Female, 80 years old, with right cranial nerve VI palsy. Periventricular and scattered subcortical foci of white T2 hyperintensity are seen. Patchy foci of T2 hyperintensity are also seen within the pons including relatively asymmetric involvement of the right dorsal pons at the level of the sixth cranial nerve nucleus. However, no diffusion restricting lesions are detected. A more well-circumscribed 2-mm T2 hyperintense focus is also seen at midline in the dorsal pons at the level of the facial colliculi.No evidence of significant parenchymal edema or mass effect is observed. No acute intracranial hemorrhage or any abnormal extra axial fluid collection is seen. The ventricles are normal in size and morphology. No pathologic parenchymal or extra-axial enhancement is detected.The globes are round and symmetric. The extraocular muscles demonstrate normal signal intensity and morphology. The intraorbital fat is clean. No signal abnormality of the optic nerves is detected. A fine pattern of enhancement is noted along the bilateral optic nerve sheaths which is of uncertain significance.The cranial nerves as visualized are within normal limits. Specifically, the left abducens nerve is only vaguely discerned, and the right abducens nerve is not clearly seen. However, no evidence of pathologic cisternal enhancement is detected. The IACs and CP angles are unremarkable.
1.Evidence of chronic microvascular ischemic disease is seen within the brain and brainstem. This includes lesions within the dorsal pons and, specifically, in the region of the right abducens nucleus. A small T2 hyperintense focus is also demonstrated at midline within the dorsal pons at the level of the facial colliculi which may also reflect chronic ischemic disease.2.On dedicated imaging, no definite orbital or cranial nerve abnormalities are seen. The sixth cranial nerves are not well visualized due to technical limitations, though no pathologic cisternal enhancement is appreciated. 3.There is, however, a fine pattern of enhancement along the bilateral intraorbital optic nerve sheaths which is of uncertain significance. The enhancement is more than typically seen in normal individuals, though there is no evidence of optic nerve signal abnormality or any other pathologic intracranial enhancement to support this finding. This may reflect normal variation, but clinical assessment for an inflammatory process of the optic apparatus should be considered.