Sickle cell disease (SCD) is an inherited condition that affects red blood cells. There are several different types of sickle cell disease, with a range of symptoms. It can increase the risk of a stroke, especially in young children. Young people and adults are also more likely to have a stroke. Stroke is more common with certain types of SCD.
SCD causes symptoms including painful episodes, anaemia and frequent infections. Around 10,000 people in the UK have SCD, and it mostly affects people of African, Caribbean, Asian, and Mediterranean origin. All newborn babies in the UK have a blood test to screen for SCD. Some people can carry a gene for SCD without having any symptoms, known as sickle cell trait.
Why does sickle cell disease increase the risk of stroke?
Healthy red blood cells are round in shape, but a 'sickled' red blood cell is crescent-shaped and stiff. Sickled cells tend to stick together, and they can't move easily through the blood vessels. They can clump together and block blood vessels. This can lead to a clot forming and moving to the brain, causing a stroke. A stroke can also be due to damage to the blood vessels in the brain caused by SCD. SCD can sometimes lead to bleeding in the brain (haemorrhagic stroke).
Reducing the risk of stroke from sickle cell disease
Sickle cell disease is a lifelong condition. A person with SCD will have treatments to manage their symptoms, and reduce their risk of stroke and serious infections. Stem cell transplants can cure SCD, but they can be very risky, so it's only considered if someone has very serious complications.
If a child is diagnosed with sickle cell disease they should have a transcranial Doppler (TCD) scan every year from the age of two. This scan uses ultrasound to measure the flow of blood through the brain and can show if there is a risk of a blockage. If the scan shows that they are at a high risk of stroke, they should have more frequent scans and medication or blood transfusions.
The main medication used to reduce painful symptoms and lower the risk of stroke is hydroxycarbamide (hydroxyurea).
Treating a stroke in someone with sickle cell disease
If a person with sickle cell is diagnosed with a stroke, they will be given an urgent blood transfusion. Thrombolysis (clot-busting medication) can be used for some adults, depending on the cause of their stroke and where the stroke is in the brain. People with other conditions that can lead to a stroke, like high blood pressure and diabetes, will be given treatment and support to reduce their risk of a stroke.
If a child or young person has a stroke, as well as having any help they need with rehabilitation, they may need support with learning and development.
For information and resources about childhood stroke including information for children and a schools pack, visit our childhood stroke support page.
The charity Sickle Cell and Young Stroke Survivors provides advice and support including groups for parents and carers.