Direct Brain Recordings Reveal Impaired Neural Function in Infants With Single-Suture Craniosynostosis: A Future Modality for Guiding Management?

Long-term Follow-up of Preoperative Infant Event-related Potentials in School-age Children with Craniosynostosis

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Background:

Previous studies demonstrated impaired auditory processing in children with sagittal and metopic craniosynostosis before surgical correction. This study investigated whether worse presurgical neural response as assessed by event-related potentials (ERP) was predictive of poorer school-age neurocognition.

Methods:

Preoperative infant ERP was recorded in 15 sagittal and 18 metopic patients. Mismatch negativity and P150 paradigms were derived from ERP recordings, as previously published. Of those, 13 sagittal and 13 metopic patients returned for neurocognitive evaluation 6 or more years later. ERP was correlated to neurocognitive outcomes using Spearman's correlations controlling for age. Two-tailed t-tests were used to evaluate the influence of age at the time of surgery (6 months) and morphologic severity on neurocognitive outcomes

Results:

In the sagittal group, no significant correlations were found between preoperative mismatch negativity or P150 amplitudes and neurocognitive outcomes. Although no correlation was found between mismatch negativity and neurocognitive outcome in the metopic group, those with lower P150 amplitudes had higher scores in performance IQ (r = −0.877, P < 0.001) and full-scale IQ (r = −0.893, P < 0.001). Morphologic severity and neurocognitive outcomes showed no relationship in the sagittal or metopic groups. Patients who received surgery at less than 6 months had higher full-scale IQ (109.69 versus 95.92, P = 0.025), visuomotor integration (103.15 versus 90.46, P = 0.041), and visual perception scores (105.69 versus 96.08, P = 0.033).

Conclusions:

Preoperative infant ERP does not correlate with school-age neurocognitive outcomes. Earlier age at the time of surgery was associated with improved neurocognitive outcomes.

Socioeconomic Disparities in the Surgical Management of Craniosynostosis

BACKGROUND

The updated ICD-10 coding system introduced partway through 2015 offers codes with increased granularity for disease and procedure types. This is the first study to use ICD-10 codes to investigate disparities in the surgical management for craniosynostosis.

METHODS

Using the Kids' Inpatient Database univariable analyses were performed to compare the relative odds of undergoing strip craniectomy, either endoscopic (ESC) or open (OSC), or calvarial vault remodeling (CVR) based on a variety of demographic and hospital-level variables.

RESULTS

Of the 2,874 patients identified, 2,352 underwent CVR while 522 underwent SC. Of those undergoing SC, 295 and 228 had an endoscopic and open procedure, respectively. A greater proportion of patients who had private insurance (58.14% versus 47.49%) or were self-pay (8.06% versus 6.28%) underwent SC, whereas a higher percentage who were covered under Medicaid (46.23% versus 32.8%; P < 0.001) received CVR. ESC patients were 2.16 times more likely to have private insurance and 2.07 times more likely to be from the highest income quartile compared to OSC patients. However, there were no differences in terms of insurance type or income level between those undergoing CVR compared to OSC.

CONCLUSIONS

Our study found that the difference between CVR and SC can be attributed to the difference in the endoscopic versus open approaches to SC. Although the socioeconomic disparities persisted in the comparison between ESC and OSC, with patients receiving ESC coming from wealthier and commercially insured families, the same differences were not observed when comparing CVR with OSC.

Long-Term Neurocognitive Outcomes of Spring-Assisted Surgery versus Cranial Vault Remodeling for Sagittal Synostosis

BACKGROUND

A long-term neurocognitive comparison of patients with sagittal synostosis who underwent spring-assisted surgery or cranial vault remodeling has not been performed.

METHODS

Patients with sagittal synostosis who underwent spring-assisted surgery or cranial vault remodeling were recruited from Wake Forest School of Medicine and Yale School of Medicine, respectively. Cognitive tests administered included an abbreviated intelligence quotient, academic achievement, and visuomotor integration. An analysis of covariance model compared cohorts controlling for demographic variables.

RESULTS

Thirty-nine spring-assisted surgery and 36 cranial vault remodeling patients were included in the study. No significant differences between cohorts were found with respect to age at surgery, sex, race, birth weight, family income, or parental education. The cranial vault cohort had significantly older parental age (p < 0.001), and mean age at testing for the spring cohort was significantly higher (p = 0.001). After adjusting for covariates, the cranial vault cohort had significantly higher verbal intelligence quotient (116.5 versus 104.3; p = 0.0024), performance intelligence quotient (109.2 versus 101.5; p = 0.041), and full-scale intelligence quotient (114.3 versus 103.2; p = 0.0032). When included patients were limited to intelligence quotients from 80 to 120, the cranial vault cohort maintained higher verbal (108.0 versus 100.4; p = 0.036), performance (104.5 versus 97.7; p = 0.016), and full-scale (107.6 versus 101.5; p = 0.038) intelligence quotients. The cranial vault cohort had higher visuomotor integration scores than the surgery group (111.1 versus 98.1; p < 0.001). There were no significant differences in academic achievement.

CONCLUSIONS

Sagittal synostosis patients who underwent cranial vault remodeling had higher intelligence quotient and visuomotor integration scores. There were no differences in academic achievement. Both cohorts had intelligence quotient scores at or above the normal range. Further studies are warranted to identify factors that may contribute to cognitive outcome differences.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Functional Network Development in Sagittal Craniosynostosis Treated With Whole Vault Cranioplasty

INTRODUCTION

In this study, the authors seek to clarify the neurological changes before and after whole vault cranioplasty (WVC) in patients born with sagittal craniosynostosis.

METHODS

A case control study design was performed that included thirty functional MRI scans, from 25 individual patients. Functional MRI and diffusion tension imaging data were analyzed with BioImageSuite (Yale University, USA). 9 functional brain networks were analyzed, with appropriate correlated functional regions of the brain and utilized for analysis.

RESULTS

Comparing functional MRI the infants after WVC versus infants before WVC group, the after WVC group demonstrated an increased connectivity in the left frontoparietal, secondary (V2), and third (V3) visual networks (P < 0.001). The right frontoparietal (RFPN) had decreased connectivity (P < 0.001). There is also a decrease and increase in anisotropy in the cingulum and precuneus despite surgery, respectively (P < 0.05). Adolescents treated with WVC compared to controls, demonstrated an increased connectivity in the salience and decreased connectivity in the RFPN relative to adolescent controls.

CONCLUSIONS

Patients born with sagittal craniosynostosis have different connections in infancy in most of the defined cerebral networks compared to controls. After surgery, there are specific connectivity changes that occur in the RFPN, left frontoparietal, V2, and V3 networks, which are areas associated with executive function and emotional control. Changes identified in white matter tract microstructure connections could be influential in changes in functional connectivity. Although, as a child with sagittal craniosynostosis develops, much of the abnormal network connections, seen in infancy preoperatively, corrects to some degree after surgery. However, some aberrancies in the salience and RFPN networks remain potentially affecting executive functioning.

Neurologic Characterization of Craniosynostosis: Can Direct Brain Recordings Predict Language Development?

PURPOSE

Nonsyndromic craniosynostosis (NSC) is associated with language deficits. Conventional tests, such as the Bayley Scales of Infant Development (BSID), may not reflect accurate long-term cognition. Alternatively, mismatch negativity (MMN) waves recorded via electroencephalogram (EEG) measure neural responses to speech and may objectively predict language development. This study aimed to (1) correlate infant MMN to future language achievement and (2) compare MMN among subtypes of NSC.

METHODS

Pre and postoperatively (mean operative age 9.5 months), NSC participants received the BSID and EEG phoneme-discrimination paradigm(80 dB,250 Hz). The MMN was the largest negative amplitude in the difference wave 80 to 300 ms after stimuli. To measure cognitive outcome, patients completed a neurodevelopmental battery (Wechsler-Abbreviated Scale of Intelligence and Wechsler-Fundamentals) at >6 years of age.

RESULTS

Eleven NSC patients with EEG testing in infancy were neurocognitively tested (average age 8.0 years; 27% female; 55% sagittal, 27% metopic, 9% unicoronal, 9% sagittal/metopic). The left frontal cluster MMN strongly correlated with word-reading (r = 0.713, P = 0.031), reading-comprehension (r = 0.745, P = 0.021), and language-composites (r = 0.0771, P = 0.015). Conversely, BSID scores did not yield significant predictive value (r < 0.5, P > 0.05). Follow-up event related potentials (ERP) comparison included 39 normal control, 18 sagittal, 17 metopic, 6 unilateral-coronal infants. Preoperatively, sagittal (P = 0.003) and metopic (P = 0.003) patients had attenuated left frontal MMN compared to controls. Postoperatively, the sagittal cohort was normalized to controls while metopic patients retained attenuations (P = 0.041).

CONCLUSION

ERP assessment in NSC had significantly better predictive value for future neurocognition than the BSID. Preoperatively, sagittal and metopic patients had attenuated neural response to language; postoperatively, sagittal patients had improved responses in comparison to metopic patients. Use of ERP assessment may help tailor treatment for language deficits earlier in development.

Radiographic Severity of Metopic Craniosynostosis Correlates with Long-Term Neurocognitive Outcomes

BACKGROUND

Reports of neurodevelopmental delays in adolescents with metopic craniosynostosis have ranged from 15 to 61 percent. Previously, event-related potentials have correlated preoperative radiographic severity with language deficiencies in infancy. This study sought to characterize neurocognitive testing at cranial maturity and correlate outcomes to preoperative radiographic severity.

METHODS

Patients diagnosed with metopic craniosynostosis who underwent surgical correction in infancy completed a neurodevelopmental battery evaluating age-normalized intelligence quotient, academic achievement, and visuomotor integration. Data were stratified by preoperative endocranial bifrontal angle (moderate, >124 degrees; severe, <124 degrees). Multiple variable regression was used to control measured intelligence and achievement for age at surgery, age at testing, parental education, and income. Significance was set at p < 0.05.

RESULTS

Twenty patients completed neurodevelopmental testing. Mean intelligence quotient was 111.7 ± 13 and academic achievement was similar to national averages (word reading, 53.4 percent; reading comprehension, 53.4 percent; reading composite, 53.5 percent; spelling, 44 percent; and math, 52.9 percent). Radiographic measurements revealed 36 percent of patients with moderate phenotype and 64 percent with severe. Patients with severe phenotypes had lower intelligence quotient measures and scored more poorly in every academic measure tested. Word reading (113 versus 95; p = 0.035) and reading composite (109 versus 98; p = 0.014) reached significance.

CONCLUSIONS

Overall, cranial mature patients with metopic craniosynostosis had above average intelligence quotient and academic achievement near the national mean. Long-term neurocognitive function was correlated to preoperative radiographic severity in metopic craniosynostosis, with more severe cases performing worse.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Risk, II.

Syndromic Craniosynostosis

Management strategies for syndromic craniosynostosis patients require multidisciplinary subspecialty teams to provide optimal care for complex reconstructive approaches. The most common craniosynostosis syndromes include Apert (FGFR2), Crouzon (FGFR2), Muenke (FGFR3), Pfeiffer (FGFR1 and FGFR2), and Saethre-Chotzen (TWIST). Bicoronal craniosynostosis (turribrachycephaly) is most commonly associated with syndromic craniosynostosis. Disease presentation varies from mild sutural involvement to severe pansynostoses, with a spectrum of extracraniofacial dysmorphic manifestations. Understanding the multifaceted syndromic presentations while appreciating the panoply of variable presentations is central to delivering necessary individualized care. Cranial vault remodeling aims to relieve restriction of cranial development and elevated intracranial pressure and restore normal morphology.

The Etiology of Neuronal Development in Craniosynostosis: A Working Hypothesis

Craniosynostosis is one of the most common craniofacial conditions treated by neurologic and plastic surgeons. In addition to disfigurement, children with craniosynostosis experience significant cognitive dysfunction later in life. Surgery is performed in infancy to correct skull deformity; however, the field is at a crossroads regarding the best approach for correction. Since the cause of brain dysfunction in these patients has remained uncertain, the role and type of surgery might have in attenuating the later-observed cognitive deficits through impact on the brain has been unclear. Recently, however, advances in imaging such as event-related potentials, diffusion tensor imaging, and functional MRI, in conjunction with more robust clinical studies, are providing important insight into the potential etiologies of brain dysfunction in syndromic and nonsyndromic craniosynostosis patients. This review aims to outline the cause(s) of such brain dysfunction including the role extrinsic vault constriction might have on brain development and the current evidence for an intrinsic modular developmental error in brain development. Illuminating the cause of brain dysfunction will identify the role of surgery can play in improving observed functional deficits and thus direct optimal primary and adjuvant treatment.

Nonsyndromic Craniosynostosis and Associated Abnormal Speech and Language Development

BACKGROUND

Although many metrics for neurodevelopment in children with nonsyndromic craniosynostosis have been analyzed, few have directly examined early language acquisition and speech development. The authors characterized language acquisition and speech development in children with nonsyndromic craniosynostosis.

METHODS

The authors' institutional database was queried for nonsyndromic craniosynostosis from 2000 to 2014. Patients with an identified syndrome were excluded. Specific data elements included age, gender, velopharyngeal adequacy by means of the Pittsburgh Weighted Speech Scale, evaluation for anatomical motor delay, language acquisition delay/disorder, articulation or speech sound production delays/disorders, and whether speech therapy was recommended. Diagnosis of a submucous cleft palate was noted.

RESULTS

One hundred one patients met inclusion criteria, of which 57.4 percent were male. Average age at the time of the most recent speech evaluation was 6.1 years (range, 2.31 to 17.95 years); 43.6 percent had normal speech/language metrics and 56.4 percent had one or more abnormalities, including anatomical motor delay/disorder (29.7 percent), language acquisition delay/disorder (21.8 percent), articulation or speech production delay/disorder (4.0 percent), hypernasality (15.8 percent), and velopharyngeal insufficiency or borderline competency (23.8 percent). Average Pittsburgh Weighted Speech Scale score was 1.3 (range, 0 to 5), and 29.7 percent (n = 30) of patients were recommended to have speech therapy. In addition, 25.8 percent of patients were diagnosed with a submucous cleft palate.

CONCLUSIONS

One in four patients with nonsyndromic craniosynostosis carried a diagnosis of submucous cleft palate. The authors found that abnormal speech and language development occurs in one in 1.7 patients with nonsyndromic craniosynostosis, and that speech therapy for such abnormal development is warranted in one in 3.4 of them-a prevalence two to five times higher compared with the general pediatric population.

Language, learning, and memory in children with and without single-suture craniosynostosis

OBJECTIVE The language and memory functions of children with and without single-suture craniosynostosis (SSC) were compared at school age (mean 7.45 years, standard deviation [SD] 0.54 years). The children in this cohort were originally recruited in infancy and prior to cranial surgery for those with SSC. METHODS Individual evaluations of 179 school-aged children with SSC and 183 controls were conducted (70% of the original cohort) using standardized measures of language, learning, and memory. Parents participated in an interview about specialized education interventions and school progress. Parents and teachers completed questionnaires about language development. RESULTS Children with SSC (cases) obtained lower scores than controls on all measures. The adjusted differences in language, learning, and memory scores were modest, with SD ranging from 0.0 to -0.4 (p values ranged from 0.001 to 0.99). Censored normal regression was used to account for intervention services received prior to the school-age evaluation; this increased case-control differences (SD range 0.1 to -0.5, p value range 0.001 to 0.50). Mean scores for cases in each SSC diagnostic group were lower than those for controls, with the greatest differences observed among children with unilateral coronal craniosynostosis. CONCLUSIONS Children with SSC continue to show poorer performance than controls on language, learning, and memory tasks at early elementary school age, even when controlling for known confounders, although mean differences are small. Multidisciplinary care, including direct psychological assessment, for children with SSC should extend through school age with a specific focus on language and conceptual learning, as these are areas of potential risk. Future research is needed to investigate language, memory, and learning for this population during the middle to high school years.