What is Moyamoya disease?
Moyamoya disease is a rare, progressive cerebrovascular condition that affects the blood vessels in the brain. It causes the internal carotid arteries at the base of the brain to narrow. To make up for this, the body forms tiny new vessels that look like a “puff of smoke” on scans — which is what moyamoya means in Japanese.
These small vessels don’t always carry enough blood to the brain, which can increase the risk of strokes and transient ischemic attacks or “mini-strokes”. The condition is most common in children, but it can occur at any age.
The condition is lifelong, but surgery to improve blood flow and medications to control symptoms have improved quality of life for many.
What causes moyamoya disease?
The exact cause of moyamoya disease isn’t fully understood. Doctors have associated the condition with genetics as it appears to run in families. It is more common in people of Asian descent and it tends to affect females slightly more than males.
It has also been linked to other conditions such as:
- Down’s syndrome
- Neurofibromatosis type 1
- Sickle cell disease
- Some autoimmune conditions
When similar blood vessel changes happen alongside another condition, you may hear the symptoms referred to as moyamoya syndrome.
What are the symptoms of moyamoya disease?
The symptoms of moyamoya disease vary depending on the age at which they first appear:
Children
The first symptom in children is usually a brief ‘mini stroke’, or transient ischaemic attack (TIA). These may be followed by:
- Muscle weakness or clumsiness
- Seizures
- Headaches
- Learning and developmental changes
Adults
In adults stroke episodes may appear suddenly and will be more noticeable. They may also experience:
- Bleeding on the brain
- Sudden severe headaches
- Muscle weakness and numbness
- Speech problems
- Changes in thinking and memory
Symptoms vary from person to person and may develop gradually over time. Recognising the signs and seeking support early can help access the right treatment and care.
