Temporary deterioration of executive function after subthalamic deep brain stimulation in Parkinson's disease

Does early verbal fluency decline after STN implantation predict long-term cognitive outcome after STN-DBS in Parkinson's disease?

“…Nevertheless, a significant persistent impairment in verbal fluency in the on-drug condition compared to the baseline on-state pleads in favor of a microlesion effect. These results are in keeping with previous studies that failed to correlate VF decline and levodopa equivalent daily dose decrease after STN-DBS [8,9,15]. Moreover, other tests to explore executive dysfunction may have been considered as more pertinent but VF decline is recognized as the most common cognitive decline following STN-DBS surgery.…”

“…Similarly, an early and transient VF decline and impairment in frontal executive function has been described, suggesting a cognitive microlesion effect that may be partly responsible for the cognitive repercussions related to STN-DBS [7][8][9]. Whether this early cognitive impairment influences long-term cognitive performances and the incidence of Parkinson's disease dementia (PDD) after STN-DBS remains unknown.…”

Cognitive performances and DAT imaging in early Parkinson's disease with mild cognitive impairment: a preliminary study

“…The correlation found between caudate DAT availability and TMT: B‐A is interesting, because this test is usually used in PD as an index of cognitive flexibility to switch attention between two competing tasks independently of motor speed. Interestingly, worsening of TMT:B‐A has recently been associated with reduction in dopaminergic medication after subthalamic deep brain stimulation .…”

Neuropsychological Outcome in Subthalamic Nucleus Stimulation Surgeries with Electrodes Passing through the Caudate Nucleus

“…The TMT provides information on visual searching, speed of information processing and in case of part B executive function, in particular cognitive flexibility [12]. In the study of Yamanaka et al [13], a decrease in TMT performance was found at the end of the first postoperative month in PD patients undergoing STN DBS, together with a decrease in Stroop performance and verbal fluency. In the same study, it was shown that TMT-B performance and phonemic verbal fluency performance recovered to the pre-operative level, 12 months after surgery [13].…”

“…In the study of Yamanaka et al [13], a decrease in TMT performance was found at the end of the first postoperative month in PD patients undergoing STN DBS, together with a decrease in Stroop performance and verbal fluency. In the same study, it was shown that TMT-B performance and phonemic verbal fluency performance recovered to the pre-operative level, 12 months after surgery [13]. In our sample, we did not find recovery of TMT-B performance 12 months after surgery but the impact of caudate penetration appeared to be diminished at that time point.…”