The aim of this study is investigation of neuroprotective effect of zonisamide in early
Parkinson disease. A total of 60 patients with early Parkinson disease who meet the study
criteria will be enrolled and randomized into two groups alternately based on their visit
date. Demographic data, Unified Parkinson's Disease Rating Scale (UPDRS), modified Hoehn&Yahr
and modified Schwab&England activities of daily living scale will be determined and
registered for each patient. Patients of group A will be treated by zonisamide 50mg/d for 12
months and the other group will be treated by placebo for the same time. Primary endpoint is
occurrence of parkinsonian symptoms which interfere with patients' daily activity or cause
psychosocial embarrassment. The mentioned scores will be registered every 2 months for both
groups by blinded neurologist and also regular blood test will be performed to prevent drug
adverse events.