Moyamoya Disease – Symptoms and Causes

Overview

Moyamoya disease is a rare vascular disorder. It causes the carotid artery inside the skull to narrow or become blocked. This major brain artery blockage reduces blood flow to the brain.

It also causes small blood vessels to form at the brain’s base as the body attempts to maintain adequate blood supply.

This condition can lead to serious complications. These include transient ischemic attacks (mini-strokes), strokes, and brain hemorrhages. People with Moyamoya may experience cognitive issues and developmental delays or disabilities due to compromised brain function.

Children are most frequently affected by Moyamoya disease, though adults can develop it too. The disease occurs worldwide but appears more frequently in East Asian populations, particularly in:

• Korea
• Japan
• China

This geographic distribution suggests genetic factors may play a role in the development of Moyamoya disease. The higher prevalence in these regions has helped researchers identify potential genetic links to the condition.

Proper diagnosis and treatment are essential, as the condition can cause significant neurological problems if left unmanaged.

Signs and Symptoms

Moyamoya disease can affect people of any age, but it most often appears in children between 5 and 10 years old and adults between 30 and 50. Early detection of symptoms is crucial to prevent serious complications like stroke.

Children and adults experience different symptoms. Children typically first show signs through a stroke or repeated mini-strokes (transient ischemic attacks or TIAs).

Adults may have these same symptoms but are also more likely to experience bleeding in the brain (hemorrhagic stroke) due to abnormal blood vessel formation.

Common symptoms related to reduced blood flow to the brain include:

• Headaches
• Seizures
• Weakness, numbness, or paralysis (usually on one side of the body)
• Vision problems
• Difficulty speaking or understanding others
• Cognitive or developmental delays
• Involuntary movements

These symptoms might appear during activities like exercise, crying, coughing, straining, or when having a fever.

When To Get Medical Help

Get emergency medical care immediately if you notice any stroke symptoms, even if they seem to come and go quickly.

Remember the “FAST” method to identify stroke signs:

F – Face: Is one side of the face drooping when the person smiles?
A – Arms: Does one arm drift downward when both arms are raised?
S – Speech: Does the person have slurred or strange speech when repeating a simple phrase?
T – Time: Call 911 right away if you notice any of these signs.

Don’t wait to see if symptoms improve on their own. Every minute counts during a stroke. The longer treatment is delayed, the higher the risk of brain damage and disability.

If you’re with someone who might be having a stroke, watch them carefully while waiting for emergency help to arrive.

For any symptoms that might relate to moyamoya disease, even if they’re mild, it’s important to see a healthcare provider promptly.

Causes

The exact reason why moyamoya disease develops remains unknown. This condition appears most frequently in East Asian countries like Japan, Korea, and China, suggesting a possible genetic component in certain populations.

Some people develop similar blood vessel changes that resemble moyamoya disease but may have different origins. These cases are classified as moyamoya syndrome rather than the disease itself.

Several health conditions have been linked to moyamoya syndrome, including:

• Down syndrome
• Sickle cell anemia
• Neurofibromatosis type 1
• Hyperthyroidism

When blood vessel changes mimic moyamoya disease but connect to another underlying condition, doctors typically diagnose it as moyamoya syndrome. The symptoms and treatments may differ from those of the primary disease.

Risk Factors

Several factors may raise your chances of developing moyamoya disease:

Ethnic Background

• People of East Asian descent (especially from Japan, Korea, and China) have higher rates of the disease
• Asian individuals living in Western countries still maintain this increased risk

Genetic Factors

• Having a family member with moyamoya disease increases your risk 30-40 times
• This strong family connection points to genetic causes

Age and Gender

• Children under 15 are most commonly affected
• Females have slightly higher rates than males

Related Medical Conditions

The disease sometimes appears alongside other disorders such as:

• Neurofibromatosis type 1
• Sickle cell disease
• Down syndrome
• Various other conditions

While doctors don’t yet understand exactly what causes moyamoya disease, these risk factors help identify who might need closer monitoring. The combination of family history and ethnic background suggests strong genetic components in how the disease develops.

Health Problems

Moyamoya disease can lead to several health issues, mostly due to strokes. Patients might experience seizures after blood flow to the brain is reduced.

Some people develop paralysis or weakness on one side of their body. Vision problems are also common.

Other difficulties include:

• Speech difficulties
• Movement disorders
• Developmental delays in children

Preventing Complications

While no method exists to stop moyamoya disease from developing, proper treatment plans can effectively prevent complications like strokes.

Medical interventions focus on managing symptoms and reducing risks associated with this condition.

Key prevention strategies include:

• Regular medical checkups with specialists
• Prompt treatment of symptoms
• Following prescribed medication regimens
• Lifestyle modifications as recommended

Early intervention remains crucial for reducing the chance of serious complications in people with moyamoya disease.