Imaging the Autonomic Nervous System in Parkinson ’s Disease

AbstractPurpose of ReviewPatients with Parkinson ’s disease (PD) often display gastrointestinal and genitourinary autonomic symptoms years or even decades prior to diagnosis. These symptoms are thought to be caused in part by pathological α-synuclein inclusions in the peripheral autonomic and enteric nervous systems. It has been proposed that t he initial α-synuclein aggregation may in some PD patients originate in peripheral nerve terminals and then spread centripetally to the spinal cord and brainstem. In vivo imaging methods can directly quantify the degeneration of the autonomic nervous system as well as the functional consequences su ch as perturbed motility. Here, we review the methodological principles of these imaging techniques and the major findings in patients with PD and atypical parkinsonism.Recent FindingsLoss of sympathetic and parasympathetic nerve terminals in PD can be visualized using radiotracer imaging, including123I-MIBG scintigraphy, and18F-dopamine and11C-donepezil PET. Recently, ultrasonographical studies disclosed reduced diameter of the vagal nerves in PD patients. Radiological and radioisotope techniques have demonstrated dysmotility and prolonged transit time throughout all subdivisions of the gastrointestinal tract in PD. The prevalence of objective dysfunction as measured with these imaging methods is often considerably higher compared to the prevalence of subjective symptoms experienced by the patients.SummaryDegeneration of the autonomic n...
Source: Current Neurology and Neuroscience Reports - Category: Neuroscience Source Type: research