[Infratentorial superficial siderosis : a diagnostic challenge from the general practice to the hospital].

Superficial siderosis is a rare neurological evolutive condition that encompasses two distinct entities classified according to their cortical or infratentorial localisation. The disease is caused by the neuronal destruction of the central nervous system linked with hemosiderin deposits. The aetiology is a sustained low-intensity bleeding located at the supratentorial subarachnoid space for the cortical superficial siderosis or from the subarachnoid space for the infratentorial superficial siderosis. The triad sensorineural hearing loss, cerebellar ataxia and pyramidal signs should suggest infratentorial superficial siderosis. The diagnosis is made using central nervous system MRI. The management relies on the identification and surgical correction of the bleeding source. The benefit of medical treatment is discussed.