The neurocognitive evaluation in the butterfly glioma patient. A systematic review

Butterfly glioma (BG) is a rare glioma subtype defined by contiguous extension of the tumor into both hemispheres through the corpus callosum. The impairment of higher cognitive functions in BG patients is a well-known condition encountered in the clinical practice. Given the peculiar anatomical features and clinical repercussions of butterfly gliomas, we conducted a systematic review of the literature to assess the role of structured neurocognitive evaluation in this patient population. A systematic search of the literature (Embase, Pubmed, Cochrane databases) was conducted following PRISMA guidelines to identify English language studies reporting on clinical evaluation, treatment strategies and outcomes in BG patients. Screening and extraction were conducted in duplicate. Results were analyzed qualitatively. 493 unique references yielded 49 full-text papers for review; 19 studies were included in the final analysis reporting on 181 patients. A descriptive approach was used in the majority of cases to report on patients' cognitive status, where memory loss, confusion and non-specific cognitive impairment were the most frequently reported issues (67–69% of cases). Three studies conducted specific neurocognitive evaluations: one series reported on the post-operative incidence of abulia/akinesis and its resolution, two case reports applied a complete battery of neuro-psychological tests assessing attention, executive functions and memory skills. This review highlights a gap between the wide availability of validated neuropsychological tests and their utilization in the management of BG patients, according to the literature. Additional data from multi-institutional studies are needed to evaluate the actual implementation of these tests in the daily clinical practice.