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.
OBJECTIVE: Increased intracranial pressure (ICP) is most likely not being transmitted uniformly within the cranium. The ICP profiles in the supra- and infratentorial compartments remain largely unclear. Increased ICP in the cerebellum, however, is insufficiently captured by supratentorial ICP (ICPsup) monitoring due to compartmentalization through the tentorium. The authors hypothesized that additional infratentorial ICP (ICPinf) monitoring can be clinically valuable in selected patients. The aims of this study were to demonstrate the safety and feasibility of ICPinf monitoring and to investigate the influence of the ICPinf on clinical outcome in a real-world setting. METHODS: Fifteen consecutive patients with posterior fossa (PF) lesions requiring surgery and anticipated prolonged neurointensive care between June 2019 and December 2021 were included. Simultaneous ICPsup and ICPinf were recorded. ICP burden was defined as a 15-minute interval with a mean ICP > 22 mm Hg. The Glasgow Outcome Scale score was assessed after 3 months. RESULTS: The mean ICPinf was substantially higher compared with ICPsup throughout the entire period of ICP recording (16.08 ± 4.44 vs 10.74 ± 3.6 mm Hg, p < 0.01). ICPinf was significantly higher in patients with unfavorable outcome when compared with those with favorable outcome (mean 17.2 ± 4.1 vs 11.4 ± 3.5 mm Hg, p < 0.05). Patients with unfavorable outcome showed significantly higher ICPinf burden compared with those with favorable outcome (mean 40.6 ± 43.8 vs 0.3 ± 0.4 hours, p < 0.05). Neither absolute ICPsup nor ICPsup burden was significantly associated with unfavorable outcome (p = 0.13). No monitoring-associated complications occurred. CONCLUSIONS: Supplementary ICPinf monitoring is safe and reliable. There is a significant transtentorial pressure gradient within the cranium showing elevated ICPs in the PF. Elevated ICP levels in the PF were strongly associated with unfavorable neurological outcome irrespective of ICPsup values.
- Klíčová slova
- ICP burden, infratentorial compartment, intracranial monitoring, intracranial pressure, outcome, posterior fossa, supratentorial compartment, traumatic brain injury,
- MeSH
- Glasgowská stupnice následků MeSH
- intrakraniální hypertenze * etiologie terapie MeSH
- intrakraniální tlak MeSH
- lidé MeSH
- monitorování fyziologických funkcí MeSH
- mozeček MeSH
- mozek MeSH
- poranění mozku * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
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.
BACKGROUND: Machine learning (ML) approaches can significantly improve the classical Rout-based evaluation of the lumbar infusion test (LIT) and the clinical management of the normal pressure hydrocephalus. OBJECTIVE: To develop a ML model that accurately identifies patients as candidates for permanent cerebral spinal fluid shunt implantation using only intracranial pressure and electrocardiogram signals recorded throughout LIT. METHODS: This was a single-center cohort study of prospectively collected data of 96 patients who underwent LIT and 5-day external lumbar cerebral spinal fluid drainage (external lumbar drainage) as a reference diagnostic method. A set of selected 48 intracranial pressure/electrocardiogram complex signal waveform features describing nonlinear behavior, wavelet transform spectral signatures, or recurrent map patterns were calculated for each patient. After applying a leave-one-out cross-validation training-testing split of the data set, we trained and evaluated the performance of various state-of-the-art ML algorithms. RESULTS: The highest performing ML algorithm was the eXtreme Gradient Boosting. This model showed a good calibration and discrimination on the testing data, with an area under the receiver operating characteristic curve of 0.891 (accuracy: 82.3%, sensitivity: 86.1%, and specificity: 73.9%) obtained for 8 selected features. Our ML model clearly outperforms the classical Rout-based manual classification commonly used in clinical practice with an accuracy of 62.5%. CONCLUSION: This study successfully used the ML approach to predict the outcome of a 5-day external lumbar drainage and hence which patients are likely to benefit from permanent shunt implantation. Our automated ML model thus enhances the diagnostic utility of LIT in management.
BACKGROUND: Decompressive craniectomy (DC) has become the definitive surgical procedure to manage a medically intractable rise in intracranial pressure. DC is a life-saving procedure resulting in lower mortality but also higher rates of severe disability. Although technically straightforward, DC is accompanied by many complications. It has been reported that complications are associated with worse outcome. We reviewed a series of patients who underwent DC at our department to establish the incidence and types of complications. METHODS: We retrospectively evaluated the incidence of complications after DC performed in 135 patients during the time period from January 2013 to December 2018. Postoperative complications were evaluated using clinical status and CT during 6 months of follow-up. In addition, the impact of potential risk factors on the incidence of complications and the impact of complications on outcome were assessed. RESULTS: DC was performed in 135 patients, 93 of these for trauma, 22 for subarachnoid hemorrhage, 13 for malignant middle cerebral artery infarction, and 7 for intracerebral hemorrhage. Primary DC was performed in 120 patients and secondary DC in 15 patients. At least 1 complication occurred in each of 100 patients (74%), of which 22 patients (22%) were treated surgically. The following complications were found: edema or hematoma of the temporal muscle (34 times), extracerebral hematoma (33 times), extra-axial fluid collection (31 times), hemorrhagic progression of contusions (19 times), hydrocephalus (12 times), intraoperative malignant brain edema (10 times), temporal muscle atrophy (7 times), significant intraoperative blood loss (6 times), epileptic seizures (5 times), and skin necrosis (4 times). Trauma (p = 0.0006), coagulopathy (p = 0.0099), and primary DC (p = 0.0252) were identified as risk factors for complications. There was no significant impact of complications on outcome. CONCLUSIONS: The incidence of complications following DC is high. However, we did not confirm a significant impact of complications on outcome. We emphasize that some phenomena are so frequent that they can be considered a consequence of primary injury or natural sequelae of the DC rather than its direct complication.
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
Through the decades of its use in the management of neurosurgical emergencies decompressive craniectomy has found its place as a life-saving procedure capable of a radical reduction of the intracranial pressure. Clinical results and rate of survival after decompressive craniectomy vary according to the primary diagnosis, and they have been a subject of multicentric randomized trials. However, considerable attention also needs to be kept on complications associated with the craniectomy. They are based not only on the procedures invasivity but also on the pathophysiological changes associated with a conversion of the closed intracranial space to an open one. The complications may further disturb the postoperative care and convalescence in the surviving patients, and therefore in the salvageable patients the indication of decompressive craniectomy should be based on information about the expected outcome and complications rate, at the same moment prevention, early recognition and adequate therapy of the complications should be emphasized. This work describes the most common complications occurring in patients after decompressive craniectomy, their pathophysiological principles and means of treatment and prevention.
- Klíčová slova
- complications, decompressive craniectomy, intracranial hypertension,
- MeSH
- dekompresní kraniektomie škodlivé účinky MeSH
- intrakraniální tlak MeSH
- lidé MeSH
- pooperační komplikace MeSH
- poranění mozku * MeSH
- výsledek terapie MeSH
- zákroky plastické chirurgie * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
OBJECTIVES: Accurate values of the intracranial pressure (ICP) and mean arterial pressure (MAP) are the prerequisite for calculating cerebral perfusion pressure (CPP). Increased ICP values decrease CPP. The origin of ICP increase in the clinical cases after brain ischemia and diffuse brain injury is the cellular brain edema (CE). Short-term monitoring of ICP and MAP is possible only in the unconscious patients, in experiments with rats it used to be possible only in general anesthesia. Long-term monitoring of ICP or MAP in the clinical practice is not possible. We therefore introduce an experimental model with telemetric monitoring. METHODS: ICP (subdurally) and MAP (intracarotically) were monitored in freely moving rats for 72 hours by DSI™ (Data Sciences International) telemetry system. The control group consisted of 8 rats, the experimental group had 8 animals with CE-induced by water intoxication. RESULTS: The mean MAP, ICP and CPP values were significantly higher in the experimental group. Average values of MAP were 19.9 mmHg (18%), ICP 5.3 mmHg (55%), CPP 14.5 mmHg (15% higher). CONCLUSION: The results of the pilot study verified possibilities of long-term telemetric monitoring of the mean arterial and intracranial pressures for the determination of current cerebral perfusion pressure in freely moving rats under physiological conditions and with increased intracranial pressure due to the induced cerebral edema. Detailed analysis of the course of the curves in the experimental group revealed episodes of short-term CPP reduction below the optimum value of 70 mmHg. Interpretation of these episodes requires simultaneous monitoring of rat behavior.
- MeSH
- ambulantní monitorování přístrojové vybavení metody MeSH
- arteriální tlak * MeSH
- edém mozku patofyziologie MeSH
- intrakraniální tlak * MeSH
- krysa rodu Rattus MeSH
- mozkový krevní oběh MeSH
- pilotní projekty MeSH
- technologie dálkového snímání přístrojové vybavení metody MeSH
- telemetrie přístrojové vybavení metody MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- zvířata 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
Continuous monitoring of the intracranial pressure (ICP) detects impending intracranial hypertension resulting from the impaired intracranial volume homeostasis, when expanding volume generates pressure increase. In this study, cellular brain edema (CE) was induced in rats by water intoxication (WI). Methylprednisolone (MP) was administered intraperitoneally (i.p.) before the start of CE induction, during the induction and after the induction. ICP was monitored for 60 min within 20 h after the completion of the CE induction by fibreoptic pressure transmitter. In rats with induced CE, ICP was increased (Mean+/-SEM: 14.25+/-2.12) as well as in rats with MP administration before the start of CE induction (10.55+/-1.27). In control rats without CE induction (4.62+/-0.24) as well as in rats with MP applied during CE induction (5.52+/-1.32) and in rats with MP applied after the end of CE induction (6.23+/-0.73) ICP was normal. In the last two groups of rats, though the CE was induced, intracranial volume homeostasis was not impaired, intracranial volume as well as ICP were not increased. It is possible to conclude that methylprednisolone significantly influenced intracranial homeostasis and thus also the ICP values in the model of cellular brain edema.
- MeSH
- antiflogistika farmakologie terapeutické užití MeSH
- edém mozku farmakoterapie etiologie patofyziologie MeSH
- intoxikace vodou komplikace farmakoterapie patofyziologie MeSH
- intrakraniální tlak účinky léků fyziologie MeSH
- krysa rodu Rattus MeSH
- methylprednisolon farmakologie terapeutické užití MeSH
- mozek cytologie účinky léků patofyziologie MeSH
- potkani Wistar MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Názvy látek
- antiflogistika MeSH
- methylprednisolon MeSH
