Moyamoya

Puff of SmokeOne of the refreshing aspects of taking care of children is that, generally, they don’t have a mile long list of medications or an extensive known past medical history, unlike their adult counterparts.  Unfortunately, this generality can lead us to become complacent and be caught off guard when a child presents with concerning symptoms or has unusual medical problems. We have previously discussed several “adult” illness that occur in children (ex, Pulmonary Embolism, Cholelithiasis, Nephrolithiasis) and one of those surprising entities is Stroke (CVA). While children may have an AVM that leads to hemorrhagic stroke, one important condition that may be on their PMHx list and can lead to CVA in moyamoya.  Let’s take a moment to review moyamoya so we can remain vigilant!

 

Moyamoya: Basics

  • Moyamoya is a Japanese term that means “something hazy, like puff of smoke drifting in the air.” [Singhi, 2012]
    • Refers to the angiographic appearance of the abnormal collaterals that develop.
  • Cerebrovascular arteriopathy that leads to progressive stenosis and eventual occlusion.
    • It is not inflammatory and not due to atherosclerosis.
    • Stenosis is due to progressive intimal thickening and thrombosis formation.
    • Affects internal carotid, middle cerebral artery, and anterior cerebral artery [Singhi, 2012; Kim, 2010]
    • Can also affect posterior cerebral artery [Lee, 2015; Lee, 2014]
  • Rare cerebrovascular occlusive disease, but incidence varies between ethnic groups. [Smith, 2009]
  • Occurs in all ethnic groups.
  • Bimodal distribution: [Singhi, 2012]
    • One peak in childhood – usually before 10 years of age.
    • Second peak occurs during 4th decade of life.
  • Unknown cause
    • Likely combination of environmental and genetic factors
    • One large study found only 12% of cases to be familial. [Kim, 2010]

 

Moyamoya: What’s in a Name?

“Moyamoya,” “moyamoya syndrome,” “moyamoya disease” may be confused.

  • Moyamoya – generic term for the angiographic findings
  • Moyamoya Disease – bilateral, angiographic findings without associated clinical cause (i.e., idiopathic)
  • Moyamoya Syndrome – unilateral moyamoya or moyamoya found in association with systemic disorders that are known to be associated with moyamoya. [Singhi, 2012; Smith, 2012]
    • Genetic Disorders:
    • Hematologic Disorders:
    • Hyperthryoidism
    • Congenital Heart Disease
    • Tubercular meningitis
    • Previous cranial therapeutic radiation

 

Moyamoya: Presentation

  • There are 4 main types of moyamoya based on clinical manifestations:
    • Infarct Type
      • Motor deficits (in one study, ~95% of cases) [Singhi, 2012]
      • Hemiparesis (44%) [Singhi, 2012]
      • Sensory symptoms
      • Some patients will present with ischemic symptoms precipitated by crying, coughing, blowing, or hyperventilation (which leads to hypocapnia and vasoconstriction) [Smith, 2009]
    • Transient Ischemic Attacks (TIAs) Type
      • Repeated TIAs is a presentation that needs to be respected.
    • Hemorrhagic Type
      • Hemorrhage is rare in children, but does occur. More common in adults. [Singhi, 2012]
    • Epileptic Type
      • May be initial presentation or recurrent in patient with known Moyamoya
      • Seizures on presentation rates vary: ~34% in [Singhi, 2012]; 19% in [Kim, 2010]
      • Surgery shown to help reduce recurrent seizure activity (97% seizure free)  [Kim, 2010]
  • Other commonly encountered symptoms:
    • Headaches (33%) [Kim, 2010]
      • Surgery does not as greatly affect headache recurrence (26% still w/ headaches, and 16% developed new headaches) [Kim, 2010; Seol, 2005]
    • Fever
      • 30% presented with fevers [Singhi, 2012]
      • Unclear association, but fever can lead to carotid artery constriction.

 

Moyamoya: Evaluation

  • Gold standard for evaluation is Intra-arterial cerebral angiography. [Singhi, 2012]
    • Better able to fully image the blood vessels.
    • Helps with correlation of Stage of Disease.
      • Stages progress from Stage 1 to Stage 6
      • Staging based on progressive stenosis and eventual occlusion of internal carotid artery (ICA) along with development of moyamoya collaterals at base of brain and development of external carotid artery (ECA) collateral vessels.
  • MRI/MRA has been found reliable and often used for screening for disease and monitoring, but surgery often based on intra-arterial angiography. [Singhi, 2012; Smith, 2012]

 

Moyamoya: Management

  • There is no effective pharmacotherapy to treat moyamoya. [Singhi, 2012]
  • Therapies aimed at underlying syndromes, if present, for Moyamoya Syndrome. [Smith, 2012]
  • Surgical revascularization to augment collateral circulation can be helpful.
    • Various techniques debated amongst neurosurgeons.
    • Typically reserved for patients with progressive ischemic symptoms or those with evidence of inadequate cerebral perfusion. [Singhi, 2012; Smith, 2012]
  • Prognosis is highly variable.
    • May have slow progression with intermittent events.
    • May have rapid neurologic deterioration.
    • Early diagnosis and active intervention before irreversible changes occur can lead to favorable outcomes. [Bao, 2014]
    • Sadly, even in the absence of CVA, there is still often a lower quality of life observed in the patient’s with Moyamoya. [Ball, 2016]

 

Moral of the Morsel:

  • Not every child has “no significant past medical history.” Some children have rather complex medical histories.
  • “Adult” medical problems can occur in children.
  • A child with a history of possible TIAs should not be dismissed… consider Moyamoya!
  • A child with Moyamoya may present with progression of disease… be aware of the increased risk for further ischemic disease.

 

References

Ball AJ1, Steinberg GK2, Elbers J3. Quality of Life in Pediatric Moyamoya Disease. Pediatr Neurol. 2016 Oct;63:60-5. PMID: 27473648. [PubMed] [Read by QxMD]

Rashad S1, Fujimura M2, Niizuma K1, Endo H1, Tominaga T1. Long-term follow-up of pediatric moyamoya disease treated by combined direct-indirect revascularization surgery: single institute experience with surgical and perioperative management. Neurosurg Rev. 2016 Oct;39(4):615-23. PMID: 27180559. [PubMed] [Read by QxMD]

Bao XY1, Duan L, Yang WZ, Li DS, Sun WJ, Zhang ZS, Zong R, Han C. Clinical features, surgical treatment, and long-term outcome in pediatric patients with moyamoya disease in China. Cerebrovasc Dis. 2015;39(2):75-81. PMID: 25573764. [PubMed] [Read by QxMD]

Lee JY1, Kim SK2, Phi JH2, Wang KC2. Posterior Cerebral Artery Insufficiency in Pediatric Moyamoya Disease. J Korean Neurosurg Soc. 2015 Jun;57(6):436-9. PMID: 26180612. [PubMed] [Read by QxMD]

Baltsavias G1, Khan N, Valavanis A. The collateral circulation in pediatric moyamoya disease. Childs Nerv Syst. 2015 Mar;31(3):389-98. PMID: 25378261. [PubMed] [Read by QxMD]

Lee JY1, Choi YH, Cheon JE, Paeng JC, Ryu HW, Kim KJ, Phi JH, Wang KC, Cho BK, Chae JH, Kim SK. Delayed posterior circulation insufficiency in pediatric moyamoya disease. J Neurol. 2014 Dec;261(12):2305-13. PMID: 25212285. [PubMed] [Read by QxMD]

Singhi P1, Choudhary A, Khandelwal N. Pediatric moyamoya disease: clinical profile, literature review and sixteen year experience from a tertiary care teaching institute. Indian J Pediatr. 2013 Dec;80(12):1015-20. PMID: 23525975. [PubMed] [Read by QxMD]

Smith ER1, Scott RM. Spontaneous occlusion of the circle of Willis in children: pediatric moyamoya summary with proposed evidence-based practice guidelines. A review. J Neurosurg Pediatr. 2012 Apr;9(4):353-60. PMID: 22462697. [PubMed] [Read by QxMD]

Kim SK1, Cho BK, Phi JH, Lee JY, Chae JH, Kim KJ, Hwang YS, Kim IO, Lee DS, Lee J, Wang KC. Pediatric moyamoya disease: An analysis of 410 consecutive cases. Ann Neurol. 2010 Jul;68(1):92-101. PMID: 20582955. [PubMed] [Read by QxMD]

Amlie-Lefond C1, Bernard TJ, Sébire G, Friedman NR, Heyer GL, Lerner NB, DeVeber G, Fullerton HJ; International Pediatric Stroke Study Group. Predictors of cerebral arteriopathy in children with arterial ischemic stroke: results of the International Pediatric Stroke Study. Circulation. 2009 Mar 17;119(10):1417-23. PMID: 19255344. [PubMed] [Read by QxMD]

Smith JL1. Understanding and treating moyamoya disease in children. Neurosurg Focus. 2009 Apr;26(4):E4. PMID: 19335128. [PubMed] [Read by QxMD]

Seol HJ1, Wang KC, Kim SK, Hwang YS, Kim KJ, Cho BK. Headache in pediatric moyamoya disease: review of 204 consecutive cases. J Neurosurg. 2005 Nov;103(5 Suppl):439-42. PMID: 16302616. [PubMed] [Read by QxMD]

Sean Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renown educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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2 Responses

  1. Ciprian says:

    Moyamoya surgery can be done now in Romania also by doctor Sergiu Stoica. For more information pls contact me or go on the link above. https://www.spitalulmonza.ro/medic/dr-sergiu-stoica/

    The doctor operated in 2016 a 5 years old boy having moyamoya on both sides. The surgerys were both a real succes. In just 40-60 days from each surgery the mri showed that the blod vesels were growing. He made surgerys on moyamoya in Canada , USA and now in Romania.

    For admin…please do not remove my comment. I want everybody to know that in Romania it’s a very good doctor for this desease. We,parents with children having moyamoya want to know were we can look for help. Thankyou.

  1. January 21, 2017

    […] some important conditions to consider when evaluating headache (ex, AVM, RMSF, Meningitis, Post-LP, Moyamoya, Migraine, Pseudotumor, and Pheochromocytoma). Many of these are rare and require our dedicated […]

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