Cerebral perfusion pressure (CPP) is the net pressure gradient that drives oxygen delivery to cerebral tissue. It is the difference between the mean arterial pressure (MAP) and the intracranial pressure (ICP). As CPP is a calculated value, MAP and ICP must be measured simultaneously. In research models, anesthetized and acute monitoring is incapable of providing a realistic picture of the relationship between ICP and MAP under physiological and/or pathophysiological conditions. For long-term monitoring of both pressures, the principle of telemetry can be used. The aim of this study was to map changes in CPP and spontaneous behavior using continuous pressure monitoring and video recording for 7 days under physiological conditions (group C - 8 intact rats) and under altered brain microenvironment induced by brain edema (group WI - 8 rats after water intoxication) and neuroprotection with methylprednisolone - MP (group WI+MP - 8 rats with MP 100 mg/kg b.w. applicated intraperitoneally during WI). The mean CPP values in all three groups were in the range of 40-60 mm Hg. For each group of rats, the percentage of time that the rats spent during the 7 days in movement pattern A (standard movement stereotype) or B (atypical movement) was defined. Even at very low CPP values, the standard movement stereotype (A) clearly dominated over the atypical movement (B) in all rats. There was no significant difference between control and experimental groups. Chronic CPP values with correlated behavioral type may possibly answer the question of whether there is a specific, universal, optimal CPP at all.
The pressure reactivity index (PRx) is a parameter for the assessment of cerebrovascular autoregulation, but its calculation is affected by artifacts in the source biosignals-intracranial pressure (ICP) and arterial blood pressure. We sought to describe the most common short-duration artifacts and their effect on the PRx. A retrospective analysis of 935 h of multimodal monitoring data was conducted, and five types of artifacts, characterized by their shape, duration, and amplitude, were identified: rectangular, fast impulse, isoline drift, saw tooth, and constant ICP value. Subsequently, all types of artifacts were mathematically modeled and inserted into undisturbed segments of biosignals. Fast impulse, the most common artifact, did not alter the PRx index significantly when inserted into one or both signals. Artifacts present in one signal exceeded the threshold PRx in less than 5% of samples, except for isoline drift. Compared to that, the shortest rectangular artifact inserted into both signals changed PRx to a value above the set threshold in 55.4% of cases. Our analysis shows that the effect of individual artifacts on the PRx index is variable, depending on their occurrence in one or both signals, duration, and shape. This different effect suggests that potentially not all artifacts need to be removed.
- MeSH
- bolesti hlavy etiologie patofyziologie MeSH
- intrakraniální hypertenze * diagnóza etiologie patofyziologie MeSH
- intrakraniální hypotenze * diagnóza etiologie patofyziologie MeSH
- intrakraniální tlak fyziologie MeSH
- lidé MeSH
- závrať etiologie MeSH
- zvracení etiologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
- MeSH
- edém mozku * etiologie klasifikace terapie MeSH
- intrakraniální tlak * fyziologie MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Continuous monitoring of the intracranial pressure (ICP) is essential in neurocritical care. There are a variety of ICP monitoring systems currently available, with the intraventricular fluid filled catheter transducer currently representing the "gold standard". As the placement of catheters is associated with the attendant risk of infection, hematoma formation, and seizures, there is a need for a reliable, non-invasive alternative. In the present study we suggest a unique theoretical framework based on differential geometry invariants of cranial micro-motions with the potential for continuous non-invasive ICP monitoring in conservative traumatic brain injury (TBI) treatment. As a proof of this concept, we have developed a pillow with embedded mechanical sensors and collected an extensive dataset (> 550 h on 24 TBI coma patients) of cranial micro-motions and the reference intraparenchymal ICP. From the multidimensional pulsatile curve we calculated the first Cartan curvature and constructed a "fingerprint" image (Cartan map) associated with the cerebrospinal fluid (CSF) dynamics. The Cartan map features maxima bands corresponding to a pressure wave reflection corresponding to a detectable skull tremble. We give evidence for a statistically significant and patient-independent correlation between skull micro-motions and ICP time derivative. Our unique differential geometry-based method yields a broader and global perspective on intracranial CSF dynamics compared to rather local catheter-based measurement and has the potential for wider applications.
- MeSH
- dospělí MeSH
- intrakraniální hypertenze patofyziologie MeSH
- intrakraniální tlak fyziologie MeSH
- lebka patofyziologie MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- monitorování fyziologických funkcí MeSH
- senioři MeSH
- traumatické poranění mozku patofyziologie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVES: A novel method of long-term telemetric monitoring of mean arterial pressure (MAP) and intracranial pressure (ICP) for the determination of current cerebral perfusion pressure (CPP) and the time course of ICP in freely moving rats under physiological conditions and with increased ICP due to the induced cerebral edema were studied. METHODS: The brain edema, that caused volume enlargement and ICP elevation was achieved in entirely experimental conditions without any parallel pathological process. Vasogenic/extracellular edema was induced by osmotic blood-brain barrier disruption (BBBd) and for induction of cytotoxic/intracellular edema the water intoxication model (WI) was used. RESULTS: The results showed significantly elevated values of ICP both in conditions of osmotic blood-brain barrier disruption (BBBd model) and cytotoxic/intracellular edema (WI model) compared to intact rats. The average values of ICP were significantly higher in WI model compared to osmotic BBBd model. Distinct pattern of elevated ICP, related to the selected way of experimental brain edema induction, was found. In the experimental model of osmotic BBB disruption, the elevation of ICP started earlier but was of very short duration. In WI model the elevation of ICP was present during the whole period of monitoring. CONCLUSION: Our results indicate that purely experimental models of brain edema (WI, BBBd) without any parallel pathological process can compromise the basic brain homeostatic activity.
- MeSH
- edém mozku diagnóza etiologie patofyziologie MeSH
- hematoencefalická bariéra patofyziologie MeSH
- intoxikace vodou komplikace diagnóza patofyziologie MeSH
- intrakraniální hypertenze komplikace diagnóza patofyziologie MeSH
- intrakraniální tlak fyziologie MeSH
- krysa rodu rattus MeSH
- monitorování fyziologických funkcí metody MeSH
- mozek patofyziologie MeSH
- mozkový krevní oběh fyziologie MeSH
- potkani Wistar MeSH
- telemetrie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- cerebrovaskulární poruchy diagnóza etiologie terapie MeSH
- cévní mozková příhoda diagnóza etiologie terapie MeSH
- epilepsie diagnóza etiologie terapie MeSH
- homeostáza fyziologie účinky léků MeSH
- hypertenze diagnóza komplikace terapie MeSH
- intrakraniální tlak fyziologie MeSH
- kraniocerebrální traumata diagnóza etiologie terapie MeSH
- lidé MeSH
- mozkový krevní oběh fyziologie MeSH
- perfuze klasifikace normy MeSH
- příručky lékařské MeSH
- subarachnoidální krvácení diagnóza etiologie terapie MeSH
- Check Tag
- lidé MeSH
- MeSH
- antifungální látky škodlivé účinky MeSH
- Cryptococcus neoformans izolace a purifikace MeSH
- dánio pruhované MeSH
- dexamethason škodlivé účinky MeSH
- intrakraniální hypertenze MeSH
- intrakraniální tlak fyziologie MeSH
- kryptokoková meningitida * farmakoterapie imunologie mikrobiologie MeSH
- lidé MeSH
- spinální punkce * metody MeSH
- vyšetření u lůžka MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- přehledy MeSH
