Cerebral Hemodynamics in Acute Ischemic Stroke

Acute ischemic stroke arises when an arterial obstruction abruptly reduces blood supply to a region of the brain, creating an ischaemic core surrounded by a potentially salvageable penumbra. Cerebral haemodynamics in this context encompass the interplay between systemic arterial pressure, intracranial vascular resistance and collateral circulation. Under normal conditions, cerebral autoregulation preserves perfusion over a range of blood pressures by modulating arteriolar tone. In acute stroke, autoregulatory capacity is compromised in the infarcted territory, leaving perfusion vulnerable to systemic fluctuations and postural changes. Therapeutic interventions seek either to augment blood flow to the penumbra or to prevent secondary injury from hypoperfusion and oedema. Continuous monitoring techniques—from transcranial Doppler assessment of flow velocity to near-infrared spectroscopy measures of tissue oxygenation—have helped to refine the timing and nature of mobilisation, head-positioning protocols and pharmacological therapies. A clear understanding of dynamic blood flow responses underpins advances in mechanical thrombectomy, haemodynamic augmentation strategies and rehabilitation protocols aimed at optimising neurological recovery on a global scale.

Research from Nature Portfolio

One multicentre randomised trial evaluated the effect of a –20° Trendelenburg head-down position initiated within 24 hours of moderate anterior circulation stroke onset. While the intervention proved safe and feasible, with no severe adverse events, it did not significantly increase the proportion of patients achieving favourable functional outcomes at 90 days compared with standard care.

A large retrospective analysis of anterior circulation large artery occlusions characterised eight distinct occlusion subtypes and correlated each with clinical presentation and prognosis. It revealed that patients with tandem or bilateral occlusions experienced poorer outcomes and that specific subtypes were prone to artery-to-artery embolism versus hypoperfusion. These findings support tailored haemodynamic management and secondary prevention strategies according to occlusion pattern.

Cerebral Hemodynamics in Acute Ischemic Stroke publication trend

The graph below shows the total number of articles in cerebral hemodynamics in acute ischemic stroke across all publications each year (not limited to Nature Index journals).

Technical terms

Cerebral autoregulation: the intrinsic ability of cerebral blood vessels to maintain constant blood flow despite changes in systemic arterial pressure.

Cerebral perfusion pressure: the net pressure gradient driving blood flow through the brain, calculated as mean arterial pressure minus intracranial pressure.

Transcranial Doppler: a non-invasive ultrasound technique that measures blood flow velocity in large intracranial arteries.

Near-infrared spectroscopy: a optical method for monitoring regional cerebral oxygenation by measuring changes in haemoglobin species.

Large vessel occlusion: blockage of a major intracranial artery, often resulting in extensive ischaemia and poor outcomes without rapid reperfusion.

Penumbra: the peri-infarct tissue zone with critically reduced perfusion that remains viable for a limited period after arterial occlusion.

References

1. A randomized trial of Trendelenburg position for acute moderate ischemic stroke. Nature Communications (2023).
2. Subtypes of anterior circulation large artery occlusions with acute brain ischemic stroke. Scientific Reports (2020).
3. Cerebral hemodynamic response to upright position in acute ischemic stroke. Frontiers in Neurology (2024).
4. Time-domain near-infrared spectroscopy in acute ischemic stroke patients. Neurophotonics (2019).
5. Transient Laterality of Cerebral Oxygenation Changes in Response to Head-of-Bed Manipulation in Acute Ischemic Stroke. Journal of Clinical Medicine (2019).