Secondary moyamoya disease, also known as secondary moyamoya syndrome, is a medical condition characterized by the narrowing or blockage of certain arteries in the brain. This condition is considered secondary because it is not a primary or idiopathic condition, but rather a result of an underlying cause or disease.
Moyamoya disease itself refers to a rare cerebrovascular disorder where the walls of the blood vessels in the brain become progressively narrowed over time, leading to reduced blood flow to certain areas. In secondary moyamoya disease, the same narrowing of blood vessels occurs, but it is caused by an underlying condition or factor.
The underlying causes of secondary moyamoya disease can be diverse and can include autoimmune disorders, atherosclerosis, radiation therapy, sickle cell disease, certain genetic or inherited conditions, brain tumors, or brain trauma, among others. These conditions can damage the blood vessel walls, triggering a response where new, abnormal blood vessels grow in an attempt to bypass the blocked or narrowed arteries. The appearance of these vessels resembles a "puff of smoke" in Japanese, which gave moyamoya disease its name.
The symptoms of secondary moyamoya disease are similar to those of the primary form and can include recurring transient ischemic attacks (mini-strokes), headaches, cognitive deficits, seizures, and in severe cases, stroke. Treatment for secondary moyamoya disease involves addressing the underlying cause or managing the symptoms. In some cases, surgical interventions like direct or indirect revascularization may be necessary to improve blood flow and prevent further complications. Regular monitoring is essential to detect any changes in the condition and promptly manage them.
