Superficial Siderosis of the CNS Associated with Multiple Cavernous Malformations

Summary: Superficial siderosis of the CNS due to chronic, recurrent subarachnoid hemorrhage is an uncommon and potentially debilitating disorder. The classic clinical mani-festation is progressive bilateral sensorineural hearing loss (SNHL), although ataxia and pyramidal signs also are ob-served 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. Superficial siderosis of the CNS is an unusual cause of progressive sensorineural hearing loss; however, bilateral SNHL is the most common clin-ical presentation of CNS siderosis. Hemosiderin deposition along the leptomeninges, subpial tissues, and subependyma of the ventricles as a result of chronic, recurrent subarachnoid hemorrhage induc-es intracellular uptake of iron, leading to damage of neural tissue (123). Traumatic cervical nerve root avulsion, neoplasms, and vascular abnormali-ties are causes of siderosis. Nevertheless, in as many as 46 % of the patients, no source for the siderosis is identified (326). We present a report of a patient with a 15-year history of progressive, bilateral hearing loss whose MR imaging evaluation revealed CNS siderosis as-sociated with multiple intracranial cavernous mal-formations. Although intra- and perilesional hem-orrhages may occur with cavernous malformations, resulting in seizures or focal neurologic deficits, subarachnoid hemorrhage is an unusual sequela of these lesions. Rare cases of subarachnoid hemor-rhage associated with optic nerve or spinal cord cavernous malformations have been reported (7). Several of the cavernous malformations in the pa-tient we present are superficial, and we speculate that recurrent bleeding into the subarachnoid spac