AUTHOR=Moustafa Ahmed A., Poletti Michele TITLE=Neural and behavioral substrates of subtypes of Parkinson’s disease JOURNAL=Frontiers in Systems Neuroscience VOLUME=7 YEAR=2013 URL=https://www.frontiersin.org/journals/systems-neuroscience/articles/10.3389/fnsys.2013.00117 DOI=10.3389/fnsys.2013.00117 ISSN=1662-5137 ABSTRACT=

Parkinson’s disease (PD) is a neurological disorder, associated with rigidity, bradykinesia, and resting tremor, among other motor symptoms. In addition, patients with PD also show cognitive and psychiatric dysfunction, including dementia, mild cognitive impairment (MCI), depression, hallucinations, among others. Interestingly, the occurrence of these symptoms—motor, cognitive, and psychiatric—vary among individuals, such that a subgroup of PD patients might show some of the symptoms, but another subgroup does not. This has prompted neurologists and scientists to subtype PD patients depending on the severity of symptoms they show. Neural studies have also mapped different motor, cognitive, and psychiatric symptoms in PD to different brain networks. In this review, we discuss the neural and behavioral substrates of most common subtypes of PD patients, that are related to the occurrence of: (a) resting tremor (vs. nontremor-dominant); (b) MCI; (c) dementia; (d) impulse control disorders (ICD); (e) depression; and/or (f) hallucinations. We end by discussing the relationship among subtypes of PD subgroups, and the relationship among motor, cognitive, psychiatric factors in PD.