Ikemura M et al. (2008) Lewy body pathology involves cutaneous nerves. J Neuropathol Exp Neurol 67: 945–953

Involvement of the peripheral autonomic nervous system (PANS) is an important feature of Lewy body diseases (LBDs) such as Parkinson disease (PD). The PANS structures in which Lewy body (LB) pathology manifests—the sympathetic ganglia and adrenal glands—are not appropriate sites for diagnostic biopsy. Ikemura et al. have shown that LB-related pathology manifests in the cutaneous nerves in patients with proven LBD.

First, the authors assessed LB pathology in skin biopsy samples taken prospectively at autopsy from 279 consecutive patients and compared the incidence with that in the CNS and adrenal glands in the same patients. A total of 20 (23.5%) of the 85 patients who had CNS LB pathology also had LBs in the dermal nerve fibers. There was no evidence of LB pathology in the skin in any of the 194 individuals who did not have CNS LB pathology; therefore, the specificity of dermal LB pathology for detection of LBD was 100%.

Second, the authors retrospectively assessed LB pathology in 142 autopsied patients with subclinical LBD. In this cohort, the sensitivity of skin LB pathology for CNS LBD was only ∼20%; however, in patients who had PD with or without dementia or had dementia with LBs, the sensitivity rose to 70% and 40.4%, respectively. The presence of dermal LB pathology was associated with decreased activities of daily living score.

The authors conclude that skin biopsy might have a diagnostic application in patients with PD with or without dementia.