Cerebral Vasospasm Affects Arterial Critical Closing Pressure

Abstract

The effect of cerebral vasospasm (CVS) after aneurysmal subarachnoid hemorrhage (SAH) on critical closing pressure (CrCP) has not been fully delineated. Using cerebral impedance methodology, we sought to assess the behavior of CrCP during CVS. As CrCP expresses the sum of intracranial pressure (ICP) and vascular wall tension, we also explored its role in reflecting changes in vascular tone occurring in small vessels distal to spasm. This retrospective analysis was performed using recordings from 52 patients, diagnosed with CVS through transcranial Doppler measurements. Critical closing pressure was calculated noninvasively using arterial blood pressure and blood flow velocity. Outcome was assessed at both discharge and 3 months after ictus with the Glasgow Outcome Scale. The onset of CVS caused significant decreases in CrCP (P = 0.025), without any observed significant changes in ICP (P = 0.134). Vasospasm induced asymmetry, with CrCP ipsilateral to CVS becoming significantly lower than contralateral (P = 0.025). Unfavorable outcomes were associated with a significantly lower CrCP after the onset of CVS (discharge: P = 0.014; 3 months after SAH: P = 0.020). Critical closing pressure is reduced in the presence of CVS in both temporal and spatial assessments. As ICP remained unchanged during CVS, reduced CrCP most probably reflects a lower wall tension in dilated small vessels distal to spasm.

Review of studies on dynamic cerebral autoregulation in the acute phase of stroke and the relationship with clinical outcome

“…Our review has several limitations: 1) we did not perform a meta-analysis with the data retrieved; though the studies are very heterogeneous, it would be interesting to perform an individual patient data meta-analysis (IPDMA) for all the sub-sections, as is planned for acute IS in the INFOMATAS initiative; 64 2) we did not perform a systematic review, although we intended to provide a comprehensive view of the state of the art of the issue; 3) several articles had to be excluded because they included data from patients > 48 hours after the ictus or the time of measurement was unclear or not reported; 118–130 and 4) our literature search was limited to the two most commonly used literature databases. However, in all the articles retrieved, the bibliographic reference was checked for further studies.…”

Middle cerebral artery flow, the critical closing pressure, and the optimal mean arterial pressure in comatose cardiac arrest survivors—An observational study

“…10 CrCP is a valuable and clinically relevant tool in cerebrovascular research, as it allows to estimate changes in cerebrovascular tone and minimal cerebral perfusion pressure to prevent collapse of vessels and ischemia. [11][12][13] The aim of the current study was to estimate CrCP of cerebrovascular motor tone during the post-cardiac arrest syndrome and to determine if CrCP differs between survivors and non-survivors. To place these values in a broader context, we also compared CrCP in post-cardiac arrest patients to normal controls.…”

Relationship Between Baroreflex and Cerebral Autoregulation in Patients With Cerebral Vasospasm After Aneurysmal Subarachnoid Hemorrhage

“…The cohort of patients utilized in our study has already been analyzed for assessment of prognosis in relation to BRS ( 5 ), and cerebral hemodynamic parameters ( 4 , 37 , 38 ). In this study, we aimed to assess integrative pathophysiology evaluating the interaction between the two main cardiovascular and cerebral homeostatic mechanisms that have been associated with prognosis after aSAH, e.g., BRS ( 5 ) and CA ( 4 ).…”