Prevalence of Parkinson's disease in Bulgaria.

Despite some publications on Parkinson's disease prevalence in Bulgaria, its frequency in the country still remains uncertain. Earlier studies in Bulgaria were carried out on large population groups and were based on medical records without further diagnostic confirmation. The aim of the present study was to perform an epidemiological investigation on Parkinson's disease in Bulgaria, using strict diagnostic criteria in an attempt to obtain a more accurate estimate of its frequency in this country.