Parkinson's disease and deep brain stimulation of the subthalamic nucleus (STN-DBS): long-term disease evaluation and neuropsychological outcomes in a 9-year matched-controlled study

Matched-controlled long-term disease evaluation and neuropsychological outcomes derived from deep brain stimulation of the subthalamic nucleus (STN-DBS) in Parkinson<acute accent>s disease (PD) are lacking, with inconsistent results regarding the cognitive impact of this procedure. Here we study the long-term effects associated to DBS comparing outcomes with a matched control group. A prospective observational study of 40 patients with PD with bilateral STN-DBS, with a mean follow-up of 9 (6-12) years was conducted. Disease evaluation was performed using the UPDRS-III, UPDRS-II, Hoehn-Yahr, and Schwab-England scales. Neuropsychological assessments were achieved utilizing the MMSE, DRS, RAVLT, BVRT, Stroop, and verbal fluency tests. A control group was used for comparison. Statistical analysis was performed with SPSSv.26. 40 patients were included, with a mean age of 62.8 +/- 8.5 at the time of intervention. An improvement in motor symptoms of 48.6% (p < 0.001) and a reduction in LED of 58.6% (p < 0.001) was observed. No significant differences were observed in the MMSE (p = 0.414), DRS (p = 0.251), memory or interference assessments. A worsening in the construction subscale of DRS (p < 0.05) and in verbal fluency (phonemic and semantic) (p < 0.05) was observed. A head-to-head comparison showed significant differences between groups. An age <= 60 years was associated with a good long-term clinical prognosis (p = 0.019;OR = 6.75). STN-DBS is an effective and safe therapeutic option for the control of motor symptoms. However, it is associated with a selective deterioration in some cognitive functions in the long term. This study comprehensively evaluates STN-DBS in Parkinson<acute accent>s disease in the long term, with findings that should be considered when indicating surgery in PD patients.