A case of severe dysexecutive syndrome consecutive to chronic bilateral pallidal stimulation

In treatment for severe Parkinson's disease (PD), a recent procedure was de veloped which consists of implanting electrodes in the internal Globus Pall idus (GPi) for chronic electrical stimulation. The consequences on cognitiv e function of such an intervention are quite variable. Although most group studies observed no significant post-operative change, individual cases of post-operative cognitive impairment were reported. The present study report s the case of a PD patient who underwent bilateral implantation of deep bra in stimulation electrodes in the GPi and who, after surgery, suffered from a severe dysexecutive syndrome. An extensive neuropsychological examination showed a selective negative effect of pallidal stimulation on tests assess ing executive function. When the stimulation was turned off, the impairment was partly reversible. This observation emphasizes the role of the GPI in executive function. (C) 2000 Elsevier Science Ltd. All rights reserved.