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Joanne C. McQuire, John C. Sutcliffe and Tim J. Coats

mean blood flow velocity were calculated according to the method described by Ringelstein. 27 The lower limit of the normal range was taken as 2 standard deviations below the mean. The normal value for the PI does not vary with age. 30 The severity of head injury in this study has been classified according to the GCS and AIS scores. 25 The age, sex, and initial GCS score of each patient were recorded. On discharge from the hospital or death the AIS score of the head was calculated. This is an anatomically based system in which individual injuries are classified

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Stéphanie Lenck, Fabrice Vallée, Vittorio Civelli, Jean-Pierre Saint-Maurice, Patrick Nicholson, Alex Hong and Emmanuel Houdart

with measurement of pressures alone. 9 The purpose of the present study was to evaluate the hemodynamic consequences of symptomatic dural-sinus stenoses in terms of venous blood flow velocities (BFVs) and venous pressures in a prospective series of 14 patients in whom exploration was performed using a dual-sensor pressure and Doppler velocity guidewire. Methods After receiving institutional review board approval, we collected the clinical, radiological, and hemodynamic data of patients in whom exploration was performed using a dual-sensor guidewire (ComboWire

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Kwan-Hon Chan, J. Douglas Miller, N. Mark Dearden, Peter J. D. Andrews and Susan Midgley

I n the past decade, transcranial Doppler (TCD) ultrasonography has allowed repeated and continuous bedside assessment of blood flow velocity in major basal intracranial vessels. 1 Continuous recording of arterial and jugular bulb venous blood oxygen saturation (SJO 2 ) permits calculation of the cerebral arteriovenous oxygen content difference (AVDO 2 ). This reflects the ratio of global cerebral oxygen supply to demand. 2 Whether these investigative tools can be used as a practice aid to the management of patients with severe brain injury remains

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Christopher Wendel, Ricardo Scheibe, Sören Wagner, Wiebke Tangemann, Hans Henkes, Oliver Ganslandt and Jan-Henrik Schiff

technique with only a few limitations, is further used at the bedside in daily routine to detect a CV by assessing cerebral blood flow velocity (CBFV). A systematic review compared the use of TCD ultrasonography for the detection of CBFV of ≥ 120 cm/sec in the middle cerebral artery (MCA) to angiography and showed a 99% specificity and 67% sensitivity for identifying a vasospasm compared to angiography. There is a lack of studies available on TCD ultrasonography criteria for all other situations and arteries. 7 , 8 , 16 Standard prevention therapy for CV consists of

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David W. Newell, Rune Aaslid, Renate Stooss and Hans J. Reulen

. Discussion Theoretical Aspects of TCD Monitoring Monitoring of the blood flow velocity of the MCA, both intraoperatively and in the intensive care unit, has been reported previously. 8, 12 For continuous recording, the TCD velocity signal can be taken from the outline of the velocity spectrum, which is normally calculated by the TCD instrument. This tracing corresponds to the V max of blood flow at the center of the MCA. 1 During laminar flow, which is the normal condition in the basal arteries, the flow velocity at the center of the MCA will be directly

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Satoshi Tateshima, Fernando Viñuela, J. Pablo Villablanca, Yuichi Murayama, Taku Morino, Kiyoe Nomura and Kazuo Tanishita

was noted at the center of the lesion, dividing two outflow zones located at the distal and proximal areas of the orifice. The inflow zone moved to the distal and medial aspects of the aneurysm opening and became smaller in size during the early systolic phase. There was no appreciable change in the shape of the inflow zone between the early systolic and peak systolic phases, but blood flow velocity rapidly increased. The inflow zone moved to the distal area of the orifice during the early diastolic phase. Another small inflow zone was formed at the proximal lateral

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Karl-Fredrik Lindegaard, Peter Grolimund, Rune Aaslid and Helge Nornes

have considerable clinical value. Transcranial Doppler ultrasound permits noninvasive recording of blood flow velocities in basal cerebral arteries. 2, 11 In a series of healthy volunteers, we have previously demonstrated that there is relatively little variation with regard to the time-mean value and the pulsatility of the velocity spectrum outlines that are recorded from different basal cerebral arteries in the same individual. 11 This indicates that identical hemodynamic conditions prevail in different areas of the normal brain. In an AVM, the resistance is

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Rune Aaslid, Peter Huber and Helge Nornes

✓ The use of an ultrasonic transcranial Doppler technique for noninvasive evalution of cerebral vasospasm is described. Middle cerebral arteries (MCA's), classified as spastic on angiography, demonstrated blood-flow velocity between 120 and 230 cm/sec. The flow velocities in these arteries had a clear inverse relationship to the diameter as measured from angiograms in 38 patients with recent subarachnoid hemorrhage. This relationship in the proximal anterior cerebral artery (ACA) was found to be more complicated to assess, due to the collateral channels in the anterior part of the circle of Willis. The authors conclude, however, that the new method of measuring vasospasm will also detect spasm in the ACA if it has a hemodynamically significant effect upon flow resistance.

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Zenon Mariak, Jaroslaw Krejza, Miroslaw Swiercz, Kazimierz Kordecki and Janusz Lewko

, Dander D, Holzgraefe M, et al: Cerebral vasospasm evaluated by transcranial Doppler ultrasonography at different intracranial pressures. J Neurosurg 75: 752–758, 1991 32. Krejza J , Mariak Z , Babikian VL : Importance of angle-correction in measurement of blood flow velocity with transcranial Doppler sonography. AJNR 22 : 1743 – 1747 , 2001 Krejza J, Mariak Z, Babikian VL: Importance of angle-correction in measurement of blood flow velocity with transcranial Doppler sonography. AJNR 22: 1743–1747, 2001 33

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Rune Aaslid and Helge Nornes

A transcranial ultrasound Doppler technique for recording blood flow velocity in basal cerebral arteries has been described previously. 1, 2 In the course of a routine recording in a patient with spontaneous subarachnoid hemorrhage (SAH), we noticed tones of a musical quality from the loudspeaker of the instrument. We realized that an instrument designed to detect Doppler shifts would also act as a demodulator for phase- and amplitude-modulated ultrasonic signals, and thus could be used as a focused microphone. This type of ultrasonic detection is used