Transient ischemic attack may present a target for normobaric hyperoxia treatment

According to the new revised tissue-based definition, transient ischemic attack is a transient episode of neurological dysfunction caused by a focal brain, spinal cord, or retinal ischemia without acute infarction. This review addresses the pathophysiology of transient ischemic attack and the impact of normobaric hyperoxia on the penumbral tissue. Neuroimaging in transient ischemic attack patients and advances in penumbra imaging allow the transient ischemic attack, from pathophysiological viewpoint, to be defined as an ischemic penumbra of varied duration, which could proceed to a cerebral infarction or reduce to a benign oligemia. Persisting perfusion abnormalities are observed, despite resolution of the neurological symptoms. Preclinical and clinical studies have shown that the normobaric hyperoxia treatment is associated with improvement of hemodynamic and metabolic disturbances, particularly in the penumbral tissue. Transient ischemic attack, considered an ischemic penumbra, may present an ideal target for early normobaric hyperoxia therapy, administered as soon as possible after the onset of the neurological deficit. Follow-up perfusion imaging could guide and individualize the treatment.