Neuropsychological predictors of patient-reported cognitive decline after deep brain stimulation in Parkinson's disease.

BACKGROUND: Deep brain stimulation (DBS) is effective for treatment of motor complications of dopaminergic therapy in Parkinson's disease (PD) but occasionally has been associated with multidomain cognitive decline. Patient- and caregiver-reported cognitive decline are clinically meaningful and increasingly recognized as important to consider when evaluating therapeutic interventions for PD.

OBJECTIVE: The objective was to assess presurgical neuropsychological and clinical factors associated with PD patient- and caregiver-reported cognitive decline in two or more domains after DBS.

METHOD: A single telephone survey was used to assess patient- and caregiver-reported cognitive decline in five domains at both one and four months after DBS surgery. Decline in two or more domains was considered multidomain cognitive decline (MDCD). Baseline demographic, clinical, and neuropsychological factors were compared in those with or without MDCD. Preoperative neuropsychological measures were evaluated as risk factors and regressed on the presence of MDCD, with demographic covariates, using multiple logistic regression.

RESULTS: Preoperative performance in verbal recognition memory, language knowledge, and verbal processing decline were associated with postoperative, patient-reported MDCD in the first four weeks. MDCD at four months after DBS was associated with worse preoperative verbal reasoning, verbal recall, and semantic verbal fluency. Caregiver-reported MDCD one month after DBS was associated with poorer baseline verbal memory recognition accuracy/discriminability, visuospatial problem solving, and constructional praxis.

CONCLUSION: Poor presurgical performance in verbal memory recognition, language processing, and visuospatial performance is associated with patient- or caregiver-reported decline following DBS surgery. Posterior cortical dysfunction seems to portend significant self-reported cognitive decline following deep brain stimulation.