Acta neurochirurgica. Supplement
-
Acta Neurochir. Suppl. · Jan 2012
Pulse amplitude and Lempel-Ziv complexity of the cerebrospinal fluid pressure signal.
The complexity of the intracranial pressure (ICP) signal decreases with intracranial hypertension in children with acute brain injury as well as during infusion studies in adults with hydrocephalus. In this study we have analysed the pressure signal obtained in the lumbar subarachnoid space during infusion testing. The pulse amplitude rises when the ICP is increased by additional external volume. Our objective was to determine the relative influence of the pressure range and pulse amplitude on the loss of complexity observed during infusion-related intracranial hypertension. ⋯ The pulse amplitude of the CSFP signal seems to be a major determinant of the waveform complexity.
-
Acta Neurochir. Suppl. · Jan 2012
Correlation of clinical outcome and angiographic vasospasm with the dynamic autoregulatory response after aneurysmal subarachnoid hemorrhage.
A certain correlation between unfavorable clinical outcome, incidence of vasospasm, and impaired pressure autoregulation in patients following aneurysmal subarachnoid hemorrhage (aSAH) has been suggested. However, determination of vasospasm is inaccurate and the measurement technique of cerebral vasoreactivity seems not to have been sufficiently validated. Therefore, a correlation of clinical outcome and the extent of angiographic VS was performed using an established autoregulation test. ⋯ Incidence of angiographic vasospasm and impaired clinical outcome seems to be related to impaired pressure autoregulation following aSAH.
-
Acta Neurochir. Suppl. · Jan 2012
Realization of a comprehensive non-invasive detection of intracranial pressure analyzer based upon FVEP and TCD.
Up to now, several methods, such as flash visual evoked potential (FVEP) and transcranial Doppler (TCD), have been studied with regard to assessing intracranial pressure (ICP) non-invasively. However, there are still no instruments that are readily available for non-invasive measurement of ICP in clinical practice. Based on the advantages of FVEP and TCD for ICP assessment, the two methods are synthesized to develop a specific instrument to non-invasively measure ICP more reliably and applicably, as the integration of FVEP and TCD overcomes the shortcomings of a single method of ICP measurement.
-
Acta Neurochir. Suppl. · Jan 2012
Near infrared spectroscopy as possible non-invasive monitor of slow vasogenic ICP waves.
We aimed to study synchronisation between ICP and near infrared spectroscopy (NIRS) variables induced by vasogenic waves of ICP during an infusion study in hydrocephalic patients and after TBI. Nineteen patients presenting with hydrocephalus underwent a diagnostic intraventricular constant-flow infusion test. The original concept of the methodology, presented in the current paper, was derived from this material. ⋯ Fluctuations of Hb and HbO(2) at baseline negatively correlated with each other, but switched to high positive values during periods of increased ICP slow-wave activity during infusion (p < 0.001). Similar behaviour was observed in TBI patients: baseline negative Hb/HbO(2) correlation changed to positive values during peaks of ICP of vasogenic nature. Correlating changes in Hb and HbO(2) may be of use as a method of non-invasive detection of vasogenic ICP waves.
-
Acta Neurochir. Suppl. · Jan 2012
Telemetric ICP measurement with the first CE-approved device: data from animal experiments and initial clinical experiences.
The objective was to evaluate the qualification of the new telemetric intracranial pressure (ICP) measurement (t-ICP) device Raumedic(®) NEUROVENT P-Tel and S-Tel. The proof of concept was examined in a pilot animal study measuring intraperitoneal pressure with a telemetric and a conventional ICP measurement probe at five rates for 1 h each. Moderate external pressure load allowed measuring values between 0 and 40 mmHg. ⋯ Raumedic's NEUROVENT(®) P-Tel/S-Tel proved to provide reliable data over periods of up to 18 months. Minor zero drift can be well tolerated as the dynamic ICP signal is measured with excellent stability. Clinicians should focus more on such ICP dynamic signal information than on static ICP when using the device over longer follow-up periods.