The cervical spine in Crouzon syndrome

Molecular landscape of congenital vertebral malformations: recent discoveries and future directions

Vertebral malformations (VMs) pose a significant global health problem, causing chronic pain and disability. Vertebral defects occur as isolated conditions or within the spectrum of various congenital disorders, such as Klippel-Feil syndrome, congenital scoliosis, spondylocostal dysostosis, sacral agenesis, and neural tube defects. Although both genetic abnormalities and environmental factors can contribute to abnormal vertebral development, our knowledge on molecular mechanisms of numerous VMs is still limited. Furthermore, there is a lack of resource that consolidates the current knowledge in this field. In this pioneering review, we provide a comprehensive analysis of the latest research on the molecular basis of VMs and the association of the VMs-related causative genes with bone developmental signaling pathways. Our study identifies 118 genes linked to VMs, with 98 genes involved in biological pathways crucial for the formation of the vertebral column. Overall, the review summarizes the current knowledge on VM genetics, and provides new insights into potential involvement of biological pathways in VM pathogenesis. We also present an overview of available data regarding the role of epigenetic and environmental factors in VMs. We identify areas where knowledge is lacking, such as precise molecular mechanisms in which specific genes contribute to the development of VMs. Finally, we propose future research avenues that could address knowledge gaps.

Classification of Subtypes of Crouzon Syndrome Based on the Type of Vault Suture Synostosis

BACKGROUND

Patients with Crouzon syndrome develop various types of anatomic deformities due to different forms of craniosynostosis, yet they have similar craniofacial characteristics. However, exact homology is not evident. Different pathology then may be best treated by different forms of surgical technique. Therefore, precise classification of Crouzon syndrome, based on individual patterns of cranial suture involvement is needed.

METHODS

Ninety-five computed tomography (CT) scans (Crouzon, n = 33; control, n = 62) were included in this study. All the CT scans are divided into 4 types based on premature closure of sutures: class I = coronal and lambdoidal synostosis; class II = sagittal synostosis; class III = pansynostosis; and class IV = "Others." The CT scan anatomy was measured by Materialise software.

RESULTS

The class III, pansynostosis, is the most prevalent (63.6%). The classes I, III, and IV of Crouzon have significantly shortened entire anteroposterior cranial base length, with the shortest base length in class III. The external cranial measurements in class I show primarily a decreased posterior facial skeleton, while the class III presented with holistic facial skeleton reduction. Class II has the least severe craniofacial malformations, while class III had the most severe.

CONCLUSION

The morphology of patients with Crouzon syndrome is not identical in both cranial base and facial characteristics, especially when they associated with different subtypes of cranial suture synostosis. The classification of Crouzon syndrome proposed in this study, summarizes the differences among each subgroup of craniosynostosis suture involvement, which, theoretically, may ultimately influence both the timing and type of surgical intervention.

Butterfly Vertebrae: A Systematic Review of the Literature and Analysis

STUDY DESIGN

Systematic review (Level 4).

OBJECTIVE

To summarize the demographics, clinical presentations, and conditions associated with butterfly vertebrae.

METHODS

A systematic search was performed of multiple databases. A total of 279 articles were identified for screening. Case series or case reports of butterfly vertebrae with adequate clinical detail were complied.

RESULTS

Eighty-two total articles (109 patients) were selected for final inclusion. Sixty-one percent of patients presented with a single butterfly vertebra, while 39% were multiple. The most common location for butterfly vertebrae was T1. Fifty-six percent of cases were associated with a syndrome, the most common being spondylocostal dysostosis. The presence of multiple butterfly vertebra was strongly associated with a syndrome or additional anomalies (P < .001). Overall, the most common presenting complaint was low back pain. Seventy percent of patients had associated spinal disease. Other organ systems affected included musculoskeletal (43%), craniofacial (30%), neurologic (27%), cardiovascular (24%), genitourinary (23%), gastrointestinal (22%), laboratory abnormality (16%), and endocrine (9%).

CONCLUSIONS

This study is the largest collection of butterfly vertebrae cases to date. Butterfly vertebrae are associated with spinal deformity and multiple butterfly vertebrae may indicate a syndromic illness. Low back pain or disc herniation may occur with lumbar butterfly vertebrae however the etiology of this phenomena has not been rigorously explained. Many diseases and syndromes are associated with butterfly vertebrae.

Surgical Correction of Severe Kyphoscoliosis Associated with Crouzon Syndrome with Serious Postoperative Respiratory Problems: A Case Report

CASE

A 12-year-old girl with Crouzon syndrome presented to our hospital with scoliosis (114°) and kyphosis from T8 to T12 (138°). After she had been in halo-gravity traction for 2 weeks, we performed posterior correction and fusion surgery from T3 to L3, with a posterior vertebral column resection of T10. She experienced postoperative respiratory failure and remained on a ventilator for 4 weeks. With rehabilitation, the respiratory function had recovered by postoperative week 8. At the 2-year follow-up, there was no loss of correction or any other complication.

CONCLUSION

Serious perioperative respiratory complications may occur when a patient with Crouzon syndrome is treated surgically.

Syndromic Craniosynostosis: Complexities of Clinical Care

Patients with syndromic craniosynostosis have a molecularly identified genetic cause for the premature closure of their cranial sutures and associated facial and extra-cranial features. Their clinical complexity demands comprehensive management by an extensive multidisciplinary team. This review aims to marry genotypic and phenotypic knowledge with clinical presentation and management of the craniofacial syndromes presenting most frequently to the craniofacial unit at Great Ormond Street Hospital for Children NHS Foundation Trust.

Spinal Anomalies in Goldenhar Syndrome

Objective

Goldenhar syndrome consists of the triad of craniofacial microsomia, occular dermoid cysts, and spinal anomalies. The exact nature of the spinal anomalies remains poorly defined in the existing craniofacial literature, possibly due to these anomalies being managed by orthopedic surgeons rather than by craniofacial surgeons. The aim of this study was to clarify the nature and extent of these spinal anomalies.

Method

Review of case notes of patients who had their diagnosis confirmed following review by a clinical geneticist and in conjunction with radiographs (supplemented by three-dimensional computed tomographic [CT] scans where available).

Results

Seven patients fulfilled the entry criteria and had material available for study. A wide range of anomalies was present, including butterfly vertebrae; hemivertebrae, which produced secondary scoliosis; kyphosis; and rib anomalies. Anomalies occurred at all levels within the spine.

Conclusion

The possibility of spinal anomalies at all levels of the spine should be considered by those treating cases of Goldenhar syndrome, because these anomalies cannot be predicted from the severity of the facial malformation.

Extensive phenotyping of the orofacial and dental complex in Crouzon syndrome

OBJECTIVES

Fibroblast growth factor receptor 2 (FGFR2) ^C342Y/+ mutation is a known cause of Crouzon syndrome that is characterised by craniosynostosis and midfacial hypoplasia. Our aim was to conduct extensive phenotyping of the maxillary, mandibular and dental morphology associated with this mutation.

MATERIALS AND METHODS

Morphometric data were obtained from 40 mice, representing two genotypes (Crouzon and wild-type) and two sexes (males and females) (n=10 in each group). Dental analysis further categorised the first molars into the two jaws (maxillary and mandibular) (n=20 in each group). Maxillary, mandibular and dental morphology was compared by analysing 23 linear landmark-based dimensions in three-dimensional micro-computed tomography reconstructions.

RESULTS

Compared with wild-type, Crouzon (FGFR2^C342Y/+) maxillae were significantly shorter in maximum height, anterior and posterior lengths and middle width, but larger in posterior width (p<0.05 for height; p<0.001 for other comparisons). In the Crouzon mandible, the ascending and descending heights, effective and mandibular lengths, and intercoronoid and intercondylar widths were significantly shorter, whereas intergonial width was larger (p<0.01 for intercondylar width; p<0.001 for other comparisons). Crouzon teeth were significantly smaller mesiodistally, but larger in crown height (p<0.001 for each comparison). All Crouzon mice presented with bifid mandibular condyles and a quarter presented with expansive bone lesions in the mandibular incisor alveolus.

CONCLUSIONS

Our findings of hypoplasia in all three planes in Crouzon maxillae and mandibles, together with the presence of bifid mandibular condyles and expansive bone lesions, may be relevant to maxillofacial surgery and orthodontics. Beyond skeletal effects, the FGFR2^C342Y/+ mutation is now implicated in affecting tooth development. This study's skeletal phenomics data also provides baseline data against which the effect of various treatments can now be assessed.

Analysis of the Fgfr2C342Y mouse model shows condensation defects due to misregulation of Sox9 expression in prechondrocytic mesenchyme

Syndromic craniosynostosis caused by mutations in FGFR2 is characterised by developmental pathology in both endochondral and membranous skeletogenesis. Detailed phenotypic characterisation of features in the membranous calvarium, the endochondral cranial base and other structures in the axial and appendicular skeleton has not been performed at embryonic stages. We investigated bone development in the Crouzon mouse model (Fgfr2^C342Y) at pre- and post-ossification stages to improve understanding of the underlying pathogenesis. Phenotypic analysis was performed by whole-mount skeletal staining (Alcian Blue/Alizarin Red) and histological staining of sections of CD1 wild-type (WT), Fgfr2^C342Y/+ heterozygous (HET) and Fgfr2^C342Y/C342Y homozygous (HOM) mouse embryos from embryonic day (E)12.5-E17.5 stages. Gene expression (Sox9, Shh, Fgf10 and Runx2) was studied by in situ hybridisation and protein expression (COL2A1) by immunohistochemistry. Our analysis has identified severely decreased osteogenesis in parts of the craniofacial skeleton together with increased chondrogenesis in parts of the endochondral and cartilaginous skeleton in HOM embryos. The Sox9 expression domain in tracheal and basi-cranial chondrocytic precursors at E13.5 in HOM embryos is increased and expanded, correlating with the phenotypic observations which suggest FGFR2 signalling regulates Sox9 expression. Combined with abnormal staining of type II collagen in pre-chondrocytic mesenchyme, this is indicative of a mesenchymal condensation defect. An expanded spectrum of phenotypic features observed in the Fgfr2^C342Y/C342Y mouse embryo paves the way towards better understanding the clinical attributes of human Crouzon-Pfeiffer syndrome. FGFR2 mutation results in impaired skeletogenesis; however, our findings suggest that many phenotypic aberrations stem from a primary failure of pre-chondrogenic/osteogenic mesenchymal condensation and link FGFR2 to SOX9, a principal regulator of skeletogenesis.

Raised intracranial pressure in Crouzon syndrome: incidence, causes, and management

OBJECT Patients with Crouzon syndrome (CS) are at risk for developing raised intracranial pressure (ICP), which has the potential to impair both vision and neurocognitive development. For this reason, some experts recommend early prophylactic cranial vault expansion on the basis that if ICP is not currently raised, it is likely to become so. The aim of this study was to examine the justification for such a policy. This was done by analyzing the incidence, causes, and subsequent risk of recurrence in a series of patients with CS, in whom raised ICP was treated only after it had been diagnosed. METHODS This study was a retrospective review of the medical records and imaging data of patients with a clinical diagnosis of CS. RESULTS There were 49 patients in the study, of whom 30 (61.2%) developed at least 1 episode of raised ICP. First episodes occurred at an average age of 1.42 years and were attributable to craniocerebral disproportion/venous hypertension (19 patients), hydrocephalus (8 patients), and airway obstruction (3 patients). They were managed, respectively, by vault expansion, ventriculoperitoneal shunt insertion, and airway improvement. Fourteen of the 30 patients developed a second episode of raised ICP an average of 1.42 years after treatment for their initial episode, and 3 patients developed a third episode an average of 3.15 years after that. Causes of subsequent episodes of raised ICP often differed from previous episodes and required different management. Patients who were < 1 year old when the first episode was diagnosed were at increased risk of recurrence. CONCLUSIONS Although the incidence of raised ICP in CS is high, it did not occur in nearly 40% of children during the course of this study. The several possible causes of CS require different management and may vary from episode to episode. The authors recommend an expectant policy toward these children with careful clinical, ophthalmological, respiratory, and radiological monitoring for raised ICP, reserving intervention for when it has been detected and the appropriate treatment can be initiated.

Differential diagnosis of multiple vertebral compression: butterfly vertebrae

[Purpose] A butterfly vertebra is a rare congenital anomaly resulting from a symmetric fusion defect. Only a few cases of butterfly vertebra have been described. This anomaly may be isolated or associated with Pfeiffer, Jarcho-Levins, Crouzon, or Alagille syndrome. [Subject and Methods] We herein describe a 38-year-old man who presented with neck and low back pain and was found to have butterfly vertebrae at the T9 and L3 levels. He also had Behçet’s disease and psoriasis. [Results] The patient’s symptoms improved with analgesics and physiotherapy. [Conclusion] To our knowledge, butterfly vertebrae at two levels have never been reported. Butterfly vertebrae may be confused with vertebral fractures in lateral radiographs, and awareness of this anomaly is important for a correct diagnosis.

Differentiating between Traumatic Pathology and Congenital Variant: A Case Report of Butterfly Vertebra

Butterfly vertebra is a rare congenital malformation of the spine, which is usually reported in the literature as an isolated finding. We describe a 40-year-old woman that presented to our emergency department with back pain and sciatica. Initial radiological evaluation revealed an incidental finding of a L4 butterfly vertebra in the anteroposterior and lateral view radiographs. The patient presented with no neurological deficit. This rare congenital anomaly is usually asymptomatic, and awareness of its non-traumatic nature is critical in order to establish a correct diagnosis. Further evaluation of the patient is necessary to exclude pathologic fracture, infection, or associated vertebral anomalies and syndromes, such as Alagille, Jarcho-Levin, Crouzon, and Pfeiffer syndromes. Furthermore, in the emergency setting, awareness of this entity is needed so that a correct diagnosis can be established.

Atypical post-adenoidectomy Grisel's syndrome in Crouzon child with kyphotic skull base

Crouzon syndrome is characterized by abnormal craniofacial growth due to craniosynostosis. Skull base may also be involved in the pattern of malformations. Grisel's syndrome, an inflammation-mediated atlanto-axial instability occurs rarely in children after adenoidectomy. We report a 9-year-old female Crouzon patient, without vertebral anomalies, who developed severe torticollis few days after adenoid curettage. A deformity of the skull base alone might have induced an irregular arrangement of the craniocervical junction elements, thus increasing the susceptibility to cervical spine complications.

Common skeletal features in rare diseases: New links between ciliopathies and FGF-related syndromes

Congenital skeletal anomalies are rare disorders, with a subset affecting both the cranial and appendicular skeleton. Two categories, craniosynostosis syndromes and chondrodysplasias, frequently result from aberrant regulation of the fibroblast growth factor (FGF) signaling pathway. Our recent work has implicated FGF signaling in a third category: ciliopathic skeletal dysplasias. In this work, we have used mouse mutants in two ciliopathy genes, Fuzzy (Fuz) and orofacial digital syndrome-1 (Ofd-1), to demonstrate increase in Fgf8 gene expression during critical stages of embryogenesis. While the mechanisms underlying FGF dysregulation differ in the different syndromes, our data raise the possibility that convergence on FGF signal transduction may underlie a wide range of skeletal anomalies. Here, we provide additional evidence of the skeletal phenotypes from the Fuz mouse model and highlight similarities between human ciliopathies and FGF-related syndromes.

Fuz mutant mice reveal shared mechanisms between ciliopathies and FGF-related syndromes

Ciliopathies are a broad class of human disorders with craniofacial dysmorphology as a common feature. Among these is high arched palate, a condition that affects speech and quality of life. Using the ciliopathic Fuz mutant mouse, we find that high arched palate does not, as commonly suggested, arise from midface hypoplasia. Rather, increased neural crest expands the maxillary primordia. In Fuz mutants, this phenotype stems from dysregulated Gli processing, which in turn results in excessive craniofacial Fgf8 gene expression. Accordingly, genetic reduction of Fgf8 ameliorates the maxillary phenotypes. Similar phenotypes result from mutation of oral-facial-digital syndrome 1 (Ofd1), suggesting that aberrant transcription of Fgf8 is a common feature of ciliopathies. High arched palate is also a prevalent feature of fibroblast growth factor (FGF) hyperactivation syndromes. Thus, our findings elucidate the etiology for a common craniofacial anomaly and identify links between two classes of human disease: FGF-hyperactivation syndromes and ciliopathies.

•

A genetic model for high arched palate, commonly seen in human craniofacial syndromes

•

In ciliopathic mice, Fgf8 overexpression leads to cranial neural crest hyperplasia

•

Enlargement of the maxillary primordia underlies high arched palate in Fuz mutants

•

An etiological link between ciliopathies and FGF-hyperactivation syndromes

Surgical timing of craniosynostosis: what to do and when

Craniosynostosis, both isolated and syndromic, are challenging malformations for the craniofacial team. They present the team with an articulated cascade of choices, which need to be addressed early in life and in the growing age to intercept, remove, or correct the direct and indirect consequences of the malformation. Timing of treatment is thus critical and it stands on the experience of a multi-specialty trained craniofacial team. In this paper the authors discuss the timing of treatment of the major craniosynostosis, isolated and syndromic, reviewing the options for treatment and their experience in this complex field.

Cervical vertebral column morphology in patients with obstructive sleep apnoea assessed using lateral cephalograms and cone beam CT. A comparative study

OBJECTIVES

Few studies have described morphological deviations in obstructive sleep apnoea (OSA) patients on two-dimensional (2D) lateral cephalograms, and the reliability of 2D radiographs has been discussed. The objective is to describe the morphology of the cervical vertebral column on cone beam CT (CBCT) in adult patients with OSA and to compare 2D lateral cephalograms with three-dimensional (3D) CBCT images.

METHODS

For all 57 OSA patients, the cervical vertebral column morphology was evaluated on lateral cephalograms and CBCT images and compared according to fusion anomalies and posterior arch deficiency.

RESULTS

The CBCT assessment showed that 21.1% had fusion anomalies of the cervical column, i.e. fusion between two cervical vertebrae (10.5%), block fusions (8.8%) or occipitalization (1.8%). Posterior arch deficiency occurred in 14% as partial cleft of C1 and in 3.5% in combination with block fusions. The agreement between the occurrence of morphological deviations in the cervical vertebral column between lateral cephalograms and CBCT images showed good agreement (κ = 0.64).

CONCLUSIONS

Prevalence and pattern in the cervical column morphology have now been confirmed on CBCT. The occurrence of morphological deviations in the cervical vertebral column showed good agreement between lateral cephalograms and CBCT images. This indicates that 2D lateral cephalograms (already available after indication in connection with, e.g. treatment planning) are sufficient for identifying morphological deviations in the cervical vertebral column. For a more accurate diagnosis and location of the deviations, CBCT is required. New 3D methods will suggest a need for new detailed characterization and division of deviations in cervical vertebral column morphology.

Butterfly vertebra with lumbar intervertebral disc herniation

A butterfly vertebra is a rare congenital anomaly that is usually asymptomatic. The authors, however, describe a novel case involving a butterfly vertebra overlapping with disc herniation that presented as radiculopathy. A butterfly vertebra is characterized by a symmetrical fusion defect resulting in a sagittal cleft vertebra. Only a few cases of butterfly vertebrae have been reported as incidental findings. This spinal anomaly may be associated with other congenital conditions such as Pfeiffer, Crouzon, Jarcho-Levin, and Alagille syndromes. Moreover, there is no previous report of a case associated with symptomatic disc herniation from the sagittal cleft. The authors excised the herniated disc fragment. They performed intraoperative discography after exposure of the corresponding intervertebral space via a conventional interlaminar approach. Histological examination of a tissue specimen showed scattered chondrocytes in the myxohyaline stroma, which indicated the nucleus pulposus.

Interpedicular graft using a titanium mesh cage in a patient with lumbar scoliosis associated with a congenital butterfly vertebra

A butterfly vertebra is a congenital anomaly often associated with a series of syndromic diseases and is often recognized incidentally without any presenting symptoms. The authors report the case of a 13-year-old girl with lumbar scoliosis and mild spondylolisthesis associated with a butterfly vertebra at L-6 causing radiculopathy. The L-5 and L-6 nerve roots were entrapped at the intervertebral foramina between L-5 and the butterfly vertebra (L-6) and between L-6 and S-1 in the concave side. To decompress and preserve the two nerve roots, correct the deformity, and obtain a solid bone fusion, surgery involving the thorough removal of the facet joints between L-5 and L-6 and between L-6 and S-1 in the concave side was performed, with a partial resection of the butterfly vertebra and the placement of a titanium mesh cage between the L-5 and S-1 pedicles dorsal to the nerve roots. Complete pain relief and correction of the deformity with solid bone fusion was obtained after a 2-year follow-up period.

Associations between the Cervical Vertebral Column and Craniofacial Morphology

Aim. To summarize recent studies on morphological deviations of the cervical vertebral column and associations with craniofacial morphology and head posture in nonsyndromic patients and in patients with obstructive sleep apnoea (OSA). Design. In these recent studies, visual assessment of the cervical vertebral column and cephalometric analysis of the craniofacial skeleton were performed on profile radiographs of subjects with neutral occlusion, patients with severe skeletal malocclusions and patients with OSA. Material from human triploid foetuses and mouse embryos was analysed histologically. Results. Recent studies have documented associations between fusion of the cervical vertebral column and craniofacial morphology, including head posture in patients with severe skeletal malocclusions. Histological studies on prenatal material supported these findings. Conclusion. It is suggested that fusion of the cervical vertebral column is associated with development and function of the craniofacial morphology. This finding is expected to have importance for diagnostics and elucidation of aetiology and thereby for optimal treatment.

Butterfly vertebra: an uncommon congenital spinal anomaly

STUDY DESIGN

This is a report of a patient with T6 butterfly vertebra, which is an uncommon congenital spinal anomaly.

OBJECTIVE

To illustrate the significance of identifying butterfly vertebra that may be confused with other pathologic conditions like fractures, infections, and metastases.

SUMMARY OF BACKGROUND DATA

We report a 46-year-old woman with butterfly vertebra of T6 spine. The patient presented with complaints of low back pain and examination showed an abnormal bony prominence at midthoracic level. Radiologic and hematologic investigations confirmed the presence of butterfly vertebrae at T6 level, which proved to be a coincidental finding along with nonspecific low back pain. Knowledge about this condition is very important, since the condition can be easily confused with a pathologic fracture.

METHODS

The patient presented with a history of low back pain of 2 months. The patient was evaluated clinically and with hematological investigations. The diagnosis was confirmed with computerized tomography (CT) and magnetic resonance imaging (MRI) scans.

RESULTS

Routine examination of the motor and sensory system was found to be normal. Roentgenogram of the thoracic and lumbosacral spine showed anterior wedging of T6 vertebrae in the lateral view and features suggestive of the presence of a butterfly vertebra at T6 level in the anteroposterior (AP) view. Hematologic evaluation was done to rule out pathologic causes of anterior wedging of the vertebra like infections and metastases in the spine. MRI and CT scans of the spine confirmed the presence of T6 butterfly vertebra. Patient was treated for her low back pain and assured that the abnormal midthoracic bony prominence was a benign condition that needs no treatment.

CONCLUSION

A high index of suspicion is needed to identify this benign spinal anomaly that may be confused with many pathologic conditions. Knowledge of this condition helps in making rational use of extensive noninvasive and invasive diagnostic procedures.

Crouzon with acanthosis nigricans. Further delineation of the syndrome

Patients with Crouzon and acanthosis nigricans syndrome show craniofacial features similar to those observed in patients with classic Crouzon syndrome, in addition to acanthosis nigricans with peculiar characteristics. More severe physical manifestations, such as Chiari malformation, hydrocephalus, and atresia or stenosis of the choanas, which are unusual in individuals with classic Crouzon syndrome, are reported in these patients. The molecular abnormality associated with Crouzon syndrome with acanthosis nigricans (CAN) is a transition in the transmembrane domain of the FGFR3 gene that results in an Ala391Glu mutation. We describe two unrelated patients showing this mutation and compare their clinical features with those of other patients with CAN reported in the literature. In addition to craniosynostosis with crouzonoid facies and acanthosis nigricans (present in all patients), melanocytic nevi, choanal atresia or stenosis, hydrocephalus, Chiari malformations and oral abnormalities were observed in the majority of the 35 patients analyzed. Vertebral anomalies and conductive hearing loss were present with less frequency. Some characteristics considered typical of this condition (jaw cementomas, acanthomas and finger abnormalities) were absent in most of the patients.

Chiari malformation and odontoid panus causing craniovertebral stenosis in a child with Crouzon's syndrome

Crouzon's disease is a well-known disorder affecting multiple organ systems, specifically a craniofacial disorder with highly variable penetrance and severity of deformity. Crouzon's patients typically have anomalies of the skull base leading to gross distortion of the cranium and in some cases the cervicocranium. We present a 5-year-old girl with Crouzon's disease who suffered from an acquired Chiari I malformation after insertion of a ventriculoperitoneal shunt and a coexistent ventral odontoid panus. Both these lesions were causing cervicomedullary compression. The literature is controversial on the surgical management of anterior and posterior compression at the craniocervical junction. We review the literature on surgical options for decompression at the craniocervical junction and offer our surgical case as a treatment option for patients in this rare clinical situation.

Clinically mild, atypical, and aged craniofacial syndrome is diagnosed as Crouzon syndrome by identification of a point mutation in the fibroblast growth factor receptor 2 gene (FGFR2)

A 53-year-old Japanese woman presented with mild mental retardation, short stature, hypertelorism, saddle nose, vertebral fusion, and hydrocephalus, implying an underlying bone growth impairment mainly of the head and neck. A point mutation in fibroblast growth factor receptor 2 (FGFR2) was identified that had previously been seen only in sporadic cases of Crouzon syndrome. This patient did not exhibit any of the typical features of Crouzon syndrome primarily seen in affected infants, such as a severely deformed skull, an apical shaped skull, or severe mental retardation. The patient was diagnosed with a mild form of Crouzon syndrome. The patient's symptoms very early in life may have been ameliorated and modified through growth and aging. The age-related phenotype modifications in Crouzon syndrome are discussed.

Butterfly vertebra: a case report

Butterfly vertebra is a rare congenital anomaly associated with syndromes such as Pfeiffer, Jarcho-Levin, Crousen, Alagille. In the literature, only a few cases of butterfly vertebra have been reported as incidental finding. We described a 37-year-old male who had an L3 butterfly vertebra associated with an L4-L5 disc protrusion. Awareness of this anomaly is important for making correct diagnosis. Although this uncommon anomaly is considered to be usually asymptomatic, we suggest that it might increase the incidence of disc herniation, because the condition may alter the spinal biomechanics.

Abnormal timing in the prenatal ossification of vertebral column and hand in Crouzon syndrome

We report on a radiographically examined fetus (gestational age 13 weeks) with Crouzon syndrome caused by a mutation in the gene encoding the fibroblast growth factor 2 (FGFR2). We found an approximately 2-week delay in vertebral body and hand ossification with normal vertebral arch ossification, suggesting that regionally delayed skeletal maturation might be a manifestation of FGFR2 mutation syndromes. The findings support other studies indicating that different signaling pathways control skeletal maturation in vertebral bodies and vertebral arches.