RESUMEN
BACKGROUND: Superficial siderosis (SS) of the central nervous system is a disease characterized by deposition of hemosiderin in the leptomeninges (arachnoid and pia mater) due to chronic intradural bleeding. One of the etiologic mechanisms proposed is a dural breach secondary to trauma with a consequent arachnoidocele in contact with an exuberant venous plexus. We describe a unique case of clival arachnoidocele treated by an endoscopic endonasal approach and closure of the defect with fat and nasoseptal flap. CASE DESCRIPTION: A 35-year-old man with a history of severe head trauma 20 years ago presented with hearing deficit and a mild motor ataxia impairing gait. Magnetic resonance imaging disclosed hemosiderin deposition throughout the brain cortical layer and in the cerebellum, affecting the dentate nucleus as well. A computed tomography revealed an osteolytic formation in the clivus, involving the inner bone table and bone marrow. The patient was then submitted to an endoscopic endonasal transclival approach to close the defect. CONCLUSIONS: SS may be a result of several etiologies generating repetitive meningeal bleeding. Our patient had the diagnosis of posttraumatic clival arachnoidocele and SS probably related to trauma with some dural injury. An endoscopic endonasal approach with tear reconstruction is feasible and successful to address clival arachnoidoceles and, in this case, to avoid progression of the SS.
