Prognosis Of Moyamoya Disease

Moyamoya disease is progressive and can be fatal without treatment. Intracerebral hemorrhage (condition where bleeding within the brain occurs due to rupture of blood vessels) is the most common cause of death due to Moyamoya, unless effectively treated at right time. The prognosis or outcome of the disease is determined by severity of disease and nature of hemorrhage, prognosis depends on recurrent stroke attacks. Occurrence of Moyamoya disease is seen highest in Japan. It not only occurs in Asians, but also occur in whites, blacks, Hispanics and Haitians with varied range of severity.

Prognosis Of Moyamoya Disease

Prognosis of the disease primarily depends on the treatment compliance and disease stage at which treatment initiated. Patients with Moyamoya who got treatment at early stage of disease (i.e., stage at which symptoms of disease are evolving) reported a better prognosis than who present with static symptoms (indicates a completed stroke episode).

Stroke is usually categorized into two types – ischemic stroke and hemorrhagic stroke. Transient ischemic attack (TIA) is a warning sign prior to stroke occurrence. Prognosis of the ischemic attacks and hemorrhagic stroke resulting epileptics and TIA are good. Prognosis of patients with cerebral ischemic stroke is better than prognosis of patients presented with hemorrhage. A study reported that 96% of TIA group patients work regularly and live a normal everyday life. In that particular study, they reported that 70% participants had shown good results. In case of children, study revealed that 37.5% participants could not cope up with normal schooling. Children had also judged to have poor mental development; this is due to neurological deficits. Key factors that are indicative of a poor prognosis include onset of disease before the age of 6 years, progression from TIA to apoplexy and Maki’s angiographic type III. Another study conducted among adults reported a greater number of cases, accounting 44%, showing poor prognosis with respect to functional (motor) as well as mental health. A meta-analysis pooled data from various studies on Moyamoya, in 2018, reported that nearly 30% of children and adults had shown cognitive impairment, without the history of stroke. Another study reported that 30% of patients with unilateral disease showed arteriopathy on the other side within an average period of 2.2 years.

Prognosis of disease is quite different among TIA and Non-TIA groups. TIA group without epilepsy or symptoms other than headache had shown good results. Prompt treatment is of utmost important. A study reported that prognosis of cases was good in TIA group compared to Non-TIA group. Treatment for Moyamoya includes procedures for revascularization like superficial temporal artery- middle cerebral artery (STA-MCA) anastomosis and/or Encephalomyosynangiosis (EMS). STA-MCA or EMS was reported to improve the IQ levels and motor function particularly in children of age group 6 to 8 years. Though TIA is dangerous, it would be better if we can prevent the further ischemia formation or occurrence of infarction. In return, it further helps in the prevention of aneurysm formation in the blood vessels. When treatment targeted, by neurosurgeon, at preventing further aggravation of condition, prognosis will show positive outcome. Among pregnant women, good prognosis was reported in a research study.

Without surgery, majority of the diseased people experienced recurrent onset of stroke and progressive deterioration of cognitive function. The long term follow up studies conducted among untreated Moyamoya patients reported that 50 to 66% were exhibiting progressive neurological deficits like cognitive impairment and poor outcome. Cognitive function deterioration is due to recurrent attacks. As far as mortality of this disease is concerned, it is 4.3% in children and about 10% in adult population.


Prognosis of Moyamoya disease depends on prompt treatment initiation to prevent hemorrhagic stroke or ischemic stroke occurrence. Especially in children, early treatment can prevent cognitive impairment and motor function disability in patients. Better prognosis of disease depends on effective management to prevent recurrence of stroke.

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