Characteristics and temporal evolution of asymptomatic diffusion-weighted imaging lesions in patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)

Background and purpose: The role of asymptomatic diffusion-weighted imaging-positive (aDWI+) lesions in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) patients remains unclear, and their radiographic features may differ from those of symptomatic diffusion-weighted imaging-positive (sDWI+) lesions. We aimed to investigate the clinicoradiographic characteristics of aDWI+ lesions in CADASIL patients.

Methods: We conducted a retrospective analysis using data from the Taiwan CADASIL Registry. aDWI+ lesions were defined as incidentally detected DWI+ lesions without corresponding acute neurological deficits. We compared the baseline clinical characteristics of patients with and without aDWI+ lesions and analyzed their radiological features and evolution in relation to sDWI+ lesions.

Results: Among 154 enrolled patients (mean age 62 ± 10 years), 17 (11%) had aDWI+ lesions. Baseline clinical characteristics were similar in the two groups, but those with aDWI+ lesions had more lacunes (median 8 vs. 2), multiple cerebral microbleeds (CMBs; 85% vs. 40%), and anterior temporal white matter hyperintensity (WMH; 47% vs. 14%). Multivariable analysis showed that aDWI+ lesions were associated with anterior temporal WMH (odds ratio 5.7, 95% confidence interval 1.5-21.0) after adjusting for multiple lacunes, multiple CMBs, and total WMH score. Compared to sDWI+ lesions, aDWI+ lesions were more often small infarcts (<1 cm; 89% vs. 23%) and less likely to involve the corticospinal tract (11% vs. 96%). Among the 11 aDWI+ lesions with follow-up magnetic resonance imaging, seven became microinfarcts, three became lacunes, and one disappeared.

Conclusions: aDWI+ lesions in CADASIL are not uncommon and are associated with higher burdens of small vessel disease and anterior temporal WMH. Further research is needed to assess their long-term impact on CADASIL.