Typical magnetic resonance imaging (MRI) patterns in juvenile bulbospinal Alexander disease (juvenile/type II disease)

In the bulbospinal (type II) form that typically presents in juveniles, the frontal white matter is spared or mildly involved as shown in (A). Supratentorially, despite the paucity of white matter findings, basal ganglia abnormalities (B) and a periventricular rim (C) are often present. The most frequent brainstem finding is a mass lesion in the dorsal medulla, which can be bilateral as in (D) or unilateral as in (E). The mass lesions may enhance after gadolinium.