ICH is a heterogeneous disease with deep and lobar subtypes distinguishable on an epidemiologic basis. The different patterns of these two subtypes in our race-ethnically diverse population lend credence to the notion that ICH should no longer be treated as a single entity.

American blacks and Hispanics may have a greater incidence of subarachnoid hemorrhage (SAH) than whites, but incidence data are scant. We used an active hospital and community surveillance program and autopsy reports to identify incident SAH cases among white, black and Hispanic adults living in Northern Manhattan between July 1993 and June 1997. The annual incidence adjusted for age and sex to the 1990 US Census was 9.7 per 100,000 (95% CI 7.5–12.0). Compared with whites (9 cases, age- and sex-adjusted annual incidence 8.2 per 100,000), the rate ratio of SAH was 1.3 (95% CI 0.7–2.4) for Hispanics (34 cases, incidence 10.9), and 1.6 (95% CI 0.8–2.8) for blacks (9 cases, incidence 12.8). The 30-day case fatality rate was 26%. Risk of death increased significantly with age and severity at onset but was not influenced by gender or race-ethnicity.

Environmental risk factors were examined using univariate and multivariate unconditional logistic regression models in 89 nondemented patients with Parkinson's disease (PD) and 188 control subjects in a multiethnic urban community. Rural living, area farming, and drinking well water were associated with PD only in African-Americans. In Hispanics, area farming was protective, whereas drinking unfiltered water was a risk factor for PD. Consideration of ethnic and cultural origin may add to the epidemiologic study of PD.