Analysis of colonic alpha-synuclein pathology in multiple system atrophy.

Routine colonic biopsies allow the detection of alpha-synuclein aggregates in the enteric nervous system (ENS) in living Parkinson's disease (PD) patients. Whether the ENS is affected by alpha-synuclein pathology in multiple system atrophy (MSA) has not been studied yet. The aim of the present research was therefore to analyze colonic biopsies in MSA for the presence of alpha-synuclein pathology. Six MSA and 9 PD patients were included. Four biopsies, taken from the descending colon during the course of a rectosigmoidscopy were microdissected, and analyzed by immunohistochemistry using antibodies against phosphorylated alpha-synuclein and neurofilaments NF 200 kDa. Aggregates of alpha-synuclein were detected in one out of 6 MSA patients and in 5 out of 9 PD patients. This demonstrates that, despite being less frequent than in PD, alpha-synuclein deposits can be observed in the ENS in MSA.