Predictive Value of Mean Flow Velocity by TCD in Early Cerebral Vasospasm in Aneurysmal Subarachnoid Hemorrhage
Condition: Subarachnoid Hemorrhage
MeSH terms: Subarachnoid Hemorrhage; Vasospasm, Intracranial; Hemorrhage
Study type: Observational

Summary: 
      Aim of this work is to evaluate the transcranial doppler in prediction of cerebral vasospasm
      in aneurysmal subarachnoid hemorrhage and also to evaluate their advantages over clinical
      scales in predicting CV.
    

Detailed description: 
      Cerebral vasospasm is defined as narrowing of a cerebral blood vessel enough to cause
      reduction in distal blood flow. Seventy percent of aSAH patients develop angiographic
      vasospasm but only 30% progress to develop evident neurological deficits. Cerebral vasospasm
      may be asymptomatic with no clinical symptoms and signs but only abnormal investigations,
      such as vascular stenosis by angiography or high blood flow speed by Doppler ultrasound.

      Standard tests used to determine the source of bleeding and diagnose cerebral vasospasm (CV)
      include neuroimaging studies that administer contrast either intravenously (computed
      tomography angiography [CTA]) or intra-arterially (digital subtraction angiography [DSA]).
      Cerebral blood flow measurements using computed tomography (CT) perfusion techniques may
      detect the degree of cerebral ischemia in a very early stage. Although well-tolerated, these
      studies cannot be readily performed on the bedside and expose the patient to additional
      radiation, thus significantly restricting their use in daily cerebral hemodynamics
      monitoring. Moreover, they involve patient transportation to the CT scanner and utilization
      of resources such as nurses, technologists, and ancillary personnel.

      Early detection of cerebral vasospasm is an important step in the way of the improvement of
      the outcome and the survival of aSAH patients. Transcranial duplex (TCD) is a non-invasive
      modality which can assess the cerebral blood vessels diameters and flow velocities that can
      be a useful maneuver in early detection of vasospasm after aSAH
    

Intervention name(s): Transcranial doppler
Intervention type(s): Device
Intervention description(s): TCD examination was performed using DWL-EZ-Dop machine Compumedics GmbH, Singen, Germany. TCD utilizes low-frequency pulsed insonation (2 MHz) to measure blood flow velocity within proximal cerebral arteries, obtaining systolic and diastolic peaks and mean flow velocities (MFV). MFV is defined as (systolic + diastolic)/3 + diastolic velocities, according to Alexandrov et al..
Initial TCD examination was done after admission serving as a baseline state for cerebral circulation. Follow-up TCD examinations was done at fixed intervals on the first, third, fifth, seventh and tenth days of the onset of SAH.
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Probability Sample
Study population: 
        This study was a prospective study conducted on 45 consecutive aSAH patients Forty patients
        continued in the study and five patients were excluded because of their clinical
        deterioration within the first five days of the onset and or the associated decompensated
        systemic illness. SAH cases divided according to the presence of vasospasm into two groups;
        the first group included 27 cases without vasospasm, while the second group included 13
        cases with vasospasm.