Can Revascularization Surgery Improve Memory in Moyamoya Disease Patients? Benefits and Limitations for Cognitive Function

What is Moyamoya Disease? Why Does It Affect Cognitive Function?

Moyamoya disease is a chronic cerebrovascular disorder in which the main arteries inside the skull gradually narrow or even become occluded, leading to long-term insufficient blood supply to the brain. To compensate, the brain forms numerous tiny new blood vessels.

Although these collateral vessels can partially maintain cerebral blood flow, they often cannot fully meet the brain's long-term needs.

In addition to stroke, chronic cerebral ischemia can affect multiple brain regions responsible for higher functions, so patients may experience:

• Memory decline
• Difficulty concentrating
• Decreased learning ability
• Slower thinking speed
• Reduced reasoning ability
• Impaired spatial judgment
• Reduced executive function (difficulty completing complex tasks)

These changes are sometimes subtle and can easily be mistaken for normal aging, work stress, or lack of sleep.

What is Revascularization Surgery? What Problem Does It Solve?

Revascularization surgery is currently one of the main treatment options for moyamoya disease.

Its core purpose is to establish new blood supply pathways for brain tissue, so that areas of the brain with insufficient blood flow can receive more blood.

Depending on the patient's condition, doctors may use:

• Direct revascularization
• Indirect revascularization
• Combined revascularization

Each surgical approach has its own indications. The specific choice depends on the patient's age, disease status, and cerebral blood flow assessment results.

Why Might Improving Cerebral Blood Flow Help Restore Cognitive Function?

The brain is like a city that is always running.

If the power supply is insufficient for a long time, the city may not shut down immediately, but its functions will gradually decline.

In moyamoya disease, chronic insufficient cerebral blood flow can affect multiple brain regions responsible for cognitive activities.

When surgery improves cerebral blood flow, some brain tissue receives more oxygen and nutrients, and certain cognitive functions may recover. This is an area of increasing interest among doctors in recent years.

However, the degree of recovery varies among different cognitive abilities.

What Benefits Can Revascularization Surgery Bring?

Patients who undergo revascularization surgery may experience improvements in some cognitive functions, mainly including:

1. Improvement in Verbal Memory

Verbal memory refers to the ability to remember what others say, reading material, or new knowledge. During follow-up, patients performed better on verbal memory tests compared to before treatment.

In daily life, this may manifest as:

• Finding it easier to remember conversations
• Improved learning efficiency
• Easier recall of information

2. Possible Improvement in Spatial Processing Ability

Spatial processing ability helps people judge direction, distance, and spatial relationships. For example:

• Judging distance while driving
• Finding directions
• Reading maps
• Determining object locations

Studies have found that this ability also improved in some patients.

3. Possible Improvement in Logical Reasoning Ability

Logical reasoning is related to analyzing problems, finding patterns, and solving complex issues. After surgery, some patients performed better on related tests than before treatment.

However, this improvement is a statistical result and does not mean that all patients will experience the same degree of recovery.

Will All Cognitive Abilities Improve?

The answer is no.

Aside from verbal memory, spatial processing, and logical reasoning, no significant short-term improvements were observed in several other cognitive domains, such as:

• Attention
• Working memory
• Executive function
• Some reaction speeds
• Mathematical calculation ability

This indicates that improving cerebral blood flow does not mean all cognitive functions will recover simultaneously. Different brain regions may recover at different rates, and there is considerable variation between patients.

Are the Recovery Effects the Same for Left-Sided and Right-Sided Surgery?

Patients who underwent right-sided revascularization surgery showed more significant improvement in forward verbal memory, while those who had left-sided surgery did not show the same degree of improvement.

However, researchers believe that more studies are needed to confirm this result. At present, it cannot be concluded that:

• Right-sided surgery is definitely better than left-sided surgery
• The surgical side determines cognitive recovery

Factors that truly influence recovery still include:

• Patient age
• Duration of disease
• Whether a stroke has occurred
• Degree of improvement in cerebral blood flow
• Individual differences in brain function

Which Patients May Benefit More from Surgery?

Patients who meet the indications for revascularization surgery may experience some improvement in cognitive function based on improved cerebral blood flow.

However, whether surgery is appropriate still requires a comprehensive assessment of:

• Presence of cerebral ischemic symptoms
• Significant reduction in cerebral blood flow
• Risk of cerebral hemorrhage
• Degree of vascular stenosis
• Age and overall health status

Doctors usually make a comprehensive judgment based on cerebral perfusion studies, CTA, MRA, DSA, and other examination results, rather than relying solely on cognitive symptoms to decide on surgery.

How Should Patients and Families View Revascularization Surgery?

For moyamoya disease patients who already meet the surgical indications, surgery should not be seen solely as "stroke prevention."

After improving cerebral blood flow, some patients may experience improvements in verbal memory, spatial processing, and logical reasoning, which can positively impact learning, work, and quality of life.

At the same time, it is important to maintain realistic expectations. Cognitive function is influenced by disease course, extent of brain tissue damage, age, and rehabilitation training. Surgery cannot guarantee a return to normal.

After surgery, patients should continue long-term follow-up as advised by their doctor, actively control risk factors, and maintain a healthy lifestyle to promote brain function recovery.

Frequently Asked Questions (FAQ)

Q1: Will memory definitely recover after revascularization surgery for moyamoya disease?

There is no guarantee. This study shows that some patients experience improvement in verbal memory, but the degree of recovery varies from person to person, and not all patients will see significant changes.

Q2: Does revascularization surgery only reduce stroke risk?

No. After improving cerebral blood flow, some patients may also experience improvements in verbal memory, spatial processing, and logical reasoning, but these are additional benefits and not all patients will experience them.

Q3: Which cognitive abilities show the most improvement?

In short-term follow-up, verbal memory, spatial processing, and logical reasoning showed relatively more improvement, while most other cognitive domains did not show significant changes.

Q4: How long after surgery was cognitive assessment performed?

This study mainly conducted follow-up assessments about 6 months after treatment, so the results reflect short-term changes.

Q5: Is cognitive training still necessary?

Yes. Even after revascularization surgery, cognitive recovery is a long-term process. Regular follow-up, a healthy lifestyle, and cognitive rehabilitation training when necessary may all help promote brain function recovery.

References

Tie, Y., Li, J., Liu, Z., et al. (2026). Short-term effects of revascularization surgery on cognitive function in patients with moyamoya disease. Chinese Journal of Neurosurgery, 42(6), 560–565. https://doi.org/10.3760/cma.j.cn112050-20260111-00015