Pure autonomic failure in association with human alpha-synucleinopathy.

We studied an autopsy case with pure autonomic failure, using anti-alpha-synuclein antibody. Until now there has been no report about the immunohistochemical properties of alpha-synuclein in pure autonomic failure. In conventional stainings, both pre- and post-ganglionic lesions of the sympathetic and parasympathetic nervous systems were found. Lewy bodies and Lewy neurites were abundant especially in the sympathetic nervous system. These inclusions were immunoreactive to anti-alpha-synuclein antibody. The intensity of alpha-synuclein immunoreactivity was stronger in the halos than in the cores of the Lewy bodies. The edges of the swollen neurites had strong immunoreactivity. The substantia nigra was well preserved, and no cortical Lewy bodies were seen. These findings indicate that pure autonomic failure is one of the Lewy body type alpha-synucleinopathies, such as Parkinson's disease and dementia with Lewy bodies, targeting the peripheral autonomic nervous system.