Neuroimaging studies of different cognitive profiles in Parkinson's disease

It is now clear that cognitive deficits exist even early in Parkinson's disease, having a significant impact on daily activities. However, the nature and the neural origins of cognitive dysfunction in PD are still under debate. Furthermore, a great heterogeneity seems to exist with respect to the cognitive profiles found in patients at the early stages of the disease, and these initial differences are likely predictive of distinct outcomes regarding the later occurrence of dementia. These include the early presence of Mild Cognitive Impairments, the nature and number of domains affected, as well as the occurrence of depression or apathy. Here, we will review studies involving anatomical and functional neuroimaging, and neuropsychological evaluation that have attempted to address these issues. Recommendations for future work will also be discussed.