Appendectomy History is not Related to Parkinson's Disease.

BACKGROUND: It has been suggested that appendectomy may modify the emergence of Parkinson's disease (PD) by affecting the retrograde transport of α-synuclein (α-syn) from the gastrointestinal system. OBJECTIVE: To explore the possible role of appendectomy on PD. METHODS: The retrospective data of the 1625 patients (839 PD, 633 non-α-syn parkinsonism and 153 controls) were compared. Disease specific measures between PD patients with (n = 69) and without (n = 770) appendectomy were also evaluated. RESULTS: The prevalence of appendectomy was not significantly lower in the PD group (8.2%) compared to the other groups (8.4% and 7.9%, p = 0.98), and the odds of having PD against other diagnoses (OR) were not significantly different in the appendectomy group (OR = 0.99, p = 0.96). No difference was determined between PD patients with and without appendectomy with respect to the age of disease onset, disease duration and severity. Appendectomy-first symptom interval was not determined to be related with PD diagnosis (hazard ratio = 1.12, p = 0.39) and did not predict disease severity in the PD group (OR = 0.99, p = 0.54). Age of appendectomy (lower or higher than 20) also did not affect future PD diagnosis (Relative Risk = 0.9, p = 0.54) or the disease severity. CONCLUSIONS: The results of the study suggest no effect of appendectomy on the emergence and clinical manifestations of PD. The removal of the appendix is possibly not sufficient to suppress the exposure of the brain stem to α-syn via vagal retrograde transport. Further studies are needed to elucidate the role of appendix in PD.