Presumed periventricular venous infarction on magnetic resonance imaging and its association with increased white matter edema in CADASIL.

OBJECTIVES

Venous pathology could contribute to the development of parenchymal lesions in cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). We aim to identify presumed periventricular venous infarction (PPVI) in CADASIL and analyze the associations between PPVI, white matter edema, and microstructural integrity within white matter hyperintensities (WMHs) regions.

METHODS

We included forty-nine patients with CADASIL from a prospectively enrolled cohort. PPVI was identified according to previously established MRI criteria. White matter edema was evaluated using the free water (FW) index derived from diffusion tensor imaging (DTI), and microstructural integrity was evaluated using FW-corrected DTI parameters. We compared the mean FW values and regional volumes with different levels of FW (ranging from 0.3 to 0.8) in WMHs regions between the PPVI and non-PPVI groups. We used intracranial volume to normalize each volume. We also analyzed the association between FW and microstructural integrity in fiber tracts connected with PPVI.

RESULTS

We found 16 PPVIs in 10 of 49 CADASIL patients (20.4%). The PPVI group had larger WMHs volume (0.068 versus 0.046, p = 0.036) and higher FW in WMHs (0.55 versus 0.52, p = 0.032) than the non-PPVI group. Larger areas with high FW content were also found in the PPVI group (threshold: 0.7, 0.47 versus 0.37, p = 0.015; threshold: 0.8, 0.33 versus 0.25, p = 0.003). Furthermore, higher FW correlated with decreased microstructural integrity (p = 0.009) in fiber tracts connected with PPVI.

CONCLUSIONS

PPVI was associated with increased FW content and white matter degeneration in CADASIL patients.

CLINICAL RELEVANCE STATEMENT

PPVI is an important factor related with WMHs, and therefore, preventing the occurrence of PPVI would be beneficial for patients with CADASIL.

KEY POINTS

•Presumed periventricular venous infarction is important and occurs in about 20% of patients with CADASIL. •Presumed periventricular venous infarction was associated with increased free water content in the regions of white matter hyperintensities. •Free water correlated with microstructural degenerations in white matter tracts connected with the presumed periventricular venous infarction.