Magnetic resonance imaging (MRI) criteria for Alexander disease

The 5 imaging criteria in Alexander disease include (A) extensive white matter involvement, (B) deep gray T2/FLAIR signal abnormality and/or swelling of the deep gray structures, (C) a periventricular rim, (D to F) brainstem involvement, and (G to I) contrast enhancement. Variability exists, especially in the white matter involvement, brainstem, and areas that enhance postgadolinium administration. For example, patients may have symmetric T2 hyperintensities in the medulla (D), mass-like lesions in the dorsal medulla (E), or medulla atrophy (F). Contrast enhancement also varies, such as in the periventricular lining (G), cerebellar peduncles and dentate (H), or periventricular lining, basal ganglia, and/or brainstem (I).