Neuropsychological and psychiatric changes after deep brain stimulation for Parkinson's disease: a randomised, multicentre study

Abstract

SummaryBackground Deep brain stimulation (DBS) of the subthalamic nucleus (STN) reduces motor symptoms in patients with Parkinson's disease (PD) and improves their quality of life; however, the eff ect of DBS on cognitive functions and its psychiatric side-eff ects are still controversial. To assess the neuropsychiatric consequences of DBS in patients with PD we did an ancillary protocol as part of a randomised study that compared DBS with the best medical treatment.

Negative impact of borderline global cognitive scores on quality of life after subthalamic nucleus stimulation in Parkinson's disease

“…The original study included 156 patients [1,8]. In a randomised pair-design 78 patients were randomised into the STN-DBS group to receive DBS surgery within 6 weeks after enrolment and 78 patients were randomised receiving best medical treatment for 6 months according to German guidelines.…”

“…The study protocol was approved by the ethics committee at each participating centre, and all patients gave written informed consent. The study protocol and the peri-and postoperative procedures have been reported in detail elsewhere [1,8]. All clinical assessments (except the UPDRS III 'off' assessment and the levodopachallenge test) were performed under medication 'on' at baseline and at 6 months with neurostimulation 'on' and medication 'on.…”

Deep brain stimulation in Parkinson disease—what went wrong?

“…This finding led to studies investigating the role of STN in cognitive functions in the rat [38,39] in parallel with clinical studies assessing cognitive and nonmotor functions in PD patients subjected to STN DBS [22,[40][41][42][43]. An early imaging study of PD patients showed that STN DBS, performed during a motor task involving decision-making and motivational aspects, induced metabolic activation of the supplementary motor area, the dorsolateral prefrontal cortex and the anterior cingulate [ ( F i g u r e _ 1 ) T D $ F I G ] cortex [24].…”

“…Accumulated data from the literature is confusing on first sight, because postoperative mood outcome is influenced not only by STN DBS itself, but also by a reduction in medication, occasionally leading to a dopamine withdrawal syndrome with increases in anxiety, apathy and depression [63,64]. A controlled study revealed that STN DBS improves anxiety in PD compared to the best medical treatment, with no changes in apathy or depression [42].…”

l‐Dopa/carbidopa intestinal gel and subthalamic nucleus stimulation: Effects on cognition and behavior

“…The effects of STN‐DBS have been studied with findings ranging from no significant changes in cognition and behavior to mild increase in anxiety and worsening of some cognitive functions (Alegret et al., 2001; Saint‐Cyr, Trépanier, Kumar, Lozano, & Lang, 2000). Some studies found mild improvement in mood such as anxiety and depressive symptoms, but no changes in cognitive performance (Witt et al., 2008). Comparative studies revealed equivalent positive subjective and mood‐related effects (Funkiewiez et al., 2004).…”