Superficial siderosis by a dural foramen

Superficial siderosis (SS) of the central nervous system is a rare but welldocumented condition.1 We experienced the case of a 55yearold Japanese man who had gradually progressing sensory deafness and vertigo (bilateral VIII nerve palsy) that began at age 42. At age 47, he underwent surgery for a cochlear implant in his right ear that was moderately merited.1 At age 50, he developed aseptic meningitis. After the meningitis resolved, he was found to have mild cerebellar ataxia. T2weighted images of the brain MRI scan showed lowsignal intensity, diffuse thin lesions, which superficially diffusely circumscribed the brainstem and the cerebellum bilaterally, and to a much lesser extent, the cerebral cortex bilaterally. The above neurological findings and the imaging abnormalities indicated the presence of SS (Figure 1A, arrowheads), which might have led to all his neurological signs. An ironchelating agent (deferasirox, 720 mg/d) did not relieve his symptoms. At age 53, T2weighted images of the spinal MRI scan revealed a dural foramen (defect, arrowheads, axial image, middle panel) with extradural liquid pooling at the ventral C36 spinal level (arrows, left panel, sagittal image; axial image, middle panel). An orthopedic surgery confirmed the presence of a dural foramen at the ventral spinal cord (right panel) (Figure 1B, arrowheads and arrows).2 Dural patch surgery successfully stopped the progression of the disease, and the patient's cerebellar ataxia gradually improved. ACKNOWLEDG MENT None.