Background:
Stroke is a leading global cause of mortality and morbidity. Early recognition of stroke and rapid appropriate treatment significantly improves patient outcomes and reduces long-term disability. Continuous non-invasive optical brain pulse monitoring (OBPM) enables early detection of stroke, reducing time to treatment.
Methods:
Sensors from a non-invasive OBPM (Cyban, Melbourne Australia) were placed bilaterally over the middle cerebral artery (MCA) territories in 11 large vessel occlusion (LVO) stroke patients during emergency endovascular clot retrievals (ECR). The OBPM uses both red and infrared light to detect brain pulse waves associated with blood volume changes with each cardiac pulse. A qualitative assessment of unique brain pulse waveforms associated with stroke was completed.
Results:
Waveforms produced by the OBPM presented on a continuum resembling an arterial pressure trace to a venous pressure trace. Venous waveforms along this continuum were repeatably observed during periods of low cerebral blood flow in all 11 stroke patients.
Discussion
The repeatable waveforms identified in this study offer pathophysiological understanding suggesting the venous circulation has a dominant influence on the cerebral microcirculation in LVO strokes due to reduced arterial pressure levels. The presence of venous features in the waveform indicates very low arterial pressure and cerebral blood flow, which is typically associated with severe stroke and increased morbidity.
Conclusion: Detection of stroke is possible using continuous non-invasive optical brain pulse monitoring. Unique, repeatable waveforms provide insight into the pathophysiological mechanisms associated with stroke and brain injury enabling early detection and prognostication of stroke.