Symptoms of moyamoya disease vary depending on the age of the patient. Adults with the condition experience bleeding or strokes. Other symptoms in adults include:
- Fainting or blacking out
- Loss of sight in one eye
- Blurry vision
- Poor vision in both eyes
- Inability to recognize objects
The condition tends to get worse without treatment, and can lead to severe brain damage or death.
In children, moyamoya disease tends to cause transient ischemic attacks (TIA), also known as microstrokes or "warning strokes." In children, it also may cause seizures.
Other symptoms may include:
- Uncontrolled movements
- Developmental disabilities
- Speech difficulties
- Periods of being unable to move their feet, legs or arms
Because this condition involves bleeding, patients may also experience a shortage of red blood cells (anemia), which has symptoms such as fatigue and pale skin.
Causes and Risk Factors
The cause of moyamoya disease is unknown. The narrowing of the brain's blood vessels may be due to injuries or genetic abnormalities. There may be some links between the condition and neurofibromatosis, or to procedures such as X-rays of the skull or heart surgery, or treatments such as chemotherapy.
Moyamoya disease is most commonly diagnosed in children, but it can affect adults as well. There appears to be a higher rate of incidence in Japan and other Asian countries; however cases have been diagnosed in the United States, Europe, Australia and Africa.