Occlusive hyperemia: a radiosurgical phenomenon?
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Updated: Oct 10, 2026
Near-Infrared Spectroscopy During Reactive Hyperemia for the Assessment of Lower Limb Vascular Function
Published on: March 22, 2024
1Department of Neurological Surgery, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA. pollock.bruce@mayo.edu
Objective:
Causes of neurological deficits after arteriovenous malformation (AVM) radiosurgery, including hemorrhage, radiation injury, and delayed cyst formation, are described.
Concept:
Occlusive hyperemia has been described as a reason for neurological deterioration after AVM resection. Thrombosis of draining veins or dural sinuses is thought to cause postoperative bleeding or neurological deficits secondary to venous hypertension. In a similar manner, local hemodynamic changes can occur in the brain adjacent to an AVM after radiosurgery if venous outflow is obstructed. Two patients are presented whose cases demonstrate this phenomenon.
Conclusion:
Patients can experience clinical worsening after AVM radiosurgery from premature thrombosis of draining veins. Local hemodynamic changes could explain why imaging changes thought to be radiation related occur more frequently after radiosurgery of AVMs than of tumors.
