Elevated transcranial Doppler flow velocities after severe head injury: cerebral vasospasm or hyperemia?

Romner, Bertil; Bellner, Johan; Kongstad, Poul; Sjøholm, Hans

doi:10.3171/jns.1996.85.1.0090

Cited by 78 publications

(35 citation statements)

References 30 publications

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“…In situations of increased MCA or tICA velocity, low ratios suggest hyperemia, while high ratios suggest narrowing (26). Such differentiation is frequently impossible on the basis of only intracranial velocity measurements because of common side-toside velocity differences (24,25).…”

Section: Discussionmentioning

confidence: 99%

Sickle Cell Disease: Ratio of Blood Flow Velocity of Intracranial to Extracranial Cerebral Arteries—Initial Experience

et al. 2009

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Purpose:To establish reference values of the ratios of flow velocity in the middle cerebral artery (V MCA ) and the terminal portion of the internal carotid artery (V tICA ) to flow velocity in the extracranial portion of internal carotid artery (V ICA ) in children with sickle cell disease (SCD). Materials and Methods:Institutional ethics committee approval and parental informed consent were obtained for this prospective HIPAAcompliant study. Sixty-eight children (38 female; mean age, 7.7 years Ϯ 3.3; range, 2-14 years) with HbSS genotype, without neurologic deficits and no history of stroke, were enrolled. Final study population comprised 56 (mean age 8.0 Ϯ 3.3 years, 26 females) children who underwent magnetic resonance (MR) angiography, which excluded intracranial arterial narrowing, transcranial color-coded duplex ultrasonography (US), and carotid US to determine V MCA /V ICA and V tICA /V ICA ratios from angle-corrected and uncorrected velocities. Tolerance interval estimates were used to calculate reference ranges and linear regression was used to quantify associations of Doppler parameters with age adjusted for hemoglobin and hematocrit. Results:Reference ranges in centimeters per second for mean angle-corrected V MCA on the left and right sides were 62-198 and 69 -153; those for V tICA were 30 -196 and 36 -175; and those for V ICA were 18 -116 and 15-95, respectively. Reference ranges for mean angle-corrected V MCA /V ICA ratio on the left and right sides were 1.2-4.0 and 0.4 -3.4 and those for V tICA /V ICA ratio were 0.5-2.9 and 0.5-2.7, respectively. V MCA , V tICA , and V tICA /V ICA ratio were not age dependent, contrary to V ICA and V MCA /V ICA ratio, after controlling for hematocrit and hemoglobin. Conclusion:The study provides reference limits for V MCA , V tICA , V ICA , and velocity ratios obtained from children with SCD. Note: This copy is for your personal, non-commercial use only. To order presentation-ready copies for distribution to your colleagues or clients, use the Radiology Reprints form at the end of this article. Children with sickle cell disease (SCD) who develop intracranial arterial narrowing are at high risk of stroke (1). Transcranial Doppler ultrasonography (US) is a noninvasive method extensively used to detect narrowing based on flow velocity thresholds (1,2). Chronic transfusions can substantially reduce the risk of stroke in children with high velocities at transcranial Doppler US (1), yet even 70% of patients with high velocity who do not undergo transfusions do not develop stroke (3). Chronic transfusions are costly and associated with substantial morbidity and some mortality from transfusion-related infections, alloimmunization, and hemosiderosis (4,5). Children with high hyperemic velocity due to anemia may not have the same benefits from the transfusion therapy as those with arterial narrowing. Transcranial Doppler US screening should be improved since currently more patients may be exposed to substantial risk than the number that benefit from transfusion.False-po...

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Section: Discussionmentioning

confidence: 99%

Sickle Cell Disease: Ratio of Blood Flow Velocity of Intracranial to Extracranial Cerebral Arteries—Initial Experience

et al. 2009

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“…For instance, in patients with subarachnoid hemorrhage and vasospasm, an increase of blood flow velocities paradoxically indicates a decrease rather than an increase of CBF. 1 Methodologies for truly quantitative measurement of CBF are mostly based on diffusible tracers such as inert gases, labeled water, or others. However, these methods for quantitative measurement of CBF have mainly been applied in the context of scientific studies; they are unpractical for clinical purposes because of large and bulky equipment and/or the use of radioactive tracers.…”

mentioning

confidence: 99%

Bedside Assessment of Cerebral Blood Flow by Double-indicator Dilution Technique

et al. 2000

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Background: Currently, quantitative measurement of global cerebral blood flow (CBF) at bedside is not widely performed. The aim of the present study was to evaluate a newly developed method for bedside measurement of CBF based on thermodilution in a clinical setting.Methods: The investigation was performed in 14 anesthetized patients before coronary bypass surgery. CBF was altered by hypocapnia, normocapnia, and hypercapnia. CBF was measured simultaneously by the Kety-Schmidt inert-gas technique with argon and a newly developed transcerebral double-indicator dilution technique (TCID). For TCID, bolus injections of ice-cold indocyanine green were performed via a central venous line, and the resulting thermo-dye dilution curves were recorded simultaneously in the aorta and the jugular bulb using combined fiberoptic thermistor catheters. CBF was calculated from the mean transit times of the indicators through the brain.Results: Both methods of measurement of CBF indicate a decrease during hypocapnia and an increase during hypercapnia, whereas cerebral metabolic rate remained unchanged. Bias between CBF TCID and CBF argon was ؊7.1 ؎ 2.2 (SEM) ml ⅐ min ؊1 ⅐

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“…[158][159][160] VSP has been shown to occur following tSAH in 2% to 41% of TBI patients by DSA 153 and in as high as 60% of patients by TCD, 161,162 even in the absence of tSAH. 163,164 It is recommended that serial TCD examinations be started in the first 72 h post-injury, to detect VSP.…”

Section: Tcd and Vasospasm Diagnosis After Subarachnoid Hemorrhagementioning

confidence: 99%

A Review of the Effectiveness of Neuroimaging Modalities for the Detection of Traumatic Brain Injury

Amyot

Arciniegas

et al. 2015

Journal of Neurotrauma

183

147

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The incidence of traumatic brain injury (TBI) in the United States was 3.5 million cases in 2009, according to the Centers for Disease Control and Prevention. It is a contributing factor in 30.5% of injury-related deaths among civilians. Additionally, since 2000, more than 260,000 service members were diagnosed with TBI, with the vast majority classified as mild or concussive (76%). The objective assessment of TBI via imaging is a critical research gap, both in the military and civilian communities. In 2011, the Department of Defense (DoD) prepared a congressional report summarizing the effectiveness of seven neuroimaging modalities (computed tomography [CT], magnetic resonance imaging [MRI], transcranial Doppler [TCD], positron emission tomography, single photon emission computed tomography, electrophysiologic techniques [magnetoencephalography and electroencephalography], and functional near-infrared spectroscopy) to assess the spectrum of TBI from concussion to coma. For this report, neuroimaging experts identified the most relevant peer-reviewed publications and assessed the quality of the literature for each of these imaging technique in the clinical and research settings. Although CT, MRI, and TCD were determined to be the most useful modalities in the clinical setting, no single imaging modality proved sufficient for all patients due to the heterogeneity of TBI. All imaging modalities reviewed demonstrated the potential to emerge as part of future clinical care. This paper describes and updates the results of the DoD report and also expands on the use of angiography in patients with TBI.

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Elevated transcranial Doppler flow velocities after severe head injury: cerebral vasospasm or hyperemia?

Cited by 78 publications

References 30 publications

Sickle Cell Disease: Ratio of Blood Flow Velocity of Intracranial to Extracranial Cerebral Arteries—Initial Experience

Sickle Cell Disease: Ratio of Blood Flow Velocity of Intracranial to Extracranial Cerebral Arteries—Initial Experience

Bedside Assessment of Cerebral Blood Flow by Double-indicator Dilution Technique

A Review of the Effectiveness of Neuroimaging Modalities for the Detection of Traumatic Brain Injury

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