Aicardi–Goutières syndrome

Specific Imaging Findings, The cardinal features of Aicardi-Goutières syndrome (AGS) on brain imaging consist of intracranial calcification, leukodystrophy, and cerebral atrophy. CT scan may be normal in the earliest stages of the disease, but almost invariably shows extensive calcifications involving the basal ganglia, thalami, periventricular white matter, and cerebellum. Calcifications are not always recognized on MRI; when seen, they appear as T2 hypointense, T1 hyperintense spots that stand out against the background of diffusely dysmyelinated white matter, and are better depicted on susceptibility-weighted (T2*) sequences. The abnormal signal (mild T1 hypointensity and moderate to marked T2 hyperintensity) in bilateral supratentorial white matter ranges from just periventricular involvement in milder cases to a striking frontotemporal leukodystrophy with temporal cystic lesions in the most severely affected patients. Abnormal white matter shows two patterns of distribution: diffuse or anteroposterior gradient, each present in about half of the patients. Infra-tentorially, the pyramidal tracts within the medulla oblongata may be involved while the cerebellum is spared. Cortical atrophy can already be present at the onset and progresses over time; the corpus callosum may be markedly atrophic. Pertinent Clinical Information, Affected patients present during early infancy with a rapidly progressive picture characterized by feeding difficulties, delayed psychomotor development, progressive microcephaly, irritability, truncal hypotonia with limb spasticity and dystonic ocular and buccolingual movements, convulsions, opisthotonus, and blindness. Demise usually occurs within a few months or years in these severe forms, although patients with apparently static or slowly progressive disease, sometimes presenting after several months of normal development, have also been reported.