Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL)
Presentation
The patient and his sister have cognitive deficits.
Patient Data
Extensive confluent deep and subcortical cerebral white matter hypoattenuation involving bilateral periventricular areas, cerebellum, external capsule and temporal lobes.
MRI shows diffuse, confluent white matter hyperintensities on T2/FLAIR that involve bilateral periventricular white matter, centrum semiovale, cerebellum, corpus callosum, external capsules and the anterior part of the temporal lobes. The subcortical U-fibers, basal ganglia and thalami are spared.
T2* images show punctate hemosiderin deposits in the right centrum semiovale, representing old microbleeds.
There are scattered lesions with T2/FLAIR hyperintense rim in the subcortical white matter and basal ganglia, isointense to CSF on all sequences, suggestive of chronic ischemia.
There is no abnormal post-contrast enhancement (not shown).
Parenchymal volume loss with marked prominence of the sulci, consistent with cerebral atrophy.
Case Discussion
MRI shows widespread confluent white matter hyperintense on T2/FLAIR, mainly affecting the anterior temporal lobes and external capsules, as well as lacunar and subcortical infarcts, and microhemorrhages. The imaging findings in a young patient with a significant family history is in keeping with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL).
The differential diagnosis includes Binswanger disease, MELAS, Susac syndrome, and CNS vasculitis.
In Binswanger disease, the white matter lesions are usually small, commonly grouped around the frontal and occipital horns and in the centrum semiovale, along with cerebral atrophy and lacunar infarcts. Binswanger's disease is nonhereditary, and the patient has a history of hypertension.
MELAS shows multiple infarcts of varying ages in different arterial territories. MR spectroscopy may demonstrate elevated lactate. The patient may develop muscle weakness.
Susac syndrome is a rare syndrome typically affecting young to middle-aged women. It is clinically characterized by the triad of acute or subacute encephalopathy, bilateral sensorineural hearing loss, and branch retinal arterial occlusions. The lesions tend to be multiple, small white matter lesions that have a predilection for the corpus callosum.
In CNS vasculitis, MRI shows non-specific findings. The cerebral arteries may demonstrate a beaded appearance and contrast enhancement of the vessel wall.