Distinguishing Craniomorphometric Characteristics of Unilateral Lambdoid Craniosynostosis

Long-term neurocognitive outcomes in 204 single-suture craniosynostosis patients

PURPOSE

Craniosynostosis, which describes premature fusion of one or more cranial sutures, has been associated with a variety of neurocognitive deficits. We sought to explore the cognitive profiles of the various types of single-suture, non-syndromic craniosynostosis (NSC).

METHODS

A retrospective review of children 6-18 years old with surgically corrected NSC who underwent neurocognitive testing (Weschler Abbreviated Scale of Intelligence, Beery-Buktenica Developmental Test of Visuomotor Integration) from the years 2014-2022 was conducted.

RESULTS

204 patients completed neurocognitive testing (139 sagittal, 39 metopic, 22 unicoronal, 4 lambdoid suture). 110 (54%) of the cohort was male, and 150 (74%) were White. Mean IQ was 106.10±14.01 and mean age at surgery and testing were 9.0±12.2 months and 10.9±4.0 years, respectively. Sagittal synostosis was associated with higher scores than metopic synostosis, with significant differences in verbal IQ (109.42±15.76 vs 101.37±10.41), full-scale IQ (108.32±14.44 vs 100.05±11.76), visuomotor integration (101.62±13.64 vs 92.44±12.07), visual perception (103.81±12.42 vs 95.87±11.23), and motor coordination (90.45±15.60 vs 84.21±15.44). Sagittal synostosis was associated with significantly higher scores for visuomotor integration (101.62±13.64 vs 94.95±10.24) and visual perception (103.81±12.42 vs 94.82±12.75) than unicoronal synostosis.

CONCLUSIONS

Compared to patients with sagittal synostosis, patients with metopic synostosis exhibited lower scores in verbal IQ, full-scale IQ, visuomotor integration, visual perception, and motor control after surgical correction. Despite surgical correction for premature metopic suture fusion, the effect on the adjacent frontal lobe and white matter connections to other regions of the brain may have a lasting functional impact. Patients with unicoronal synostosis exhibited lower visuomotor integration and visual perception scores.

Frontofacial Features of Unilateral Lambdoid Craniosynostosis: A Multicenter Assessment

Unilateral lambdoid craniosynostosis is differentiated from deformational plagiocephaly primarily by assessing the cranium from posterior and bird's-eye views. Findings include posterior displacement of the ipsilateral ear, ipsilateral occipitomastoid bossing, ipsilateral occipitoparietal flattening, contralateral parietal bossing, and contralateral frontal bossing. Diagnosis based off facial morphology may be an easier approach because the face is less obstructed by hair and head-coverings, and can easily be assessed when supine. However, frontofacial characteristics of unilateral lambdoid craniosynostosis are not well described.

Methods

A retrospective cohort review of patients with isolated, unilateral lambdoid craniosynostosis from the Children's Hospital of Pittsburgh and the Children's Hospital of Philadelphia was performed. Preoperative frontal and profile photographs were reviewed for salient characteristics.

Results

Nineteen patients met inclusion criteria. Eleven patients had left lambdoid craniosynostosis, and eight had right lambdoid craniosynostosis. All patients were nonsyndromic. Patients demonstrated contralateral parietal bossing and greater visibility of the ipsilateral ear. Contralateral frontal bossing was mild. The orbits were tall and turricephaly was present in varying severity. Facial scoliosis as a C-shaped deformity was present in varying severity. The nasal root and chin pointed to the contralateral side.

Conclusions

The combination of greater visibility of the ipsilateral ear, contralateral parietal bossing, and C-shaped convex ipsilateral facial scoliosis are hallmark frontofacial features of unilateral lambdoid craniosynostosis. Although the ipsilateral ear is more posterior, the greater visibility may be attributed to lateral displacement from the mastoid bulge. Evaluation of long-term postoperative results is needed to assess if this pathognomonic facial morphology is corrected following posterior vault reconstruction.

Utilizing Computer-Assisted Design and Virtual Surgical Planning for Correction of Unilateral Lambdoid Synostosis

Unilateral lambdoid synostosis is the rarest form of single-suture craniosynostosis. Although various surgical approaches have been described, cranial vault remodeling remains the predominant approach. To aid in surgical planning, preoperative virtual surgical modeling using a patient's presenting computed tomography scan can be used to increase reconstructive precision and to reduce operative time. Presented is a 7-month-old male with unilateral lambdoid synostosis who underwent medically modeled cranial vault reconstruction.

Conventional posterior cranial vault expansion: indications and results-review of the literature

In the late 1980s, craniofacial surgery units reported suboptimal cosmetic results, cranial volume restriction, and intracranial hypertension after anterior cranial vault remodeling in bilateral coronal synostosis associated with severe brachyturricephaly. A possible explanation was a severe associated growth restriction of the posterior calvaria with radiological synostosis at the lambda sutures. "Conventional" or "fixed" posterior cranial vault expansion techniques were developed to address these limitations, sometimes as the first surgical step in a two-staged protocol of total calvarial reconstruction, combined with suboccipital decompression in cases of symptomatic cerebellar tonsillar herniation or, more easily, to resolve the characteristic occipital flattening of lambdoid synostosis. Various surgical approaches have been described; however, the indications for and timing of surgical treatment and postoperative evaluation of results still remain controversial. Although more invasive, conventional posterior cranial vault expansion has proven to be safe and offers a remodeled and protective bony vault immediately after surgery, but the underlying cranial base malformation remained untreated, with implications in the postoperative growth of the facial skeleton. Overcorrection, rigid stabilization, and grafting are also concerns to be addressed.

Long-Term Results After Head Orthosis Therapy for Early Childhood Position-Related Cranial Deformities: Stability of Treatment Outcome and Parental Satisfaction

The purpose of this study was to determine whether different types of position-related cranial deformities show changes after completion of head orthosis therapy. We investigated how children's age at the begin of molding helmet therapy affects the duration and long-term stability of treatment. In addition, parental satisfaction with helmet therapy has been investigated. Between 2012 and 2019, 47 patients have been analyzed after undergoing helmet therapy. At the beginning of treatment different disease pattern were classified. Posterior deformational Plagiocephalus defined by a cranial vault index (CVA) > 1 cm and a cranial index (CI) <= 90%. Posterior deformational Brachycephalus defined by CVA <= 1 cm and CI > 90%. Posterior deformational combined Plagio- and Brachycephalus defined by CVA > 1 cm and CI > 90%. At the beginning of therapy, the end of therapy and within 5-year-follow-up CI and CVA was measured by three-dimensional photogrammetry for 2 age groups (4-6 and 7-12 months). Additionally, parents completed a standardized questionnaire to evaluate the personal assessment of treatment outcome. During treatment CI and CVA of all children decreased significantly (P < 0.001). Furthermore, CI significantly decreased after ending helmet therapy (P < 0.001). Cranial vault index decreased not significantly in the same period (P = 0.361). For the 4 to 6 months old group treatment time was significantly shorter than for the older group. Before starting helmet therapy nearly half of the parents graded the scull as moderate and one-third as severe deformed. After ending treatment, the majority of parents report satisfaction and compliance. However, one-third of parents noted a slight scull deformation and personal load during therapy. After completion of therapy an improvement of head shape can be expected for the majority of children. This is particularly evident for improvement of the CI and a shorter treatment time until the age of 6 months at the beginning of therapy. Parents reported satisfaction and child compliance. Almost all parents were convinced that treatment was useful and would repeat it again.