Systematic review of neuropsychological instruments used in subthalamic nucleus deep brain stimulation in Parkinson´s disease patients

Abstract

ABSTRACT. In addition to drug treatment, surgical intervention represents an alternative to PD patients with motor deficits. The most common intervention is subthalamic nucleus deep brain stimulation (STN-DBS). It is extremely important to perform a neuropsychological assessment in patients with STN-DBS, not only to identify losses related to the disease, but also to compare influence on cognition both pre and postoperatively. Objective: the objective of this systematic review was to investigate the instruments frequently used in studies related to STN-DBS in PD patients. Methods: articles were retrieved from Medline/Pubmed databases published in the 2007-2017 period using PRISMA criteria. Results: after analyzing 27 articles, the absence of a specific evaluation protocol for PD with STN-DBS was evident. Conclusion: non-motor symptoms are not given due importance in neuropsychological assessments. It is crucial to acknowledge that these symptoms have a major impact on the quality of life of patients. Greater engagement in assessing these aspects is required, in order to bridge the gaps in research.

How is cognition in subthalamic nucleus deep brain stimulation Parkinson’s disease patients?

“…There is no specific protocol defining the most appropriate instruments for this evaluation, but knowing which functions are influenced by PD makes choosing the tests easier. Establishing a protocol to be used by studies and research centers would render it easier to access, understand and compare results, leading to further investigation of the impaired aspects 37. Any change indicated by the tests is subtle, as cognitive impairment detected in specialized tests is not commonly reported by patients, caregivers or health professionals.…”

“…This discrepancy makes a fair comparison and reliable analysis of the data unfeasible. Using the same battery of tests at such widely varying time intervals may give the impression of an improvement simply by the learning effect of a short-term reassessment and a marked worsening as the disease progresses naturally over a long-term reassessment 37…”

“…This is cause for concern since patients with MCI in PD are more likely to progress to dementia as the disease progresses, and it is necessary to understand which cognitive functions become impaired in this disease after DBS implantation to avoid miscalculating normal with worsening evolution. Much of this can also be attributed to the lack of a specific PD assessment protocol 37…”

Parkinson S Disease: Innovative Perspectives in Diagnosis and Treatment

“…With the dopaminergic deficit and the degeneration of the neurons of the basal ganglia nuclei in the pathology of PD, this processing and the level of pre-activation of priming and procedural learning are impaired. Barbosa and Charchat-Fichman (2019b) brought results of several studies showing that executive functions were the most impaired function after DBS, however we cannot consider it something unique due to its characteristic of encompassing different aspects such as flexibility, monitoring and inhibitory control -aspects that showed a difference between the ON stages and OFF.…”

“…In the early stages of the disease, cognitive impairment was found in memory (20%), in addition to executive functions (30%) and global cognitive functioning (50%) (Muslimovic et al, 2005). In the systematic review conducted by Barbosa and Charchat-Fichman (2019b) was demonstrated that the global cognitive functioning is quite assessed, as well as different aspects of executive functions and memory.…”