Moyamoya disease is a rare vascular condition characterised by the progressive narrowing of arteries supplying oxygen and essential nutrients to the brain. This occlusion encourages the formation of a network of small blood vessels to bypass the blockage.
Most commonly occurring among children and adolescents of Asian race, moyamoya can lead to damage or death of brain tissue, producing headaches, cognitive or learning difficulties, seizures and mental retardation. Medical emergencies may include intracranial haemorrhage (bleeding in the brain), transient ischemic attack (numbness, weakness, speech impairment or visual abnormalities) or a complete stroke, which require immediate medical interventions.
To diagnose moyamoya disease, your doctor will review your symptoms and perform a physical examination. Your doctor may order imaging studies such as Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scans. To confirm the diagnosis of moyamoya disease, a cerebral angiogram is conducted. In this test, a contrast substance (dye) is injected into the arteries of the brain and X-ray images are taken. The study reveals the narrowed arteries and the characteristic appearance of the collateral blood vessels. Other imaging tests may be conducted to identify areas of the brain with diminished oxygen supply.
Symptomatic treatment is provided in cases of significant neurological impairment due to the progressive nature of the disease. Surgery is usually the main form of treatment to prevent recurrent stroke and permanent neurological deficits and involves redirecting blood towards the oxygen-deficient areas of the brain from other parts of the head such as arteries in the scalp or muscles.