Brain Disorders & Therapy

Abstract

Identification of Disturbances of Autoregulation of Cerebral Hemodynamics and Blood Vessels Reactivity in Patients with Consequences of Mild Traumatic Brain Injuries

Litovchenko T and Iakubenko I

The purpose of the current research was to revise the disturbances of autoregulation of cerebral hemodynamics and reactivity of vessels in patients with consequences of mild traumatic brain injuries by using Doppler ultrasonography with hyper-and hypocapnic tests.

Methods: We examined 65 patients with consequences of mild traumatic brain injuries. Doppler ultrasonography with hyper-and hypocapnic tests were carried out according to the standard method.

Results: During the research by Doppler ultrasonography with the hypercapnic and hypocapnic tests in patients with consequences of mild TBI the coefficient of overshoot of 1.13 ± 0.04 was identified. A paradoxical cerebral vascular response was evident as a delayed response to the tests as carried out. The above response was accompanied by the increase of the LVF after the hypercapnic test to 28.7% (48.8% in the control group) and by the increase of the LVF after the hypocapnic test to 36.8% (27.5% in the control group). Under the hypercapnic load in patients with consequences of mild TBI the coefficient of reactivity was lower than that of the patients in the control group (0.34 ± 0.07 and 0.46 ± 0.03 RVU respectively, p<0.05). Under the hypocapnic load in patients with consequences of mild TBI the coefficient of reactivity was lower than that of healthy subjects (0.44 ± 0.02 and 0.55 ± 0.04 RVU respectively, p<0.05). The index of vasomotor reactivity in patients with TBI consequences was lower, than that of the control group (73.1 ± 0.05 and 97.3 ± 0.02 respectively, p<0.0001). The increase of PI up to 1.73 ± 0.02; and the increase of RI up to 0.97 ± 0.02 (p<0.0001) were present in all the patients in the survey sample with consequences of traumatic brain injuries.

Conclusions: During our investigation we detected changes of reactivity of vessels towards the decrease of indicators of linear velocity of blood flow under the tests. A paradoxical vascular response was marked in all the patients under the hyper- and hypocapnic load; a test-induced delayed vessels reaction was marked in 52 out of 65 patients.