Superficial siderosis of the CNS associated with multiple cavernous malformations

Abstract

Superficial siderosis of the CNS due to chronic, recurrent subarachnoid hemorrhage is an uncommon and potentially debilitating disorder. The classic clinical manifestation is progressive bilateral sensorineural hearing loss (SNHL), although ataxia and pyramidal signs also are observed frequently. Cavernous malformations rarely present with subarachnoid hemorrhage. We describe an unusual case of a young patient who presented with progressive, bilateral SNHL who was found to have superficial CNS siderosis associated with multiple cavernous malformations.

fig. 1. Images of a 32-year-old male patient with CNS siderosis associated with multiple cavernous malformations. A, Axial spin-echo 3500/98/1 (TR/TE/excitations) T2-weighted MR image, centered at the level of the pons, suggests mild hypointensity along the ventral surface of the pons, particularly on the left. B, Axial gradient-echo 750/40/2 susceptibility MR image with a flip angle of 10°, obtained at the same level as that shown in A, shows focal regions of hypointensity in the ventral left pons (solid arrow) as well as the central pons (arrowhead), consistent with cavernous malformations. In addition, hypointensity along the ventral surface of the pons is better appreciated, as is hypointensity along the folia of the vermis of the cerebellum (open arrows). C, Axial spin-echo 3500/98/1 T2-weighted MR image, obtained at the level of the upper pons, raises the possibility of mild hypointensity along the surface of the brain stem (open arrows), as well as a small focal region of hypointensity within the left upper pons (solid arrow). D, Axial gradient-echo 750/40/2 susceptibility MR image with a flip angle of 10°, acquired at the identical level as that shown in C, shows “blooming” of the hypointensity within the left side of the brain stem, consistent with cavernous malformations that are superficial, as well as markedly improved visualization of hypointensity consistent with siderosis along the cerebellar folia and surface of the brain stem, as compared with the T2-weighted image shown in C. E, Axial gradient-echo 750/40/2 susceptibility MR image with a flip angle of 10°, obtained at a more cephalad level, shows hypointensity consistent with siderosis along the folia of the superior vermis (open arrows). F, Axial gradient-echo 750/40/2 susceptibility MR image with a flip angle of 10°, obtained at the level of the lateral ventricles, shows cavernous malformations along the ependymal/subependymal region (solid arrows) but no hemosiderin staining of the ependyma.