脳表ヘモジデリン沈着症の臨床症候

抄録

Superficial siderosis (SS) is a rare condition in which hemosiderin is deposited on the pial surface of the brain and/or spinal cord. It is supposed that hemosiderin deposition is a result of recurrent or persistent hemorrhage in the subarachnoid space. There are two types of SS. One is a “classical type”, in which low intensity of MRI is diffuse and symmetrical in brainstem and cerebellum. Patients with classical SS usually reveal slowly progressive and irreversible cerebellar ataxia, sensorineural hearing loss, myelopathy and/or cognitive decline due to involvement of the acoustic nerve, cerebellum, spinal cord and/or cerebral cortex. The other is a “localized (cortical) type”, in which low intensity of MRI is localized in cerebral cortex without infratentorial involvement. The most common causes of hemorrhage in “localized type” are cerebral amyloid angiopathy and/or Alzheimer's disease.