Stroop Test for Parkinson's Disease with Deep Brain Stimulation: A Systematic Review.

Background: Deep brain stimulation (DBS) is considered an alternative treatment for patients with rapidly developing Parkinson's disease (PD). DBS can cause cognitive changes, and it is necessary to perform an executive assessment before and after DBS to better define the prognosis.

Objective: The aim of this study was to analyze the use of the Stroop test for assessment of cognitive functions in patients with PD undergoing DBS.

Methods: The systematic review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Pubmed, Scopus, PsycInfo, and Web of Science were used as electronic databases. All included studies assessed the cognitive ability of patients with PD undergoing DBS through the application of the Stroop test.

Results: Thirty-five articles met the inclusion criteria. Among the studies, there were different formats of Stroop applications. Twenty-three articles presented negative results in relation to the individuals' performances in Stroop, compared to the control groups. The results suggested that there was no correlation between low performance in the test and global cognitive risk for the patients.

Conclusion: Patients with DBS declined in Stroop performance and showed impairments in response inhibition and speed. These results are not related to the lack of cognitive security of DBS. The Stroop test can be combined with other cognitive instruments to ensure greater approximation of results with reality measures.