Impacto de la estimulación subtalámica a largo plazo sobre la situación cognitiva de los pacientes con enfermedad de Parkinson avanzada

Abstract

ObjectiveThe aim of this study was to evaluate the effects of deep brain stimulation of the subthalamic nucleus (DBS-SN) on cognitive function in patients with Parkinson's disease (PD) 5 years after surgery. Material and methodsWe conducted a prospective study including 50 patients with PD who underwent DBS-SN (62.5% were men; mean age of 62.2±8.2 years; mean progression time of 14.1±6.3 years). All patients were assessed before the procedure and at one year after surgery; 40 patients were further followed up until the 5-year mark. Follow-up assessments included the following neuropsychological tests: Mini–Mental State Examination (MMSE), Mattis Dementia Rating Scale (MDRS), letter-number sequencing of the WAIS-III (WAIS-III-LN), clock-drawing test, Rey auditory verbal learning test (RAVLT), Benton Visual Retention Test (BVRT), Judgment of Line Orientation (JLO) test, FAS Phonemic Verbal Fluency Test, Stroop test, and the Montgomery-Asberg Depression Rating Scale (MADRS). ResultsPatients were found to score lower on the MMSE (−0.89%), clock-drawing test (−2.61%), MDRS (−1.72%), and especially phonemic (−13.28%) and sematic verbal fluency tests (−12.40%) at one year after surgery. Delayed recall on the RAVLT worsened one year after the procedure (−10.12%). At 5 years, impairment affected mainly verbal fluency; scores decreased an additional 16.10% and 16.60% in semantic and phonemic verbal fluency, respectively. Moderate decreases were observed in immediate recall (−16.87%), WAIS-III-LN (−16.67%), and JLO test (−11.56%). DiscussionIn our sample, DBS-SN did not result in global cognitive impairment 5 years after surgery. Verbal function was found to be significantly impaired one year after the procedure. Impaired learning and visuospatial function may be attributed to degeneration associated with PD.