scholarly journals Cardiac output in idiopathic normal pressure hydrocephalus: association with arterial blood pressure and intracranial pressure wave amplitudes and outcome of shunt surgery

2011 ◽  
Vol 8 (1) ◽  
Author(s):  
Per K Eide
Keyword(s):  
Blood Pressure ◽  
Cardiac Output ◽  
Intracranial Pressure ◽  
Arterial Blood Pressure ◽  
Normal Pressure Hydrocephalus ◽  
Pressure Wave ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Shunt Surgery ◽  
Arterial Blood

Cerebral microdialysis and intracranial pressure monitoring in patients with idiopathic normal-pressure hydrocephalus: association with clinical response to extended lumbar drainage and shunt surgery

2010 ◽  
Vol 112 (2) ◽  
pp. 414-424 ◽  
Author(s):  
Per K. Eide ◽  
Milo Stanisic
Keyword(s):  
Intracranial Pressure ◽  
Normal Pressure Hydrocephalus ◽  
Wave Amplitude ◽  
Cerebral Metabolism ◽  
Normal Pressure ◽  
Idiopathic Normal Pressure Hydrocephalus ◽  
Clinical Severity ◽  
Cerebral Microdialysis ◽  
Shunt Surgery ◽  
Lumbar Drainage

Object This study was performed in patients with idiopathic normal-pressure hydrocephalus (iNPH) to monitor cerebral metabolism with microdialysis (MD) and intracranial pressure (ICP) readings, and relate to the clinical responses to extended lumbar drainage (ELD) and shunt surgery. Methods The baseline levels of MD metabolites and ICP were monitored overnight in 40 consecutive patients with iNPH. In a subset of 28 patients, monitoring was continued during 3 days of ELD. Thirty-one patients received a ventriculoperitoneal shunt. The clinical severity of iNPH was determined before and then 3 and 6–12 months after shunt surgery. Results Altered levels of MD markers (lactate, pyruvate, lactate/pyruvate ratio, glutamate, and/or glycerol) were seen in all patients at baseline; these improved during ELD. Despite normal static ICP (mean ICP), the pulsatile ICP (the ICP wave amplitude) was increased in 24 patients (60%). Only the level of the ICP wave amplitude differentiated the ELD and/or shunt responders from nonresponders. Conclusions The MD monitoring indicated low-grade cerebral ischemia in patients with iNPH; during ELD, cerebral metabolism improved. The pulsatile ICP (the ICP wave amplitude) was the only variable differentiating the clinical responders from the nonresponders. The authors suggest that the pulsatile ICP reflects the intracranial compliance and that CSF diversion improves the biophysical milieu of the nerve cells, which subsequently may improve their biochemical milieu.

Circulatory effects of moderately and severely increased intracranial pressure in the dog

1972 ◽  
Vol 36 (6) ◽  
pp. 721-727 ◽  
Author(s):  
Norberto C. Gonzalez ◽  
John Overman ◽  
John A. Maxwell
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Cardiac Output ◽  
Intracranial Pressure ◽  
Arterial Blood Pressure ◽  
Peripheral Resistance ◽  
Arterial Blood ◽  
Femoral Blood Flow ◽  
Femoral Blood

✓ Anesthetized dogs were subjected to elevated intracranial pressure (ICP) of 60 and 100 mm Hg. At 60 mm Hg, decreases in heart rate and arterial blood pressure were observed associated with an increase in femoral blood flow that suggested vasodilation in the somatic areas. Cardiac output showed little change. Subsequent elevation of ICP to 100 mm Hg was followed by an increase in arterial blood pressure; cardiac output increased, and femoral flow increased still further. Since resistance to flow did not change, the hypertension was thought to be due to an increase in flow rather than peripheral resistance. An increase in heart rate was associated with the elevation in cardiac output; the fact that femoral blood flow increased proportionately more than cardiac output suggested a redistribution of blood flow. The changes in peripheral blood flow and in cardiac output were associated with a decrease in the arteriovenous oxygen (A–VO2) difference. No signs of tissue hypoxia were observed; specifically there was no significant change in the lactate-to-pyruvate ratio; the changes in A–VO2 difference were correlated with changes in flow and the product of the two variables, namely, oxygen consumption, remained unchanged. The data show that experimental elevation of ICP restricted to moderate levels is followed by hemodynamic changes suggesting peripheral vasodilation, and that when an increase in blood pressure then occurs, it is due to an increase in blood flow despite the decrease in peripheral resistance.

scholarly journals Quantifying the contribution of intracranial pressure and arterial blood pressure to spontaneous tympanic membrane displacement

2018 ◽  
Vol 39 (8) ◽  
pp. 085002
Author(s):  
Wahbi K El-Bouri ◽  
Dario Vignali ◽  
Konstantina Iliadi ◽  
Diederik Bulters ◽  
Robert J Marchbanks ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Intracranial Pressure ◽  
Tympanic Membrane ◽  
Arterial Blood Pressure ◽  
Arterial Blood ◽  
Membrane Displacement

The relationship of blood flow velocity fluctuations to intracranial pressure B waves

1992 ◽  
Vol 76 (3) ◽  
pp. 415-421 ◽  
Author(s):  
David W. Newell ◽  
Rune Aaslid ◽  
Renate Stooss ◽  
Hans J. Reulen
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Intracranial Pressure ◽  
Arterial Blood Pressure ◽  
Wave Amplitude ◽  
Transcranial Doppler Ultrasound ◽  
Normal Subjects ◽  
Content Type ◽  
Arterial Blood ◽  
Flow Fluctuations

✓ Intracranial pressure (ICP) and continuous transcranial Doppler ultrasound signals were monitored in 20 head-injured patients and simultaneous synchronous fluctuations of middle cerebral artery (MCA) velocity and B waves of the ICP were observed. Continuous simultaneous monitoring of MCA velocity, ICP, arterial blood pressure, and expired CO2 revealed that both velocity waves and B waves occurred despite a constant CO2 concentration in ventilated patients and were usually not accompanied by fluctuations in the arterial blood pressure. Additional recordings from the extracranial carotid artery during the ICP B waves revealed similar synchronous fluctuations in the velocity of this artery, strongly supporting the hypothesis that blood flow fluctuations produce the velocity waves. The ratio between ICP wave amplitude and velocity wave amplitude was highly correlated to the ICP (r = 0.81, p < 0.001). Velocity waves of similar characteristics and frequency, but usually of shorter duration, were observed in seven of 10 normal subjects in whom MCA velocity was recorded for 1 hour. The findings in this report strongly suggest that B waves in the ICP are a secondary effect of vasomotor waves, producing cerebral blood flow fluctuations that become amplified in the ICP tracing, in states of reduced intracranial compliance.

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