Search Results

You are looking at 11 - 20 of 299 items for :

  • "blood flow velocity" x
Clear All
Restricted access

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.

Restricted access

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

Restricted access

Posthemorrhagic hydrocephalus

Low incidence in very low birth weight neonates with intraventricular hemorrhage

Laura R. Ment, Charles C. Duncan, David T. Scott and Richard A. Ehrenkranz

. New York : S Karger , 1982 , pp 1 – 146 Paraicz E: ICP in Infancy and Childhood. Monographs in Paediatrics, No. 15. New York: S Karger, 1982, pp 1–146 31. Perlman JM , Volpe JJ : Cerebral blood flow velocity in relation to intraventricular hemorrhage in the premature newborn infant. J Pediatr 100 : 956 – 959 , 1982 Perlman JM, Volpe JJ: Cerebral blood flow velocity in relation to intraventricular hemorrhage in the premature newborn infant. J Pediatr 100: 956–959, 1982 32. Rothberg AD

Restricted access

Beagle puppy model of intraventricular hemorrhage

Effect of superoxide dismutase on cerebral blood flow and prostaglandins

Laura R. Ment, William B. Stewart and Charles C. Duncan

: Regional cerebral blood flow in the awake newborn dog: the germinal matrix is a “low-flow” structure. Ann Neurol 10 : 283 – 284 , 1981 (Abstract) Pasternak JF, Groothuis DR, Fischer JM: Regional cerebral blood flow in the awake newborn dog: the germinal matrix is a “low-flow” structure. Ann Neurol 10: 283–284, 1981 (Abstract) 56. Perlman JM , Volpe JJ : Cerebral blood flow velocity in relation to intraventricular hemorrhage in the premature newborn infant. J Pediatr 100 : 956 – 959 , 1982 Perlman JM, Volpe

Restricted access

Karl-Fredrik Lindegaard, Søren Jacob Bakke, Peter Grolimund, Rune Aaslid, Peter Huber and Helge Nornes

designed to establish a procedure for assessing the effect of ICA stenoses on flow patterns in basal cerebral arteries and to compare this noninvasive technique with angiographic parameters. Theoretical Considerations Stenosis of an artery causes a pressure loss that is reflected by a damping of blood flow velocity waveforms recorded distally. 7, 9, 11 The MCA can be regarded as being an end artery. Hence, it was expected that the net hemodynamic effect of ICA stenoses could be assessed from recordings of MCA flow velocity. Gosling and King 9 introduced a

Restricted access

Jaime Broseta, José Barberá, J. A. de Vera, Juan Luis Barcia-Salorio, Guillermo Garcia-March, José González-Darder, Francisco Rovaina and Vicente Joanes

distance increased from less than 50 and 250 m, respectively, to more than 500 m. The walking capacity was increased by 250 m in another two cases, and in 12 cases walking ability was also increased although significantly less. There was no change in eight cases. Blood Flow Studies Spinal cord stimulation seems not to have influenced distal arterial pressure, judging by the ankle/brachial pressure ratio. Doppler ultrasound recordings showed an improvement of blood flow in the lower-limb distal circulation after stimulation, expressed by higher blood flow

Restricted access

Rolf W. Seiler, Peter Grolimund, Rune Aaslid, Peter Huber and Helge Nornes

: Clinical Group 1 (no neurological symptoms); Clinical Group 2 (delayed neurological symptoms, but fully reversible); Clinical Group 3a (delayed neurological symptoms not fully reversible within 6 months because of cerebral infarction); and Clinical Group 3b (delayed neurological symptoms leading to death because of massive cerebral infarction). Grading of CT-Visualized Blood Flow velocities were correlated with the CT-visualized subarachnoid blood only in the 35 patients who had a CT scan within 5 days after the SAH, because Scotti, et al. , 15 found that

Restricted access

Edwin G. Fischer, Antonio V. Lorenzo, William J. Landis, Keasley Welch, Stephen K. Ofori-Kwakye, Brent Dorval, Karen J. Hodgens and Clare S. Kerr

injection. Lund Univ Arsskrift 56: 1–55, 1960 12. Kuban KCK , Gilles FH : Human telencephalic angiogenesis. Ann Neurol 17 : 539 – 548 , 1985 Kuban KCK, Gilles FH: Human telencephalic angiogenesis. Ann Neurol 17: 539–548, 1985 13. Lipman B , Brazy JE : Cerebral blood flow velocity in intraventricular hemorrhage. J Pediatr 102 : 324 – 325 , 1983 (Letter) Lipman B, Brazy JE: Cerebral blood flow velocity in intraventricular hemorrhage. J Pediatr 102: 324–325, 1983 (Letter) 14

Restricted access

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

Restricted access

Beagle puppy model of perinatal cerebral insults

Cerebral blood flow changes and intraventricular hemorrhage evoked by hypoxemia

Laura R. Ment, William B. Stewart, Charles C. Duncan and Bruce R. Pitt

in the newborn beagle pup: the germinal matrix is a “low-flow” structure. Pediatr Res 16 : 499 – 503 , 1982 Pasternak JF, Groothuis DR, Fischer JM, et al: Regional cerebral blood flow in the newborn beagle pup: the germinal matrix is a “low-flow” structure. Pediatr Res 16: 499–503, 1982 19. Perlman JM , Volpe JJ : Cerebral blood flow velocity in relation to intraventricular hemorrhage in the premature newborn infant. J Pediatr 100 : 956 – 959 , 1982 Perlman JM, Volpe JJ: Cerebral blood flow velocity in