Asymmetry of intracranial hemodynamics as an indicator of mass effect in acute intracerebral hemorrhage: A transcranial Doppler study

Background and Purpose: Hematoma volume is an important determinant of outcome and predictor of clinical deterioration in patients with intracerebral hemorrhage. In many cases, worsening result from herniation due to compartmentalized pressure gradient. We used transcranial sonography (TCD) to asses the impact of hematoma volume on symmetry of intracranial hemodynamics in patients with acute intracerebral hemorrhage. The goal was to evaluate TCD as a noninvasive method for monitoring compartmentalized mass effect. Methods TCD was performed an average of 1.1 day (range, 0 to 3 days after onset in 30 patient with supratentorial intracerebral hemorrhage. Hematoma, hematoma+edema, and intraventricular hemorrhage volume were calculated from admission CT scan using computerized planimetry and were compared with combined TCD values from the middle cerebral and internal carotid arteries. Results: Ipsilateral pulsatility indexes were consistently elevated and mean velocities consistently depressed when intracerebral hemorrhage volume exceeded 2.5 mL. Compared with patients with small hemorrhage those with large hemorrhage (≤2.5 mL, n=10) had significantly higher ipsilateral pulsatility index (1.72 versus 1.13 P<.0001) and higher ratios of ipsilateral-to-contralateral pulsatility (1.29 versus 1.06, P=.001). The ratio of ipsilateral-to-contralateral mean velocity was similarly reduced in patients with large versus small hemorrhage (0.87 versus 1.06, P=.01), but this effect wa less pronounced. In a multiple regression analysis, ipsilateral and contralateral pulsatility index correlated primarily with intraventricular hemorrhage volume (P=.001), whereas the ratio of ipsilateral-to-contralateral pulsatility correlated with total hemispheric legion (hematoma+edema) volume (P=.003). Conclusions: Asymmetry of intracranial hemodynamics a assessed by TCD occur when intracerebral hemorrhage volume exceed 2.5 mL. Alternation of pulsatility index reflect intracranial lesion volume more reliably than mean velocity. Although pulsatility is strongly influenced by the presence of intarventricular blood, elevated ratios of ipsilateral-to-contralateral pulsatility correlate primarily with hemispheric lesion volume and may reflect compartmentalized intracranial pressure gradients.