Continuous evaluation of regional oxygen saturation using invosr for monitoring of cerebral vasospasm after subarachnoid hemorrhage

Shigeki Ono, Keisuke Onoda, Koji Tokunaga, Kenji Sugiu, Isao Date

Research output: Contribution to journalArticlepeer-review


Objective: There are several tools for detection of cerebral vasospasm (VS) after subarachnoid hemorrhage (SAH), however, transcranial Doppler (TCD) is not always accurate for detecting VS, and microdialysis is, somehow, an invasive method. Although angiography is a gold-standard method to make a diagnosis of VS, it is not continuous and is not a bed-side examination for detecting VS. INVOSR monitoring which measures the regional oxygen saturation (rSO2) by using near inflated spectroscopy has been used for detecting cerebral ischemia during operations as reported elsewhere. We here use this noninvasive monitoring system for detecting cortical ischemia due to VS by measuring the continuous rSO2 after SAH, and determine whether it is useful for detecting VS and beneficial for treatment of VS. Methods: Six patients who suffered from SAH were nominated in this study. The probes of INVOSR (INVOS 5100R, Somanetics Corporation, MI, USA) were attached to the scalp in the areas anticipated to show VS considering the thickness of clots, from day 3 to the end of VS. After clipping or coiling, angiography was routinely performed around day 7 after SAH, or, at the timing if rSO2 continuously decreased by 10% compared to that of the contralateral side, or when the patients showed additional neurological deficits. If VS was detected, interventional treatment was performed using superselective intraarterial injection of Fasudil hydrochloride by microcatheters or percutaneous transluminal angioplasty if possible. This performance was once in a day at a maximum, and if the patients deteriorated the next day, the interventional therapy was repeatedly performed until the neurological deficits recovered. Results: The locations of ruptured aneurysms were 2 distal anterior cerebral artery, and 2 internal carotidposterior communicating artery, one middle cerebral artery, and one basilar artery-superior cerebral artery. Angiographic VS was seen in 4 of 6 patients. Symptomatic VS was seen in 2 of the patients having angiographic VS. Generally, INVOS value was around 70-65 in the both side in the early phase of the hemorrhagic attack, and then, gradually stabilized around the value of 60 from around the day 4 to 6. When INVOS value became less than 55, angiographic or symptomatic VS tended to occur. Recovery from ischemia seen on angiography or single photon emission CT also correlated with reincrease of rSO2 by INVOSR. Discussion: INVOSR is handy and noninvasive monitor for detecting VS after SAH. And it also evaluates chronological real-time rSO2 in the region of VS. This monitoring system may be superior to the conventional monitoring systems such as TCD or single photon emission CT.

Original languageEnglish
Pages (from-to)BP55-08H
JournalJournal of Cerebral Blood Flow and Metabolism
Issue numberSUPPL. 1
Publication statusPublished - Nov 13 2007

ASJC Scopus subject areas

  • Neurology
  • Clinical Neurology
  • Cardiology and Cardiovascular Medicine


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