5-Second Science: Transient Ischemic Attacks Are Not Harmless

The recent study by Del Bene and colleagues (2025) in JAMA Neurology challenges our traditional understanding of transient ischemic attacks (TIAs). For many years, the medical community has mistakenly viewed these "mini-strokes" as relatively harmless events because their symptoms—such as slurred speech, muscle weakness, or sensory disturbances—typically resolve within 24 hours and often much sooner. This research, however, reveals that even a single TIA without visible brain damage on imaging can lead to long-term cognitive impairment comparable to what occurs after a full ischemic stroke.

The researchers utilized data from the REGARDS study, which followed over 30,000 participants across the United States. They created three comparison groups: people who experienced a first-time TIA, those who had a first-time stroke, and individuals with no history of either condition. Through periodic cognitive assessments measuring memory and verbal fluency, they tracked cognitive function over time while controlling for important variables like age, race, and vascular risk factors such as hypertension. This methodological approach helped isolate the specific effects of TIAs on cognitive function.

The findings revealed a concerning pattern: while stroke patients showed more immediate cognitive decline, TIA patients experienced a similar rate of decline over the long term, despite having no visible brain damage on MRI. Interestingly, individuals who later experienced a stroke already demonstrated slightly lower cognitive performance before their event compared to the other groups, suggesting that cognitive changes may begin before obvious clinical symptoms appear.

Why This Transient Ischemic Attack Study Is Important

This study transforms our understanding of TIAs from benign, temporary events to potential harbingers of lasting cognitive impairment. It emphasizes the need for clinicians to monitor cognitive function in all TIA patients, even those who seem to make a complete recovery. It suggests that early intervention strategies might be necessary to prevent or slow this decline. Future research will need to explore the underlying mechanisms by which TIAs affect cognition and identify effective interventions to preserve cognitive health in affected individuals.

Reference

Del Bene, V. A., Howard, G., Gropen, T. I., Lyerly, M. J., Howard, V. J., Sawyer, R. P., & Lazar, R. M. (2025). Cognitive decline after first-time transient ischemic attack. JAMA Neurology, e245082. Advance online publication. https://doi.org/10.1001/jamaneurol.2024.5082