Executive function in Parkinson's disease and subcortical disorders.

Changes in cognitive function that accompany the progression of subcortical disorders such as Parkinson's disease are often overlooked in the early stages because of a "context of discovery" that accompanies the diagnostic progress. This article discusses the nature of that context, a subcortical cognitive profile, and the contribution of executive function failure to that profile. The utility of using brief assessments of executive function and other measures, such as a brief screen for apathy, are shown with Parkinson's disease patients. Several suggestions are provided for means by which clinicians can help patients, caregivers, and families adjust to patients' impairments in executive function.