Moyamoya Disease

For people with moyamoya disease and moyamoya syndrome, UT Southwestern Medical Center offers something most institutes cannot: three neurosurgeons highly trained in the treatment of this rare, progressive cerebrovascular disorder. They work closely with neurologists, neuroradiologists, and other brain disorder specialists who have decades of experience evaluating and treating the condition.

Institutions throughout Texas and surrounding areas refer their moyamoya patients to UT Southwestern because of our team’s expertise and the array of evaluation and treatment options we offer.

Unique Expertise for a Rare Disease

Moyamoya disease (MMD) is a rare condition that typically affects younger children. The condition causes continued narrowing of carotid arteries at the base of the brain. Reduced blood flow associated with this vessel narrowing can result in bleeding or nonbleeding strokes. In an effort to create blood flow around the narrowed arteries, many small blood vessels form. 

The name moyamoya, a Japanese term meaning puff of smoke, refers to how these new blood vessels look on an arteriogram (a special blood vessel X-ray) and not the cause of the problem. Moyamoya syndrome (MMS) refers to a similar appearance of blood vessels in young adults that is frequently related to other diseases such as uncontrolled diabetes, sickle cell disease, or other syndromes (such as Down syndrome). 

Because moyamoya is quite rare, many institutions have limited or no experience in caring for people with the disease. UT Southwestern’s team of neurosurgeons, neurologists, and neuroradiologists have decades of experience evaluating and treating patients with the disease and syndrome – something few other medical centers in the U.S. can offer.

Cause and Symptoms of Moyamoya Disease

While the exact cause of MMD/MMS is unknown, women are more likely than men to be diagnosed with it. In 6 to 12 percent of cases, there is a family history of the disease, implying that these cases might result from inherited genetic abnormalities.

Moyamoya symptoms first appear with a hemorrhagic (bleeding) or ischemic (nonbleeding) stroke or transient ischemic attack (TIA or mini-stroke). Patients might experience:

• Cognitive or learning impairments
  
• Difficulty speaking
  
• Headache
  
• Paralysis affecting one side of the body
  
• Seizures
  
• Weakness or numbness in an arm or leg
  

Diagnosis

Brain disorder specialists at UT Southwestern always consider MMS/MMD when evaluating any patient who has had a stroke or is experiencing stroke symptoms, particularly if the patient is young and has no obvious risk factors for stroke. Misdiagnosis of MMD/MMS or a delay in diagnosis can be life threatening.

The first step in evaluating and diagnosing moyamoya is a computed tomography (CT) or magnetic resonance imaging (MRI) scan using the latest, most advanced imaging equipment. These imaging studies can reveal the characteristic arterial narrowing and abnormal blood vessels of MMD/MMS that have the appearance of a puff of smoke. Imaging also can reveal evidence of a history of multiple small strokes.

If imaging studies suggest MMD/MMS, specialists might perform a cerebral angiography, a test that creates images of the blood flow through the brain, to confirm the diagnosis. When necessary, additional blood flow studies might be done to identify the exact areas of the brain that aren’t receiving enough oxygen.

While imaging studies usually reveal MMD/MMS, additional diagnostic tools include:

• Medical and family history
  
• Neuropsychological assessment: Examining a patient’s memory and ability to think and speak helps physicians determine any cognitive changes the patient might be experiencing as a result of decreased blood flow. Physicians also use this assessment as a baseline of cognitive abilities to compare with those of a second assessment after surgical treatment.
  

Treatment for Moyamoya Disease

UT Southwestern offers both nonsurgical and surgical treatment for moyamoya disease. For each patient, the clinical team collaborates to determine the best possible approach to treatment.

Our neurosurgeons are skilled in revascularization surgeries, which are procedures to restore blood flow to the affected areas of the brain. Our experience has helped us achieve a high success rate with these options, which include:

• Indirect bypass: This procedure can gradually restore blood flow to the brain. It involves removing a portion of the skull to access the superficial temporal artery, known as the scalp artery, and dissecting several inches of it. The separated section is laid onto the brain, where it eventually sprouts new blood vessels that supply the brain with oxygen.
  
• Direct bypass: If a patient’s condition is progressing rapidly or imaging suggests an increased risk of stroke, a direct bypass procedure might be necessary. A direct bypass procedure involves opening the skull and the dura (the outermost membrane enveloping the brain) and connecting the superficial temporal artery to the middle cerebral artery. This method immediately reroutes and increases blood flow in the brain.
  

Rehabilitation

After surgery, patients spend recovery time in our neurocritical care unit and begin seeing our rehabilitation specialists as soon as they are ready.

UT Southwestern offers a dedicated neurorehabilitation unit for brain disorder patients. Rehabilitation can include physical, psychological, occupational, or speech therapy, depending on the patient’s symptoms and whether the patient has suffered a stroke. Our goal is to help patients regain as much function and independence as possible.