Presentation
Gradually decreased vision of the right eye.
Patient Data
Fusiform enlargement of the right optic nerve intraorbital segment with tortuous course displaying isointense signal intensity on T2/FLAIR sequences and no post-contrast enhancement.
Intracanalicular and intracranial segments of the right optic nerve and left optic nerve are unremarkable. Features are suggestive of right optic nerve glioma.
There are abnormal hyperintensities on FLAIR, and T2WI with no enhancement of the dentate nuclei, pons, midbrain, thalami, and globi pallidi. These mostly represent focal areas of signal intensity (FASI).
Case Discussion
The association of optic pathway gliomas and T2/FLAIR hyperintensity areas with no contrast enhancement within the white matter and basal ganglia are most consistent with neurofibromatosis type 1.
Focal areas of signal intensity (FASI) tend to occur in the basal ganglia (often globus pallidus and thalamus), brainstem, cerebellum, and hippocampus.
Optic nerve gliomas can have variable signal intensity and variable post-contrast enhancement.