Heart rate variability and vasovagal tone index in brachycephalic dogs.

Brachycephalic breeds of dogs, most of which show signs of the brachycephalic syndrome may have greater parasympathetic stimulation than other breeds, leading to higher values of heart rate variability and vagal tone index. The aim of this study was to establish a computerized electrocardiographic study and an assessment of the vagus sympathetic balance through heart rate variability and vagal tone index of five brachycephalic breeds compared to mesocephalic dogs. Sixty dogs were used, divided into groups made up of Boxers, English Bulldogs, French Bulldogs, Pugs, Shih-Tzu and no defined breed mesocephalic dogs. Statistical analysis was carried out using the Shapiro-Wilk test, Kruskal-Wallis and Dunn's test or ANOVA and Bonferroni (p<0.05). In the evaluation of vagal sympathetic balance among all the dogs, there was a negative correlation between heart rate and HRV 10RR (r = - 0.7678; p < 0.0001), HRV 20RR (r = - 0.8548, p < 0.0001) and VVTI (r = - 0.2770; p = 0.0321). It can therefore be concluded that the dog's breed and morphology did not alter its electrocardiographic parameters or heart rate variability. The vagal tone index, which in other studies differed in brachycephalic dogs, showed no difference when compared separately in brachycephalic breeds.

Geospatial and Socioeconomic Disparities Influencing the Management of Craniosynostosis.

BACKGROUND: Various social determinants of health have been described as predictors of clinical outcomes for the craniosynostosis population. However, literature lacks a granular depiction of socioeconomic factors that impact these outcomes, and little is known about the relationship between patients' proximity to the care center and management of the condition. METHODS/DESIGN: This study retrospectively evaluated patients with craniosynostosis who presented to a tertiary children's hospital between 2000 and 2019. Outcomes of interest included age at presentation for surgery, incidence of reoperation, and length of follow-up. Patient addresses were geocoded and plotted on two separate shapefiles containing block group information within San Diego County. The shapefiles included percent parental educational attainment (bachelor's degree or higher) and median household income from 2010. The year 2010 was chosen for the shapefiles because it is the median year of data collection for this study. Multivariate linear, logistic, and polynomial regression models were used to analyze the relationship between geospatial and socioeconomic predictors and clinical outcomes. RESULTS: There were 574 patients with craniosynostosis included in this study. The mean ± SD Haversine distance from the patient's home coordinates to the hospital coordinates was 107.2 ± 321.2 miles. After adjusting for the suture fused and insurance coverage, there was a significant positive correlation between distance to the hospital and age at index surgery (P = 0.018). There was no correlation between distance and incidence of reoperation (P = 0.266) or distance and duration of follow-up (P = 0.369). Using the same statistical adjustments, lower parental percent educational attainment and lower median household income correlated with older age at index surgery (P = 0.008 and P = 0.0066, respectively) but were not correlated with reoperation (P = 0.986 and P = 0.813, respectively) or duration of follow-up (P = 0.107 and P = 0.984, respectively). CONCLUSIONS: The results offer evidence that living a greater distance from the hospital and socioeconomic disparities including parental education and median household income may serve as barriers to prompt recognition of diagnosis and timely care in this population. However, the geospatial and socioeconomic factors studied do not seem to hinder incidence of reoperation or length of follow-up, suggesting that, once care has been initiated, longitudinal outcomes may be less impacted.

Flat Head Syndrome in Infants.

This JAMA Patient Page describes the types of flat head syndrome and its prevention and treatment.

Whole genome sequencing identifies associations for nonsyndromic sagittal craniosynostosis with the intergenic region of BMP2 and noncoding RNA gene LINC01428.

Craniosynostosis (CS) is a major birth defect resulting from premature fusion of cranial sutures. Nonsyndromic CS occurs more frequently than syndromic CS, with sagittal nonsyndromic craniosynostosis (sNCS) presenting as the most common CS phenotype. Previous genome-wide association and targeted sequencing analyses of sNCS have identified multiple associated loci, with the strongest association on chromosome 20. Herein, we report the first whole-genome sequencing study of sNCS using 63 proband-parent trios. Sequencing data for these trios were analyzed using the transmission disequilibrium test (TDT) and rare variant TDT (rvTDT) to identify high-risk rare gene variants. Sequencing data were also examined for copy number variants (CNVs) and de novo variants. TDT analysis identified a highly significant locus at 20p12.3, localized to the intergenic region between BMP2 and the noncoding RNA gene LINC01428. Three variants (rs6054763, rs6054764, rs932517) were identified as potential causal variants due to their probability of being transcription factor binding sites, deleterious combined annotation dependent depletion scores, and high minor allele enrichment in probands. Morphometric analysis of cranial vault shape in an unaffected cohort validated the effect of these three single nucleotide variants (SNVs) on dolichocephaly. No genome-wide significant rare variants, de novo loci, or CNVs were identified. Future efforts to identify risk variants for sNCS should include sequencing of larger and more diverse population samples and increased omics analyses, such as RNA-seq and ATAC-seq.

Long-term results of minimally invasive strip craniectomy without helmet therapy for scaphocephaly - a single-centre experience.

Scaphocephaly is the most common type of craniosynostosis and various surgical techniques are used for treatment. Due to late postoperative changes of the head shape, long-term outcome data is important for evaluating any new surgical technique. At our institution, minimally invasive strip craniectomy without regular helmet therapy is the standard treatment in scaphocephalic patients. Between October 2021 and February 2023, we retrospectively examined the skull shape of patients who underwent minimally invasive strip craniectomy for scaphocephaly using a 3D surface scan technique. The cephalic index (CI), the need for helmet therapy and additional cosmetic outcome parameters were investigated. We included 70 patients (72.5% male). The mean follow-up time was 46 (10-125) months and the mean CI was 75.7 (66.7-85.2). In 58 patients, the final cosmetic result was rated as "excellent/good" (mean CI: 76.3; 70.4-85.0), in 11 as "intermediate" (mean CI: 73.3; 66.7-77.6), and in one case as "unsatisfactory" (CI 69.3). The presence of a suboccipital protrusion was associated with a "less than good" outcome. The CI correlated significantly with the overall outcome, the presence of frontal bossing, and the interval between scan and surgery (age at scan). Minimally invasive strip craniectomy is an elegant and safe method to correct scaphocephaly. Our data show good cosmetic results in the long term even without regular postoperative helmet therapy.

An Ultra-Rare Mixed Phenotype with Combined AP-4 and ERF Mutations: The First Report in a Pediatric Patient and a Literature Review.

The adaptor protein 4 (AP-4) constitutes a conserved hetero-tetrameric complex within the family of adaptor protein (AP) complex, crucial for the signal-mediated trafficking of integral membrane proteins. Mutations affecting all subunits of the AP-4 complex have been linked to autosomal-recessive cerebral palsy and a complex hereditary spastic paraparesis (HSP) phenotype. Our report details the case of a 14-year-old boy born to consanguineous parents, presenting psychomotor delay, severe intellectual disability, microcephaly, and trigonocephaly. Despite a history of febrile seizures, subsequent years were devoid of seizures, with normal EEG. Exome sequencing revealed pathogenic variants in both the AP4B1 and ERF genes. Significantly, the patient exhibited features associated with AP4B1 mutations, including distinctive traits such as cranial malformations. The ERF gene variant, linked to craniosynostosis, likely contributes to the observed trigonocephaly. This case represents the initial documentation of a concurrent mutation in the AP4B1 and ERF genes, underscoring the critical role of exome analysis in unraveling complex phenotypes. Understanding these complex genotypes offers valuable insights into broader syndromic conditions, facilitating comprehensive patient management.

Cognitive Outcomes of Children With Sagittal Craniosynostosis Treated With Either Endoscopic or Open Calvarial Vault Surgery.

Importance: Several studies have reported a higher incidence of neurodevelopmental delays and cognitive deficits in patients with single-suture craniosynostosis; however, there are few studies examining the associations of repair type with cognitive outcomes. Objective: To measure differences in neuropsychological outcomes between school-age children who were treated for sagittal craniosynostosis and unaffected controls and explore differences in cognitive function among children with sagittal craniosynostosis who were previously treated with either endoscopic strip craniectomy or open calvarial vault surgery. Design, Setting, and Participants: This cohort study was performed between 2018 and 2022. Eligible participants included patients aged 5 to 17 years who had previously been seen as infants or toddlers (<3 years) at 1 of 3 surgical centers for craniosynostosis repair with either endoscopic surgery or open calvarial vault surgery. A separate cohort of unaffected controls were included for comparison. Data analysis was conducted from November 2023 to February 2024. Exposures: Open calvarial vault surgery or endoscopic repair for single-suture craniosynostosis. Main Outcomes and Measures: The primary outcome was the Differential Ability Scales-II (DAS-II) General Conceptual Ability (GCA) score, an index for overall intellectual ability. Secondary outcomes included DAS-II subscale scores (Verbal Ability, Nonverbal Reasoning, Spatial Ability, Working Memory, and Processing Speed), and Patient-Reported Outcomes Measurement Information System (PROMIS) cognitive function scores. Results: A total of 81 patients with sagittal craniosynostosis (59 male [73%]; 22 female [27%]) and 141 controls (81 male [57%]; 60 female [43%]) were included. Of the 81 participants with sagittal craniosynostosis, 46 underwent endoscopic repair and 35 underwent open repair. Median (range) age at time of follow-up assessment was 7.7 (5.0-14.8) years for children with sagittal craniosynostosis and median age at assessment was 8.5 (7.7-10.5) years for controls. After controlling for age at assessment, sex, and socioeconomic status, there was no statistically significant or clinically meaningful difference in GCA scores between children who underwent endoscopic repair (adjusted mean score, 100; 95% CI, 96-104) and open repair (adjusted mean score, 103; 95% CI, 98-108) (P > .99). We found no significant difference in PROMIS scores between repair types (median [range] for endoscopic repair 54 [31-68] vs median [range] for open repair 50 [32-63]; P = .14). When comparing the treatment groups with the unaffected controls, differences in subscale scores for GCA and working memory were observed but were within normal range. Conclusions and Relevance: In this cohort study, there were no statistically or clinically significant differences in cognitive outcomes among school-age children by and type of surgical procedure used to repair nonsyndromic sagittal craniosynostosis. These findings suggest primary care clinicians should be educated about different options for craniosynostosis surgery to ensure early referral of these patients so that all treatment options remain viable.

Skeletal expansion via craniofacial distraction osteogenesis technique in syndromic craniosynostosis: impact on ophthalmic parameters.

BACKGROUND: This study aims to compare the changes in ophthalmic parameters among syndromic craniosynostosis patients who underwent craniofacial skeletal expansion procedures via distraction osteogenesis (DO). METHOD: A retrospective study was conducted involving syndromic craniosynostosis patients who underwent surgical expansion via the DO technique from the year 2012 to March 2022. Changes in six parameters which consist of visual acuity, refractive error, optic disc health, intraocular pressure, degree of proptosis and orbital volume were measured objectively pre and post-surgery. For categorical parameters, the Chi-square cross-tab test was done. Paired sample T-test was used for normally distributed variables. Wilcoxon signed-rank test was used for non-normally distributed data. RESULTS: Visual impairment was present in 21.4% of eyes before surgery and increased to 28.5% post-surgery. Three patients had changes of refractive error post-surgery with one developed hypermetropia, another developed anisometropia and the last had improvement to no refractive error. Two patients had optic disc swelling which was resolved post-surgery. Intraocular pressure changes were inconsistent post-surgery. All patients achieved a significant reduction in the degree of proptosis post-surgery. Orbital volume calculation using computed tomography (CT) scans shows a significant increase in volume post-surgery for all patients. CONCLUSION: Our study shows a significant increase in orbital volume post-surgery with a reduction in the degree of proptosis. Optic disc and nerve health improved after the surgery. Changes in terms of visual acuity, refractive error and IOP were inconsistent after the surgical intervention.

The most common congenital malformations in dogs: Literature review and practical guide.

Congenital malformations can affect almost 7% of canine newborns. The increase of commercial dog breeding and inbreeding used to maintain the striking characteristics of each breed, the appearance of malformations has become increasingly common, especially in brachycephalic dogs. The causes are diverse, and include genetic, nutritional, iatrogenic, and infectious factors, often making it difficult to establish a cause-consequence relationship. The high mortality associated with malformations comes not only from the fact that some are incompatible with life, but also because even if many undergo surgical treatment or correction, they require specific management, monitoring, and clinical treatment for an indefinite period of time. The most common malformations such as cleft lip and palate, hydrocephalus and anasarca have been studied for a long time, and it is currently known that brachycephalic dogs have a greater predisposition, however, for other less common conditions as gastroschisis and hypospadias, there is only a few case reports. The appearance of congenital defects in a litter leads to financial losses for the breeder, emotional losses for the owner and the veterinarian and harms the well-being of that individual. For this reason, the aim of this review article is to gather relevant information on the characteristics, diagnosis, and management of the main malformations in puppies. It is essential that the veterinarian is prepared to diagnose and treat these conditions, reducing negative impacts on animals and owners.

Vertebral and spinal malformations in small brachycephalic dog breeds: Current knowledge and remaining questions.

Small brachycephalic dog breeds, such as the French bulldog, English bulldog and pug have become increasingly popular. These breeds are predisposed to a variety of vertebral and spinal malformations, including hemivertebra, caudal articular process dysplasia, transitional vertebra, cranial thoracic vertebral canal stenosis, spinal arachnoid diverticulum and meningeal fibrosis. Recent studies have provided new insights into the prevalence, anatomical characteristics, pathophysiology and treatment of these conditions. Thoracic hemivertebra, caudal articular process dysplasia, transitional vertebra, and cranial thoracic vertebral canal stenosis occur commonly in neurologically normal dogs. Although the clinical relevance of these vertebral anomalies has therefore been questioned, severe kyphosis and hemivertebra in pugs have been associated with an increased likelihood of neurological signs. Meningeal fibrosis is characterised by the formation of dense intradural fibrotic adhesions, constricting the spinal cord. This condition has been heavily associated with the pug breed. It is in pugs further common to observe multiple concurrent spinal disorder in association with chronic progressive pelvic limb gait abnormalities. This clinical presentation has been referred to as 'pug dog thoracolumbar myelopathy' and potential genetic risk factors have recently been identified. Despite our increased knowledge, many questions remain currently unanswered. This review discusses our current understanding and controversies surrounding vertebral and spinal malformations in small brachycephalic dog breeds.

Heterozygous MAP3K20 variants cause ectodermal dysplasia, craniosynostosis, sensorineural hearing loss, and limb anomalies.

Biallelic pathogenic variants in MAP3K20, which encodes a mitogen-activated protein kinase, are a rare cause of split-hand foot malformation (SHFM), hearing loss, and nail abnormalities or congenital myopathy. However, heterozygous variants in this gene have not been definitively associated with a phenotype. Here, we describe the phenotypic spectrum associated with heterozygous de novo variants in the linker region between the kinase domain and leucine zipper domain of MAP3K20. We report five individuals with diverse clinical features, including craniosynostosis, limb anomalies, sensorineural hearing loss, and ectodermal dysplasia-like phenotypes who have heterozygous de novo variants in this specific region of the gene. These individuals exhibit both shared and unique clinical manifestations, highlighting the complexity and variability of the disorder. We propose that the involvement of MAP3K20 in endothelial-mesenchymal transition provides a plausible etiology of these features. Together, these findings characterize a disorder that both expands the phenotypic spectrum associated with MAP3K20 and highlights the need for further studies on its role in early human development.

Evaluation of risk factors for sleep-disordered breathing in dogs.

BACKGROUND: Brachycephalic dogs display sleep-disordered breathing (SDB). The risk factors for SDB remain unknown. OBJECTIVES: To identify risk factors for SDB. We hypothesized that brachycephaly, increasing severity of brachycephalic obstructive airway syndrome (BOAS), excess weight, and aging predispose to SDB. ANIMALS: Sixty-three privately owned pet dogs were prospectively recruited: 28 brachycephalic and 35 normocephalic (mesaticephalic or dolicocephalic) dogs. METHODS: Prospective observational cross-sectional study with convenience sampling. Recording with the neckband was done over 1 night at each dog's home. The primary outcome measure was the obstructive respiratory event index (OREI). Body condition score (BCS) was assessed, and BOAS severity was graded for brachycephalic dogs. RESULTS: Brachycephaly was a significant risk factor for high OREI value (ratio of the geometric means 5.6, 95% confidence interval [CI] 3.2-9.9; P < .001) but aging was not (1.1, 95% CI 1.0-1.2; P = .2). Excess weight, defined as a BCS of over 5/9, (3.5, 95% CI 1.8-6.7; P < .001) was a significant risk factor. In brachycephalic dogs, BOAS-positive class (moderate or severe BOAS signs) was a significant risk factor (2.5, 95% CI 1.1-5.6; P = .03). CONCLUSIONS AND CLINICAL IMPORTANCE: Brachycephaly decreases welfare in a multitude of ways, including disrupting sleep. Brachycephaly, increasing severity of BOAS and excess weight are risk factors for obstructive SDB.

Craniosynostosis-associated variants in the IL-11R complex: new insights and questions.

Skull growth involves the expansion of both the flat calvarial bones of the skull and the fibrous marginal zones, termed sutures, between them. This process depends on co-ordinated proliferation of mesenchymal-derived progenitor cells within the sutures, and their differentiation to osteoblasts which produce the bone matrix required to expand the size of the bony plates. Defects lead to premature closure of these sutures, termed craniosynostosis, resulting in heterogeneous head shape differences due to restricted growth of one or more sutures. The impact on the individual depends on how many and which sutures are affected and the severity of the effect. Several genetic loci are responsible, including a wide range of variants in the gene for the interleukin 11 receptor (IL11RA, OMIM#600939). Recent work from Kespohl and colleagues provides new insights into how some of these variants influence IL-11R function; we discuss their influences on IL-11R structure and IL-11 function as a stimulus of osteoblast differentiation.

Prevalence of craniosynostosis in Finland, 1987-2010: A population-based study.

BACKGROUND: Craniosynostosis is a prevalent craniofacial malformation in Finland; however, comprehensive population-based epidemiological data are limited. This study aimed to estimate the total and birth prevalence of craniosynostosis in Finland from 1987 to 2010 and examine temporal trends. METHODS: We collected the data from nationwide registers maintained by the Finnish Institute for Health and Welfare and Statistics Finland, as well as treating hospitals, encompassing live births, stillbirths, terminations for fetal anomalies, and infant deaths with suspected or diagnosed craniosynostosis or skull deformation. A craniofacial surgeon and a clinical geneticist reviewed 1878 medical records for diagnostic confirmation. RESULTS: Out of 877 craniosynostosis cases, 83% were single-suture synostoses (all live births), 10% craniosynostosis syndromes, and 7% multisutural non-syndromic synostoses. Live birth prevalence from 1987 to 2010 was 6.0/10,000 live births, ranging from 5.0/10,000 in 1987 to 7.5/10,000 in 2010. Total prevalence, including live births, stillbirths, and terminations, varied from 5.0/10,000 in 1987 to 8.0/10,000 in 2010. Sagittal synostosis was the most common synostosis, with a prevalence of 3.9/10,000 live births, followed by metopic (0.6/10,000), unicoronal (0.4/10,000), and unilambdoid (0.1/10,000) synostoses. CONCLUSIONS: The total combined prevalence of all craniosynostosis types significantly increased driven by a nonsignificant rise across all subgroups and a significant increase in the syndrome group. In live births increase was significant only within the syndrome subgroup, primarily due to an increase in Muenke syndrome patients. The rising prevalence of syndromes necessitates further investigation. Contrasting with trends in Europe, Australia, and the USA, Finland showed no significant increase in metopic craniosynostosis.

Arterial blood gas measurements are different for brachycephalic and nonbrachycephalic dogs acclimatized to an altitude of 1,535 meters.

OBJECTIVE: To define reference intervals (RIs) for arterial blood gas (aBG) measurements in healthy, nonsedated, dolichocephalic, and mesocephalic (nonbrachycephalic) dogs at approximately 1,535 m above sea level and compare these findings with healthy, nonsedated, brachycephalic dogs living at the same altitude. ANIMALS: 120 adult nonbrachycephalic dogs and 20 adult brachycephalic dogs. METHODS: Cases were prospectively enrolled from October 2021 to June 2022. Dogs were enrolled from the community or after presentation for wellness examinations or minor injuries including lacerations, nail injuries, and lameness. Physical examinations and systolic blood pressure (sBP) measurements were obtained before blood sample collection. Arterial blood was collected from the dorsal pedal artery or femoral artery. After data collection, brachycephalic dogs underwent pre- and postexercise tolerance assessments. RESULTS: The mean and RI values for arterial pH (7.442; 7.375 to 7.515), partial pressure of oxygen in arterial blood (Pao2; 78.3; 59.2 to 92.7 mm Hg), partial pressure of carbon dioxide in arterial blood (Paco2; 28.0; 21.5 to 34.4 mm Hg), saturation of arterial oxygen (Sao2; 98.4; 84.3% to 101.4%), HCO3 (18.9; 14.9 to 22.4 mmol/L), concentration of total hemoglobin (ctHb; 17.5; 13.4 to 21.1 g/dL), and sBP (133; 94 to 180 mm Hg) were established for healthy nonbrachycephalic dogs at 1,535-m altitude. All aBG measurements were statistically and clinically different from those previously reported for dogs at sea level. Brachycephalic dogs had significantly lower Pao2 and Sao2 (P = .0150 and P = .0237, respectively) and significantly higher ctHb (P = .0396) compared to nonbrachycephalic dogs acclimatized to the same altitude; the nonbrachycephalic RIs were not transferable to the brachycephalic dogs for Pao2. CLINICAL RELEVANCE: This study represents the first collation of aBG measurements for healthy nonbrachycephalic dogs acclimatized to an altitude of 1,535 m. Additionally, this study identified differences in arterial oxygenation measurements between brachycephalic and nonbrachycephalic dogs. RIs in brachycephalic dogs need to be established.

The mobility of the brachycephalic canine nostril in relation to the degree of nostril stenosis.

Previous studies have shown that the most reliable external conformational risk factor of whether a brachycephalic dog will develop Brachycephalic Obstructive Airway Syndrome (BOAS) is the status of nostril stenosis, assessed as a static observation using the brachycephalic nostril grading scheme. The nostrils however are a dynamic structure, opening further when the dog is exercising, sniffing or panting. The hypothesis of this study was that brachycephalic dogs with open or mildly stenotic nostrils are more likely to have nostril mobility whilst dogs with moderately or severely stenotic nostrils are more likely to have immobile nostrils. A retrospective study of dogs presented for BOAS assessment at two UK referral centres between 2012 and 2020 was performed. Data extracted included nares stenosis status and nares mobility. A mesocephalic pilot control group was recruited from a third referral centre. Statistical analysis was performed with χ2, Cochran-Armitage, spearman's rho and linear-by-linear tests as appropriate. Of the 974 brachycephalic dogs included in the study: 124 had open nostrils (68.5% mobile); 212 mildly stenotic nostrils (58.5% mobile); 379 moderately stenotic nostrils (35% mobile) and 259 severely stenotic nostrils (19.3% mobile). The nostril stenotic status was significantly associated with nostril wing mobility (χ2 =135.55; P<0.0001). When considering open and mildly stenotic (considered acceptable) nostrils versus moderate and severely stenotic nostrils, mobility was 62% versus 25.5% (χ2= 135.88; P = <0.0001). All 27 mesocephalic dogs had nostril mobility. Brachycephalic dogs with moderate and severely stenotic nares have reduced nasal mobility compared to brachycephalic dogs with mildly stenotic and open nares. Data is further evidence that dogs with moderately and severely stenotic nares should not be bred.

A novel case of Horner syndrome as the presenting sign of craniosynostosis.

Craniosynostosis, the premature fusion of cranial sutures, can lead to distortion of skull shape and neurological dysfunction. We present a novel case of Horner syndrome as the presenting sign of craniosynostosis associated with elevated intracranial pressure. A 10-year-old boy presenting for strabismus follow-up was noted to have new-onset anisocoria, greater in the dark, and mild right upper eyelid ptosis. Apraclonidine testing was concerning for Horner syndrome. Neuroimaging demonstrated previously undiagnosed sagittal craniosynostosis with tortuous optic nerves and large cerebrospinal fluid spaces around both optic nerves. The patient was referred to neurosurgery and underwent a lumbar puncture with an opening pressure of 44 cm H2O. He underwent surgical cranial expansion. By six months postoperatively, his anisocoria had resolved.