Cerebrospinal fluid ferritin and siderophages in the diagnosis of superficial cerebral siderosis

We observed a case of superficial siderosis (SS) of the central nervous system caused by an hemorrhagic trauma forty years before. We questioned whether SS was the stabilized effect of a remote bleeding or an evolutionary process indirectly related to the trauma. Moreover, we aimed to evaluate whether an iron chelator can affect the level of iron deposition. Magnetic Resonance (MRI) demonstrated iron accumulation mainly on the surface of the cerebellum and brain stem. Cerebrospinal fluid (CSF) microscopic analysis revealed few siderophages; CSF ferritin level was 76 ng/mL (reference value <12). After treatment with an iron chelator (deferiprone) for three months, MRI was unchanged, but the CSF ferritin was about 20% less. The presence of few siderophages supported the hypothesis of a persistent subarachnoid microbleeding. CSF ferritin, as an iron deposition index, allowed a diagnosis of SS and a more sensitive evaluation of the efficacy of the treatment than the MRI.