Subcortical arteriosclerotic encephalopathy

Subcortical arteriosclerotic encephalopathy, also known as Binswanger disease or small vessel dementia, refers to slowly progressive, nonhereditary, exclusively white-matter vascular dementia.

Clinical presentation

Patients usually present with subcortical dementia symptoms including forgetfulness, personality and emotional changes.

Clinical criteria for the diagnosis are as follows:

• marked subcortical microangiopathic lesions at MR imaging

• negative family history of strokes, early cognitive impairment, or psychiatric disorders in first- and second-degree relatives

• documented arterial hypertension: systolic values higher than 160 mmHg, diastolic values higher than 95 mmHg, or both, measured on several occasions ⁵

Pathology

Pathologically, relatively symmetrical and diffuse bilateral deep periventricular white matter lesions are associated with severe arteriosclerosis of the small penetrating arteries which are thickened, lipohyalinised, stenotic, or even occluded. In most patients, multiple lacunar infarcts are also present in the basal ganglia, thalami, and pons ³. 

Radiographic features

CT

Diffuse, incompletely symmetrical hypodensities are present in deep white matter, especially prominent in the frontal lobes and centrum semiovale ³.

MRI

MRI changes are much more striking, consisting of subcortical and periventricular hyperintense lesions visible on FLAIR, T2-weighted, and proton-density sequences. Subcortical U-fibers are usually spared ⁶.

The white matter lesions are usually small, commonly grouped around the frontal and occipital horns and in the centrum semiovale. 

Moderate diffuse cerebral atrophy is invariably present, and lacunar infarcts in the basal ganglia and thalami are common ³.

History and etymology

It was first described in 1894 by Otto Ludwig Binswanger (1852-1929), a Swiss psychiatrist and neurologist ⁴. 

Differential diagnosis 

• CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy)

  • phenotypically similar white matter disease but hereditary/genetically defined

  • more likely to involve anterior temporal and superior frontal lobes and arcuate fibers

  • have more pronounced low signal intensity of the basal ganglia and dentate nuclei ⁵

  • also present subcortical U-fibers sparing

• CNS vasculitis