Superficial Siderosis and Sudden Sensorineural Hearing Loss: A Case Report and Review of the Literature

This case report highlights an unusual case of sudden sensorineural hearing loss related to superficial siderosis (SS). Our patient had a craniotomy for medulloblastoma 23 years earlier, and this may represent a delayed complication related to this procedure. Magnetic resonance imaging (MRI) remains the key diagnostic investigation to illustrate the imaging features of superficial siderosis and exclude other pathologies. Increased awareness of progressive and sudden hearing complications caused by SS is important in the otolaryngologic community to expedite management and better counsel patients during the consent process. 1. Introduction Superficial siderosis (SS) classically affects the leptomeninges, brain, brainstem, cerebellum, cranial nerves and spinal cord secondary to hemorrhage and hemosiderin deposition [1]. Hemosiderin, a by-product of iron, releases cytotoxic hydroxyl radicals that cause bilateral sensorineural hearing loss in 95% of patients and cerebella signs [2]. Common etiologies include traumatic nerve root avulsion, bleeding, CNS neoplasm, vascular malformations, and aneurysm. It is an uncommon condition with only approximately 100 cases reported [3]. Early clinical suspicion for SS should be raised for patients who present with progressive bilateral hearing loss with the adjunct of MRI for confirmation of diagnosis as it can cause severe long-term neurological effects. This case report provides an account of a young male who presented with sudden sensorineural hearing loss. 2. Case Presentation A 30-year-old Caucasian male patient presented to our clinic with sudden-onset left-sided sensorineural hearing loss and nonpulsatile tinnitus. His medical background was remarkable for a medulloblastoma treated with a suboccipital craniotomy and tumour resection with adjuvant radiotherapy at the age of seven. The patient had no postoperative complications or evidence of tumour recurrence on long-term followup. Examination revealed bilateral sensorineural hearing loss on tuning fork testing with normal otoscopic findings. Dysdiadochokinesia, past pointing, and intention tremor were also noted affecting the patient’s left upper limb. Audiometry showed bilateral down-sloping moderate-severe sensorineural hearing loss, which was slightly worse on the left side. No prior audiometry was available for comparison. 3. Discussion The pathogenesis of SS results from chronic hemorrhage into the subpial layers with a predilection for the superior vermis, crests of the cerebellar folia, basal frontal lobe, temporal cortex, brainstem, spinal cord, nerve