Executive Functions in Parkinson's disease with and without Deep Brain Stimulation (DBS): A systematic review

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.

Speech dysfunction, cognition, and Parkinson's disease

Communication difficulties are a ubiquitous symptom of Parkinson's disease and include changes to both motor speech and language systems. Communication challenges are a significant driver of lower quality of life. They are associated with decreased communication participation, social withdrawal, and increased risks for social isolation and stigmatization in persons with Parkinson's disease. Recent theoretical advances and experimental evidence underscore the intersection of cognition and motor processes in speech production and their impact on spoken language. This chapter overviews a growing evidence base demonstrating that cognitive impairments interact with motor changes in Parkinson's disease to negatively affect communication abilities in myriad ways, at all stages of the disease, both in the absence and presence of dementia. The chapter highlights common PD interventions (pharmacological, surgical, and non-pharmacological) and how cognitive influences on speech production outcomes are considered in each.