Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 2002
New methods for monitoring cerebral oxygenation and hemodynamics in patients with subarachnoid hemorrhage.
Radiographic cerebral vasospasm (CVS) after subarachnoid hemorrhage (SAH) do not reflect cerebral hemodynamics and oxygenation and may occur in the absence of clinical deficit and vice-versa. This report is to describe preliminary findings in further development of a non invasive method to estimate regional cerebral oxygenation and perfusion. Measurements were performed with a technique combining near infrared spectroscopy (NIRS) and indocyaningreen (ICG) dye dilution. ⋯ The influence of extracerebral bone and surface tissue on cerebral NIRS signal has not been clarified yet. Therefore a new subdural NIRS probe has been developed, which gives the opportunity to measure directly the concentration of the chromophores in the brain without the influence of extracerebral contamination. In future comparative measurements with conventional NIRS probes on the scalp will allow to quantify and eliminate extracerebral contamination from the NIRS signal.
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Acta Neurochir. Suppl. · Jan 2002
ICP and CBF regulation: a new hypothesis to explain the "windkessel" phenomenon.
The brain tamponade represents the final condition of a progressive intracranial pressure (ICP) increase up to values close to arterial blood pressure (BP) producing a reverberating flow pattern in the cerebral arteries with no net flow. This finding implies intracranial volume changes, therefore a full application of the Monro-Kellie doctrine is impossible. To resolve this contradiction, in eight pigs a reversible condition of brain tamponade was produced by infusing saline into a cerebral ventricle. ⋯ When ICP approached carotid BP values, reverberating BFV waves both at ICA and SS site were simultaneously observed. The arterial and venous reverberating waves appeared to be almost exactly superimposable, with a delay of about 40 msec. This synchronism between the pulsatile arterial and venous BFV indicates that the residual pulsation, still occurring at the arterial proximal level, is compensated by a passive compression-distension of the SS with no blood volume (that is net flow) crossing the intracranial vasculature.
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Acta Neurochir. Suppl. · Jan 2002
Appropriate analysis and presentation of data is a must for good clinical practice.
Good Clinical Practice (GCP) is defined as an international ethical and scientific quality standard for designing, conducting, monitoring, auditing, analyzing and reporting trials that involve the participation of human subjects. This paper focuses mainly on the issues that need attention at the time of statistical analysis and reporting of results. Findings from a review of published articles in Turkey are also presented. ⋯ The review of a stratified sample of research articles from 60 journals published in 1992 in Turkey revealed that in 56% of the cases the statistical methods were improper or inadequate. In 15% of the articles the authors failed to select an appropriate design for the proposed aim mentioned in the manuscript. Despite the recent improvements, the necessity and the value of performing and presenting research according to the international standards remains to be assimilated better by Turkish investigators.
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Disturbed cerebral autoregulation is believed to be associated with an unfavourable outcome following head injury. Previously, using ICP monitoring and transcranial Doppler ultrasonography, we investigated whether cerebral response to spontaneous variations in arterial pressure (ABP) or cerebral perfusion pressure (CPP) provide reliable information on cerebral autoregulatory reserve. In the present study we have correlated these methods with clinical findings. ⋯ Positive values of indices of autoregulation, expressing positive association between slow waves of CPP and blood flow velocity or ABP and ICP, indicate disturbed autoregulation. These indices correlate with unfavourable outcome following head injury and should be used to guide intensive therapy.
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Acta Neurochir. Suppl. · Jan 2002
Neuro-rehabilitation--a challenge for neurosurgeons in the century 21st concepts and visions of the WFNS-Committee on neurosurgical rehabilitation.
Patients with severe brain, spinal cord and peripheral nerve lesions today survive surgery. This, however, is quite often achieved at the burden of disabilities. Neuro-rehabilitation could improve significantly patient's quality of life (QoL). ⋯ The WFNS Committee can influence neurosurgeons to take over the challenge of neuro-rehabilitation to improve patient's outcome in respect to ICIDH-2 WHO classification. Delegates of all neurosurgical societies are kindly invited to join us.