Abstract
The great potential of transcranial Doppler (TCD) as a tool for neuromonitoring is
limited by the current parameterization of the signal. This article proposes a set
of new parameters that more accurately represents the shape of the waveform and eliminates
a number of confounding factors. This set of parameters was tested in 227 patients
with ipsilateral carotid artery stenosis and compared with 31 normal subjects recruited
at our laboratory. From the TCD waveform, we calculated on a beat-to-beat basis the
maximal change in flow velocity at stroke onset (acceleration or acc), the maximal
flow velocity during the first 100 ms of systole (sys1) and the maximal flow velocity
in the remaining part of systole (sys2). All data were normalized relative to the
mean diastolic flow velocity over an interval ranging from 520 till 600 ms after stroke
onset ([email protected]). For the group with carotid stenosis compared with the normal controls the average ± SD
for acc (20.2 ± 9.5 vs. 20.2 ± 6.7; p = 0.98) and sys1 (1.82 ± 0.38 vs. 1.77 ± 0.56; p = 0.35) did not differ significantly. The average ±SD for sys2 (1.94 ± 0.33 vs. 1.50 ± 0.12;
p < 0.001), however, was significantly higher in the group with carotid stenosis than
in the group of normal subjects. The difference between sys1 and sys2 (“sys1–sys2”)
was lower in the patient group than in controls (−0.12 ± 0.16 vs. 0.27 ± 0.22; p < 0.001). For the acc, there was a significantly higher variance in the group with
stenosis than without (p < 0.001). Of the old parameters, the beat-to-beat mean (37.0 ± 13.1 vs. 41.3 ± 15.9;
p = 0.17) and the pulsatility index (PI; 1.00 ± 0.26 vs. 0.91 ± 0.23; p = 0.06) were not significantly different between groups. Graphed together the acc
and “sys1–sys2” parameters allowed a clear demarcation of both groups whereas in a
graph of the old parameters mean and PI both groups overlapped considerably. In conclusion,
the proposed set of new parameters not only has theoretical and practical benefits
but also has excellent discriminative power in a group of carotid patients compared
with normal controls.
Key Words
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References
- Noninvasive transcranial Doppler ultrasound recording of flow velocity in basal cerebral arteries.J Neurosurg. 1982; 57: 769-774
- Neuromonitoring in the intensive care unit. 1. Intracranial pressure and cerebral blood flow monitoring.Intensive Care Med. 2007; 33: 1263-1271
- Transcranial Doppler sonography pulsatility index (PI) reflects intracranial pressure (ICP).Surg Neurol. 2004; 62: 45-51
- Wave intensity analysis from the common carotid artery: A new noninvasive index of cerebral vasomotor tone.Heart Vessels. 2003; 18: 202-206
- Differentiating vascular pathophysiological states by objective analysis of flow dynamics.J Neuroimaging. 2004; 14: 97-107
- Continuous assessment of cerebral autoregulation: Clinical and laboratory experience.Acta Neurochir Scand. 2003; 86: 581-585
- Risk of stroke in the distribution of an asymptomatic carotid artery.Lancet. 1995; 345: 209-212
- Value of transcranial Doppler indices in predicting raised ICP in infantile hydrocephalus. A study with review of the literature.Childs Nerv Syst. 1995; 11: 595-603
- Defective cererbral autoregulation after carotid endarterectomy.Eur J Vasc Surg. 1993; 7: 370-379
- Validation of a semi-classical signal analysis method for stroke volume variation assessment: A comparison with the PiCCO technique.Ann Biomed Eng. 2010; 38: 3618-3629
- Comparison of caffeine-induced changes in cerebral blood flow and middle cerebral artery blood velocity shows that caffeine reduces middle cerebral artery diameter.Physiol Meas. 2004; 25: 467-474
- Severely impaired cerebrovascular reactivity predicts stroke and TIA risk in patients with carotid artery stenosis and occlusion.Brain. 2001; 124: 457-467
- Handbook of Transcranial Doppler.Springer-Verlag, New York1997
- Migraine is associated with enhanced arterial stiffness.Hypertens Res. 2007; 30: 577-583
- Transcranial Doppler sonography in adult hydrocephalic patients.Neurosurg Rev. 2000; 23: 34-38
- Cerebral hyperperfusion syndrome: A cause of neurologic dysfunction after carotid endarterectomy.J Vasc Surg. 1987; 5: 628-634
- Post-carotid endarterectomy hyperperfusion syndrome: Preliminary observations for identifying at risk patients by transcranial Doppler sonography and the acetazolamide test.Eur J Vasc Surg. 1993; 7: 252-257
- Three cases of hyperperfusion syndrome identified by daily transcranial Doppler investigation after carotid surgery.Eur J Vasc Endovasc Surg. 2002; 23: 17-22
Article info
Publication history
Published online: May 14, 2012
Accepted:
March 19,
2012
Received in revised form:
February 25,
2012
Received:
November 18,
2011
Identification
Copyright
© 2012 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.
