Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2008
Mathematical models of cerebral hemodynamics for detection of vasospasm in major cerebral arteries.
Vasospasm is a common complication of aneurismal subarachnoid hemorrhage (SAH) that may lead to cerebral ischemia and death. The standard method for detection of vasospasm is conventional cerebral angiography, which is invasive and does not allow continuous monitoring of arterial radius. Monitoring of vasospasm is typically performed by measuring Cerebral Blood Flow Velocity (CBFV) in the major cerebral arteries and calculating the Lindegaard ratio. We describe an alternative approach to estimate intracranial arterial radius, which is based on modeling and state-estimation techniques. The objective is to obtain a better estimation than that offered by the Lindegaard ratio, that might allow for continuous monitoring and possibly vasospam prediction without the need for angiography. ⋯ Our results indicate that arterial radius may be estimated using measurements of ABP, ICP and CBFV, allowing the detection of vasospasm.
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Acta Neurochir. Suppl. · Jan 2008
Clinical TrialHyperbaric oxygen therapy for consciousness disturbance following head injury in subacute phase.
Hyperbaric oxygen (HBO) therapy has been shown to improve outcome after brain injury, however its mechanisms are not understood. The purpose of the present study was to investigate the effect of hyperbaric oxygen (HBO) therapy on the cerebral circulation and metabolism of patients with disturbances in consciousness after head injury in the subacute phase. ⋯ The measurement of cerebral circulation and metabolism parameters, especially PI and lac-JV, is useful for estimation of effect of HBO therapy in patients with distubances in consciousness after head injury in the subacute phase.
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Acta Neurochir. Suppl. · Jan 2008
Noninvasive estimation of intracranial compliance in idiopathic NPH using MRI.
The pathophysiology of idiopathic normal pressure hydrocephalus (I-NPH) is still unclear and the diagnosis is sometimes difficult. The aim of this study was to assess the biophysics of I-NPH by measuring intracranial compliance using cine MRI. ⋯ It is possible to estimate intracranial compliance as CI non-invasively using cine MRI. CI could become a useful method for the diagnosis of I-NPH.
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Acta Neurochir. Suppl. · Jan 2008
The antioxidant effects of melatonin after intracerebral hemorrhage in rats.
Free radical mechanisms are involved in secondary brain injury after intracerebral hemorrhage (ICH). Since melatonin is a potent free radical scavenger and indirect antioxidant, the objective of this study was to evaluate whether melatonin administration would attenuate oxidative stress, brain edema, and neurological deficits in a rat model of ICH. Animals were assigned into groups consisting of sham (needle trauma), vehicle, and melatonin (15 or 150 mg/kg). ⋯ Results demonstrated dramatically increased lipid peroxidation after collagenase-induced ICH; however, melatonin treatment effectively attenuated this lipid peroxidation. Nonetheless, neurological scoring and brain water content in the right basal ganglia was without significant difference between any treatment regimens (15 or 150 mg/kg of melatonin) or time points of drug administration (15 min or 3 h post-ICH). Therefore, melatonin reduced oxidative stress but did not change extent of brain edema or neurologic deficits.
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Acta Neurochir. Suppl. · Jan 2008
Low frequency pressure waves of possible autonomic origin in severely head-injured children.
Useful information (both clinical and pathophysiological) which may be extracted from intracranial pressure (ICP) recordings include: (1) the mean level of ICP (and CPP), (2) cerebrovascular autoregulation status, (3) the intracranial pulse pressure (the pulse wave index, ICPpp/ICPm) or the pressure-volume compensatory reserve index (RAP) and (4) the presence of any abnormal ICP waveform. This paper describes a slow frequency ICP waveform in children with TBI and postulates the pathophysiological basis and whether it contains clinically useful detail. ⋯ We postulate that these previously unreported slow waveforms may reflect the very low frequency (VLF) and ultra low frequency (ULF; < or = 1 per 5 min) components of heart rate and arterial blood pressure variability.