- Macquarie University, Faculty of Medicine, Health and Human Sciences, Department Memberadd
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In patients with subarachnoid haemorrhage, pulsatile intracranial pressure (ICP) is more strongly associated with adverse events than mean ICP. Furthermore, patients with idiopathic normal-pressure hydrocephalus (iNPH), and pulsatile ICP... more
In patients with subarachnoid haemorrhage, pulsatile intracranial pressure (ICP) is more strongly associated with adverse events than mean ICP. Furthermore, patients with idiopathic normal-pressure hydrocephalus (iNPH), and pulsatile ICP of 5 mmHg or more, gain more benefit from cerebrospinal fluid (CSF) shunting than those whose pulsatile ICP is lower than 5 mmHg.Our study aims to investigate the morphological relationship between ICP pulsations, aortic pressure pulsations and radial artery pulsations. Central aortic pulse pressure has been known to be the best predictor of adverse cardiac events, whereas radial artery pulse pressure is generally measured and displayed in intensive care environments.We studied 10 patients with iNPH, and their ICP and aortic and radial pressures were digitised, ensemble-averaged and compared in the time and frequency domains. The ICP wave contour was quite different to the radial pressure waveform. By contrast, the ICP waveform was similar to the ao...
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While intracranial pressure (ICP), arterial pressure and transcranial middle cerebral artery flow velocity (MCAFV) are often monitored in unconscious patients following stroke or head injury, the value of waveform indices has not been... more
While intracranial pressure (ICP), arterial pressure and transcranial middle cerebral artery flow velocity (MCAFV) are often monitored in unconscious patients following stroke or head injury, the value of waveform indices has not been fully established. We retrospectively analysed the data of eight adults (aged 19-36 years) with closed head injury who had spontaneous and repeated episodes of elevated ICP (i.e. "plateau waves"). MCAFV was measured using transcranial Doppler, ICP using a Codman catheter and radial artery pressure using cannulation. Ascending aortic pressure (AAP) was generated from the radial artery using SphygmoCor(TM). Cerebral perfusion pressure (CPP) was calculated as AAP - ICP in the time domain.During the period of increased ICP, ICP and cerebral flow velocity amplitude increased significantly compared with the basal condition, while cerebral mean flow decreased. Amplitude of the secondary peak in ICP, AAP and MCAFV waveform became apparent.An increase...
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The response of Hope et al. [ 1 ] to previous criticism [ 2 ] extends problems in their original article of 2002 [ 3 ], and the apparent duplicate publication of data in 2003 [ 4 ]. The authors' citations in their tables... more
The response of Hope et al. [ 1 ] to previous criticism [ 2 ] extends problems in their original article of 2002 [ 3 ], and the apparent duplicate publication of data in 2003 [ 4 ]. The authors' citations in their tables omit the additional 439 patients and subjects described in the standard text ...
Research Interests: Humans, Hypertension, Female, Male, Clinical Sciences, and 3 moreTransfer Function, Pulse, and Aorta
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Research Interests: Humans, Female, Male, Marfan syndrome, Clinical Sciences, and 3 moreLosartan, Aortic Aneurysm, and Atenolol
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The brain is highly vascular and richly perfused, and dependent on continuous flow for normal function. Although confined within the skull, pressure within the brain is usually less than 15 mmHg, and shows small pulsations related to... more
The brain is highly vascular and richly perfused, and dependent on continuous flow for normal function. Although confined within the skull, pressure within the brain is usually less than 15 mmHg, and shows small pulsations related to arterial pulse under normal circumstances. Pulsatile arterial hemodynamics in the brain have been studied before, but are still inadequately understood, especially during changes of intracranial pressure (ICP) after head injury. In seeking cohesive explanations, we measured ICP and radial artery pressure (RAP) invasively with high-fidelity manometer systems, together with middle cerebral artery flow velocity (MCAFV) (transcranial Doppler) and central aortic pressure (CAP) generated from RAP, using a generalized transfer function technique, in eight young unconscious, ventilated adults following closed head trauma. We focused on vascular effects of spontaneous rises of ICP ('plateau waves'). A rise in mean ICP from 29 to 53 mmHg caused no consist...