ABSTRACT
This chapter focuses on Parkinson's disease (PD), an α-synucleinopathy associated primarily with dysfunction of the basal ganglia and fronto-striatal circuits and manifesting as a hypokinetic movement disorder with a constellation of nonmotor symptoms. It describes the epidemiology, genetics, pathology, pathophysiology, and neurobehavioral features of the disease, including the recent concept of mild cognitive impairment (MCI) in PD (PD-MCI). An important feature of the neuropathology of PD is the presence of Lewy bodies in the brain stem and/or amygdala and, later in the disease, in neocortex. Neurobehavioral changes in PD (and its motor signs) can also be understood by considering the pathophysiology of fronto-striatal circuits. Medical and surgical treatments of PD and their impact on cognition and behavior are also reviewed. The chapter summarizes neuropsychological aspects of a hyper-kinetic movement disorder (Huntington's disease, or HD) and describes the key neuropsychological features of essential tremor and dystonia.
