New Insights on Moyamoya Disease: Symptoms Not Sole Indicators of Brain Injury

Moyamoya disease, a rare and progressive cerebrovascular disorder characterized by the narrowing of blood vessels in the brain, has recently come under scrutiny following a pivotal study at Boston Children’s Hospital. This research, published in the Journal of Pediatrics on June 26, 2025, reveals that symptoms alone may not adequately reflect the severity of brain injury in affected children. The study, led by Dr. Laura Lehman, MD, MPH, at the Cerebrovascular Surgery & Intervention Center, aimed to assess white matter damage in children diagnosed with moyamoya compared to a control group without the condition.

Moyamoya disease significantly increases the risk of strokes and other serious neurological conditions. Treatment options, particularly the decision to perform revascularization surgery—which bypasses narrowed blood vessels to restore blood flow—often hinge on the presence of observable symptoms, such as strokes or transient ischemic attacks (TIAs). However, the findings from Dr. Lehman's team challenge the established belief that symptomatic presentation is the best predictor of neurological damage.

Utilizing diffusion magnetic resonance imaging (dMRI), the researchers compared 17 children with moyamoya disease to 27 asymptomatic controls. The dMRI technique, which tracks water movement in the brain's white matter, revealed elevated mean diffusivity (MD) levels across both symptomatic and asymptomatic hemispheres in the moyamoya group. Higher MD indicates potential brain tissue damage, suggesting that significant white matter injury can occur even in the absence of overt symptoms.

According to Dr. Lehman, "Our findings challenge the assumption that the presence of symptoms is the best indicator of moyamoya's severity. Children without symptoms might still be at risk of significant white matter injury, and our findings open the door to reevaluating how these children are treated." This revelation underscores the necessity for clinicians to adopt a more nuanced approach to managing moyamoya disease, especially in asymptomatic cases, where treatment decisions can vary widely.

The implications of this study extend beyond clinical practice. For families, the notion that a child may be silently suffering from brain injury can be challenging. However, it also opens avenues for more proactive management of the disease. The ongoing research at Boston Children’s aims to better understand the long-term effects of treatment on asymptomatic moyamoya patients, potentially leading to improved care strategies.

Dr. Andrew Zinin, a leading editor at the Journal of Pediatrics, emphasizes the importance of this research in shifting clinical paradigms. He states, "These insights may help clinicians reconsider treatment decisions for asymptomatic patients, ensuring that early signs of serious brain damage are not overlooked."

Future directions for the study include examining the efficacy of revascularization surgery in asymptomatic children and tracking white matter injury as a marker for disease progression. Such research could refine treatment protocols and enhance patient outcomes.

In conclusion, the findings from Boston Children’s Hospital represent a significant advancement in understanding moyamoya disease. By recognizing that symptoms are not the sole predictors of brain injury, healthcare providers can develop more effective, personalized treatment plans that address the complexities of this rare condition. The research not only has the potential to change clinical practices but also offers hope for families navigating the uncertainties of moyamoya disease.