Moyamoya Disease | Diagnosis & Treatment

How is moyamoya diagnosed?

The standard test for both diagnosing moyamoya and planning for surgery is a cerebral angiogram. This is a minimally invasive procedure that produces a “map” of your child’s carotid arteries.

How is moyamoya treated?

Moymoya is treated with surgery to fix the narrowed arteries in the brain and decrease the risk of stroke. While surgery is the only viable treatment for moyamoya disease in the long term, your doctor may also recommend medication to manage some of your child’s symptoms. These may include aspirin (to help prevent blood from clotting) and calcium channel blockers, such as verapamil (to help lower blood pressure).

Several surgical treatments for moyamoya are effective at bypassing narrowed arteries and creating a new blood supply for the affected areas of the brain.

There are several types of surgical treatments for moyamoya:

  • Pial synangiosis. This is a type of surgery that reroutes the healthy scalp blood vessel to the brain, bypassing the narrowed vessels.
  • EDAS (encephaloduroarteriosynangiosis). In this procedure, the superficial temporal artery in the child’s brain is laid over an opening in the cortex. The artery is then sewed to the dura (the firm layer of tissue that covers the brain). Over time, small new arterial vessels begin to develop.
  • EMS (encephalomyosynangiosis). In this procedure, small portions of the temporalis muscle in the jaw are attached in a parallel direction to the surface of the child’s brain. The transplanted muscle gradually generates new blood vessels, forming a supplementary source of blood flow to the brain.
  • Omental transposition/transfer. In this procedure, the child’s omentum, the blood-rich lining that surrounds the organs in the abdomen, is laid over the surface of the brain. New vessels eventually develop and grow into the brain.
  • Dural inversion. In this procedure, neurosurgeons invert the flaps of fibrous dural tissue on the child’s meningeal vessel, a large artery within the skull. This places the outer dural surface, which has plentiful blood vessels, in direct contact with the parts of the brain that were previously deprived of essential blood flow.
  • Direct arterial bypass. This surgery is also known as superficial temporal to middle cerebral artery anastomosis, or STA-MCA bypass. During this procedure, neurosurgeons join a blood vessel from the child’s scalp directly to a vessel in the brain. Blood flow throughout the brain should improve over the next several months.