Researchers of a new cohort study revealed that a single, diffusion-weighted image-negative transient ischemic attack is associated with long-term cognitive decline, independent of preexisting vascular and demographic risk factors.

Published in JAMA Neurology, the study analyzed data from 16,203 participants in the Reasons for Geographic and Racial Differences in Stroke (REGARDS) cohort, including 356 individuals with first-time TIA (mean age, 66.6 years), 965 individuals with first-time stroke (mean age, 66.8 years), and 14,882 asymptomatic controls (mean age 63.2 years).

Before the index event, cognitive performance among the TIA group (−0.05) did not differ significantly from asymptomatic controls (0). However, postevent annual cognitive decline was faster in the TIA group (−0.05) than in the asymptomatic group (−0.02), and comparable to the stroke group (−0.04).

"These findings suggest that despite the quick resolution of symptoms and no radiological evidence of injury, TIA appears to be sufficient either directly or indirectly to initiate a pathological process leading to long-term changes in cognition," said Victor A. Del Bene, PhD from the Department of Neurology, The University of Alabama at Birmingham Heersink School of Medicine, Birmingham.

The cognitive decline observed post-TIA was primarily driven by declines in immediate and delayed memory recall rather than verbal fluency. Secondary analyses showed minimal impact from additional adjustments for factors such as low-density lipoprotein cholesterol, obesity, low exercise levels, and depression

Limitations include reliance on a telephone-based cognitive test battery, which may not capture visual-spatial or motor deficits, and lack of pre-event neuroimaging data to rule out prior cerebrovascular pathology. The REGARDS study cohort was limited to non-Hispanic Black and White participants, potentially limiting generalizability.

No conflicts of interest were disclosed by the authors.