Skip to
  1. Homepage
  2. Rare diseases
  3. Search
Simple search

Simple search

(*) mandatory field


Other search option(s)

Moyamoya disease

Synonym(s) -
Prevalence 1-9 / 1 000 000
Inheritance Autosomal dominant
or Autosomal recessive
or Not applicable
Age of onset All ages
  • I67.5
  • C0026654
  • C2931384
  • C536991
  • D009072
  • 10028047


Moyamoya disease is an angiogenic disease caused by progressive stenosis of the cerebral arteries located at the base of the brain. It affects the intracerebral part of the internal carotids and causes a secondary collateral network to develop following a pattern resembling cigarette smoke ('moya-moya' in Japanese).

This disease remains asymptomatic in many cases: radiological criteria are observed in the absence of clinical signs in 1/2,000 adults in Japan, whereas the prevalence of Moyamoya syndrome is 1/32,000 in the general Japanese population. It is ten times less frequent in Europe.

Spontaneous progression may be insidious with headaches, epileptic seizures, language disorders and upper cerebral dysfunction. More often, acute and focal signs such as hemiplegia and sometimes hemichorea occur. Repeated deficiencies and frequently alternating hemiplegia represent the usual picture. Episodes are precipitated by hyperpnoea. The clinical picture can vary according to age, adults more often suffer from hemorrhages and children from ischemic accidents.

Moyamoya disease may be secondary to a known cause (drepanocytic anemia, radiotherapy, or in some patients affected by neurofibromatosis type I or William's syndrome; see these terms), or idiopathic. Hereditary forms of the disease, following an autosomal recessive pattern of transmission, have been described in about 10% of the cases. Various genetic localizations (chromosomes 3, 6, 8 and 17) have been reported in these familial forms.

The diagnosis is suggested by brain scans and magnetic resonance images showing multiple ischemic accidents of different ages, possibly hemorrhage and abnormal vessels at the base of the brain. Conventional angiography is used to ascertain the diagnosis and to assess the stage of evolution of the disease.

A variety of surgical techniques that stimulate peripheral angiogenesis can be proposed to compensate for deep ischemia. Treatment should begin early in the disease course to prevent vascular stenoses from affecting brain parenchyma.

Mortality rates are increased, especially by the occurrence of hemorrhagic accidents.

Expert reviewer(s)

  • Pr Josette MANCINI

(*) Required fields.

Attention: Only comments seeking to improve the quality and accuracy of information on the Orphanet website are accepted. For all other comments, please send your remarks via contact us. Only comments written in English can be processed.

Captcha image

Detailed information

Summary information
Emergency guidelines
  • FR (2013,pdf)
Anesthesia guidelines
  • EN (2014,pdf)
Clinical practice guidelines
  • EN (2012)
Article for general public
  • EN (2013)
  • FR (2008,pdf)
Get Acrobat Reader
The documents contained in this web site are presented for information purposes only. The material is in no way intended to replace professional medical care by a qualified specialist and should not be used as a basis for diagnosis or treatment.