Is Moyamoya A Serious Disease?
Is Moyamoya A Serious Disease?
Moyamoya disease is a serious disease leading to either temporary or permanent brain injury. It is an extremely rare condition, wherein the carotid artery in the skull, basically the base of the brain called the basal area; encounters narrowing or thinning of the vessels leading to reduced blood flow to the brain. It is classified as a type of progressive blood vessel (vascular) disorder. The group of meek tiny blood vessels appears like a cluster, hence, the word "moyamoya" meaning "puff of smoke" in Japanese. These vessels are not sufficiently equipped to transfer the required oxygen and blood to the brain, resulting in brain injury. In medical terminology, it is a highly progressive, occlusive disease of the cerebral vasculature with particular involvement of the circle of Willis and the arteries that feed it.(1)
The Moyamoya condition is known to affect the younger age group, mainly children; but adults may too develop it. It is highly predominant in East Asian Countries, especially Korea and China.
The disease is can result in multiple consequences like, aneurysm of vessels (bulging/bleeding in the blood vessel); acute stroke or transient ischemic attack; cognitive/memory impairment; delayed developmental milestones; etc. Most importantly, if, a major quadrant of the vessels is affected, it can lead to permanent disability for the patient.
The primary symptom of Moyamoya Disease’s presentation is recurrent transient ischemic attacks/stroke( even mini-stroke); particularly in children. Basically all signs and symptoms in Moyamoya disease are a consequence of abnormal/reduced blood flow in the vessels:
- Severe headache
- Numbness of extremities
- Partial or complete paralysis of limbs or face
- Hemorrhagic stroke because of sudden bleeding (chances being higher in adults); occasionally multiple mini-strokes
- Visual impairment including blurring vision
- Aphasia- difficulty speaking
- Developmentally delayed milestones in children between the age of 1-5 years
- Cognitive and memory impairment
These symptoms can be further aggravated by any strenuous activity or stress. Henceforth, caution must be executed especially in case of children; as there are chances of accentuation of symptoms while crying.(2)
Predisposing Risk Factors For Moyamoya
Significant Family History. In case, even 1 family member is affected with the disease; it is a must to get all members of the family genetically screened; especially young children. Thus, as per the genetics, there is a very high probability of the disease to travel through the family tree.
Prior Medical Conditions. Congenital or Acquired. Moyamoya disease can be seen in association with many other predisposing medical conditions, which tend to lead to immunosuppression. Such diseases include neurofibromatosis type 1, Down’s syndrome, sickle cell anemia, congenital heart disease, fibromuscular dysplasia, activated protein C resistance etc. The Acquired causes include primarily severe head trauma or accidental head injury.
Geographical Distribution. The disease is known to affect Asians more as in comparison to any other zone; especially Japan and Korea. The genetic correlation regarding the same is still under discussion.
Demographics. Moyamoya disease is known to affect younger children especially below the age of 12-15 years. The reason though is unknown, but the disease is more prevalent in Female gender.
As described earlier, it is a progressive disease and must be stopped with the help of treatment or surgery. In children, the disease is known to present as microstrokes or "warning strokes." The disease if not cured or operated can definitely lead to fatal consequences of death following intracerebral hemorrhage.
Symptomatic relief can be attained by following prolonged stroke risk management plan in individuals prone to slightest bleed after the first episode itself. Medications like blood thinning agents can help control seizure or minimize chances of stroke. Topical eye drops are also used to provide first hand relief in case of eye symptoms. Precaution
should be executed in case painkillers are taken for headache, as NSAIDs like Diclofenac are known to aggravate bleeding.
Thereby, the mainstay of treatment is operating the affected area. It takes almost 6-12 months for the rejuvenation of new vessels post-surgery. Two types of surgical approaches are offered for patients with Moyamoya: Direct and Indirect revascularization.(2)
Though symptomatic relief is possible to restrain symptoms like stroke or seizures or visual disturbances; but surgical intervention is a must in Moyamoya patients to provide long term relief.