Intracranial hypertension and cortical thickness in syndromic craniosynostosis

Utility of Papilledema for Detection of Elevated Intracranial Pressure in Craniosynostosis

Papilledema is swelling of the optic disk due to fluid accumulation around the optic nerve and is commonly used to detect increased intracranial (ICP) in craniosynostosis. This study aimed to assess the prevalence and utility of papilledema detection in patients with single-suture, multi-suture, and syndromic craniosynostosis and the differences before and after surgical intervention. A retrospective review of ophthalmology examinations of patients diagnosed with craniosynostosis treated between 2008 and 2023 was performed. Demographics, diagnosis, and operative data were collected. A total of 1509 ophthalmology exams of 519 patients were reviewed. The overall rate of papilledema in patients with craniosynostosis was 2.12%. The single-suture and multi-suture involvement rates were 1.15% and 5.81%, respectively. Non-syndromic patients with preoperative and postoperative examinations had an overall rate of 3.13%. Most had single suture involvement, and the average age of papilledema examination was 72 months. Syndromic patients with preoperative and postoperative examinations had an overall rate of 17.65%. The majority had multiple suture involvement, and the average age of papilledema examination was 26 months. The overall papilledema detection rate was low in patients with craniosynostosis. Multi-suture involvement and syndromic diagnosis had increased rates of papilledema. The average age of diagnosis was in older children. Syndromic patients had papilledema examination at a younger age. The authors' findings support the concept that fundoscopic ophthalmologic examination will benefit patients with multi-suture involvement, an associated syndrome, and older age.

Cerebral Cortical Changes in Craniosynostosis: A Systematic Review

This study aims to review the existing literature on cerebral cortical changes in craniosynostosis during the months of August and September 2023. It focuses on alterations occurring in cases of both syndromic and non-syndromic forms of the disease. In particular, variations in volume, size, and structure (e.g., connectivity) of the cortex are studied. For the present review, a systematic search of the PubMed database was performed using the terms "cerebral cortex"[tw] OR "Cerebral Cortex"[Mesh] AND "Craniosynostoses"[Mesh]. The initial search retrieved 50 articles, which were studied in their entirety. After applying the selection and exclusion criteria, 34 articles were excluded, and finally, 16 qualified and were included in this study. The Anatomical Quality Assessment (AQUA) tool was preferred for the quality assessment of the included publications. Part of the articles used refers to the syndromic form of the disease and discusses temporal lobe and frontal cortex abnormalities, thinning and disproportionate increase in cerebral cortical surface area, and simplified gyroscopic pattern. The remaining articles, referring to non-syndromic craniosynostosis, are focused on neuronal connectivity, grey matter volume, and Sylvian fissure volume. In the existing literature, two theories have been proposed to describe the relationship between craniosynostosis and cortical changes. The deformation theory states that skull deformities result in brain architecture malformations, and the deformity theory supports that brain abnormalities pre-exist and lead to premature fusion of the cranial sutures. The existing data are not sufficient to resolve the above dilemma. Regarding the therapeutic approach, it differs depending on the type of craniosynostosis. Surgery remains the most common method, while innovative treatments are also emerging, including the application of regenerative medicine.

Analysis of intracranial pressure waveform using a non-invasive method in individuals with craniosynostosis

PURPOSE

Craniosynostosis can lead to symptoms resulting from cranial compliance (CC) changes and intracranial hypertension (ICH), which may cause cognitive and visual impairment. Non-invasive methods have emerged, including a new device that captures and processes the intracranial pressure waveform (ICPw) by the skull's oscillation. The present study evaluates ICPw obtained non-invasively (NIICPw) in patients with craniosynostosis.

METHODS

This prospective, cross-sectional, and descriptive study was conducted at a single center. Patients diagnosed with craniosynostosis and who provided informed consent were included. A US Food and Drug Administration-approved mechanical extensometer device (Brain4Care Corp.) was used to obtain a NIICPw. An ophthalmologist did a point-of-care retinography to check the optic nerve papilla. The P2/P1 ratio and the morphology of the NIICPw were analyzed, as well as the retinography.

RESULTS

Thirty-five patients were evaluated, and 42 registers were obtained because seven were assessed before and after the surgery. The two patients who presented papilledema had low CC (NIICPw shape Class 3 or 4). There was a significant association between NIICPw and papilledema.

CONCLUSION

The ratio P2/P1 and the NIICPw morphology provided by a non-invasive monitor are related to CC changes before papilledema occurs. This is especially useful in patients with craniosynostosis because invasive ICP monitoring is not always feasible. Further studies are warranted to establish the clinical utility of NIICPw in patients with craniosynostosis.

The Paediatric Vault Score (PVS)-A Novel Scoring Tool for Prioritisation of Surgical Management of Craniosynostosis Patients

Craniosynostosis is the premature fusion of the skull sutures, resulting in abnormal skull shape and volume. Timely management is a priority in avoiding raised intracranial pressure which can result in blindness and neurodevelopmental delay. Due to the COVID-19 pandemic, theater access was reduced. A risk stratification scoring system was thus devised to score patients attending surgery and aid in prioritization according to surgical need. The authors present the Paediatric Vault Score (PVS), which can also be customized to each unit's individual protocols. Ten patients on the waiting list were randomly selected and their clinical information was summarized in uniform anonymized reports. Six craniofacial consultants were selected as assessors and given 1 week to independently rank the patients from 1 to 10. Each scorer's ranking was verified against the PVS template and concordance was analyzed using the Kendall tau correlation coefficient (KT). Three cycles of the scoring process were carried out. Improvements were made to the scoring tool following cycle 1. Cycle 1 revealed 2 clinicians to be concordant with the PVS system and 4 to be discordant. Cycle 2 revealed all 6 clinicians to be concordant, with a mean KT score of 0.61. The final cycle revealed all 6 clinicians to be concordant, with a mean KT score of 0.70. Four scorers increased their concordance once the scoring sheet was introduced. Kendall's correlation of concordance calculated the interrater reliability to be 0.81. The PVS is the first known vault scoring system to aid in risk stratification and waiting list prioritization.

Behavioral, Learning Skills, and Visual Improvement in Crouzon Syndrome Patient Following Late Posterior Vault Distraction Osteogenesis

BACKGROUND

It is well accepted among craniofacial surgeons that surgery does not improve mental status but does prevent worsening or deterioration of cognitive and mental function. In this report, we describe significant improvement in behavioral, learning skills and visual acuity for a Crouzon patient who underwent late posteriorvault distraction osteogenesis.

METHODS

A 9-year-old Crouzon patient was referred to our hospital, presenting severe intracranial hypertension. The patient had previously undergone a strip craniectomy in early infancy at another medical institution, but there was no subsequent follow-up. Magnetic resonance imaging showed Chiari type I malformation and fundoscopy revealed papilledema. At the time of referral, the patient was not attending a regular school, had not acquired reading skills, was unable to concentrate, and could not accomplish school-related tasks that were standard for children in his age group.

RESULTS

The patient underwent posterior vault distraction osteogenesis and showed concentration improvement and acquisition of fluent reading skills. Chiari type I malformation resolved as well as papilledema. visual acuity improved at Snellen test preoperatively from 20/200 to 20/60 at postoperative test. Ventricle size remained unchanged subsequent to performance of the posterior cranial vault distraction. The occipital veins were less visible upon clinical examination and less pronounced when palpated, and the bruit had completely disappeared.

CONCLUSION

Late posterior vault distraction osteogenesis can improve behavioral, learning skills and visual acuity as shown in this 9-year-old Crouzon patient.

Cerebral cortex maldevelopment in syndromic craniosynostosis

AIM

To assess the relationship of surface area of the cerebral cortex to intracranial volume (ICV) in syndromic craniosynostosis.

METHOD

Records of 140 patients (64 males, 76 females; mean age 8y 6mo [SD 5y 6mo], range 1y 2mo-24y 2mo) with syndromic craniosynostosis were reviewed to include clinical and imaging data. Two hundred and three total magnetic resonance imaging (MRI) scans were evaluated in this study (148 patients with fibroblast growth factor receptor [FGFR], 19 patients with TWIST1, and 36 controls). MRIs were processed via FreeSurfer pipeline to determine total ICV and cortical surface area (CSA). Scaling coefficients were calculated from log-transformed data via mixed regression to account for multiple measurements, sex, syndrome, and age. Educational outcomes were reported by syndrome.

RESULTS

Mean ICV was greater in patients with FGFR (1519cm³ , SD 269cm³ , p=0.016) than in patients with TWIST1 (1304cm³ , SD 145cm³ ) or controls (1405cm³ , SD 158cm³ ). CSA was related to ICV by a scaling law with an exponent of 0.68 (95% confidence interval [CI] 0.61-0.76) in patients with FGFR compared to 0.81 (95% CI 0.50-1.12) in patients with TWIST1 and 0.77 (95% CI 0.61-0.93) in controls. Lobar analysis revealed reduced scaling in the parietal (0.50, 95% CI 0.42-0.59) and occipital (0.67, 95% CI 0.54-0.80) lobes of patients with FGFR compared with controls. Modified learning environments were needed more often in patients with FGFR.

INTERPRETATION

Despite adequate ICV in FGFR-mediated craniosynostosis, CSA development is reduced, indicating maldevelopment, particularly in parietal and occipital lobes. Modified education is also more common in patients with FGFR.

Late Presenting Multi-Suture Craniosynostosis

ABSTRACT

The authors provide the case of a 6-year-old male who presented late with multi-suture craniosynostosis and chronically elevated intracranial pressures (ICPs). He was surgically managed with frontal orbital advancement. This particular case illustrates the significant bleeding and unique bony pathology that can occur in patients with high ICP with concomitant venous collateralization. At 1-month follow-up, he demonstrated significant improvement with maintained expansion and no signs of elevated ICP despite delayed intervention. Frontal orbital advancement serves as an effective method for cranial vault expansion and correction of frontal deformities caused by craniosynostosis.

Nervous system involvement in Pfeiffer syndrome

Pfeiffer syndrome (PS) is a rare autosomal dominant craniofacial disorder characterized by primary craniosynostosis, midface hypoplasia, and extremities' abnormalities including syndactyly. The purpose of this article was to review the current knowledge regarding how PS affects the nervous system. Methodologically, we conducted a systematic review of the existing literature concerning involvement of the nervous system in PS. Multiple-suture synostosis is common, and it is the premature fusion and abnormal growth of the facial skeleton's bones that cause the characteristic facial features of these patients. Brain abnormalities in PS can be primary or secondary. Primary anomalies are specific developmental brain defects including disorders of the white matter. Secondary anomalies are the result of skull deformity and include intracranial hypertension, hydrocephalus, and Chiari type I malformation. Spinal anomalies in PS patients include fusion of vertebrae, "butterfly" vertebra, and sacrococcygeal extension. Different features have been observed in different types of this syndrome. Cloverleaf skull deformity characterizes PS type II. The main neurological abnormalities are mental retardation, learning difficulties, and seizures. The tricky neurological examination in severely affected patients makes difficult the early diagnosis of neurological and neurosurgical complications. Prenatal diagnosis of PS is possible either molecularly or by sonography, and the differential diagnosis includes other craniosynostosis syndromes. Knowing how PS affects the nervous system is important, not only for understanding its pathogenesis and determining its prognosis but also for the guidance of decision-making in the various critical steps of its management. The latter necessitates an experienced multidisciplinary team.

Cortical Thickness in Crouzon-Pfeiffer Syndrome: Findings in Relation to Primary Cranial Vault Expansion

Background

Episodes of intracranial hypertension are associated with reductions in cerebral cortical thickness (CT) in syndromic craniosynostosis. Here we focus on Crouzon-Pfeiffer syndrome patients to measure CT and evaluate associations with type of primary cranial vault expansion and synostosis pattern.

Methods

Records from 34 Crouzon-Pfeiffer patients were reviewed along with MRI data on CT and intracranial volume to examine associations. Patients were grouped according to initial cranial vault expansion (frontal/occipital). Data were analyzed by multiple linear regression controlled for age and brain volume to determine an association between global/lobar CT and vault expansion type. Synostosis pattern effect sizes on global/lobar CT were calculated as secondary outcomes.

Results

Occipital expansion patients demonstrated 0.02 mm thicker cortex globally (P = 0.81) with regional findings, including: thicker cortex in frontal (0.02 mm, P = 0.77), parietal (0.06 mm, P = 0.44) and occipital (0.04 mm, P = 0.54) regions; and thinner cortex in temporal (-0.03 mm, P = 0.69), cingulate (-0.04 mm, P = 0.785), and, insula (-0.09 mm, P = 0.51) regions. Greatest effect sizes were observed between left lambdoid synostosis and the right cingulate (d = -1.00) and right lambdoid synostosis and the left cingulate (d = -1.23). Left and right coronal synostosis yielded effect sizes of d = -0.56 and d = -0.42 on respective frontal lobes.

Conclusions

Both frontal and occipital primary cranial vault expansions correlate to similar regional CT in Crouzon-Pfeiffer patients. Lambdoid synostosis appears to be associated with cortical thinning, particularly in the cingulate gyri.