Neuroimaging of Parkinson's disease: Expanding views

Carol P. Weingarten, Mark H. Sundman, Patrick Hickey, Nan-kuei Chen
2015 Neuroscience and Biobehavioral Reviews  
Advances in molecular and structural and functional neuroimaging are rapidly expanding the complexity of neurobiological understanding of Parkinson's disease (PD). This review article begins with an introduction to PD neurobiology as a foundation for interpreting neuroimaging findings that may further lead to more integrated and comprehensive understanding of PD. Diverse areas of PD neuroimaging are then reviewed and summarized, including positron emission tomography, single photon emission
more » ... uted tomography, magnetic resonance spectroscopy and imaging, transcranial sonography, magnetoencephalography, and multimodal imaging, with focus on human studies published over the last five years. These included studies on differential diagnosis, co-morbidity, genetic and prodromal PD, and treatments from L-DOPA to brain stimulation approaches, transplantation and gene therapies. Overall, neuroimaging has shown that PD is a neurodegenerative disorder involving many neurotransmitters, brain regions, structural and functional connections, and neurocognitive systems. A broad neurobiological understanding of PD will be essential for translational efforts to develop better treatments and preventive strategies. Many questions remain and we conclude with some suggestions for future directions of neuroimaging of PD. We begin with description of motor features of Parkinsonism, other diagnoses that may be considered in the differential diagnosis of PD, and the importance of nonmotor co-morbid syndromes (section 2.1). Brain regions, structural pathways, and neurotransmitters of the most well known model of motor involvement in PD -the cortico-basal gangliathalamocortical motor circuit -will then be presented (section 2.2). Neuropathology of PD will be discussed centered on Braak's staging of PD, which describes the progression of pathological abnormalities in regions throughout the brain (section 2.3). Finally, biochemistry of neurotransmitter systems involved in PD will be summarized (section 2.4). These topics are a useful foundation for understanding and interpreting PD neuroimaging findings (sections 3 and 4). 2.
doi:10.1016/j.neubiorev.2015.09.007 pmid:26409344 pmcid:PMC4763948 fatcat:66ruxnmpyjdoplebvahzyibydq