Our aim was to investigate head of bed (HOB) positioning maneuvers during an acute LVO presentation using continuous, non-invasive multimodality neuromonitoring to evaluate dynamic cerebral autoregulation (CA) changes.  

We retrospectively analyzed adult patients with acute LVO admitted to the Neurointensive Care Unit between 01/2021- 04/2021. Invasive blood pressure (ABP) monitoring and Transcranial doppler (TCD) or near-infrared spectroscopy (NIRS) monitoring was used to calculate non-invasive CA indices (MXa/TOx respectively). Patients were monitored for a minimum of 10 minutes with HOB at 0 and 30 degrees. TOx/MXa were calculated as moving correlation coefficient of ABP and ipsilateral cerebral oximetry or mean flow velocities. A previously validated threshold of 0.3 was used with intact CA trending to a near zero or negative correlation.  Neurologic outcomes were reported by discharge modified rankin score (mRS). Data was analyzed using ICM+ and RStudio software platforms.

10 patients (50% male, 65±10.5 years, NIHSS 6±3.65) were identified.  CT Angiography revealed internal carotid (4/10), proximal middle cerebral artery (5/10), or tandem (1/10) occlusion. Thrombolytic and immediate endovascular therapy was deferred in all patients for minimal deficits or lack of clinical-perfusion mismatch. Before HOB maneuvers,4 patients had impaired CA at 30 degrees. There was significant improvement in CA at head of bed positioning to 0 degrees (0.190±0.409) in comparison to 30 degrees (0.241± 0.322, p=0.001). CA was also found to be significantly impaired in those with higher neurologic disability at discharge (mRS 0-2: 0.163±0.312 vs mRS 3-6: 0.202±0.389, p=0.001).

This pilot study suggests head positioning may improve cerebral autoregulation in acute LVO patients. Further investigations to correlate CA monitoring with clinical outcomes is needed to help identify LVO patients that are at high-risk for neurologic deterioration.