Flow velocity in head injury of different severity: findings of transcranial duplex sonography

Introduction

Most commonly, transcranial duplex sonography (TCDS) is used to evaluate the flow velocity (FV). The main signs of cerebral blood flow disturbances in head injury are olygemia, hyperemia and vasospasm [1], which are closely connected with traumatic brain injury and dynamics of the disease. The influence of FV values measured by TCDS on the course and outcome of head injury of different severity is of special importance.

Methods

FV was measured using an ultrasound triplex system in 83 patients with head injuries. The traumatic brain injury substrate was verified by CT and nuclear MRI. Mean values for FV were registered in the MCA every 48 hours. The hemispheric index (HI) was measured to differentiate a vasospasm (HI = mean MCA/mean ICA).

Results

Depending on values of CFV, all patients were divided into three groups: Group I, 22 patients with FV < 70 cm/s; Group II, 23 patients with FV 70–120 cm/s and HI < 3; Group III, 38 patients with FV > 120 cm/s and HI > 3.0. Severity of cerebral lesions in Group I was caused by unilateral intracranial haematomas in six cases, contusion of type 1–2 in nine cases and diffuse axonal injury (DAI) in 12 cases. Patients in Group II and Group III revealed bilateral intracranial haematomas combined with type 2 and 3 contusions and DAI; patients in Group II showed contusion predominance, and patients in Group III had concomitant brain damage predominance (that is, intracranial haematomas combined with type 2–3 contusions and post-traumatic SAH). Outcome analysis in Group I revealed a GOS score of 1–2 in 13 patients, of 3 in seven patients and of 4 in two patients. In Group II the GOS score was 1 or 2 in 17 patients, 3 in four patients and 4 in two patients. In Group III the GOS score was 1 or 2 in 12 patients, 3 in 14 patients and 4 in six patients, and mortality was marked in five patients.

Conclusion

The performed analysis allowed us to conclude that there existed a close relationship between the severity of traumatic brain damage and the character of FV disturbances. Marked traumatic brain injuries presented by multiple contusions and intracranial haematomas, DAI of type 2–3 and combined with SAH resulted in development of vasospasm in the MCA. Low values of FV as well as development of vasospasm in the cerebral middle artery are regarded as unfavourable prognosis for patients in the acute period of severe head injury.