Management of Lambdoid Craniosynostosis: A Comprehensive and Systematic Review

<b><i>Background:</i></b> Craniosynostosis is a condition characterized by the premature fusion of 2 or more skull bones. Craniosynostosis of the lambdoid suture is one of the rarest forms, accounting for 1–4% of all craniosynostoses. Documented cases are separated into simple (single suture), complex (bilateral), and associated with adjacent synostoses (“Mercedes Benz” Pattern) or syndromes (i.e., Crouzon, Sathre-Chotzen, Antley-Bixler). This condition can manifest phenotypic deformities and neurological sequelae that can lead to impaired cognitive function if improperly treated or left undiagnosed. Preferred surgical techniques have varied over time but all maintain the common goals of establishing proper head shape and preventing of complications that could contribute to aforementioned sequelae. <b><i>Summary:</i></b> This comprehensive review highlights demographic distributions, embryological development, pathogenesis, clinical presentation, neurological sequelae, radiologic findings, surgical techniques, surgical outcomes, and postoperative considerations of patients with lambdoid craniosynostosis presentation. In addition, a systematic review was conducted to explore the operative management of lambdoid craniosynostosis using PubMed, Embase, and Scopus databases, with 38 articles included after screening. <b><i>Key Messages:</i></b> Due to a low volume of published cases, diagnosis and treatment can vary. Large overlap in presentation can occur in patients that display lambdoid craniosynostosis and posterior plagiocephaly, furthering the need for comprehensive analysis. Possessing the knowledge and tools to properly assess patients with lambdoid craniosynostosis will allow for more precise care and improved outcomes.

Academic Achievement in School-Aged Children with Single Suture Craniosynostosis Over Time

Introduction: Children with single suture craniosynostosis (SSC) are at risk for neurocognitive problems. The reported magnitude of differences between children with SSC and their normative peers on standardized tests of academic and intellectual ability are small. Evaluation of real-world academic outcomes of these children and its impact on educational resources have not been conducted. Methods: A retrospective cohort study of academic outcomes of children with SSC was conducted using the data from Ontario's Education Quality and Accountability Office (EQAO) standardized provincial reading, writing and mathematics tests. The need for special education was identified by documentation of the child's need for an Identification, Placement, and Review Committee (IPRC). Results: Of 296 eligible children, 42 participated in the study. Half of the children had sagittal synostosis, while the remaining were 10 (24%) unicoronal, 9 (21%) metopic, and 2 (5%) lambdoid synostosis. Thirty-six (86%) underwent operative management. The EQAO scores of operated children with SSC met the provincial academic standards on the Grade 3 and 6 EQAO scores across the 3 academic subjects. Converted grade-matched EQAO scores decreased in reading and writing over time, while math improved. Of the 21 patients with special education data, one child required an IPRC in Grade 3, while an additional four (24%) required an IPRC in Grade 6. Conclusions: Operated children with SSC had average academic performance, however, their needs appeared to change over time. Future studies are needed to evaluate academic difficulties and special education needs as these children progress through grade school.

Elevated intracranial pressure with craniosynostosis: a multivariate model of age, syndromic status, and number of involved cranial sutures

OBJECTIVE Children with multiple prematurely fused cranial sutures and those undergoing surgical correction later in life appear to experience worse neurocognitive outcomes, but it is unclear whether higher intracranial pressure (ICP) is implicated in this process. The purpose of this study was to elucidate the effect of age at intervention and number of involved cranial sutures on ICP, as well as to assess which cranial suture closure may be more associated with elevated ICP. METHODS The prospective craniofacial database at the authors’ institution was queried for patients undergoing initial corrective surgery for craniosynostosis in whom intraoperative measurement of ICP was obtained prior to craniectomy. Age, involved sutures, and syndromic status were analyzed in the context of measured ICP by using multiple linear regression. RESULTS Fifty patients met the inclusion criteria. Age at procedure (p = 0.028, β = +0.060 mm Hg/month) and multiple-suture involvement (p = 0.010, β = +4.175 mm Hg if multisuture) were both significantly implicated in elevated ICP. The actual number of major sutures involved was significantly correlated to ICP (p = 0.001; β = +1.687 mm Hg/suture). Among patients with single-suture involvement, there was an overall significant difference of median ICP across the suture types (p = 0.008), with metopic having the lowest (12.5 mm Hg) and sagittal having the highest (16.0 mm Hg). Patients with multiple-suture involvement had significantly higher ICP (p = 0.003; 18.5 mm Hg). Patients with craniofacial syndromes were 79.3 times more likely to have multiple-suture involvement (p < 0.001). Corrective surgery for craniosynostosis demonstrated significant intraoperative reduction of elevated ICP (all p < 0.050). CONCLUSIONS Syndromic status, older age at intervention for craniosynostosis, and multiple premature fusion of cranial sutures were associated with significantly higher ICP.

Preoperative imaging patterns and intracranial findings in single-suture craniosynostosis: a study from the Synostosis Research Group

OBJECTIVE The diagnosis of single-suture craniosynostosis can be made by physical examination, but the use of confirmatory imaging is common practice. The authors sought to investigate preoperative imaging use and to describe intracranial findings in children with single-suture synostosis from a large, prospective multicenter cohort. METHODS In this study from the Synostosis Research Group, the study population included children with clinically diagnosed single-suture synostosis between March 1, 2017, and October 31, 2020, at 5 institutions. The primary analysis correlated the clinical diagnosis and imaging diagnosis; secondary outcomes included intracranial findings by pathological suture type. RESULTS A total of 403 children (67% male) were identified with single-suture synostosis. Sagittal (n = 267), metopic (n = 77), coronal (n = 52), and lambdoid (n = 7) synostoses were reported; the most common presentation was abnormal head shape (97%), followed by a palpable or visible ridge (37%). Preoperative cranial imaging was performed in 90% of children; findings on 97% of these imaging studies matched the initial clinical diagnosis. Thirty-one additional fused sutures were identified in 18 children (5%) that differed from the clinical diagnosis. The most commonly used imaging modality by far was CT (n = 360), followed by radiography (n = 9) and MRI (n = 7). Most preoperative imaging was ordered as part of a protocolized pathway (67%); some images were obtained as a result of a nondiagnostic clinical examination (5.2%). Of the 360 patients who had CT imaging, 150 underwent total cranial vault surgery and 210 underwent strip craniectomy. The imaging findings influenced the surgical treatment 0.95% of the time. Among the 24% of children with additional (nonsynostosis) abnormal findings on CT, only 3.5% required further monitoring. CONCLUSIONS The authors found that a clinical diagnosis of single-suture craniosynostosis and the findings on CT were the same with rare exceptions. CT imaging very rarely altered the surgical treatment of children with single-suture synostosis.

Non-syndromic craniosynostosis

Craniosynostosis is defined as the premature fusion of a skull suture and has an incidence of approximately 1:2000 live births. Historically, craniosynostosis was subdivided into primary and secondary synostosis. Further subclassifications included syndromic/non-syndromic and single/multisuture. Multisuture synostoses also give rise to characteristic head shapes, which, with experience, are readily identifiable by experienced clinicians using clinical examination alone. While in the past, single-suture craniosynostosis was classified as ‘non-syndromic’, advances in genetic analysis has shown that this may not be the case in a proportion of these cases, just as some multisuture presentations may also be non-syndromic. This particularly applies to unicoronal craniosynostosis along with some metopic and bicoronal synostosis. Given the higher rate of syndromic association in these patients, along with the tendency to require late surgery for facial scoliosis in unicoronal and unilambdoid patients, this cohort should be regarded as a more complex subset.