Pre- and postoperative self-reported and objectively assessed neurocognitive functioning in lower grade glioma patients.

Due to the tumor itself or its therapy glioma patients may complain on cognitive impairment, while validated neuropsychological testing (NPT) capturing specific neuropsychological domains does not indicate "objective" dysfunction. Little is known on the relevance of this disturbance for patients' everyday life. We aimed to address whether glioma patients treated with state-of-the-art neurosurgical techniques complain on neuropsychological impairment and whether these subjective complaints are disclosed in formal NPT. We assessed both, "objective" and "subjective" neurocognitive functioning in 13 patients with newly diagnosed WHO grade 2 and 3 gliomas, operated between 06/2018 and 12/2020. All underwent both, preoperative and follow-up NPT as well as a semi-structured interview on subjective complaints and specific questionnaires (post-therapeutic) on attention, memory and executive functioning. On group level, no significant changes between preoperative and post-therapeutic NPT occurred. On the individual level, in 3/13 patients new post-therapeutic deficits in objective NPT were detected in specific domains (verbal memory, non-verbal memory, verbal fluency). By contrast, 8/13 patients reported on "subjective" memory impairments post-therapeutically. Furthermore, on specific questionnaires cognitive and emotional executive dysfunction and increased fatigue occurred in patients relative to normative data. Although the findings have to be replicated in larger populations, a discrepancy between "subjective" and "objective" measures was evident. While subjective neurocognitive impairment may simply not represent a true dysfunction, an alternative explanation might be that established standardized NPT is not suitable to detect subtle dysfunction in this population. "Subjective" and "objective" neurocognitive functioning might represent distinct constructs, which should complement each other in patient-centered Neuro-Oncology.