What is the management of Moyamoya disease?

Management of Moyamoya Disease

Surgical revascularization is the definitive treatment for moyamoya disease, particularly for symptomatic patients with evidence of compromised cerebral blood flow or perfusion reserve. 1

Diagnosis and Evaluation

• Digital subtraction angiography (DSA) is the gold standard for diagnosis, evaluating Suzuki classification stage and collateral circulation 2
• MRI/MRA to assess ischemic changes, vascular stenosis, and collateral formation 2
• Techniques to measure cerebral perfusion (TCD, perfusion CT, PET, SPECT with acetazolamide challenge) assist in evaluation and follow-up 1, 2

Treatment Algorithm

Surgical Management (First-line for symptomatic patients)

1. Indications for revascularization:

   • Ongoing ischemic symptoms
   • Evidence of compromised blood flow or cerebral perfusion reserve
   • Asymptomatic patients with radiographic evidence of impaired cerebral perfusion 1

2. Surgical approaches:

   • Direct bypass (STA-MCA): Provides immediate augmentation of cerebral blood flow 2
   • Indirect bypass (EDAMS): Relies on development of new collateral vessels over time 2
   • Combined procedures: Often provide optimal outcomes for ischemic presentation 2

3. Specific considerations:

   • Direct bypass is preferred for hemorrhagic presentation 1, 2
   • Indirect techniques may be preferred in pediatric patients 2
   • Surgery should be performed at high-volume centers with experienced teams 1

Perioperative Management

1. Preoperative:

   • Maintain euvolemia to mild hypervolemia 2
   • Avoid dehydration which can trigger ischemic events 2
   • Avoid medications causing vasoconstriction (triptans, ergots) 1, 2

2. Intraoperative:

   • Avoid hypotension, hypovolemia, hyperthermia, and hypocarbia 1
   • Consider neuroprotective anesthetic agents (propofol) 1
   • Maintain tight blood pressure control 1

3. Postoperative:

   • Intravenous fluids at 1.5 times normal maintenance rate for 48-72 hours 1, 2
   • Maintain systolic blood pressure <130 mmHg to prevent hyperperfusion syndrome 2
   • Implement pain management techniques to prevent hyperventilation-induced vasoconstriction 1, 2
   • Monitor for cerebral hyperperfusion syndrome (occurs in ~16.5% of cases) 2

Medical Management

1. Antiplatelet therapy:

   • May be considered in patients after revascularization surgery or in asymptomatic individuals for whom surgery is not anticipated 1
   • Aspirin (75-100mg daily) is most commonly used 1, 2
   • Cilostazol may improve survival, cerebral blood flow, and cognition compared to other antiplatelet drugs 1
   • Antiplatelet therapy does not increase risk of cerebral hemorrhage 3

2. Anticoagulants:

   • Generally not recommended due to hemorrhage risk 1, 2
   • Exception: Selected individuals with frequent TIAs or multiple infarctions despite antiplatelet therapy and surgery 1

3. Management of vascular risk factors:

   • Control diabetes, hypertension, and dyslipidemia 1
   • Consider atorvastatin after surgical revascularization to improve collateral circulation 1

4. Headache management:

   • Avoid medications that limit vasodilation, enhance vasoconstriction, or lower blood pressure 1, 2
   • Surgical revascularization often improves headache symptoms 1

Long-term Follow-up

• Regular clinical and radiographic follow-up is essential 2
• Monitor for development of bilateral disease (occurs in 27% of patients with unilateral disease) 2
• Assess for neuropsychological effects, headache, and epilepsy 4

Outcomes and Prognosis

• Surgical revascularization significantly reduces stroke rates 2, 5
• Annual risk after combined procedures: 0.4% for symptomatic hemorrhage and 0.2% for infarction 2
• Long-term follow-up shows stroke recurrence rate of only 4.3% after 5 years with surgical treatment 1

Pitfalls and Caveats

• Avoid dehydration which can trigger ischemic events 2
• Aggressive blood pressure lowering may compromise cerebral perfusion 2
• Endovascular treatment with stents or angioplasty shows low success rates and high complication rates 2
• Perioperative ischemic events occur following 4-18% of surgical cases 4
• Careful timing of surgery is important; delays may be necessary for medical optimization 1