Date of Award

January 2017

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

John A. Persing


The purpose of this investigation was to examine the impact of treatment factors (type of surgery, timing of surgery, and reoperation influence) on neurocognitive outcomes of nonsyndromic sagittal craniosynostosis (NSC). We also wished to examine the impact of skull remodeling surgery on language processing in infants with NSC. We hypothesized that: a) there would be a difference between whole-vault cranioplasty and isolated strip craniectomy related to neurocognitive outcomes, b) age at surgery would be associated with a difference in neurocognitive outcomes, with and without reoperation, and c) skull remodeling surgery would influence language processing in infants with NSC. Seventy-three school-age children with NSC (44 whole-vault cranioplasty, 29 isolated strip craniectomy) were administered a battery of standardized neuropsychological measures (Wechsler Abbreviated Scale of Intelligence, Wechsler Fundamentals, Beery-Buktenica Visual Motor Integration, Behavior Assessment System of Children, Behavior Rating Inventory of Executive Function) to assess their neurocognitive outcomes for comparison of surgery type, reoperation, and timing. 39 infants (12 NSC, 27 control) underwent EEG recordings while listening to a non-native phonemic discrimination task for evaluation of a language processing component, the mismatch negativity (MMN) event-related potential (ERP). Comparing surgery type, in participants who were operated on at <6 months age, whole-vault patients performed higher on verbal IQ, word reading, spelling, and visuomotor integration compared to isolated strip patients (p<0.05 for all). Whole-vault cranioplasty patients demonstrated lower incidence of word reading-related learning disability (p<0.05). Isolated strip patients were rated better on parent-reported measures of executive function (p<0.05). Regarding reoperations after whole-vault cranioplasty, eleven out of the 41 whole-vault patients, for which reoperation data was available, underwent a reoperation (27%); 9 out of the 11 reoperations were minor revisions while 2 reoperations were cranioplasties. Reoperation rate was not statistically different between patients who had early surgery (at age <6 months) versus late surgery (at age >6 months) (p>0.05). Non-reoperated patients did not perform statistically better than reoperated patients on any outcome measure of neurocognitive function (p>0.05 for all assessments). Comparing reoperated early surgery patients with non-reoperated late surgery patients, reoperated early surgery patients scored significantly higher on full-scale IQ, verbal IQ, word reading, reading comprehension, spelling, numerical operations, and visuomotor integration, and had fewer indicators of suspected learning disabilities compared to non-reoperated late surgery patients (p<0.05 for all). Regarding language processing in infancy, MMN amplitude was attenuated in magnitude in the infants with NSC prior to surgery compared to controls (p=.047). After surgery, infants with NSC showed no significant difference in MMN from controls (p=.344). The increase in MMN amplitude from preoperatively to postoperatively in the infants with NSC was at a trend level (p=.059). We concluded that whole-vault cranioplasty for NSC is associated with better neurocognitive outcomes than isolated strip craniectomy. Reoperation was not associated with worse neurocognitive outcome, and reoperated early surgery patients attained better neurocognitive outcomes compared with non-reoperated late surgery patients. Infants with NSC demonstrated atypical neural response to language preoperatively, and whole-vault cranioplasty is associated with normalization of language processing in infants with NSC.


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