Prevalence of essential tremor: a door-to-door survey in Terrasini, Sicily. Sicilian Neuro-Epidemiologic Study Group.

As part of a door-to-door neuroepidemiologic survey, we investigated the frequency and distribution of essential tremor (ET) in a Sicilian municipality. During phase 1, we administered a screening instrument for tremor to 7,653 persons residing in Terrasini (Palermo province). During phase 2, neurologists evaluated those subjects who had screened positive. The diagnoses, based on specified clinical criteria, were reviewed to increase reliability across neurologists. We found 31 subjects affected by ET (17 men, 14 women); 11 patients (35.5%) reported a familial aggregation. The prevalence of ET as of November 1, 1987, was 405.1 per 100,000 for the total population, and 1,074.9 per 100,000 for those 40 years old or older. The prevalence increased with advancing age for both sexes and was slightly but consistently higher in men. Comparison with other studies suggests striking geographic variation, which may reflect genetic differences.

Incidence of multiple sclerosis in Bagheria City, Sicily, Italy.

We investigated the incidence of multiple sclerosis (MS) in a Sicilian community located at sea level. The study was a retrospective search for MS patients. Incidence was studied in the period from 1 January 1985 to 31 December 1994. We searched for definite MS patients, according to Poser's criteria, among the population resident in Bagheria (Palermo province). There were 25 subjects affected by MS, of which 20 were incident MS patients. The average annual incidence was 4.4 per 100,000 persons (n = 453,385 person-years). The incidence increased over time (1985-1989 = 3.5, 1990-1994 = 5.3). A parallel decrease of the interval between onset and diagnosis of MS was observed (1985-1989, 3.7 years, 95% CI = 1.6-7.3; 1990-1994, 1.9 years, 95% CI = 1.0-3.3). These results confirm that MS is frequent in Sicily.