This makes the blood leak out of the arteries, causing pressure to the brain and subsequent headaches. Over the last six decades since the disease was first described,  pathogenesis of moyamoya disease remained elusive, although the gene ring finger protein 213 (RNF213) has been implicated. In September 2021, a south Indian researcher has proposed a pathbreaking theory on moyamoya pathogenesis. Coined the "Mechano-biological theory", the disease has a multifactorial pathogenesis. The authors provide a tangible explanation of the occurrence of moyamoya phenomenon in the idiopathic and syndromic variants of the disease. In short, the authors report that moyamoya disease likely occurs due to a number of factors (e.g., differences in vascular anatomy) that ultimately contribute to broad cerebral blood vessel occlusion and consequent shifts in vessel connections to try to provide blood for the compromised brain.Once it begins, the vascular occlusion tends to continue despite any known medical management. In some people this leads to transient ischemic attacks or repeated strokes with severe functional impairment or even death. In others, the blockage may not cause any symptoms.The disease causes constrictions primarily in the internal carotid artery, and often extends to the middle and anterior cerebral arteries, branches of the internal carotid artery inside the skull. When the internal carotid artery becomes completely blocked, the fine collateral circulation that it supplies is obliterated. Patients often survive on the collateral circulation from the back (posterior) of the circle of Willis, arising from the basilar artery.The arterial constrictions in moyamoya disease are unlike the constrictions in atherosclerosis.
Diagnosis
There are various ways of diagnosing this congenital heart defect both prenatally and postnatally, these methods include:
Ultrasound
Pulse oximetry
Chest X-ray
Echocardiogram
Electrocardiogram
Cardiac catheterization
Cardiac CT scan
Genetic testing (particularly if other systemic birth anomalies are seen alongside the pulmonary atresia and ventricular septal defect). Management
When the disorder is detected (usually before or soon after birth), prostaglandin will be temporarily used as soon as possible in order to keep the ductus arteriosus open for as long as possible until surgery can be done, this is done so that blood can keep flowing to the lungs, since the bodies of babies with pulmonary atresia usually use the ductus arteriosus for lung blood flow pre-natally until birth, after which it closes.Afterwards, this anomaly is usually managed with surgeries for improvement of blood flow and function of the heart, although what kind of treatment one gets depends on the structure of the cardiorespiratory system.The surgical methods that can be used to treat (for the long-term) this condition include:
Catheter procedure for pulmonary artery branches
Systemic-to-pulmonary artery shunt
Neonatal complete repair
One-stage complete repair
Balloon septostomy

Staged unifocalization

Frequency
Frequency estimates vary between populations, estimates range from 0.01% to 0.2% of live births with PAVSD. It is believed to make up for 1-2% of cases of congenital heart defects worldwide.Of all patients with PAVSD, around 25-32% of them have a microdeletion of the 22q11.2 chromosome. Prognosis
Without treatment, it is a highly life-threatening condition, so prognosis is poor.