Cerebral hemodynamics in stroke and traumatic brain injury. The interplay between blood pressure, cerebral perfusion, body position and autoregulation

PhD ceremony: Mr. M.J.H. Aries, 16.15 uur, Academiegebouw, Broerstraat 5, Groningen

Dissertation: Cerebral hemodynamics in stroke and traumatic brain injury. The interplay between blood pressure, cerebral perfusion, body position and autoregulation

Promotor(s): prof. H.P.H. Kremer, prof. J.H.A. de Keyser

Faculty: Medical Sciences

Following an acute ischemic stroke, patients are admitted to a special hospital ward to monitor and treat circulatory and respiratory disturbances. Quick upright care or out of bed mobilisation might be beneficial to recover from stroke, but there are indications that this position compromises cerebral blood flow in vulnerable brain tissue. In this study we found that during upright positioning the blood pressure increased in these patients. This phenomenon was mainly observed on day 1 after acute stroke. Noteworthy, patients who had a significant rise in blood pressure upon standing (> 20%) appeared to have a better recovery after three months. In a group of 50 stroke patients ‘upright sitting’ was studied in detail. First, disability did not increase with postural changes. Second, continuous blood pressure and ultrasound measurements in the large cerebral vessels together with near-infrared measurements of the anterior brain regions showed no differences between acute stroke patients and healthy subjects. We found no evidence that the sitting position in mildly to moderately affected stroke patients is unsafe during the first three days in the ward. In a large study using a new mathematical method to estimate cerebral blood flow regulation based on continuous ‘pressure inside the skull’ (intracranial pressure) and blood pressure measurements, we demonstrated that intensive monitoring is also important for patients with significantly swollen or bruised brains after a serious accident (severe traumatic brain injury).