NEUROCOGNITIVE CORRELATES OF GROUP MEMBERSHIP: A COMPARISON OF HYDROCEPHALUS PATIENTS SHUNTED WITHIN THE FIRST YEAR OF LIFE AND NORMAL CONTROLS

Objectives: To identify long-term patterns of neurocognitive development in children with congenital hydrocephalus, who were shunted within the first year of life. The overarching goal of this study is to identify and describe underlying pathophysiology of cognitive and behavioral deficiencies in shunted hydrocephalus.

Methods: Thirty-six children, ages 6–15 (M=9.7 years), with a history of congenital hydrocephalus, who were shunted within the first year of life, underwent comprehensive neuropsychological testing. Eleven normal controls, aged 6–15 (M=10.3 years), were used for comparison.

Results: Previous research has identified significant impairment in hydrocephalic patients across multiple cognitive domains, including general intellectual functioning, verbal and visuospatial learning and memory, working memory, divided attention, and response inhibition. The variables selected for this analysis are representative of these significant domains. A hierarchical regression analysis predicting group membership (controls vs. shunted patients; Criterion/Dependent variable) was conducted. Predictor/Independent variables included; scores from the WISC-III: VIQ, PIQ, and FDI scales; Rey Complex Figure Test Delayed Recall; California Verbal Learning Test-Children's Version (CVLT-C) Long Delay Free Recall; Cognitive Assessment System (CAS) Expressive Attention and the Composite Attention Index. This analysis revealed CAS Expressive Attention, CVLT-C LDFR, and CAS Attention Index as significant predictors of group membership (R=0.697, p=0.014). All other variables were excluded using an exclusion criteria assessing significance of change at p=0.1. The reduced model including only the three significant predictors accounted for 48.6% of the variance.

Conclusion: Results from this study suggest that despite significant differences previously noted between groups across domains, children with shunted hydrocephalus show primary deficits in terms of attention, response inhibition, and verbal delayed recall. Verbal recall of information after a delay, response inhibition, and a composite measure of attention including divided attention, response inhibition, and non-verbal processing speed significantly predict group membership when comparing shunted patients to non-shunted controls. This preliminary analysis suggests that these variables of attention and verbal recall may be reflective of a primary deficit in subcortical-frontal networks. Further research with an expanded sample size and increased power is warranted.