Neuropsychological changes between “off” and “on” STN or GPi stimulation in Parkinson’s disease

Abstract

Article abstract-Background: In a previous study on a consecutive series of 62 patients with PD, the authors showed that bilateral subthalamic or pallidal continuous high-frequency deep brain stimulation (DBS) affects neither memory nor executive functions 3 to 6 months after surgery. Objective: To investigate the specific effects of DBS by comparing the performance of patients with the stimulator turned "on" and "off." Methods: The performance of 56 patients on clinical tests of executive function was compared after 3 and 12 months of DBS of the subthalamic nucleus (STN; n ϭ 48) or the internal globus pallidus (GPi; n ϭ 8) with the stimulator "on" or "off." Global intellectual efficiency, verbal learning, and mood were also evaluated with the stimulator "on." The performance of another group of 20 patients was compared after 6 months of DBS of the STN (n ϭ 15) or the GPi (n ϭ 5) with the stimulator "on" or "off " on more experimental tests recently shown to be more sensitive to L-dopa therapy. Results: When the stimulator was "on," STN patients showed a mild but significant improvement in psychomotor speed and working memory. In comparison with the presurgical state, STN patients had no cognitive deficit at 12 months, except for lexical fluency. There was no differential effect of STN or GPi stimulation. Conclusions: 1) The specific effect of DBS seems to mimic the action of L-dopa treatment in the cognitive as in the motor domain; 2) the surgery associated with DBS does not appear to affect the cognitive performance of patients with PD 12 months later, except for a mild deficit in lexical fluency.

Network modulation by the subthalamic nucleus in the treatment of Parkinson's disease

“…These findings may be attributed to potentiation of prefrontal-parietal pathways, as observed both in the resting state (Sestini et al, 2002;Hilker et al, 2004) and during motor learning (Carbon et al, 2003). Increases in the activity of this transcortical projection system with stimulation may be responsible for the improvement in working memory and other forms of executive functioning reported in PD patients undergoing DBS (Jahanshahi et al, 2000;Pillon et al, 2000;Fukuda et al, 2002).…”

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].…”

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

“…Comparative studies revealed equivalent positive subjective and mood‐related effects (Funkiewiez et al., 2004). Assessment of turning on the stimulator improved executive function, but worsened conditional associative and visual conditional learning (Jahanshahi et al., 2000; Pillon et al., 2000). A study comparing the effects on cognition of STN‐DBS and subcutaneous continuous infusion of apomorphine (APM‐CSI) showed that, contrary to APM‐CSI, STN‐DBS produced a worsening in executive functions (Alegret et al., 2004).…”