general neuropsychological testing, assessments of their spatial abilities and spatial neglect in particular were performed. 4 We followed the standard rules to assess spatial neglect: for all the paper-and-pencil tests, the sheet of paper was preoperatively centered to the patient's sagittal head plane, and no time limit was given for task execution (except for the Diller Letter Cancellation Test, when the time limit was 2 minutes).…”

Functional preoperative and intraoperative mapping and monitoring: increasing safety and efficacy in glioma surgery

“…Several authors have already highlighted the importance of neuropsychological testing before, during, and after glioma surgery. 22,98,114,124 The clinical relevance of monitoring other cognitive functions like calculation 20 has been shown. Navigated TMS is not only able to map function but also to modulate it.…”