Cerebrovascular reactivity

Cerebrovascular reactivity (CVR) reflects the capacity of blood vessels to dilate and is an important marker for brain vascular reserve.

The purpose of a retrospective observational study was to investigate the long-term changes in cerebrovascular reactivity (CVR) as a measure of cerebral hemodynamics in patients with Intracranial atherosclerotic stenoocclusive disease (IC-SOD) after they have undergone an Extra intracranial bypass surgery. Twenty-six patients suffering from IC-SOD were selected from the CVR database. Nineteen patients underwent unilateral and 7 underwent bilateral revascularization. CVR measurements were done using Blood oxygen level dependent functional magnetic resonance imaging and precisely controlled CO2 and expressed as ΔBOLD (%)/Δ PETCO2 (mmHg). Trends in CVR over time were compared in both vascularized and non-vascularized hemispheres. Repeated measures analysis of variance with Greenhouse-Geisser correction was used to determine CVR changes within the grey matter MCA for longitudinal assessments. Overall, re-vascularized hemisphere showed a significant increase in CVR at the first follow-up, followed by a slight decrease at the second follow-up that significantly increased compared to the pre-bypass. However, the changes in the postoperative CVR were quite variable across the patients. Similar variability was seen in subsequent follow-ups, with a slight overall decline in the long term CVR as compared with first post-operative CVR.

The study demonstrates that EC-IC bypass has a beneficial long-term effect on cerebral hemodynamics and this effect varies between patients probably due to the variability in the underlying vascular pattern receiving the bypass. Hence, in the postoperative follow-up of patients routine functional imaging to monitor cerebral hemodynamics may be useful as the risk of stroke and cognitive decline remain present with impaired CVR 1).

Rosen C, McKetton L, Russell J, Sam K, Poublanc J, Crawley A, Han JS, Sobczyk O, Duffin J, Mandell DM, Tymianski M, Fisher JA, Mikulis DJ, Venkatraghavan L. Long-term changes in cerebrovascular reactivity following EC-IC bypass for intracranial steno-occlusive disease. J Clin Neurosci. 2018 Jun 12. pii: S0967-5868(18)30435-1. doi: 10.1016/j.jocn.2018.06.009. [Epub ahead of print] PubMed PMID: 29907385.
  • cerebrovascular_reactivity.txt
  • Last modified: 2018/06/17 15:56
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