Prospective cohort study of patients with early gastric cancer to detect prodromal Parkinson disease (EGC-PPD): A study protocol and baseline characteristics.

ABSTRACT

The aim of the current study is to determine the predictive value of alpha-synuclein (AS) aggregation in stomach surgical specimens in combination with selected clinical prodromal markers (CPMs) for development of Parkinson disease (PD) in a normal population. We organized a prospective, long-term, clinicopathologic cohort of patients without neurological diseases who received a radical operation for early gastric cancer (EGC) between ages 50 and 65 years. The participants will be followed for up to 10 years and screened for CPMs and motor symptoms by annual telephone interview. If a participant reports one or more positive answers to screening questions about motor symptoms, they will be regarded as having possible parkinsonism. A movement disorder specialist will then evaluate whether that participant has PD. The primary outcome is the development of PD during the 10-year follow-up. The recruitment period has been completed, and the baseline clinical characteristics are compared between participants with and without possible parkinsonism. A total of 718 participants (mean age 60.1 ±â€¯5.9) was recruited. The motor symptom screening questionnaire revealed 65 patients with possible parkinsonism (9.0%) at baseline. Patients with possible parkinsonism answered that they had subjective loss of smell more than those without parkinsonism at the time of recruitment (18.5% vs 8.3%) and operation (15.4% vs 6.3%). However, the objective odor discrimination test showed no difference between patients with and without possible parkinsonism. Baseline assessments revealed a sufficient number of patients with possible parkinsonism, which will be confirmed as PD or not in subsequent follow-up visits.