Superficial siderosis of the central nervous system : University College London Hospitals NHS Foundation Trust

This page has been written by members of the superficial siderosis multidisciplinary team at UCLH. It is intended for patients who are referred to our service, their families and carers. It is not intended to replace discussion with your treating doctor. If you have further questions, please contact a member of the team who will be happy to try to answer them for you.

What is superficial siderosis?

Superficial siderosis of the central nervous system is named after ‘sideros’ - the Greek word for iron - because it is caused by a build-up of iron-containing compounds on the surface of the brain and spinal cord. Superficial siderosis is caused by a very small and slow leak of red blood cells into the fluid that bathes the brain and spinal cord (cerebrospinal fluid). The blood usually comes from a small hole (defect) in the thick protective lining that covers the brain and spinal cord (called the ‘dura’), often due to previous trauma or surgery to the brain or spinal cord. Red blood cells contain iron and when they are broken down the iron (in the form of a substance called haemosiderin) is deposited on the surfaces of the brain and spinal cord, especially over the cerebellum, brainstem and the nerves for hearing and balance.

How common is superficial siderosis?

It is considered rare. It is being picked up more with MRI scans. It is often diagnosed in the second half of life, probably because the red blood cell leakage and iron damage go on for some years (often decades) before symptoms are noticed.

What symptoms does superficial siderosis cause?

Problems with hearing and balance are most frequent and are usually gradual (over several years or longer). Problems with thinking skills (e.g., memory, problem solving), reduced smell function, problems with bladder and bowel function like constipation or incontinence, are less common.

How can we diagnose superficial siderosis?

The easiest way to diagnose superficial siderosis is with magnetic resonance imaging (MRI) which can show haemosiderin as a black line around the brain and spine. We may use other tests to find the leak, such as CT (computerised tomography) myelogram which involves injecting a dye (contrast) into cerebrospinal fluid during the scan to see where it travels. We may also check if the bleeding is ongoing by testing the cerebrospinal fluid using a lumbar puncture, in which a sample of fluid is taken with a long thin needle placed between the spinal bones (vertebrae). Hearing and balance are usually tested to help guide a specific management plan.

Can we treat superficial siderosis?

The first goal is to find the source of the bleeding and repair it if we can, especially if symptoms are progressive. Another option is an iron-binding medicine (e.g., deferiprone).

Because superficial siderosis is complex and causes many symptoms, our specialist team include neurologists, neuroradiologists (scan experts), neurosurgeons, haematologists (blood experts), ataxia and neuro-otology (hearing and balance) experts, neuropsychologists (cognitive function experts), and uro-neurologists (bladder experts). The team discuss each patient’s case and propose an individualised management plan which is then discussed with the patient and their family.