2021 Volume 49 Issue 1 Pages 15-25
Purpose: Early diagnosis of cerebral vasospasm is a key factor for therapeutic management of cerebral vasospasm after subarachnoid hemorrhage (SAH). However, a noninvasive method of diagnosing delayed ischemic neurological deficit (DIND) has not been established. Therefore, we propose a new method of diagnosing cerebral ischemia by detecting changes in cerebral oxygenation using near infrared optical topography (OT) with oxygen inhalation.
Materials and Methods: We used a 44-channel OT system covering the bilateral fronto-temporo-parietal areas to assess 29 patients who underwent surgery within 72 h from the onset of SAH. The patients inhaled room air followed by oxygen for 2 min, after which peripheral oxygen saturation (SpO2) at the index fingertip was continuously monitored. The patients were assessed using I-123 iodoamphetamine single photon emission computed tomography (IMP-SPECT) and OT on the same day. Ischemic findings were confirmed using principal component analysis with reference to the systemic SpO2 value.
Results: Seven out of 29 patients developed DIND. Evidence of ischemia was identified by OT in all seven patients before the onset of DIND. The OT findings were consistent with SPECT findings in 26 (89.7%) of the 29 patients. Enhanced treatment of vasospasm improved ischemia in 65% of patients in whom early ischemic findings had been detected by OT, and consequently, DIND did not develop. After arterial fasudil injection, OT detected an improvement in ischemic findings.
Discussion and Conclusions: Our method might help in early detection of cerebral ischemia before the onset of DIND and, thus, be clinically useful in the assessment of cerebral ischemia with vasospasm and in the perioperative therapeutic management of cerebral vasospasm.
