scholarly journals Intracranial pressure dynamics in patients with acute brain damage

1997 ◽  
Vol 82 (4) ◽  
pp. 1270-1282 ◽  
Author(s):  
M. Ursino ◽  
C. A. Lodi ◽  
S. Rossi ◽  
N. Stocchetti
Keyword(s):  
Intracranial Pressure ◽  
Brain Damage ◽  
Blood Volume ◽  
Time Constant ◽  
Cerebral Blood Volume ◽  
Volume Index ◽  
Parameter Estimates ◽  
Time Pattern ◽  
Pressure Dynamics ◽  
Parameter Values

Ursino, M., C. A. Lodi, S. Rossi, and N. Stocchetti.Intracranial pressure dynamics in patients with acute brain damage. J. Appl. Physiol. 82(4): 1270–1282, 1997.—The time pattern of intracranial pressure (ICP) during pressure-volume index (PVI) tests was analyzed in 20 patients with severe acute brain damage by means of a simple mathematical model. In most cases, a satisfactory fitting between model response and patient data was achieved by adjusting only four parameters: the cerebrospinal fluid (CSF) outflow resistance, the intracranial elastance coefficient, and the gain and time constant of cerebral autoregulation. The correlation between the parameter estimates was also analyzed to elucidate the main mechanisms responsible for ICP changes in each patient. Starting from information on the estimated parameter values and their correlation, the patients were classified into two main classes: those with weak autoregulation (8 of 20 patients) and those with strong autoregulation (12 of 20 patients). In the first group of patients, ICP mainly reflects CSF circulation and passive cerebral blood volume changes. In the second group, ICP exhibits paradoxical responses attributable to active changes in cerebral blood volume. Moreover, in two patients of the second group, the time constant of autoregulation is significantly increased (>40 s). The correlation between the parameter estimates was significantly different in the two groups of patients, suggesting the existence of different mechanisms responsible for ICP changes. Moreover, analysis of the correlation between the parameter estimates might give information on the directions of parameter changes that have a greater impact on ICP.

Cerebral blood volume index as a predictor of functional independence after basilar artery thrombectomy

2021 ◽  
Author(s):  
Rahul R. Karamchandani ◽  
Dale Strong ◽  
Jeremy B. Rhoten ◽  
Tanushree Prasad ◽  
Jacob Selig ◽  
...  
Keyword(s):  
Blood Volume ◽  
Basilar Artery ◽  
Cerebral Blood Volume ◽  
Functional Independence ◽  
Volume Index

Rheographic assessment of cerebral blood volume and correlations with changes in intracranial pressure

1976 ◽  
Vol 34 (1-4) ◽  
pp. 287-294 ◽  
Author(s):  
A. L. Benabid ◽  
J. C. Persat ◽  
J. F. Piquard ◽  
M. Barge ◽  
J. P. Chirossel
Keyword(s):  
Intracranial Pressure ◽  
Blood Volume ◽  
Cerebral Blood Volume

Effects of increased intracranial pressure on cerebral blood volume, blood flow, and oxygen utilization in monkeys

1975 ◽  
Vol 43 (4) ◽  
pp. 385-398 ◽  
Author(s):  
Robert L. Grubb ◽  
Marcus E. Raichle ◽  
Michael E. Phelps ◽  
Robert A. Ratcheson
Keyword(s):  
Blood Flow ◽  
Intracranial Pressure ◽  
Metabolic Rate ◽  
Intracranial Hypertension ◽  
Cerebral Perfusion Pressure ◽  
Blood Volume ◽  
Cerebral Perfusion ◽  
Cerebral Blood Volume ◽  
Perfusion Pressure ◽  
Cerebral Metabolic Rate

✓ The relationship of cerebral blood volume (CBV) to cerebral perfusion pressure (CPP), cerebral blood flow (CBF), and the cerebral metabolic rate for oxygen (CMRO2) was examined in rhesus monkeys. In vivo tracer methods employing radioactive oxygen-15 were used to measure CBV, CBF, and CMRO2. Cerebral perfusion pressure was decreased by raising the intracranial pressure (ICP) by infusion of artificial cerebrospinal fluid (CSF) into the cisterna magna. The production of progressive intracranial hypertension to an ICP of 70 torr (CPP of 40 torr) caused a rise in CBV accompanied by a steady CBF. With a further increase in ICP to 94 torr, CBV remained elevated without change while CBF declined significantly. Cerebral metabolic rate for oxygen did not change significantly during intracranial hypertension. For comparison, CPP was lowered by reducing mean arterial blood pressure in a second group of monkeys. Only CBF was measured in this group. In this second group of animals, the lower limit of CBF autoregulation was reached at a higher CPP (CPP ∼ 80 torr) than when an increase in ICP was employed (CPP ∼ 30 torr).

Abstract P557: Hypoperfusion Intensity Ratio and Cerebral Blood Volume Index as Predictors of Outcome for Recanalized Middle Cerebral Artery Occlusions

Stroke ◽  
2021 ◽  
Vol 52 (Suppl_1) ◽  
Author(s):  
Jonathan M Parish ◽  
Dale Strong ◽  
Tanushree Prasad ◽  
Jeremy B Rhoten ◽  
Jonathan D Clemente ◽  
...  
Keyword(s):  
Middle Cerebral Artery ◽  
Computerized Tomography ◽  
Blood Volume ◽  
Cerebral Artery ◽  
Intensity Ratio ◽  
Cerebral Blood Volume ◽  
Favorable Outcome ◽  
Volume Index ◽  
Collateral Flow ◽  
Mca Occlusion

Introduction: Preliminary data suggest the Hypoperfusion Intensity Ratio (HIR) and the Cerebral Blood Volume Index (CBVI) derived from Computerized Tomography Perfusion (CTP) imaging predict the rate of collateral flow, speed of infarct growth, and clinical outcome. We hypothesized that functional outcomes at hospital discharge would be significantly better for middle cerebral artery (MCA) occlusion patients achieving Thrombolysis in Cerebral Infarction (TICI) 2b or greater recanalization with presenting hospital CTPs consistent with “good” (HIR <0.5 and CBVI >0.7) versus “poor” (HIR ≥0.5 and CBVI ≤0.7) indices. Methods: We conducted a retrospective cohort study. A neuroradiologist confirmed the MCA occlusion based on the initial Computerized Tomography Angiogram (CTA). All TICI scores were confirmed by neurointerventionalists blinded to patient outcomes. We defined independent outcome as mRS ≤2, and favorable outcome as an mRS ≤3. We additionally stratified patients as initially presenting to thrombectomy versus non-thrombectomy centers. Results: We identified a total of 162 patients over a 3 ½ year period with an MCA occlusion achieving TICI 2b recanalization or greater, of whom 67 had good indices and 48 had poor indices. For patients with good compared to poor indices, there was a trend for achieving independent outcome (55% vs 37%, p=0.061) that reached significance for favorable outcome (69% vs 50%, p=0.043). Limiting the analysis to only patients presenting to non-thrombectomy centers (n=67), these findings were consistent, with a trend for achieving independent outcome for good versus poor collaterals (48% vs 30% p=0.173), which was again significant for a favorable outcome (66% vs 39%, p=0.036). Across all patients, HIR <0.5 (n=86) or CBVI >0.7 (n=95) were not independently associated with independent outcomes, but for patients presenting to non-thrombectomy centers, an HIR <0.5 alone (n=51) was significantly associated with favorable outcome. Conclusion: For MCA occlusion patients achieving TICI 2b recanalization, the combination of good HIR and CBVI is significantly associated with a favorable functional outcome. For patients presenting to non-thrombectomy centers, HIR alone may be sufficient to predict favorable outcome.

Abstract T P371: Utility of Cerebral Oximetry with Cerebral Blood Volume Index (CBVI) in Detecting Pediatric Strokes

Stroke ◽  
2015 ◽  
Vol 46 (suppl_1) ◽  
Author(s):  
Thomas J Abramo ◽  
Lori Jordan ◽  
Zeah Harris ◽  
Mark Meredith ◽  
Mark Meredith ◽  
...  
Keyword(s):  
Blood Volume ◽  
Cerebral Blood Volume ◽  
Screening Tool ◽  
Altered Mental Status ◽  
Contralateral Side ◽  
Cerebral Oximetry ◽  
Volume Index ◽  
Pediatric Stroke ◽  
Cerebral Pathology ◽  
Stroke Knowledge

Pediatric Strokes are increasing with recognition and imaging delays. Limited pediatric stroke knowledge, vague signs & symptoms and no reliable stroke detection tools is the cause. Improving recognition improves outcomes. Objective: To assess utility of Left & Right Cerebral rcSO2 and cerebral blood volume index (CBVI) in Pediatric Stroke Alert and Altered Mental Status (AMS) patients. Methods: Observational study of Stroke Alert & AMS patient’s Cerebral rcSO2 and CBVI. Stroke rcSO2 and CBVI values in stroke patients were compared to controls & AMS (no cerebral pathology) patients. Results: Controls (N=133), Stroke alert (N=25) & AMS stroke (N=52)'s rcSO2, CBVI means were consistent 0-60 minutes. Lower rcSO2 with or without CBVI readings correlated with stroke (Left rcSO2, CBVI (P<0.0001), Right rcSO2 (P=0.0038), CBVI (p=0.0006)). A 19.1% rcSO2 side difference had 100% PPV for stroke. Across 0-60 minutes, rcSO2, CBVI were consistent for stroke & type (Hemorrhagic or Ischemic) (P<0.0001). Left Stroke’s rcSO2, CBVI were lower than Right Strokes (P<0.0001). Hemorrhagic ipsilateral stroke and contralateral side had lower rcSO2, CBVI (P<0.001) then Ischemic. Conclusion: The rcSO2, CBVI difference between sidess objectively and consistently detected stroke, location, and stroke types (Hemorrhagic or Ischemic). A 19.1% rcSO2 differencehad had 100% PPV for detecting strokes demonstrating cerebral oximetry’s utility. Cerebral Oximetry with CBVI has shown its’ potential as an objective screening tool for identify pediatric strokes and types. Cerebral Oximetry with CBVI has potential for expediting stroke recognition and decreasing imaging time.

Cerebrovascular carbon dioxide reactivity assessed by intracranial pressure dynamics in severely head injured patients

1995 ◽  
Vol 82 (3) ◽  
pp. 386-393 ◽  
Author(s):  
Masaaki Yoshihara ◽  
Kuniaki Bandoh ◽  
Anthony Marmarou
Keyword(s):  
Intracranial Pressure ◽  
Glasgow Coma Scale ◽  
Blood Volume ◽  
Volume Change ◽  
Volume Index ◽  
Content Type ◽  
Coma Scale ◽  
Head Injured ◽  
Injured Patients ◽  
Fine Print

✓ Appropriate management of intracranial pressure (ICP) in severely head injured patients depends in part on the cerebral vessel reactivity to PCO2; loss of CO2 reactivity has been associated with poor outcome. This study describes a new method for evaluating vascular reactivity in head-injured patients by determining the sensitivity of ICP change to alterations in PCO2. This method was combined with measurements of the pressure volume index (PVI), which allowed calculation of blood volume change necessary to alter ICP. The objective of this study was to investigate the ICP response and the blood volume change corresponding to alterations in PCO2 and to examine the correlation of responsivity and outcome as measured on the Glasgow Outcome Scale. The PVI and ICP at different end-tidal PCO2 levels produced by mild hypo- and hyperventilation were obtained in 49 patients with Glasgow Coma Scale scores of less than 8 and over a wide range of PCO2 (25 to 40 mm Hg) in eight patients. Given the assumption that the PVI remained constant during alteration of PaCO2, the estimated blood volume change per torr change of PCO2 was calculated by the following equation: BVR = PVI × Δlog(ICP)/ΔPCO2, where BVR = blood volume reactivity. The data in this study showed that PVI remained stable with changes in PCO2, thus validating the assumption used in the blood volume estimates. Moreover, the response of ICP to PCO2 alterations followed an exponential curve that could be described in terms of the responsivity indices to capnic stimuli. It was found that responsivity to hypocapnia was reduced by 50% compared to responsivity to hypercapnia measured within 24 hours of injury (p < 0.01). The sensitivity of ICP to estimated blood volume changes in patients with a PVI of less than 15 ml was extremely high with only 4 ml of blood required to raise ICP by 10 mm Hg. The authors conclude from these data that, following traumatic injury, the resistance vessels are in a state of persistent vasoconstriction, possibly due to vasospasm or compression. Furthermore, BVR correlates with outcome on the Glasgow Coma Scale, indicating that assessment of cerebrovascular response within the first 24 hours of injury may be of prognostic value.

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