Moyamoya Disease

• Magnetic Resonance Imaging (MRI) and Magnetic Resonance Angiography (MRA): Useful for initial detection.
• Cerebral angiography: The gold standard for confirming diagnosis by visualizing stenosis or occlusion of the distal internal carotid arteries and abnormal collateral networks.
• Positron Emission Tomography (PET): Assesses cerebral metabolism.
• Single-Photon Emission Computed Tomography (SPECT): May be used to predict prognosis or evaluate cerebral perfusion after surgery.

Since the underlying cause is unknown, there is no definitive medical cure. Current treatments focus on improving cerebral blood flow through surgical revascularization.

• Direct bypass surgery: Directly connects an extracranial artery (e.g., superficial temporal artery) to an intracranial artery, providing immediate restoration of blood flow.
• Indirect bypass surgery: Involves placing vascularized tissue near the brain surface to promote the gradual growth of new collateral vessels. This is technically simpler and less invasive.
• Combined revascularization: Incorporates both direct and indirect techniques and has shown favorable long-term outcomes in recent studies.

Conservative management with medications (e.g., antiplatelet therapy) may be used, but surgery remains the standard of care for most symptomatic patients.