An Investigation of Brain Functional Connectivity by Form of Craniosynostosis

Long-term neurocognitive sequelae of nonsyndromic craniosynostosis (NSC) patients are just beginning to be clarified. This study uses functional MRI (fMRI) to determine if there is evidence of altered brain functional connectivity in NSC, and whether these aberrations vary by form of synostosis.

Twenty adolescent participants with surgically treated NSC (10 sagittal synostosis, 5 right unilateral coronal synostosis [UCS], 5 metopic synostosis [MSO]) were individually matched to controls by age, gender, and handedness. A subgroup of MSO was classified as severe metopic synostosis (SMS) based on the endocranial bifrontal angle. Resting state fMRI was acquired in a 3T Siemens TIM Trio scanner (Erlangen, Germany), and data were motion corrected and then analyzed with BioImage Suite (Yale School of Medicine). Resulting group-level t-maps were cluster corrected with nonparametric permutation tests. A region of interest analysis was performed based on the left Brodmann's Areas 7, 39, and 40.

Sagittal synostosis had decreased whole-brain intrinsic connectivity compared to controls in the superior parietal lobules and the angular gyrus (P = 0.071). Unilateral coronal synostosis had decreased intrinsic connectivity throughout the prefrontal cortex (P = 0.031). The MSO cohort did not have significant findings on intrinsic connectivity, but the SMS subgroup had significantly decreased connectivity among multiple subcortical structures.

Sagittal synostosis had decreased connectivity in regions associated with visuomotor integration and attention, while UCS had decreased connectivity in circuits crucial in executive function and cognition. Finally, severity of metopic synostosis may influence the degree of neurocognitive aberration. This study provides data suggestive of long-term sequelae of NSC that varies by suture type, which may underlie different phenotypes of neurocognitive impairment.