Confluent Thalamic Hyperintensities in CADASIL

Abstract

Background: CADASIL is responsible for diffuse hyperintensities in the white matter on FLAIR images. These lesions are often associated with focal lesions in the basal ganglia such as lacunar infarctions. The prevalence and significance of diffuse or confluent thalamic hyperintensities (CTH) remain unknown. Methods: The frequency of hyperintensities on FLAIR images in the thalamus was assessed in 147 CADASIL patients, and signal abnormalities on both FLAIR and T₁-weighted images were categorized as focal/punctuate or diffuse/confluent by the same reader. The areas of increased diffusion were also analyzed on apparent diffusion coefficient maps. The association of CTH with vascular risk factors, the main clinical manifestations of the disease and MRI markers (brain parenchymal fraction, volume of white matter hyperintensities, volume of lacunar infarcts and number of microbleeds) was analyzed with generalized linear regression models. Results: CTH were detected in 12% of the CADASIL subjects in association with hypointensities on T₁-weighted images. CTH corresponded to areas of increased diffusion on apparent diffusion coefficient maps. CTH were found significantly associated with age and independently related to the volume of white matter hyperintensities but not to that of lacunar infarctions or to cerebral atrophy after adjustment for age and sex. No significant association was found between CTH and global cognitive performances. Conclusion: CTH are observed on FLAIR images in a sizeable proportion of CADASIL patients. They are mainly related to the extent of white matter hyperintensities and do not correlate with cognitive decline. Demyelination and/or loss of glial cells appear to be the most plausible cause of these confluent signal changes in the thalamus.

Cerebral Small Vessel Disease: A Review of Clinical, Radiological, and Histopathological Phenotypes

“…WMLs in CADASIL tend to have a unique predilection for the anterior temporal pole and external capsule (101), whereas this is unusual in ageing. Confluent hyperintensities on T1-weighted imaging in both thalami have also been reported in around 12% of a case series, possibly reflecting demyelination or glial loss (102). Cerebral atrophy has been shown to progress three times more rapidly in CADASIL compared with normal ageing (103).…”

Extensive White Matter Hyperintensities May Increase Brain Volume in Cerebral Autosomal-Dominant Arteriopathy With Subcortical Infarcts and Leukoencephalopathy

“…Indeed, extensive changes of T1 or T2 signal are detected not only in the white matter, but also in the subcortical gray matter of most patients with CADASIL. 23 Such signal changes can dramatically alter the contrast needed for segmentation of the white and gray matter at the subcortical level, but also for isolating the cortex from the rest of the brain. Thus, correlations with gray matter volume and white matter volume were not evaluated.…”

Isolated Lacunar Infarct: An Early Clinical Presentation of CADASIL?

“…migraine with aura, subcortical ischemic events, mood disturbance, apathy and cognitive impairment [1]. Diagnosis is supported by MRI findings including diffuse white-matter hyperintensities on FLAIR or T2-weighted images, lacunar infarcts and microbleeds [2]. White matter hyperintensities presumably appear during the third decade and are constant after 40 years.…”