Trans-cranial Doppler in severe head injury: Evaluation of pattern of changes in cerebral blood flow velocity and its impact on outcome

Background: Trans-cranial Doppler (TCD) studies after head injury have been done in the first 24 hours after injury and do not specify the exact interval between injury and time of recordings. We have studied cerebral blood flow changes in patients with severe head injury using serial TCD starting within 6 hours after trauma, and present our findings and its correlation with clinical outcome. Methods: Thirty-two patients with closed severe brain injuries formed the study group. Six-hourly serial TCD studies were done starting within 6 hours after trauma until 48 hours after trauma or death of the patient, whichever was earlier. Flow velocities of the extracranial internal carotid (VEC-ICA) and middle cerebral artery (V-MCA) were recorded to identify vasospasm, hyperemia, or oligemia. Serial changes in flow velocities were correlated with the clinical outcome of the patients at 12 months' follow-up after injury. Result: Oligemia (n = 30) and vasospasm (n = 2) were the earliest changes observed within 6 hours of trauma. In the oligemia group, persistent oligemia (n = 14), hyperemia (n = 6), normal flow velocity (n = 5), and vasospasm developing within 24 hours (n = 5) were observed. Eight patients developed vasospasm after 24 hours. All patients with persistent oligemia and vasospasm developing within 24 hours had poor outcome. Conclusion: Oligemia is the most common change within 6 hours of head injury. Persistence of oligemia beyond 24 hours is associated with poor outcome. Early (within 24 hours posttrauma) onset of vasospasm is associated with poor outcome; however, delayed (> 24 hours after trauma) vasospasm is not associated with poor outcome. (c) 2005 Published by Elsevier Inc.