Asymptomatic Ventriculomegaly in Myelomeningocele: A Matched Cohort Study of Neuropsychological Outcomes Across Institutions with Varying Shunt Rates

Introduction: Hydrocephalus management in myelomeningocele (MMC) patients remains controversial. While most institutions recommend surgical intervention for enlarged ventricles, recent studies suggest asymptomatic ventriculomegaly may not require treatment. This study compared cognitive outcomes in MMC patients from different institutions with different hydrocephalus intervention rates.

Methods: Participants with MMC were recruited from two sites: Site 1 (50% shunt rate) and Site 2 (72% shunt rate). Site 1 patients were matched to two subgroups at Site 2 based on age, gender, lesion level, and race. Neuropsychological testing assessed various cognitive domains. Independent t-tests were conducted to compare outcomes between sites.

Results: This study included 111 patients (41 from Site 1, 70 from Site 2). Site 1 had significantly lower shunt rates. There were no significant differences in demographics or lesion levels between sites. Site 1 participants demonstrated significantly higher scores on several cognitive measures compared to Site 2 (Subgroup 1), including the Purdue Pegboard (fine motor dexterity; p = 0.042), Stanford-Binet Quantitative Reasoning (quantitative reasoning to solve mathematical problems; p =0.030), VMI (visuomotor integration; p=0.034), WJ Letter-Word Identification (single word reading; p =0.026), and WJ Calculation scales (math calculation problem-solving; p =0.012). No significant differences were found between Site 1 and Site 2 (Subgroup 2), though Site 1 showed better performance on some measures (Purdue Pegboard) with less executive function concerns.

Conclusion : Neuropsychological outcomes were similar across cohorts from institutions with different shunt rates. This suggests asymptomatic ventriculomegaly may not be associated with worse functional outcomes, potentially informing guidelines for hydrocephalus intervention in the MMC population.