Invited Speaker Abstract Asia Pacific Stroke Conference 2024

Non-invasive detection of stroke in sheep with optical brain pulse monitoring (111574)

Jessica M Sharkey 1 2 , Elliot J Teo 1 3 , Sung W Chung 1 , Sigrid Petautschnig 1 3 , Sally A Grace 1 , Jack Hellerstedt 1 , Thomas Krieg 4 , Michael Murphy 2 , Annabel Sorby-Adams 2 4 , Barry Dixon 1 3 5
  1. Cyban Pty Ltd, East Melbourne, VIC, Australia
  2. School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide, Adelaide, South Australia, Australia
  3. Department of Critical Care Medicine, St Vincent's Hospital, Melbourne, Victoria, Australia
  4. Department of Medicine, University of Cambridge, Hills Road, Cambridge, United Kingdom
  5. Department of Critical Care, University of Melbourne, Melbourne, Victoria, Australia

Background: Early stroke detection and intervention is critical to improve outcomes in at-risk patients. Optical brain pulse monitoring (OBPM) offers bilateral, non-invasive, continuous measurement of the brain pulse waveform, from which cerebral oxygen saturation (StO2%), intracranial pressure (ICP), and brain compliance can be derived, making it sensitive to reduced cerebral perfusion.

Objective: To observe OBPM changes during ischemic stroke and following reperfusion in a clinically relevant sheep model.

Methods: Eleven Merino wethers (18–24 months) underwent right middle cerebral artery occlusion (MCAO) for four hours, followed by reperfusion. OBPM measurements were taken in the ipsilateral hemisphere (n = 11) or bilaterally (n = 5) at baseline, during MCAO, early reperfusion (ER; ~30 minutes post-reperfusion), and late-reperfusion (LR; ~4 hours post-reperfusion). As a comparator, invasive brain tissue oxygen (PbtO2) monitoring was conducted in the ipsilateral hemisphere, and ICP monitoring in the contralateral hemisphere. Infarct volume post-reperfusion was measured using MRI. Generalized estimator models adjusted for false discovery were used with significance set at p < 0.05.

Results: The OBPM StO2% measurement showed significant decreases in both hemispheres, with larger drops in the setting of larger infarct volumes (p < 0.05). A significant reduction in PbtO2 was observed during MCAO (p < 0.001), normalizing during reperfusion. ICP analyses revealed significant reductions during MCAO and ER (p <0.01).

Conclusion: OBPM is a safe and promising tool for real-time stroke detection, with the potential to enable expeditious clinical decision-making and improve patient outcomes.