To determine factors associated with headache at onset of intracerebral hemorrhage (ICH), as well as associations with long-term outcomes.

We performed a single-center cohort study using data from consecutive ICH patients over 12 months. ICH characteristics and outcomes were prospectively collected, while presenting symptoms were retrospectively abstracted using available documentation from pre-hospital emergency personnel and hospital-based providers. We determined factors associated with headache at ICH onset using logistic regression, then determined associations with unfavorable 3-month outcomes (defined as modified Rankin Scale 3-6) using logistic regression models adjusted for established ICH predictors and time from symptom onset to hospital arrival.

Of 311 patients in our cohort, 35% (n=108) had headache at onset. Patients with headache were younger than those without headache (mean age 66.8±15.5 vs. 72.6±15.2, p=0.002), had longer time-to-arrival (median 9.6 [IQR 2.1-28.8] vs. 3.4 [1.1-13.3] hours, p=0.002), and were more likely to have intact arousal (77% vs. 63%, p=0.04); female sex, hematoma volume, and location were not significantly different between groups. Adjusted models showed that headache at ICH onset was also associated with a history of migraine (OR 9.8, 95% CI 1.7-57.2), higher blood pressure on hospital arrival (OR per 10mmHg systolic BP 1.2, 95% CI 1.1-1.3), structural vascular lesions (OR 3.7, 95% CI 1.1-12.1), and subarachnoid extravasation (OR 2.9, 95% CI 1.4-5.9). Patients with headache at onset had significantly lower odds of unfavorable outcome (OR 0.27, 95% CI 0.13-0.54), an association that persisted in a sensitivity analysis excluding patients with impaired arousal and aphasia.

Patients with headache at ICH onset may be less likely to have unfavorable functional outcomes despite longer delays to hospital presentation, suggesting that ICH patients with headache may be phenotypically distinct from other ICH patients.