Stroke disproportionately affects French Guiana, which has the highest incidence and premature stroke mortality among French territories. Beyond traditional vascular risks, cerebral small vessel disease (CSVD) may explain these disparities. This study compared MRI characteristics of acute ischemic stroke and CSVD burden in Cayenne with two mainland French centers (Besançon and Tours).

In line with the multicenter observational BECATOUR study, we analyzed ischemic stroke subtype, vascular occlusion, T2-FLAIR intravascular hyperintensities, and hemorrhagic markers. CSVD features (white matter hyperintensities, lacunes, microbleeds, enlarged perivascular spaces) were scored using validated scales. Global cardiovascular risk was estimated using a Framingham-based score.

Intravascular T2-FLAIR hyperintensities, reflecting collateral arterial circulation, were less frequent in Cayenne than in mainland France. Patients in Cayenne had a markedly higher CSVD burden (CSVD score > 2 according to Lau et al.: 42.4%, 19.8% and 17.2% respectively in Cayenne, Besançon, and Tours, P = 0.01), driven by more severe white matter hyperintensities and increased microbleeds. Among 257 patients, a cardiovascular risk > 20% was associated with severe white matter hyperintensities and higher overall CSVD burden. In Cayenne, 20% of patients would have met criteria for mechanical thrombectomy, a procedure that is not locally available.

Stroke patients in French Guiana carry a substantially higher burden of CSVD, closely linked to modifiable cardiovascular risk. Combined with limited access to advanced acute stroke interventions, these findings highlight major structural health inequities. Strengthening prevention, early risk-factor management, and access to reperfusion therapies is essential to reduce the disproportionate stroke burden in French Guiana.