Small artery dementia in Japan: radiological differences between CADASIL, leukoaraiosis and Binswanger's disease

Area of Science:

• Neurology
• Radiology
• Genetics

Background:

• Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is a hereditary small artery disease.
• It shares phenotypic similarities with Binswanger's disease (BD), a nonhereditary small artery disease.
• Previous research identified temporopolar, medial frontopolar, and external capsule lesions in Caucasian CADASIL patients.

Purpose of the Study:

• To determine if MRI findings are useful for diagnosing small artery disease in non-Caucasian populations.
• To investigate the diagnostic utility of specific MRI lesions for CADASIL in Japan, where the disease is rare but small artery disease is prevalent.

Main Methods:

• Examined 58 patients with small artery disease without major vessel occlusion or stenosis.
• Included 7 CADASIL patients from 3 families, 27 nondemented patients with extensive leukoaraiosis (LA), and 24 BD patients.
• Analyzed T(2)-weighted MRI scans for hyperintensities in specific brain regions.

Main Results:

• All 7 CADASIL patients showed temporopolar hyperintensities; only 1 patient each in the nondemented LA and BD groups did.
• Medial frontopolar hyperintensities were observed in 57% of CADASIL patients and 58% of BD patients, significantly more than in the LA group (15%).
• External capsule hyperintensities were common across all patient groups.

Conclusions:

• Temporopolar lesions are a potential diagnostic marker for CADASIL in non-Caucasian patients.
• MRI findings, particularly temporopolar lesions, can aid in diagnosing CADASIL outside of Caucasian populations.
• This study highlights the importance of specific MRI lesion patterns for diagnosing hereditary small artery diseases in diverse ethnic groups.