EARLY CHANGES IN MIDDLE CEREBRAL-ARTERY BLOOD-FLOW VELOCITY AFTER HEAD-INJURY

Object. This study was designed to investigate the incidence of early abnormalities in the cerebral circulation after head injury by relatin g the results of the initial computerized tomography (CT) scan with tr anscranial Doppler (TCD) ultrasound readings to see if the side of inj ury and the outcome can be predicted by using these modalities. Method s. Transcranial Doppler ultrasound measurements were obtained in the e mergency room in 22 head-injured patients less than 3 hours after inju ry. The middle cerebral artery (MCA) was insonated using a standard te chnique. The TCD measurements in each MCA were examined individually; of 39 measurements, 22 (56%) showed a low mean blood flow velocity, 27 (69%) demonstrated a high pulsatility index (PI), and 18 (46%) showed both abnormalities. The side of the cerebrovascular abnormality measu red by TCD ultrasound did not appear to be an accurate predictor of th e side of the injury as determined on the initial CT scan. Of 13 patie nts in whom either a space-occupying hematoma or signs of swelling wer e shown on the initial CT scan, 10 (77%) had an increased PI in one or both MCAs. which is an indication of high flow resistance. d Conclusi ons. Transcranial Doppler ultrasound examinations performed while pati ents are in the emergency room may have a role in determining treatmen t priorities, especially in those with multiple injuries.