Issues to Consider When Mild Cognitive Impairment Is Revealed in Preoperative Screening

Abstract

A 72-year-old man with Parkinson disease of 7 years duration, multifactorial gait disorder, and minor memory complaints underwent deep brain stimulation (DBS) evaluation to treat motor fluctuations and dyskinesia. Neuropsychometric evaluation revealed multidomain mild cognitive impairment, which was stable to improved on repeat testing 6 months later. He underwent bilateral subthalamic nucleus DBS with improvement in dyskinesia, and residual motor fluctuations were medically managed. He denied postoperative cognitive changes, although repeat neuropsychometric evaluation 9 months later showed decline in cognition. The patient moved to an assisted living facility shortly afterward because of progressive gait disability. One year later, he developed florid Parkinson disease psychosis, with partial improvement after cessation of entacapone. We discuss the rationale for the assessment of mild cognitive impairment before DBS, DBS target selection, risk factors associated with postoperative cognitive decline, and strategies to minimize this.