Clinical Relevance of 'Cap' and 'Track' Development after Recent Small Subcortical Infarct.
Cheng Y., Arteaga-Reyes C., Clancy U., Garcia DJ., Valdés Hernández MDC., Thrippleton MJ., Stringer MS., Blair GW., Wiseman S., Chappell FM., Zhang J., Liu X., Jochems ACC., Maniega SM., Sakka E., Bastin ME., Brown R., Loos CMJ., Makin SDJ., Liu M., Wu B., Doubal FN., Wardlaw JM., MSS‐2, MSS‐3 and the INVESTIGATE‐SVDs Study Group None.
OBJECTIVE: After a recent small subcortical infarct (RSSI), some patients develop perilesional or remote hyperintensities ('caps/tracks') to the index infarct on T2/FLAIR MRI. However, their clinical relevance remains unclear. We investigated the clinicoradiological correlates of 'caps/tracks', and their impact on long-term outcomes following RSSI. METHODS: We identified participants with lacunar stroke and MRI-confirmed RSSI from 3 prospective studies. At baseline, we collected risk factors, RSSI characteristics, small vessel disease (SVD) features, and microstructural integrity on diffusion imaging. Over 1-year, we repeated MRI and recorded 'caps/tracks' blinded to other data. We evaluated predictors of 'caps/tracks', and their association with 1-year functional (modified Rankin Scale score ≥2), mobility (Timed Up-and-Go), cognitive outcomes (Montreal Cognitive Assessment [MoCA] score <26), and recurrent cerebrovascular events (stroke/transient ischemic attack/incident infarct) using multivariable regression. RESULTS: Among 185 participants, 93 (50.3%) developed 'caps/tracks' first detected at median 198 days after stroke. 'Caps/tracks' were independently predicted by baseline factors: larger RSSI, RSSI located in white matter, higher SVD score, and higher mean diffusivity in normal-appearing white matter (odds ratio [OR] [95% confidence interval {CI}], 1.15 [1.07-1.25], 6.01 [2.80-13.57], 1.77 [1.31-2.44], 1.42 [1.01-2.03]). At 1 year, 'cap/track' formation was associated with worse functional outcome (OR: 3.17, 95% CI: 1.28-8.22), slower gait speed (β: 0.13, 95% CI: 0.01-0.25), and recurrent cerebrovascular events (hazard ratio [HR]: 2.05, 95% CI: 1.05-4.02), but not with cognitive impairment. INTERPRETATION: 'Caps/tracks' after RSSI are associated with worse clinical outcomes, and may reflect vulnerability to progressive SVD-related injury. Reducing 'caps/tracks' may offer early efficacy markers in trials aiming to improve outcome after lacunar stroke. ANN NEUROL 2025;97:942-955.