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PubMed This is a summary of 108 peer-reviewed journal articles Updated
Neurology

Moyamoya disease: A Patient Guide

At a Glance

Moyamoya disease progressively narrows the brain’s main arteries, reducing blood flow and creating fragile backup vessels. Brain imaging and blood-flow testing guide care, while revascularization surgery can restore circulation and lower stroke risk for many symptomatic patients.

Moyamoya is a rare and progressive condition that affects the way blood reaches the brain. It occurs when the main arteries at the base of the brain, known as the internal carotid arteries, begin to narrow and eventually close off. As these large vessels tighten, the brain attempts to compensate by growing hundreds of tiny, bypass-like blood vessels to find new ways to get the oxygen-rich blood it needs [1][2]. On specialized imaging, these clusters of fragile vessels look like a hazy “puff of smoke,” a description that gives the condition its name from the Japanese word for this appearance [2][3].

What You Should Do Now:

  • Do not start, stop, or change aspirin, blood pressure medications, or fluids without direct instructions from your treating team.
  • Keep an emergency plan and know who to call for sudden symptoms.
  • Bring copies of your imaging discs and a complete medication list to every consultation.

The way this condition behaves can change depending on when it is first diagnosed. In children, Moyamoya typically presents with symptoms of low blood flow, such as TIAs (mini-strokes) or ischemic strokes, which can sometimes be triggered by activities like crying or heavy breathing [4][5]. In adults, the experience is often more varied; while strokes from low blood flow still occur, adults are also at a higher risk for bleeding in the brain [4][6]. This happens because the “puff of smoke” vessels are tiny and fragile, and they or associated aneurysms can eventually rupture under the constant pressure of trying to supply the brain [7].

While the exact cause of Moyamoya is not always known, researchers have identified a specific gene called RNF213 that plays a significant role, particularly in people of East Asian descent [8]. It is important to know that having this genetic marker does not mean a person will definitely develop the disease; in fact, the vast majority of people who carry the gene variation never show any signs of the condition [9]. This suggests that other environmental or health factors interact with the gene to cause the arterial narrowing [10][9].

Confirming a diagnosis requires a specialized set of images to see the brain from several angles. While an MRI can show the “puff of smoke,” the reference standard test is a catheter angiogram, which provides a detailed, high-definition map of exactly how blood is moving—or where it is being blocked [11][12]. Doctors also use perfusion imaging to measure Cerebrovascular Reserve (CVR), which is the brain’s “emergency backup” capacity to increase blood flow when needed [13][14]. These tests help your care team determine if the brain is receiving enough blood to function safely or if it is time to intervene.

Because Moyamoya is a progressive disease, avoiding dehydration can support cerebral perfusion, and aspirin may be prescribed for selected patients to reduce ischemic risk [15][16]. However, neither stops the underlying arteriopathy, and neither replaces specialist assessment. Surgery, known as revascularization, is the main disease-directed treatment for many symptomatic or hemodynamically compromised patients [16]. By creating a surgical bypass—either by directly connecting a new artery or by placing tissue that encourages new vessels to grow over time—surgeons can restore blood flow and significantly lower the long-term risk of stroke [17][18]. With specialized care and lifelong monitoring, people with Moyamoya can navigate this diagnosis and maintain a stable, active life.

In this guide

6 chapters

01

Understanding Moyamoya Disease and Syndrome

Learn what Moyamoya disease and syndrome mean, how they affect brain blood flow, the role of RNF213 genetics, and how doctors confirm the diagnosis with imaging.

02

Symptoms, Presentation, and Warning Signs

Learn the symptoms and warning signs of Moyamoya disease, including TIAs, stroke signs, headaches, seizures, cognitive changes, triggers, and when to call 911.

03

Getting a Clear Picture: Diagnostic Tests and Imaging

Learn how Moyamoya disease is diagnosed with DSA, MRI/MRA, Suzuki staging, and cerebrovascular reserve testing, including what each result means for care.

04

Surgical Treatment: Restoring Blood Flow to the Brain

Learn how Moyamoya surgery restores brain blood flow through direct, indirect, or combined bypass, including risks, recovery, and long-term follow-up care.

05

Building Your Care Team and Preparing for Consultation

Learn how to choose a Moyamoya care team, prepare for consultation, evaluate surgical experience, organize imaging, and plan fluids, blood pressure, and aspirin.

06

Lifelong Care: Monitoring, Follow-up, and Survivorship

Learn how lifelong Moyamoya follow-up tracks bypass blood flow, watches for progression, manages lingering symptoms, and identifies emergency warning signs.

Common questions in this guide

What is Moyamoya disease, and why is it called a “puff of smoke”?
Moyamoya disease is a progressive narrowing or closure of the internal carotid arteries, which supply blood to the brain. The brain can form many small, fragile backup vessels around the blockage; on specialized imaging, their clustered appearance resembles a hazy “puff of smoke.”
What symptoms can Moyamoya disease cause in children and adults?
Children often have brief episodes called transient ischemic attacks or strokes caused by reduced blood flow, sometimes after crying or heavy breathing. Adults may also have these events and have a higher risk of bleeding in the brain. Sudden weakness, speech changes, or other stroke symptoms require emergency care.
How is Moyamoya disease diagnosed?
Doctors use brain and blood-vessel imaging, including MRI and a catheter angiogram. The catheter angiogram is the reference-standard test for mapping narrowed arteries, blocked flow, and the small backup vessels. Perfusion imaging can measure cerebrovascular reserve, or how well the brain can increase blood flow when it is under stress.
What does cerebrovascular reserve testing show in Moyamoya disease?
Cerebrovascular reserve testing estimates how much extra blood flow the brain can receive when demand rises. A reduced reserve suggests that narrowed arteries are limiting the brain’s ability to respond to stress and helps the care team decide whether revascularization should be considered.
Does an RNF213 gene variant mean I will develop Moyamoya disease?
No. An RNF213 variant is associated with Moyamoya disease, especially in people of East Asian ancestry, but most people who carry the variant never develop symptoms. Other genetic, environmental, or health factors may also influence whether arterial narrowing occurs.
What treatments are used for Moyamoya disease?
Revascularization surgery is the main disease-directed treatment for many people who have symptoms or reduced blood flow to the brain. Surgery may directly connect a new artery, indirectly encourage new vessels to grow, or use both approaches. Avoiding dehydration and prescribed aspirin may help selected patients, but they do not stop the underlying artery narrowing.
Is Moyamoya disease the same as Moyamoya syndrome?
They describe similar patterns of narrowing in the brain’s arteries, but Moyamoya syndrome is generally used when the pattern occurs with an underlying condition or another identified cause. Your specialist may evaluate for associated conditions before deciding how to monitor and treat you. Do not assume the terms are interchangeable in your medical record.

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Questions to Ask Your Doctor

Curated prompts to bring to your next appointment.

  1. 1.Based on the 'puff of smoke' collateral vessels, how much blood flow is actually reaching my (or my child's) brain compared to what is needed?
  2. 2.Is this considered Moyamoya Disease, or is there an underlying condition suggesting Moyamoya Syndrome that we need to treat simultaneously?
  3. 3.What did the cerebrovascular reserve (CVR) testing show about the brain's ability to handle stress or activity?
  4. 4.Given our specific case, do you recommend a direct, indirect, or combined surgical bypass to restore blood flow?
  5. 5.What is our long-term plan for monitoring both the surgical site and the other side of the brain?

References

References (18)
  1. 1

    Pathophysiology of Vascular Stenosis and Remodeling in Moyamoya Disease.

    Fox BM, Dorschel KB, Lawton MT, Wanebo JE

    Frontiers in neurology 2021; (12()):661578 doi:10.3389/fneur.2021.661578.

    PMID: 34539540
  2. 2

    Moyamoya: An Update and Review.

    Berry JA, Cortez V, Toor H, et al.

    Cureus 2020; (12(10)):e10994 doi:10.7759/cureus.10994.

    PMID: 33209550
  3. 3

    Childhood Moyamoya: Looking Back to the Future.

    Dlamini N, Muthusami P, Amlie-Lefond C

    Pediatric neurology 2019; (91()):11-19 doi:10.1016/j.pediatrneurol.2018.10.006.

    PMID: 30424960
  4. 4

    Moyamoya Disease: Epidemiology, Clinical Features, and Diagnosis.

    Kim JS

    Journal of stroke 2016; (18(1)):2-11 doi:10.5853/jos.2015.01627.

    PMID: 26846755
  5. 5

    Moyamoya Disease in Children: Results From the International Pediatric Stroke Study.

    Lee S, Rivkin MJ, Kirton A, et al.

    Journal of child neurology 2017; (32(11)):924-929 doi:10.1177/0883073817718730.

    PMID: 28715924
  6. 6

    Epidemiology of Moyamoya Disease in China: Single-Center, Population-Based Study.

    Bao XY, Wang QN, Zhang Y, et al.

    World neurosurgery 2019; (122()):e917-e923 doi:10.1016/j.wneu.2018.10.175.

    PMID: 30404059
  7. 7

    A Rare Case of Cardiac Myxoma With Moyamoya Phenomenon: A Disease or Syndrome?

    Konduru RA, Prasad A, Cheriyath P, Okere A

    Cureus 2024; (16(4)):e59381 doi:10.7759/cureus.59381.

    PMID: 38817499
  8. 8

    Rare variants of RNF213 and moyamoya/non-moyamoya intracranial artery stenosis/occlusion disease risk: a meta-analysis and systematic review.

    Liao X, Deng J, Dai W, et al.

    Environmental health and preventive medicine 2017; (22(1)):75 doi:10.1186/s12199-017-0680-1.

    PMID: 29165161
  9. 9

    HAPLN3 p.T34A contributes to incomplete penetrance of moyamoya disease in Chinese carrying RNF213 p.R4810K.

    Xu J, Zou Z, Liu W, et al.

    European journal of neurology 2024; (31(12)):e16473 doi:10.1111/ene.16473.

    PMID: 39315749
  10. 10

    Moyamoya disease: diagnosis and interventions.

    Ihara M, Yamamoto Y, Hattori Y, et al.

    The Lancet. Neurology 2022; (21(8)):747-758 doi:10.1016/S1474-4422(22)00165-X.

    PMID: 35605621
  11. 11

    Imaging-Based Diagnostic Approaches in Moyamoya Disease: A Scoping Review.

    Novillo-Solis C, Salvador-Orbea M, Morales-Acosta A, Leon-Rojas JE

    Journal of clinical medicine 2026; (15(6)) doi:10.3390/jcm15062410.

    PMID: 41899333
  12. 12

    Clinical Characteristics and Multi-Model Imaging Analysis of Moyamoya Disease: An Observational Study.

    Ling H, Huang H, Fu B, et al.

    The Journal of craniofacial surgery 2025; (36(1)):e45-e49 doi:10.1097/SCS.0000000000010765.

    PMID: 39436989
  13. 13

    Simultaneous phase-contrast MRI and PET for noninvasive quantification of cerebral blood flow and reactivity in healthy subjects and patients with cerebrovascular disease.

    Ishii Y, Thamm T, Guo J, et al.

    Journal of magnetic resonance imaging : JMRI 2020; (51(1)):183-194 doi:10.1002/jmri.26773.

    PMID: 31044459
  14. 14

    Revascularization improves vascular hemodynamics - a study assessing cerebrovascular reserve and transit time in Moyamoya patients using MRI.

    Zhao MY, Armindo RD, Gauden AJ, et al.

    Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism 2023; (43(2_suppl)):138-151 doi:10.1177/0271678X221140343.

    PMID: 36408536
  15. 15

    Efficacy and Safety of Antiplatelet Agents for Adult Patients With Ischemic Moyamoya Disease.

    Ye F, Li J, Wang T, et al.

    Frontiers in neurology 2020; (11()):608000 doi:10.3389/fneur.2020.608000.

    PMID: 33519687
  16. 16

    Moyamoya Across the Lifespan: Current Neurologic Care and Future Directions.

    Sun LR, Vossough A, Kossorotoff M, et al.

    Neurology 2025; (104(7)):e213484 doi:10.1212/WNL.0000000000213484.

    PMID: 40036714
  17. 17

    Superficial temporal artery-middle cerebral artery anastomosis patency correlates with cerebrovascular reserve in adult moyamoya syndrome patients.

    Aboukais R, Verbraeken B, Leclerc X, et al.

    Neuro-Chirurgie 2019; (65(4)):146-151 doi:10.1016/j.neuchi.2019.05.001.

    PMID: 31185229
  18. 18

    Superficial temporal artery-to-middle cerebral artery bypass in combination with indirect revascularization in moyamoya patients ≤ 3 years of age.

    Bot GM, Burkhardt JK, Gupta N, Lawton MT

    Journal of neurosurgery. Pediatrics 2019; (23(2)):198-203.

    PMID: 30497164

This Moyamoya guide is for educational purposes and does not replace medical advice. Decisions about aspirin, imaging, and revascularization should be made with your treating neurologist or neurosurgeon.