Background: Perihematomal edema and secondary brain injury may influence the clinical course after intracerebral hemorrhage (ICH). The role of blood pressure (BP) in edema formation in ICH has not been studied sufficiently. We hypothesize that impaired blood pressure regulation (as measured by baroreflex sensitivity) leading to excessive BP fluctuations may enhance perilesional edema. The aims of our study were therefore to explore the effects of impaired baroreflex on edema in acute ICH and to evaluate the effects of perihematomal edema on early neurologic deterioration.
Methods: In 38 patients with acute intracerebral hemorrhage we assessed baroreflex sensitivity (BRS) within the first 72 h using a time-domain cross-correlation method. Blood pressure was continuously monitored for 72 h after admission. Relative perihematomal edema was calculated from the follow-up scans at 48-72 h from ictus. Possible confounders such as body temperature, inflammation parameters, or glycemia were recorded. Early neurologic deterioration was defined as increase of 4 points at NIHSS within the first 72 h.
Results: Decreased BRS correlated significantly with increased 72-hour MAP variability (r=-0.46, p=0.004). In a stepwise multivariate linear regression model, decreased BRS was an independent predictor for relative edema (p=0.005). Relative edema (p=0.009, OR 22.6, CI 2.2-232.5) and body temperature at admission (p=0.031, OR 0.17, CI 0.04-0.85) independently predicted early neurologic deterioration.
Conclusions: We found an independent association between decreased baroreflex sensitivity with increased blood pressure fluctuations and relative perihematomal edema in ICH. Moreover, independent effects of relative edema on early neurologic deterioration have been observed.