Superficial siderosis of central nervous system of unknown cause.

A 44-year-old man with a past medical history unremarkable presented with a 4-month evolution of progressive cognitive deterioration , deafness and unsteady gait. Initial neurological examination revealed mild cognitive impairment, dysarthria, cerebellar ataxia with wide-based unsteady gait and bilateral sensorineural hypoacusia. Laboratory serum analysis was unre-markable, including vitamin B12 and thiamine levels, thyroid function, autoimmunity panel; negative serologies for human immunodeficiency virus, Borrelia burgdoferi, Tropherma whippe-lii, Treponema pallidum, besides other bacterial and fungal infections. Brain-computed tomography (CT) was normal. A non-traumatic lumbar puncture was performed and a hematic cerebrospinal fluid (CSF) was obtained, which characteristics persisted during its collection (Figure 1a). CSF analysis revealed 110 cells/ml, predominantly lymphocytes, uncountable red blood Figure 1. (a) Hematic macroscopic aspect of CSF, obtained on the first lumbar puncture. (b) Axial T2-weighted images showing a hypointense rim surrounding cerebel-lum, due to haemosiderin deposits.