The number of microbleeds on gradient T2*-weighted magnetic resonance image at the onset of intracerebral hemorrhage.

Objective: Deep intracerebral hematoma (ICH) is frequently associated with microbleed (MB) arising from degenerated MB. Increased numbers of MB are correlated with increased age, and we examined a possible relationship between MB number and ICH onset in younger patients.

Methods: Excluding patients with ICH and a history of ICH, we examined the number of MB and other risk factors in 195 patients with deep ICH (97 male, 98 female) consecutively admitted to our hospital. The patients were equally divided into 3 subgroups according to age (groups A, B, and C). Odds ratios were estimated from logistic regression analyses.

Results: The number (percentage) of MB in group A (< or =60 years old, n = 64) 5.0 +/- 9.6 (65.6%) was less than group B (61-69 years old, n = 63) 6.6 +/- 9.1 (79.4%) or group C (> or =70 years old, n = 68) 6.0 +/- 7.0 (86.8%). Multivariate analyses demonstrated that MB greater than or equal to 3 was significantly associated with higher age in group A versus B (odds ratio: 2.3; 95% confidence interval: 1.01-5.3; P = .046) and in group A versus C (odds ratio: 2.6; 95% confidence interval: 1.1-6.2; P =.030).

Conclusions: Our findings suggest that risk factors for the development of ICH may differ with age, and younger patients with deep ICH have fewer MB.