Predicting neuropsychological development from skull imaging

Craniosynostosis is a serious and common pediatric disease caused by the premature fusion of sutures of the skull. Although studies have shown an increase in risk for cognitive deficits in patients with isolated craniosynostosis, the causal basis for this association is still unclear. It is hypothesized that an abnormally shaped skull produces a secondary deformation of the brain that results in the disruption of normal neuropsychological development. In this paper, we conduct a comparative analysis of our newly developed shape descriptors in an attempt to understand the impact of skull deformations on neurobehavior. In particular, we show that our scaphocephaly severity indices and symbolic shape signatures are predictive of mental ability and psychomotor functions, respectively, which suggests the possibility that secondary deformation could influence neuro-developmental status.

Familial whole-arm translocations (1;19), (9;13), and (12;21): a review of 101 constitutional exchanges

We report here on 3 familial whole-arm translocations (WATs), namely the 8th instance of t(1;19)(p10;q10) and 2 novel exchanges: t(9;13)(p10;q10) and t(12;21)(p10;q10). The exchanges (1;19) and (12;21) were ascertained through a balanced carrier, whereas the t(9;13) was first diagnosed in a boy with a trisomy 9p syndrome and der(9p13p). Results of FISH analyses with the appropriate ?-satellite probes were as follows. Family 1, t(1;19): the D1Z5 probe gave a strong signal on both the normal chromosome 1 and the der(1q19p) as well as a weak signal on the der(1p19q). Family 2, t(9;13): the centromere-9 alphoid and D13Z1/D21Z1 probes under standard stringency gave no signal on the der(9p13p) in both the proband and a carrier brother, whereas the der(9q13q) was labelled only with the centromere-9 alphoid repeat in the latter; yet, this probe under low stringency revealed a residual amount of alphoid DNA on the der(9p13p) in the carrier. Family 3, t(12;21): the D12Z3 probe gave a signal on the normal chromosome 12 and the der(12p21q), whereas the D13Z1/D21Z1 repeat labelled the der(12q21p), the normal chromosome 21, and both chromosomes 13. Out of 101 WATs compiled here, 73 are distinct exchanges, including 32 instances between chromosomes with common alphoid repeats. Moreover, 7/9 of recurrent WATs involved chromosomes from the same alphoid family. Thus constitutional WATs appear to recur more frequently than other reciprocal exchanges, often involve chromosomes with common alphoid repeats, and can mostly be accounted for the great homology in alphoid DNA that favours mispairing and illegitimate nonhomologous recombination.

Pansynostosis: a review

INTRODUCTION

Although rare, pansynostoses are seen and treated by the craniofacial surgeon. To date, a single source that reviews these more severe forms of craniosynostosis is lacking in the literature.

MATERIALS AND METHODS

The present paper outlines and reviews the associations of both syndromic and nonsyndromic cases, potential mechanisms, and the anatomy involved with such forms of premature fusion of the cranial sutures.

RESULTS

Pansynostosis is seen in a myriad of syndromes but can also be identified in nonsyndromic cases. Raised intracranial pressure is a concern in these patients.

CONCLUSIONS

Early recognition and treatment of patients with pansynostosis of the cranial sutures is important.

Superelastic NiTi springs for corrective skull operations in children with craniosynostosis

This paper concerns the formation and characterization of superelastic springs and rings of NiTi alloys for long-term skull correction. Superelastic properties of the rings were induced in the process of ageing of the already formed rings which cause hardening of parent phase by the precipitation of coherent Ni(4)Ti(3) particles. The efficacy of the worked out springs and rings were successfully proved in several clinical applications.

RNA interference and inhibition of MEK-ERK signaling prevent abnormal skeletal phenotypes in a mouse model of craniosynostosis

Premature fusion of one or more of the cranial sutures (craniosynostosis) in humans causes over 100 skeletal diseases, which occur in 1 of approximately 2,500 live births. Among them is Apert syndrome, one of the most severe forms of craniosynostosis, primarily caused by missense mutations leading to amino acid changes S252W or P253R in fibroblast growth factor receptor 2 (FGFR2). Here we show that a small hairpin RNA targeting the dominant mutant form of Fgfr2 (Fgfr2(S252W)) completely prevents Apert-like syndrome in mice. Restoration of normal FGFR2 signaling is manifested by an alteration of the activity of extracellular signal-regulated kinases 1 and 2 (ERK1/2), implicating the gene encoding ERK and the genes downstream of it in disease expressivity. Furthermore, treatment of the mutant mice with U0126, an inhibitor of mitogen-activated protein (MAP) kinase kinase 1 and 2 (MEK1/2) that blocks phosphorylation and activation of ERK1/2, significantly inhibits craniosynostosis. These results illustrate a pathogenic role for ERK activation in craniosynostosis resulting from FGFR2 with the S252W substitution and introduce a new concept of small-molecule inhibitor-mediated prevention and therapy for diseases caused by gain-of-function mutations in the human genome.

Delayed development of frontal mucocele after fronto-orbital advancement in a child with craniosynostosis

BACKGROUND

Sinus mucoceles rarely develop as a consequence of inadequate sinus ventilation that arises due to inflammation, allergy, polyps, tumors, surgery, and trauma. The development of frontal sinus is delayed until older than 6 years. Therefore, the development of the mucocele in the frontal sinus after fronto-orbital advancement surgery in young children with craniosynostosis may provide essential information for the development of the frontal sinus.

CASE DESCRIPTION

We report a rare case of a 22-year-old man presenting with a frontal mucocele manifested by dull headache, proptosis, and diplopia, and which developed 16 years after fronto-orbital advancement surgery for craniosynostosis. Magnetic resonance imaging demonstrated that a multiple cystic mass extended from the frontal sinus to the retro-orbital space along the optic nerve. During surgery, we found that the cyst consisted of mostly thin, yellow mucosa, which developed from an anomalously overdeveloped frontal sinus containing yellow pus-like intracystic fluid. There was no gross local invasion by the cyst. We easily dissected and removed the mucosal cyst from the large frontal sinus completely with frontal sinus obliteration. We cranialized the anomalously large frontal sinus by removal of the posterior wall of the frontal sinus and then widening the ethmoidal drainage with endoscopic ethmoidectomy.

CONCLUSION

We report the first case of a frontal sinus mucocele that developed after fronto-orbital advancement surgery in the literature and suggest that the mucocele development after fronto-orbital advancement supports the hypothesis of frontal bone-inducing role in frontal sinus development.

Craniofacial morphology in Muenke syndrome

The purpose of this study was to test whether the severity of the cranial phenotype in Muenke syndrome infants with unicoronal synostosis is greater than in infants with nonsyndromic unicoronal synostosis. A total of 23 infants were included in the study. All infants included in the study had a computed tomography (CT)-verified synostosis of the coronal suture. The patients were either placed into the "Muenke" group (n=11) or the "non-Muenke" control group (n=12) on the basis of a test for the P250R mutation in the FGFR3 gene. On the basis of CT scans, a three-dimensional surface model corresponding to bone was created for each individual. The sutures were inspected for synostosis, and the degree of synostosis was assessed. Increased digital markings were recorded for both groups. Craniofacial morphology was assessed quantitatively using bony landmarks and recording of the midsagittal surface of the calvaria, cranial base, and maxillary complex. Increased digital markings were more severe posteriorly in Muenke patients than in non-Muenke patients. The Muenke patients with unilateral coronal synostosis showed a somewhat more severe asymmetry in the anterior part of the skull than the non-Muenke patients. The study indicates differences with regard to severity of increased digital markings and craniofacial asymmetry between the infants with Muenke syndrome and the infants with nonsyndromic unilateral coronal synostosis.

Intracranial volume measurement of sagittal craniosynostosis

We report 41 cases of non-syndromic isolated sagittal synostosis in which evaluation of intracranial volumes was undertaken. Twenty-six were male and fifteen were female. The measured intracranial volumes were then compared with normal age-corrected values. We have found that intracranial volumes were significantly larger than the normal population intracranial volumes in both sexes. However the statistical significance of this finding was much greater in females, (p<0.00002), than males (p<0.040), which was only of borderline significance. The results confirm smaller, earlier studies that intracranial volumes in sagittal synostosis patients are larger than average for age-corrected normal values. Analysis of a sub-set of six patients with sagittal synostosis who were found to have a common polymorphism 294C>T (Asn294Asn) in FGFR3 (fibroblast growth factor Receptor 3) on genetic testing were compared to age and sex matched cases of non-syndromic sagittal synostosis (without an underlying mutation) which confirmed that there were no discernable differences in intracranial volumes between the two groups. We conclude that this investigation supports the role of cranial re-shaping to improve cosmesis as the primary aim of surgical correction in this condition, in the absence of raised intracranial pressure.

Isolation and characterization of posterofrontal/sagittal suture mesenchymal cells in vitro

BACKGROUND

Craniosynostosis, the premature fusion of cranial sutures, affects one in 2500 children. In the mouse, the posterofrontal suture is programed to fuse postnatally, but the adjacent sagittal suture remains patent throughout life. To study the cellular process of suture fusion, the authors isolated and studied suture-derived mesenchymal cells.

METHODS

Skulls were harvested from 80 mice (2 to 5 days old), and posterofrontal and sagittal sutures were dissected meticulously. Suture mesenchymal tissue was separated from the underlying dura mater and overlying pericranium and cultured in growth media. After the cells migrated from the explant tissues, the morphologies of the two cell populations were studied carefully, and quantitative real-time polymerase chain reaction was performed to evaluate gene expression.

RESULTS

Both posterofrontal and sagittal cells exhibited highly heterogeneous morphologies, and the posterofrontal cells migrated faster than the sagittal cells. Accordingly, growth factors such as transforming growth factor-beta1 and fibroblast growth factor (FGF)-2 were expressed significantly more highly in posterofrontal compared with sagittal suture mesenchymal cells. In contrast, FGF receptor 2 and FGF-18 were expressed significantly more in sagittal than in posterofrontal suture cells. Importantly, bone morphogenic protein-3, the only osteogenic inhibitor in the bone morphogenic protein family, and noggin, a bone morphogenic protein antagonist, were expressed significantly more in sagittal than in posterofrontal suture cells, suggesting a possible mechanism of suture patency.

CONCLUSIONS

To the authors' knowledge, this is the first analysis of mouse suture-derived mesenchymal cells. The authors conclude that isolation of suture-derived mesenchymal cells will provide a useful in vitro system with which to study the mechanisms underlying suture biology.

Spring-Assisted Correction of Hypotelorism in Metopic Synostosis

BACKGROUND

Metopic synostosis, apart from the pointed forehead, typically is characterized by hypotelorism with egg-shaped orbits on cephalography and the frontoorbital axis parallel or even converging superiorly. The frontoorbital axis angle is a novel parameter for analyzing and describing the orientation of the orbits. Current methods of surgery often result in undercorrection of the almost ever-present hypotelorism. The present study was performed to analyze a new technique, capable in this respect, using steel wire springs in conjunction with a cranioplasty.

METHODS

A retrospective study of 23 metopic synostosis patients operated on between 1999 and 2004 was conducted. A strip midline craniectomy and frontal reshaping were combined with the insertion of a steel wire spring across the midline craniectomy, forcing lateral displacement of the orbits. Preoperative and postoperative follow-up cephalograms were obtained, and the bony medial interorbital distance was measured and compared with the bony medial interorbital distance of a control group. Perioperative data and complications were noted.

RESULTS

Preoperative mean bony interorbital distance was 10.6 mm (range, 7.7 to 13.2 mm). It increased to 15.7 mm (range, 10.4 to 22 mm) at 1.5 months postoperatively and to 16.2 mm (range, 10.9 to 24.5 mm) 5 months postoperatively. Results as judged clinically ranged from little effect to a definitive overcorrection. The frontoorbital axis was improved in every case. Average frontoorbital axis was -4 degrees (range, -33 to 23 degrees) preoperatively and 28 degrees (range, 11 to 46 degrees) postoperatively.

CONCLUSION

It was concluded that a spring used together with a cranioplasty is a powerful tool for the correction of both hypotelorism and orbital shape in trigonocephaly.

Somatic FGFR and TWIST Mutations are not a Common Cause of Isolated Nonsyndromic Single Suture Craniosynostosis

Pathogenic mutations in FGFR2 and TWIST genes are detected in the majority of individuals with Crouzon, Pfeiffer, Apert, and Saethre-Chotzen syndromes. In contrast, mutations have been identified rarely in cases of nonsyndromic, single suture craniosynostosis. Recently, two studies confirming somatic mosaicism with local expression of an FGFR mutation have been reported. This study investigates whether somatic mosaicism could account for nonsyndromic, single suture craniosynostosis. Eight individuals with single suture craniosynostosis who were negative for known mutations in FGFR1-3 and TWIST after screening in their leucocyte DNA were tested for the presence of pathogenic mutations in suture cell-derived DNA. Five had sagittal synostosis, two had metopic synostosis, and the other unicoronal synostosis. Osteoprogenitor cells from surgically excised fusing sutures and an adjacent open suture were cultured. DNA from the cultured cells grown to passage 3 was then examined for underlying FGFR and TWIST mutations. No mutations within the exons of the FGFR or TWIST genes studied were identified in any suture cells. This study found no evidence to support the notion that mosaicism for FGFR or TWIST mutations, normally associated with syndromal forms of craniosynostosis, occur in single suture craniosynostosis. Thus, any underlying genetic defects must occur in regions outside those normally implicated in syndromal craniosynostosis, or this disorder could arise as a consequence of some other epigenetic modification.

Distraction vs remodeling surgery for craniosynostosis

OBJECTS

We designed several distraction devices and applied these instruments in 14 patients with varying types of craniosynostosis. The aim of this report is to clarify the advantages and disadvantages of these surgical methods and to discuss current concepts for the surgical strategy in the treatment of craniosynostosis.

METHODS

From January 2000 to July 2005, 28 patients with craniosynostosis were retrospectively analyzed. Surgical treatment was performed on 14 patients using the distraction method with internal distraction devices that we designed, in which 5 patients had plagiocephaly, 3 brachycephaly, and 6 scaphocephaly. All patients underwent preoperative and postoperative evaluations, which included the patient's neurological state, and three-dimensional CT.

RESULTS

With distraction devices, the time required for the surgery could be shortened almost 3 1/3 h; the bleeding during the surgery was decreased with reduced requirement of more than 200 ml of blood transfusion as compared with remodeling surgery. Postoperatively achieved distraction distances varied from 30.0 to 47.5 mm (mean, 42.99 mm). The average increased volume percent of cranium in distraction surgery group was 20.9% (range, -11.5 to 58.9%) after full distraction.

CONCLUSION

With distraction surgery, satisfactory cranial volume expansion and aesthetically pleasing morphological states were achieved in all cases, and the efficacy was statistically significantly high as compared with remodeling method.

Expression of Indian Hedgehog, BMP-4 and Noggin in Craniosynostosis Induced by Fetal Constraint

Indian Hedgehog (Ihh), bone morphogenetic protein (BMP), and its antagonist Noggin play an important regulatory role in bone formation. We used an animal model to study the role of these molecules in craniosynostosis induced by fetal constraint. C57Bl/6 mice underwent cervical cerclage on the 18th day of gestation, and their pups were harvested 48 and 72 hours beyond the normal gestational period. Constrained and control calvariae were examined for expression of BMP-4, Noggin, Histone H4C, Ihh, Sonic Hedgehog (Shh), and Patched 1 (Ptch1), one of the Hh transcriptional target molecules/Hh receptors. Constraint-induced suture fusion was associated with decreased expression of Ihh and Noggin, whereas BMP-4 was expressed in both control and constrained sutures. Ptch1 colocalized with Ihh-positive osteogenic cells at the osteogenic fronts, but not with Shh transcripts, suggesting that Ihh, but not Shh, regulates Ptch1 expression in cranial suture development. Histone H4C was preferentially expressed in Ihh-positive cells, indicating that Ihh may regulate osteogenic cell proliferation at the osteogenic fronts. These results suggest a role for Ihh and Noggin signaling in constraint-induced craniosynostosis.

Sudden infant death in a patient with FGFR3 P250R mutation

P250R mutation in the FGFR3 gene also known as Muenke syndrome is associated with coronal craniosynostosis, sensorineural deafness, craniofacial, and digital abnormalities. We report a family with this mutation associated with sudden death in an affected newborn, most probably due to upper airway obstruction.

Obesity, hypothyroidism, craniosynostosis, cardiac hypertrophy, colitis, and developmental delay: A novel syndrome

We describe in two brothers an apparently novel syndrome comprising obesity, congenital hypothyroidism, neonatal colitis, cardiac biventricular hypertrophy, craniosynostosis, and developmental delay. The first brother presented with neonatal colitis and congenital hypothyroidism and died at age 5 weeks of fulminant colitis. The second brother presented neonatally with the same condition, but survived and subsequently developed severe obesity, sagittal and coronal synostosis, and developmental delay. Both pregnancies had been complicated by hemolysis, elevated liver enzymes, and low platelets (HELLP syndrome). Exhaustive genetic and metabolic investigations have failed to provide a unifying pathogenesis. This unique combination of manifestations appears to represent a new syndrome with probable autosomal recessive or X-linked recessive inheritance.

Quantitative and qualitative assessment of morphology in sagittal synostosis: mid-sagittal vector analysis

Consensus remains lacking regarding the optimal surgical treatment modality for sagittal synostosis. There is, however, wide agreement that objective analytical methods are required to demonstrate the characteristic morphology of the condition and to substantiate the benefits of specified surgical techniques. Simple calculated anthropomorphic indices, such as the cranial index, are commonly used but fail to provide satisfactory representation of morphology, which is far more complex than can be represented by its simple length-width ratio. Techniques to provide more comprehensive, yet practical, assessment of morphology are needed for analytic purposes. Herein, we introduce vector analysis as an objective, computed tomography (CT)-based morphometric technique for assessment of cranial morphology; this work represents the first application of the technique mid-sagittal vector analysis (MSVA). MSVA is a single plane application that was devised to address dysmorphology in sagittal synostosis. It was our hypothesis that MSVA would quantitatively and qualitatively depict preoperative morphology and postoperative correction in specific regions. Sixteen patients undergoing cranial reshaping surgery for sagittal synostosis were included in the study. All patients underwent routine preoperative and 1 year postoperative CT scans, from which the MSVA was derived. MSVA is a radial vector analysis in which distances to the cranial surface are measured from a single reference point origin in the sagittal plane. Preoperative morphology, characterized by respective vectors, was analyzed in three regions: the frontal, vertex, and occipital regions. Comparison with postoperative paired data was conducted for each patient. The analysis of postoperative change demonstrated (1) decrease in prominence in the frontal and occipital regions, (2) increase in height and forward translation of the vertex, and (3) ability to distinguish and qualify frontal versus occipital bossing and correction thereof. We conclude that the longitudinal differences associated with scaphocephaly are well characterized and differentiated by MSVA. Quantitative and qualitative assessment identifies three relevant regions affected by the condition and its treatment: the frontal, vertex, and occipital regions. The transverse dimension is not addressed in this single plane analysis; a more comprehensive application will require additional planes of analysis and the development of a normative database.

Craniofacial anomalies, humero-radial synostosis, rhizomelic limb shortness: Previously unrecognized autosomal recessive syndrome

Humero-radial synostosis (HRS) is a rare skeletal anomaly that might be seen in some craniosynostosis syndromes, notably Antley-Bixler syndrome, and in other disorders in association with skeletal anomalies. Here we report on two daughters of first cousin Saudi parents with syndromic HRS. Both patients had distinctive craniofacial features including cranium bifidum occultum, hypertelorism, epicanthus inversus, capillary hemangiomata, and malformed ears. Musculoskeletal examination revealed rhizomelic shortness with normal hands and feet. Skeletal survey showed bilateral HRS with no evidence of craniosynostosis. The craniofacial manifestations in these two patients do not match any of the syndromes known to be associated with HRS. We consider that the constellation is unique and apparently represents a previously unrecognized syndrome.

Attenuation of signaling pathways stimulated by pathologically activated FGF-receptor 2 mutants prevents craniosynostosis

Craniosynostosis, the fusion of one or more of the sutures of the skull vault before the brain completes its growth, is a common (1 in 2,500 births) craniofacial abnormality, approximately 20% of which occurrences are caused by gain-of-function mutations in FGF receptors (FGFRs). We describe a genetic and pharmacological approach for the treatment of a murine model system of Crouzon-like craniosynostosis induced by a dominant mutation in Fgfr2c. Using genetically modified mice, we demonstrate that premature fusion of sutures mediated by Crouzon-like activated Fgfr2c mutant is prevented by attenuation of signaling pathways by selective uncoupling between the docking protein Frs2alpha and activated Fgfr2c, resulting in normal skull development. We also demonstrate that attenuation of Fgfr signaling in a calvaria organ culture with an Fgfr inhibitor prevents premature fusion of sutures without adversely affecting calvaria development. These experiments show that attenuation of FGFR signaling by pharmacological intervention could be applied for the treatment of craniosynostosis or other severe bone disorders caused by mutations in FGFRs that currently have no treatment.

Aesthetic Results of Fronto-Orbital Correction in Trigonocephaly

The aesthetic results of craniofacial surgery for trigonocephaly were evaluated by a panel assessment using a scoring system based on deformities typical for this type of craniosynostosis. In this retrospective study pre-and postoperative photographs of 45 patients were scored for items typical for trigonocephaly: shape of the forehead, hypotelorism, and temporal depression. Each item was quantified as normal or absent (0 points), a mild deformity (1 point) or a severe deformity (2 points). Preoperatively, the most obvious deformity was temporal depression and this remained to be the most obvious deformity after surgery. There was a good overall correction of the presenting deformities with a decline in the mean score preoperatively from 4.49-1.13 postoperatively. There was a significant weak correlation between pre- and postoperative score only for hypotelorism. This indicates that the severity of the initial disease is not a major contributor to the final surgical result. Furthermore, surgical outcome seemed to be stable over time and was not influenced by the timing of surgery when surgery was scheduled between the ages of 6-15 months. Early craniofacial correction for trigonocephaly results in a stable, acceptable aesthetic result on which the initial deformity has little effect. The most common associated craniofacial characteristics are well- to very well-corrected when surgery is performed within the first 6-15 months. Main focus of deformity on short and long term remains the temporal depression, and thus requires extra attention during surgery.

Nell-1-induced bone regeneration in calvarial defects

Many craniofacial birth defects contain skeletal components requiring bone grafting. We previously identified the novel secreted osteogenic molecule NELL-1, first noted to be overexpressed during premature bone formation in calvarial sutures of craniosynostosis patients. Nell-1 overexpression significantly increases differentiation and mineralization selectively in osteoblasts, while newborn Nell-1 transgenic mice significantly increase premature bone formation in calvarial sutures. In the current study, cultured calvarial explants isolated from Nell-1 transgenic newborn mice (with mild sagittal synostosis) demonstrated continuous bone growth and overlapping sagittal sutures. Further investigation into gene expression cascades revealed that fibroblast growth factor-2 and transforming growth factor-beta1 stimulated Nell-1 expression, whereas bone morphogenetic protein (BMP)-2 had no direct effect. Additionally, Nell-1-induced osteogenesis in MC3T3-E1 osteoblasts through reduction in the expression of early up-regulated osteogenic regulators (OSX and ALP) but induction of later markers (OPN and OCN). Grafting Nell-1 protein-coated PLGA scaffolds into rat calvarial defects revealed the osteogenic potential of Nell-1 to induce bone regeneration equivalent to BMP-2, whereas immunohistochemistry indicated that Nell-1 reduced osterix-producing cells and increased bone sialoprotein, osteocalcin, and BMP-7 expression. Insights into Nell-1-regulated osteogenesis coupled with its ability to stimulate bone regeneration revealed a potential therapeutic role and an alternative to the currently accepted techniques for bone regeneration.

FGFR1 Pfeiffer syndrome without craniosynostosis: an additional case report

Pfeiffer syndrome is an autosomal dominant condition classically encompassing both craniosynostosis and digital abnormalities of the hands and feet. Individuals with Pfeiffer syndrome may have mutations within either fibroblast growth factor receptor 1 gene (FGFR1) or FGFR2. FGFR1 mutations often result in less severe craniofacial involvement and hand abnormalities. We report a four-generation family with an FGFR1 P252R mutation, who have typical hand and feet skeletal features of Pfeiffer syndrome without craniofacial involvement. This is the third family in the literature in which no family members have craniofacial features of Pfeiffer syndrome. The absence of craniosynostosis should not preclude the consideration of FGFR mutation analysis in cases in which digital features are characteristic of the craniosynostosis syndromes.