Preliminary study of zonisamide monotherapy in de novo patients with early Parkinson's disease

Background Little is known about single administration of zonisamide in Parkinson's disease patients. Aim We aimed to evaluate the therapeutic effects of zonisamide monotherapy in early Parkinson's disease patients. Methods A total of 10 untreated (de novo) patients with Yahr stage I or II participated. Zonisamide was given at a daily dose of 25 mg for 1 month and increased to 50 mg for the next 2 months. Unified Parkinson's Disease Rating Scale parts I–IV and tremor‐related Unified Parkinson's Disease Rating Scale (items 16, 20 and 21) were examined every month. Serum zonisamide concentrations and urinary homovanillic acid concentrations were measured. Three patients had rapid eye movement sleep behavior disorder. Sleep condition was asked to patients? spouses. Results At 1 month after zonisamide treatment, Unified Parkinson's Disease Rating Scale scores did not differ from the baseline scores statistically. At 2 and 3 months after zonisamide treatment, Unified Parkinson's Disease Rating Scale part III and tremor‐related scores were reduced significantly compared with pretreatment (P