Trigger Factors for Spontaneous Intracerebral Hemorrhage: A Case-Crossover Study

Background: Whether certain activities can trigger spontaneous intracerebral hemorrhage (ICH) remains unknown. Insights into factors that trigger vessel rupture resulting in ICH improves knowledge on the pathophysiology of ICH. We assessed potential trigger factors and their risk for ICH onset. Methods: We included consecutive patients diagnosed with ICH between July 1, 2013, and December 31, 2019. We interviewed patients on their exposure to 12 potential trigger factors (eg, Valsalva maneuvers) in the (hazard) period soon before onset of ICH and their normal exposure to these trigger factors in the year before the ICH. We used the case-crossover design to calculate relative risks (RR) for potential trigger factors. Results: We interviewed 149 patients (mean age 64, 66% male) with ICH. Sixty-seven (45%) had a lobar hemorrhage, 60 (40%) had a deep hemorrhage, 19 (13%) had a cerebellar hemorrhage, and 3 (2%) had an intraventricular hemorrhage. For ICH in general, there was an increased risk within an hour after caffeine consumption (RR=2.5 [95% CI=1.8-3.6]), within an hour after coffee consumption alone (RR=4.8 [95% CI=3.3-6.9]), within an hour after lifting >25 kg (RR=6.6 [95% CI=2.2-19.9]), within an hour after minor head trauma (RR=10.1 [95% CI=1.7-60.2]), within an hour after sexual activity (RR=30.4 [95% CI=16.8-55.0]), within an hour after straining for defecation (RR=37.6 [95% CI=22.4-63.4]), and within an hour after vigorous exercise (RR=21.8 [95% CI=12.6-37.8]). Within 24 hours after flu-like disease or fever, the risk for ICH was also increased (RR=50.7 [95% CI=27.1-95.1]). Within an hour after Valsalva maneuvers, the RR for deep ICH was 3.5 (95% CI=1.7-6.9) and for lobar ICH the RR was 2.0 (95% CI=0.9-4.2). Conclusions: We identified one infection and several blood pressure related trigger factors for ICH onset, providing new insights into the pathophysiology of vessel rupture resulting in ICH.