Purpose or Case Report: The purpose of our case series is to review the imaging, clinical, and pathologic findings of two adolescent patients that presented to our medical center who were ultimately found to have the juvenile/young adult (Prust Type II) form of Alexander Disease.

The first patient was an eleven year old male with presumed conversion disorder who was transferred from a pediatric residental mental health clinic after a suspected aspiration event. The parents reported that the patient had difficulty swallowing for years, that had worsening significantly over the preceding six months. A non-enhanced head CT was performed shortly after the patient was admitted due to a change in mental status, which revealed a focal abnormality at the cervicomedullary junction. Subsequent assessment with MRI confirmed the lesion, which demonstrated corresponding T2/FLAIR signal hyperintensity and enhancement, with the presumptive initial diagnosis of a cervicomedullary tumor. The patient was biopsied at an outside institution, and was diagnosed with Alexander Disease by that institution.

The second patient was a twelve year old male with history of cleidocranial dysplasia, in which extensive signal abnormality and enhancement was first identified throughout the posterior fossa structures on an outpatient MRI of brain obtained for paroxysmal episodes of dizziness. A small amount of signal abnormality in the periventricular white matter was also present. The patient was initially worked up and treated for a neuroinflammatory disorder, and a biopsy was performed when there was further worsening of the patient’s symptoms. A mutation in the patient's GFAP gene was subsequently identified of “uncertain significance”.

Juvenile/young adult (Prust Type II) Alexander Disease is a rare leukodystrophy, which is associated with a different set of imaging characteristics compared with the more classic infantile/juvenile (Prust Type I) form. Radiologists who regularly interpret pediatric neuroimaging studies should be aware of its existence and its spectrum of associated imaging findings, in the interest of both arriving at the correct diagnosis and in avoiding unnecessary brain biopsy.
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