Superficial siderosis of the central nervous system is a rare and possibly underdiagnosed disorder

Superficial siderosis (SS) of the central nervous system (CNS) is a rare and possibly underdiagnosed disorder resulting from chronic or intermittent bleeding into the subarachnoid space, leading to deposition of blood products in the subpial layers of the meninges. Magnetic resonance imaging (MRI) shows a characteristic curvilinear pattern of hypointensity on its blood-sensitive sequences. Methods: Series of cases collected from Brazilian centers. Results: We studied 13 cases of patients presenting with progressive histories of neurological dysfunction caused by SS-CNS. The most frequent clinical findings in these patients were progressive gait ataxia, hearing loss, hyperreflexia and cognitive dysfunction. The diagnoses of SS-CNS were made seven months to 30 years after the disease onset. Conclusion: SS-CNS is a rare disease that may remain undiagnosed for long periods. Awareness of this condition is essential for the clinician.