診断，治療に難渋した脳表ヘモジデリン沈着症例

抄録

Superficial siderosis of the central nervous system (SSCN) is a rare condition in which hemosiderin is deposited on the surface of the brain and/or spinal cord, as a consequence of recurrent or persistent hemorrhage in the subarachnoid space. Previously, SSCN could only be diagnosed at autopsy or during a neurosurgical procedure. However, recently, non-invasive diagnosis of SSCN has become possible with techniques of magnetic resonance imaging (MRI), particularly susceptibility-weighted imaging (SWI).

We report a case of SSCN of the central nervous system in a 50-year-old woman who presented with vertigo and gradually progressive bilateral sensorineural hearing loss that progressed to total deafness over a nine-year period. We performed enhanced T1 weighted-inner ear MRI at first, and found no apparent abnormalities. We suggested a hearing aid (HA), but the patient refused. We suggested cochlear implant surgery several times, but the patient resisted it. Eleven years after this first medical examination, the patient presented with severe headache and a floating sensation, and we performed head MRI, including SWI and diffusion-weighted imaging and MR-angiography. SWI revealed diffuse marginal hypo-intensities on the surface of the cerebrum and brain.

SSCN should be considered in the differential diagnosis of patients presenting with unexplained progressive sensorineural hearing loss. Head MRI, including SWI, is a very useful non-invasive tool for accurate diagnosis of SSCN.