Clinical Features and Treatment Outcomes in Patients in Their Twenties with Ischemic Moyamoya Disease.

Introduction: Revascularization surgery is recommended for all pediatric patients with moyamoya disease (MMD) with ischemic symptoms because the brains of such patients are still developing. By contrast, no clear guidelines for selective revascularization surgery in adult patients (30 years or more) with ischemic presentation have been established. Regarding the age of initial onset of ischemic MMD, patients in their 20s are at the bottom of the distribution and this age group may share features with both adult and pediatric patients. The present prospective study aimed to clarify the clinical features and treatment outcomes of patients in their 20s (younger patients) with ischemic MMD compared with patients aged 30-60 years (older patients).

Methods: While patients with misery perfusion in the symptomatic cerebral hemisphere on 15O-positron emission tomography underwent combined surgery including direct and indirect revascularizations in the first study period and indirect revascularization alone in the second study period, patients without misery perfusion in that hemisphere received pharmacotherapy alone through the two study periods. Cerebral angiography via arterial catheterization and neuropsychological testing were performed before and after surgery.

Results: During 12 years, 12 younger patients were included and comprised 6% of all adult patients (194 patients). The incidence of misery perfusion in the affected hemisphere was significantly higher in younger (12/12 [100%]) than in older patients (57/182 [31%]) (p < 0.0001). No difference in the incidence of cerebral hyperperfusion syndrome and postoperatively declined cognition was seen between younger (2/5 [40%] and 2/5 [40%], respectively) and older (11/36 [31%] and 15/36 [42%], respectively) cerebral hemispheres undergoing combined revascularization surgery. No difference in the incidence of postoperatively formed collateral flows feeding more than one-third of the middle cerebral artery cortical territory on angiograms and postoperatively improved cognition was seen between younger (9/10 [90%] and 6/10 [60%], respectively) and older (18/22 [83%] and 14/22 [64%], respectively) cerebral hemispheres undergoing indirect revascularization surgery alone.

Conclusion: Patients in their 20s with ischemic MMD always exhibit misery perfusion in the affected hemisphere, unlike older patients, and sometimes develop cerebral hyperperfusion syndrome after combined revascularization surgery, leading to cognitive decline, similar to older patients. Moreover, indirect revascularization surgery alone forms sufficient collateral circulation and restores cognitive function in patients in their 20s, similar to older patients.