Abstract

Objective
We monitored cognition during Deep brain stimulation (DBS) surgery, when the electrode is positioned at the target subthalamic nucleus (i.e., STN motor area) in 14 PD patients.
Methods
We present the Real Time Neuropsychological Testing (DBS-RTNT) protocol, our preliminary experience, along with patients’ performance comparing intraoperative results with baseline data.
Results
Compared to baseline, DBS-RTNT in the target area showed a significantly decreased performance at some tasks belonging to memory and executive functions domains. Significantly decreased short-term memory and sequencing scores were found for right (vs. left) hemisphere DBS-RTNT.
Conclusions
PD patients’ performance should be monitored during DBS surgery as STN-DBS may induce changes in cognitive performance. These preliminary data contribute to improve, during DBS-surgery the anatomo-functional topography of the STN in order to identify, in future approaches, in the individual patient the best site producing positive motor effects, without causing negative cognitive and/or emotional changes. Medications (i.e., the patients underwent surgery in a levodopa off state) could in principle have influenced our results therefore future studies are needed to address possible confounding effect of levodopa use.

• Keywords: Deep brain Stimulation; Sub-thalamic Nucleus; Real Time Neuropsychological Testing; Parkinson Disease; surgery