Systems analysis of intracranial pressure

Chopp, Michael; Portnoy, Harold D.

doi:10.3171/jns.1980.53.4.0516

Cited by 144 publications

(40 citation statements)

References 25 publications

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“…Several lines of evidence suggest that intracranial compliance is more reliably predicted by pulse pressure than by mean pressure [5,6,7,8,9]. Increased pulse pressure amplitude evaluated by short sequences of ICP charts was a predictor of adult hydrocephalus requiring treatment [9].…”

Section: Introductionmentioning

confidence: 99%

Assessment of Childhood Intracranial Pressure Recordings Using a New Method of Processing Intracranial Pressure Signals

Eide¹

2005

Pediatr Neurosurg

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Background: Intracranial compliance may be more reliably predicted by the pulsatile component (pulse pressure) than the steady (mean pressure) component of intracranial pressure (ICP). A new method of processing continuous ICP signals assessing both components of ICP is described and applied to the ICP recordings of 6 pediatric cases. Method: The new method was applied to each subsequent 6-second time sequence window of a continuous ICP signal. For time sequence windows including single ICP waves, the following time sequence (TS.x)-related parameters were computed: (a) mean ICP (i.e. TS.MeanP) was computed according to the currently used and known technology; (b) the mean ICP wave was computed according to the new method, characterized by mean wave amplitude (i.e. TS.MeanWavedP) and mean wave latency (i.e. TS.MeanWavedT). Cases No. 1–4 were treated for hydrocephalus and cases No. 5 and 6 for craniosynostosis. Results: In 5 children, clinical intracranial hypertension was associated with elevations of mean ICP above 15–20 mm Hg of variable durations. The ICP recordings of the 5 children with intracranial hypertension and successful outcome after surgery revealed mean wave amplitude values above 5 mm Hg. Mean wave latency was more variable, ranging between 0.10 and 0.25 s. Conclusions: In the children with intracranial hypertension and successful outcome after surgery, mean wave amplitude was variably above 5 mm Hg. It is suggested that mean wave amplitude may be a useful parameter by more directly predicting cerebral compliance than mean ICP.

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Section: Introductionmentioning

confidence: 99%

Assessment of Childhood Intracranial Pressure Recordings Using a New Method of Processing Intracranial Pressure Signals

Eide¹

2005

Pediatr Neurosurg

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“…They demonstrated from laboratory studies on hypercapnic preparations that during normal tone the ABP and ICP recordings do not look similar [8,9]. In contrast, during deep hypercapnia and maximal vascular dilation, when the brain has lost the ability to autoregulate flow, these pressure recordings look very similar [8,9]. The numerical approach this earlier group used to exploit their laboratory findings was to examine changes in the coherence function derived from the ICP and ABP recordings.…”

Section: Discussionmentioning

confidence: 99%

Intracranial pressure monitoring: relationship between indices of cerebrovascular reserve, system bandwidth, and cerebral perfusion

Daley

Sulhyung

Timmons³

et al.

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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Loss of cerebrovascular reserve with the resultant increase of cerebral perfusion, and disruption of capillary fluid balance generally leads to the development of cerebral edema, a serious secondary complication of traumatic brain injury. Two indices of cerebrovascular reserve derived from recordings of intracranial pressure (ICP) and arterial blood pressure (ABP) have been proposed [1][2][3]. The purpose of this study was to examine the relationship between changes of arteriolar resistance, cerebral perfusion, system bandwidth, and the indices of cerebrovascular reserve during dilatory challenge induced by ventilation with CO 2 . Steady state values of arteriolar diameter significantly increased during hypercapnia resulting in a decrease of arteriolar resistance by more than 90%. Cerebral perfusion pressure (CPP) was found to range from -18% to 12%. Significant correlation between percent change of relative flow and either indices of cerebrovascular reserve, arteriolar resistance, or system bandwidth were not determined. System bandwidth between ABP and ICP and the Correlation Index of cerebrovascular reserve (CorrX), were found to be exponentially correlated with values ranging from 0.85 to .99 with a group (n=5) mean (+S.D.) of 0.94 (+0.06). Such a relationship suggests that near minimal tone, further losses of tone lead to changes of stiffness that produce large changes in system bandwidth.

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“…About two decades ago Portnoy and his colleagues demonstrated from laboratory studies on normocapnic preparations that during normal tone the arterial and intracranial pressure signals do not look similar [3,4]. As shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

“…When the ICP and ABP recordings are nearly identical the coherence function approaches unity. Generally, their observations and the observations of others using a systems approach have suggested that the more similar the spectral components of the ICP recording are to those of the ABP recording, the more likely cerebral autoregulation is impaired [3,5,6].…”

Section: Introductionmentioning

confidence: 99%

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Modeling cyclic variation of intracranial pressure

Daley

Pasley

Leffler³

2001 Conference Proceedings of the 23rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society

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To test the theoretical feasibility that low frequency baseline changes of the intracranial pressure (ICP) recording during mechanical ventilation are due to cyclic extravascular compressional modulation primarily of the cerebral venous bed, an established isovolumetric model of cerebrospinal fluid dynamics proposed by Ursino was modified [1,2]. These modifications were made to address the hypothesis that: 1) cyclic extravascular compressional modulation of the cerebral venous bed occurs during positive pressure inhalation; and 2) the degree of modulation is diminished with increasing vascular dilation induced by increasing the level of the partial pressure of carbon dioxide (PCO 2 ) within the arterial blood. Modification of the isovolumetric model was accomplished by introducing a cyclic modulation of the resistance of the cerebral venous bed synchronized with ventilation. Simulated model recordings demonstrated that the correlation index between arterial blood pressure and ICP progressively increased monotonically as the level of PCO 2 increased from 30 mmHg to 80 mmHg. These results support the premise that during positive pressure ventilation, cyclic extravascular compressional modulation of primarily the cerebral venous bed produces a cyclic variation of ICP and the degree of modulation is dependent on the state of vascular dilation.

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Systems analysis of intracranial pressure

Cited by 144 publications

References 25 publications

Assessment of Childhood Intracranial Pressure Recordings Using a New Method of Processing Intracranial Pressure Signals

Assessment of Childhood Intracranial Pressure Recordings Using a New Method of Processing Intracranial Pressure Signals

Intracranial pressure monitoring: relationship between indices of cerebrovascular reserve, system bandwidth, and cerebral perfusion

Modeling cyclic variation of intracranial pressure

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