An unusual diagnosis in a child suffering from juvenile Alexander disease: a clinical and imaging report.

Alexander disease is a rare, sporadic leukoencephalopathy characterized by white matter abnormalities with frontal predominance and clinically as a rule associated with megalencephaly, seizures, spasticity and psychomotor deterioration. We describe a boy who was diagnosed as affected by anorexia nervosa because his refusal to eat, progressive weight loss and psychological disturbances. The observation of a hyperintense lesion on T2-weighed MR images was initially explained as a pontine and extrapontine myelinolysis related to malnutrition. Following MRI and DNA analysis we diagnosed a juvenile type of Alexander disease.