Assessment methods and prevalence of cognitive dysfunction in patients with low-grade glioma: A systematic review.

OBJECTIVE: To systematically review the literature for studies on cognitive functioning in patients with low-grade glioma to evaluate assessment methods and prevalence of cognitive dysfunction.

DATA SOURCES: A search was made in PubMed, Embase, and PsycINFO for articles published between January 2002 and June 2012 using cognition, memory, attention, executive functioning, and low-grade glioma as search terms.

STUDY SELECTION: Two reviewers independently performed the study selection and data extraction. Inclusion criteria were: studies including at least 10 adult patients, with suspected or confirmed low-grade glioma and cognitive functioning as outcome measure.

DATA EXTRACTION: A standard data extraction form was used, with items regarding study quality, patient characteristics, type of measurement instruments, cognitive domain, definition of cognitive dysfunction, and reported prevalence.

DATA SYNTHESIS: Of the 312 articles screened on title/abstract, 69 were screened on full-text and, finally, 17 were included. A total of 46 different measurement instruments were found for the assessment of cognitive functioning; 5 of these were used 5 or more times. There was variability in the definition of cognitive dysfunction. The reported prevalence of cognitive dysfunction ranged from 19% to 83%.

CONCLUSION: Many patients with low-grade glioma experience cognitive dysfunction. However, there is no consensus on how to assess cognitive functioning in these patients.