A program for neuropsychological investigation of deep brain stimulation (PNIDBS) in movement disorder patients: Development, feasibility, and preliminary data

Objective: This technical report and feasibility study propose a standardiz ed method for collecting neuropsychological data in patients undergoing the deep brain stimulation (DBS) procedure. Background: Programs for standardi zing motor data collected in studies investigating surgical therapies for P arkinson disease are already widely used (e.g., Core Assessment Program for Intracerebral Transplantations). The development and rationale for the pro posed program for Neuropsychological Investigation of Deep Brain Stimulatio n (PNIDBS) are outlined, and support for the feasibility of these methodolo gies is provided via preliminary data. Method: The PNIDBS includes a core b attery of neuropsychological tests that assesses a wide range of cognitive functions (attention, language, visuospatial, memory, and executive) as wel l as depression. Using the PNIDBS, three Parkinson disease and two dystonia patients were evaluated at baseline and after surgery, once with stimulati on off and once with stimulation on. Results: Patients with severe motor di sabilities were able to complete the PNIDBS. These preliminary data suggest that the DBS procedure as a whole had a minimal impact on cognitive functi oning in most patients studied. There was also some evidence that the one p atient who showed cognitive decline after the DBS procedure had demographic and clinical characteristics that may have put him at risk for this declin e. Conclusions: The procedures in the PNIDBS were systematically developed and are feasible to execute. The relatively brief core battery has multiple versions and can be supplemented to meet individual investigator needs. By evaluating the components of the DBS procedure (electrode placement and st imulation), the PNIDBS can address clinical questions regarding the cogniti ve effects of the DBS procedure as well as investigate basic scientific iss ues regarding how different cognitive functions are affected when subcortic al-prefrontal circuits are manipulated by the DBS procedure.