Autonomic dysfunction in Parkinson's disease

Autonomic dysfunction in patients with Parkinson's disease (PD) has been recognized since the original description by James Parkinson in 1817. Autonomic failure can be the clinical presentation of other diseases like pure autonomic failure (PAF) and multiple system atrophy (MSA). Both the central and peripheral autonomic nervous systems can be affected in PD. Rajput and Rozdilsky described cell loss and Lewy bodies within the sympathetic ganglia and antibodies to sympathetic neurons have been detected in PD patients. Lewy bodies can be seen in autonomic regulatory regions, including the hypothalamus, sympathetic (intermediolateral nucleus of the thoracic cord and sympathetic ganglia), and parasympathetic system (dorsal, vagal, and sacral parasympathetic nuclei). Lewy bodies were also found in the adrenal medulla and in the neural plexi innervating the gut, heart and pelvis. Symptoms of dysautonomia are variable, and include cardiovascular symptoms, gastrointestinal, urogenital, sudomotor and thermoregulatory dysfunction, pupillary abnormalities and sleep and respiratory disorders. They may represent a useful tool in the differential diagnosis of “atypical” or “complicated” parkinsonisms.