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Jacinto JGP, Letko A, Häfliger IM, Drögemüller C, Agerholm JS. Congenital syndromic Chiari-like malformation (CSCM) in Holstein cattle: towards unravelling of possible genetic causes. Acta Vet Scand 2024; 66:29. [PMID: 38965607 PMCID: PMC11229497 DOI: 10.1186/s13028-024-00752-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2024] [Accepted: 07/01/2024] [Indexed: 07/06/2024] Open
Abstract
BACKGROUND Chiari malformation type II (CMII) was originally reported in humans as a rare disorder characterized by the downward herniation of the hindbrain and towering cerebellum. The congenital brain malformation is usually accompanied by spina bifida, a congenital spinal anomaly resulting from incomplete closure of the dorsal aspect of the spinal neural tube, and occasionally by other lesions. A similar disorder has been reported in several animal species, including cattle, particularly as a congenital syndrome. A cause of congenital syndromic Chiari-like malformation (CSCM) in cattle has not been reported to date. We collected a series of 14 CSCM-affected Holstein calves (13 purebred, one Red Danish Dairy F1 cross) and performed whole-genome sequencing (WGS). WGS was performed on 33 cattle, including eight cases with parents (trio-based; group 1), three cases with one parent (group 2), and three single cases (solo-based; group 3). RESULTS Sequencing-based genome-wide association study of the 13 Holstein calves with CSCM and 166 controls revealed no significantly associated genome region. Assuming a single Holstein breed-specific recessive allele, no region of shared homozygosity was detected suggesting heterogeneity. Subsequent filtering for protein-changing variants that were only homozygous in the genomes of the individual cases allowed the identification of two missense variants affecting different genes, SHC4 in case 4 in group 1 and WDR45B in case 13 in group 3. Furthermore, these two variants were only observed in Holstein cattle when querying WGS data of > 5,100 animals. Alternatively, potential de novo mutational events were assessed in each case. Filtering for heterozygous private protein-changing variants identified one DYNC1H1 frameshift variant as a candidate causal dominant acting allele in case 12 in group 3. Finally, the presence of larger structural DNA variants and chromosomal abnormalities was investigated in all cases. Depth of coverage analysis revealed two different partial monosomies of chromosome 2 segments in cases 1 and 7 in group 1 and a trisomy of chromosome 12 in the WDR45B homozygous case 13 in group 3. CONCLUSIONS This study presents for the first time a detailed genomic evaluation of CSCM in Holstein cattle and suggests an unexpected genetic and allelic heterogeneity considering the mode of inheritance, as well as the type of variant. For the first time, we propose candidate causal variants that may explain bovine CSCM in a certain proportion of affected calves. We present cattle as a large animal model for human CMII and propose new genes and genomic variants as possible causes for related diseases in both animals and humans.
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Affiliation(s)
- Joana Goncalves Pontes Jacinto
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, Bern, 3012, Switzerland
- Clinic for Ruminants, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, Bern, 3012, Switzerland
| | - Anna Letko
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, Bern, 3012, Switzerland
| | - Irene Monika Häfliger
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, Bern, 3012, Switzerland
| | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, Bremgartenstrasse 109a, Bern, 3012, Switzerland.
| | - Jørgen Steen Agerholm
- Department of Veterinary Clinical Sciences, University of Copenhagen, Højbakkegaard Allé 5A, Taastrup, 2630, Denmark
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Dos Santos IR, Brunner CB, de Moraes JTR, Paz MC, Lamego ÉC, Henker LC, Alves RS, da Fontoura Budaszewski R, Tres GZ, Gomes RM, Freitas RS, Canal CW, Pavarini SP. Complex neural tube and skeletal malformations, resembling Chiari malformations, in two calves. Vet Res Commun 2024:10.1007/s11259-024-10437-6. [PMID: 38884867 DOI: 10.1007/s11259-024-10437-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 06/10/2024] [Indexed: 06/18/2024]
Abstract
Two 1-day-old full-term female calves from different farms located in the Brazilian state of Rio Grande do Sul were unable to stand due to paresis of the pelvic limbs. Both calves had spina bifida on the spinal lumbar segment and were submitted to euthanasia due to poor prognosis. Postmortem examination revealed cerebellar herniation, caudal displacement of the brainstem, rostral deviation of the cranial nerves, caudal extension of occipital lobes, absence of dorsal lamina of lumbar vertebrae with exposed spinal cord, myelodysplasia, kyphosis, segmental spinal agenesis, renal fusion, muscular atrophy, and arthrogryposis. Histology highlighted myelodysplasia (syringomyelia and diplomyelia) and muscular atrophy. The reverse transcription-polymerase chain reactions for ruminant pestivirus were negative. Based on these lesions, the diagnosis of complex neural tube and skeletal malformations was made. A review of previous publications on calves diagnosed with these malformations, originally called Chiari or Arnold-Chiari malformations, revealed a wide range of nervous system and skeletal lesions. These variations amplified the uncertainty regarding whether all cases represent the same disorder and reinforced the importance of reconfiguring the terminology.
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Affiliation(s)
- Igor Ribeiro Dos Santos
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil.
| | - Carolina Buss Brunner
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
| | - José Tiago Roza de Moraes
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
| | - Milena Carolina Paz
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
| | - Éryca Ceolin Lamego
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
| | - Luan Cleber Henker
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, USA
| | - Raquel Silva Alves
- Laboratório de Virologia Veterinária, Faculdade de Veterinária, UFRGS, Porto Alegre, RS, Brazil
| | | | - Gabrielle Zanettini Tres
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
| | | | | | - Cláudio Wageck Canal
- Laboratório de Virologia Veterinária, Faculdade de Veterinária, UFRGS, Porto Alegre, RS, Brazil
| | - Saulo Petinatti Pavarini
- Setor de Patologia Veterinária, Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul (UFRGS) , Porto Alegre, Rio Grande do Sul (RS), Brazil
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Wess L, Kneissl S. Systematic minireview of the craniocervical junction in dogs with and without brachycephaly. Front Vet Sci 2024; 11:1416670. [PMID: 38881784 PMCID: PMC11177753 DOI: 10.3389/fvets.2024.1416670] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2024] [Accepted: 05/16/2024] [Indexed: 06/18/2024] Open
Abstract
Objective To identify, quantify and compare clinical and concurrent imaging findings of occipital hypoplasia (OH), syringomyelia (SM) and atlanto-occipital overlapping (AO) in dogs with or without brachycephaly. Methods A focused systematic search for literature was performed in the Web of Science™, PubMed and Google Scholar databases. Both authors screened and classified the identified articles using EndNote and appraised the articles using the Critical Appraisal Skills Program checklists. The main clinical and concurrent imaging features were extracted and evaluated for coexistence of OH, SM, AO, and other imaging findings. Results Thirty-one articles were included in this minireview. For articles focusing on descriptions of OH, SM and AO, 249 dogs had at least one of these conditions, and 3 of these 249 dogs (1%) had coexistence of all three conditions. For articles focusing on descriptions of the dogs, OH, SM, and AO were identified in 552/19/11/11, 574/2/0/6, and 100/0/0/0 small brachycephalic, small non-brachycephalic, large brachycephalic, and large non-brachycephalic breeds, respectively. For all small brachycephalic dogs, the percentages of affected animals were 40% for OH (p = 0.01), 42% for SM (p < 0.01) and 7% for AO (p = 0.033). The number of dogs having AO and clinical symptoms is low (n = 5). Conclusion OH, SM and AO are more likely to affect small dogs. AO might be limited to small brachycephalic breeds owing to the geometry of the craniocervical junction. Hence, AO alone might not lead to SM. In individual dogs, readers should carefully interpret the clinical relevance of OH or AO in the absence of SM.
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Affiliation(s)
- Lukas Wess
- Diagnostic Imaging, Department of Small Animals and Horses, University of Veterinary Medicine, Vienna, Austria
| | - Sibylle Kneissl
- Diagnostic Imaging, Department of Small Animals and Horses, University of Veterinary Medicine, Vienna, Austria
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Bach MBT, Stougaard CL, Thøfner MS, Reimann MJ, Westrup U, Koch J, Fredholm M, Martinussen T, Berendt M, Olsen LH. Relationship between syringomyelia and myxomatous mitral valve disease in Cavalier King Charles spaniels. J Vet Intern Med 2024; 38:904-912. [PMID: 38391152 PMCID: PMC10937514 DOI: 10.1111/jvim.17018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Accepted: 01/30/2024] [Indexed: 02/24/2024] Open
Abstract
BACKGROUND Syringomyelia (SM) and myxomatous mitral valve disease (MMVD) are highly prevalent in Cavalier King Charles spaniels (CKCS). Cardiac status in CKCS with and without SM is currently unknown. OBJECTIVES To investigate the association between SM and MMVD severity in CKCS and CKCS with SM with and without clinical signs of SM. ANIMALS Fifty-five CKCS: 40 with SM (22 symptomatic and 18 asymptomatic) and 15 without SM. METHODS A combined retrospective and prospective study. MRI and echocardiography were used to diagnose SM and MMVD, respectively. The association between SM and MMVD severity (left ventricle internal diameter in diastole normalized to bodyweight [LVIDDN] and left atrium to aortic ratio [LA/Ao]) were tested using multivariable linear regression analysis adjusting for sex and age. RESULTS Overall, no significant difference in LVIDDN and LA/Ao was found between CKCS with or without SM. However, CKCS with symptomatic SM had significantly smaller LVIDDN (1.45 [1.30-1.50]) (median [IQR]) and LA/Ao (1.20 [1.10-1.28]) compared to CKCS with asymptomatic SM (1.60 [1.50-1.90] and 1.40 [1.20-1.75]) as well as CKCS without SM (0.24 [0.03-0.45] and 0.30 [0.05-0.56]) (all P values <.03). CONCLUSIONS AND CLINICAL IMPORTANCE An association between MMVD and SM was not confirmed in this cohort of CKCS, indicating that MMVD and SM do not co-segregate. However, CKCS with symptomatic SM had smaller left ventricle and atrial size compared to CKCS with asymptomatic SM and CKCS without SM.
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Affiliation(s)
- Maiken B. T. Bach
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Camilla L. Stougaard
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Maria S. Thøfner
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Maria J. Reimann
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Ulrik Westrup
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Jørgen Koch
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Merete Fredholm
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Torben Martinussen
- Department of Public HealthUniversity of CopenhagenFrederiksberg CDenmark
| | - Mette Berendt
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
| | - Lisbeth H. Olsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical SciencesUniversity of CopenhagenFrederiksberg CDenmark
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Limpens C, Smits VTM, Fieten H, Mandigers PJJ. The effect of MRI-based screening and selection on the prevalence of syringomyelia in the Dutch and Danish Cavalier King Charles Spaniels. Front Vet Sci 2024; 11:1326621. [PMID: 38348108 PMCID: PMC10859423 DOI: 10.3389/fvets.2024.1326621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024] Open
Abstract
Introduction Syringomyelia (SM) is a heritable disorder causing a fluid filled cavity (FFC) in the spinal cord with a reported overall prevalence of 39 to 46% in the Cavalier King Charles Spaniels (CKCS). Breeders started screening their CKCS with MRI in the Netherlands since 2004 and in Denmark since 2015. The goal of this study was to evaluate the effect of MRI-based selection in breeding on the prevalence of SM. Method MRI scans of 2,125 purebred CKCS were available. SM was defined as having a visible FFC in the spinal cord. The prevalence of SM per year of birth was calculated, and a logistic regression was used to evaluate the affected status of offspring from affected versus unaffected parents and age category of the parent and study the combined effect of parental status and age-category to evaluate the effect on the affected status of the offspring. Results The mean FFC in affected CKCS was 2.03 ± 1.47 mm and ranged from 0.5 to 9 mm (median of 1.5 mm). An age effect exists as older CKCS, which has a higher frequency of being affected compared with younger CKCS. There was no significant sex predilection for SM in this dataset. The mean prevalence of SM decreased slightly from 38% (2010-2014; 2.8 ± 1.3 years of age (mean ± sd); median 2.6 years) to 27% (2015-2019; 2.4 ± 1.2 years of age; median 2.1 years) in the screened population of CKCS (p = 4.3e-07). Breeding with two affected parents increased the odds ratio with 3.08 for producing affected offspring (95% CI 1.58-6.04) compared with breeding with unaffected parents. Discussion MRI-based screening and selection against SM led to a minimal decrease in the prevalence of SM in the Dutch and Danish CKCS population. Breeding with dogs with SM significantly increases the risk of affected offspring. As the disorder is progressive with age, and based on the results of this study, MRI-based screening for all CKCS is recommended at an age of 3 years or older, and to reduce SM more effectively, CKCS affected with SM should not be used for breeding.
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Affiliation(s)
- Citlalli Limpens
- Expertise Centre of Genetics, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, Netherlands
| | - Vivian T. M. Smits
- Expertise Centre of Genetics, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, Netherlands
| | - Hille Fieten
- Expertise Centre of Genetics, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, Netherlands
| | - Paul J. J. Mandigers
- Expertise Centre of Genetics, Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Utrecht, Utrecht, Netherlands
- Evidensia Referral Hospital Arnhem, Arnhem, Netherlands
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6
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Mekbib KY, Muñoz W, Allington G, McGee S, Mehta NH, Shofi JP, Fortes C, Le HT, Nelson-Williams C, Nanda P, Dennis E, Kundishora AJ, Khanna A, Smith H, Ocken J, Greenberg ABW, Wu R, Moreno-De-Luca A, DeSpenza T, Zhao S, Marlier A, Jin SC, Alper SL, Butler WE, Kahle KT. Human genetics and molecular genomics of Chiari malformation type 1. Trends Mol Med 2023; 29:1059-1075. [PMID: 37802664 DOI: 10.1016/j.molmed.2023.08.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 08/29/2023] [Accepted: 08/31/2023] [Indexed: 10/08/2023]
Abstract
Chiari malformation type 1 (CM1) is the most common structural brain disorder involving the craniocervical junction, characterized by caudal displacement of the cerebellar tonsils below the foramen magnum into the spinal canal. Despite the heterogeneity of CM1, its poorly understood patho-etiology has led to a 'one-size-fits-all' surgical approach, with predictably high rates of morbidity and treatment failure. In this review we present multiplex CM1 families, associated Mendelian syndromes, and candidate genes from recent whole exome sequencing (WES) and other genetic studies that suggest a significant genetic contribution from inherited and de novo germline variants impacting transcription regulation, craniovertebral osteogenesis, and embryonic developmental signaling. We suggest that more extensive WES may identify clinically relevant, genetically defined CM1 subtypes distinguished by unique neuroradiographic and neurophysiological endophenotypes.
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Affiliation(s)
- Kedous Y Mekbib
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA; Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA; Harvard Center for Hydrocephalus and Neurodevelopmental Disorders, Massachusetts General Hospital, Boston, MA, USA
| | - William Muñoz
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA; Harvard Center for Hydrocephalus and Neurodevelopmental Disorders, Massachusetts General Hospital, Boston, MA, USA
| | - Garrett Allington
- Department of Pathology, Yale University School of Medicine, New Haven, CT, USA
| | | | - Neel H Mehta
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - John P Shofi
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Carla Fortes
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Hao Thi Le
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | | | - Pranav Nanda
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Evan Dennis
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Adam J Kundishora
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - Arjun Khanna
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Hannah Smith
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Jack Ocken
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - Ana B W Greenberg
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Rui Wu
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Andres Moreno-De-Luca
- Department of Radiology, Autism and Developmental Medicine Institute, Genomic Medicine Institute, Geisinger, Danville, PA, USA
| | - Tyrone DeSpenza
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - Shujuan Zhao
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA
| | | | - Sheng Chih Jin
- Department of Genetics, Washington University School of Medicine, St. Louis, MO, USA; Department of Pediatrics, Washington University School of Medicine, St. Louis, MO, USA
| | - Seth L Alper
- Division of Nephrology and Vascular Biology Research Center, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - William E Butler
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Kristopher T Kahle
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA; Harvard Center for Hydrocephalus and Neurodevelopmental Disorders, Massachusetts General Hospital, Boston, MA, USA; Division of Genetics and Genomics, Boston Children's Hospital, Boston, MA, USA; Broad Institute of MIT and Harvard, Cambridge, MA, USA.
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7
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Toader C, Ples H, Covache-Busuioc RA, Costin HP, Bratu BG, Dumitrascu DI, Glavan LA, Ciurea AV. Decoding Chiari Malformation and Syringomyelia: From Epidemiology and Genetics to Advanced Diagnosis and Management Strategies. Brain Sci 2023; 13:1658. [PMID: 38137106 PMCID: PMC10741770 DOI: 10.3390/brainsci13121658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 11/24/2023] [Indexed: 12/24/2023] Open
Abstract
Chiari Malformation and Syringomyelia are neurosurgical entities that have been the subject of extensive research and clinical interest. Globally prevalent, these disorders vary demographically and have witnessed evolving temporal trends. Chiari Malformation impacts the normal cerebrospinal fluid flow, consequently affecting overall health. Key observations from canine studies offer pivotal insights into the pathogenesis of Syringomyelia and its extrapolation to human manifestations. Genetics plays a pivotal role; contemporary knowledge identifies specific genes, illuminating avenues for future exploration. Clinically, these disorders present distinct phenotypes. Diagnostically, while traditional methods have stood the test of time, innovative neurophysiological techniques are revolutionizing early detection and management. Neuroradiology, a cornerstone in diagnosis, follows defined criteria. Advanced imaging techniques are amplifying diagnostic precision. In therapeutic realms, surgery remains primary. For Chiari 1 Malformation, surgical outcomes vary based on the presence of Syringomyelia. Isolated Syringomyelia demands a unique surgical approach, the effectiveness of which is continually being optimized. Post-operative long-term prognosis and quality of life measures are crucial in assessing intervention success. In conclusion, this review amalgamates existing knowledge, paving the way for future research and enhanced clinical strategies in the management of Chiari Malformation and Syringomyelia.
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Affiliation(s)
- Corneliu Toader
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
- Department of Vascular Neurosurgery, National Institute of Neurology and Neurovascular Diseases, 077160 Bucharest, Romania
| | - Horia Ples
- Department of Neurosurgery, Centre for Cognitive Research in Neuropsychiatric Pathology 6 (NeuroPsy-Cog), 300736 Timișoara, Romania
- Department of Neurosurgery, “Victor Babeș” University of Medicine and Pharmacy, 300041 Timișoara, Romania
| | - Razvan-Adrian Covache-Busuioc
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
| | - Horia Petre Costin
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
| | - Bogdan-Gabriel Bratu
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
| | - David-Ioan Dumitrascu
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
| | - Luca Andrei Glavan
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
| | - Alexandru Vlad Ciurea
- Department of Neurosurgery, “Carol Davila” University of Medicine and Pharmacy, 020021 Bucharest, Romania; (C.T.); (R.-A.C.-B.); (H.P.C.); (B.-G.B.); (D.-I.D.); (L.A.G.); (A.V.C.)
- Neurosurgery Department, Sanador Clinical Hospital, 010991 Bucharest, Romania
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8
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Mead SE, Beijerink NJ, O’Brien M, Wade CM. Genetic Variants at the Nebulette Locus Are Associated with Myxomatous Mitral Valve Disease Severity in Cavalier King Charles Spaniels. Genes (Basel) 2022; 13:genes13122292. [PMID: 36553559 PMCID: PMC9778376 DOI: 10.3390/genes13122292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 12/01/2022] [Accepted: 12/02/2022] [Indexed: 12/12/2022] Open
Abstract
The most common cardiovascular disease in domestic dogs is myxomatous mitral valve disease (MMVD), accounting for 75% of all cardiac disease. An increase in age is generally associated with increased incidence of the disease, but Cavalier King Charles Spaniels (CKCS) exhibit an unusually high prevalence of early-onset MMVD, and thus, potentially greater cardiac morbidity and mortality compared to other breeds. Previous research has suggested that selected candidate risk alleles for MMVD are fixed in CKCSs, including six locations within the Nebulette (NEBL) gene on CFA2. The current study analysed genotypes of 180 Australian CKCSs at the identified risk loci. Of these, 178 were phenotyped for severity of disease by echocardiographic measurements of left atrium to aortic root ratio (LA:Ao) and weight normalised left ventricular end diastolic diameter (LVIDdN). Genotyping array markers correctly predicted the genotype at the risk-variant loci in the CKCS population, and the NEBL1, NEBL2 and NEBL3 variants were observed to be in perfect linkage disequilibrium in this cohort. The CKCS cohort included 6/178 dogs being heterozygous for the protective/wild-type alleles at the NEBL locus. The mean LA:Ao and LVIDdN scores of these dogs heterozygous at NEBL1-3 variants were significantly smaller, and with significantly lower variance compared to age-matched CKCSs that were homozygous for risk alleles. The lower cardiac measurements in the heterozygous dogs indicate a significantly reduced risk of severe MMVD disease. Our analysis suggests that despite relative fixation of the NEBL risk alleles, healthy reference alleles at NEBL1-3 exist in low frequency in the CKCS breed and can be used to reduce MMVD severity and mortality.
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Affiliation(s)
- Sophie E. Mead
- Faculty of Science, School of Life and Environmental Sciences Camperdown, The University of Sydney, Sydney, NSW 2006, Australia
| | - Niek J. Beijerink
- Faculty of Science, School of Life and Environmental Sciences Camperdown, The University of Sydney, Sydney, NSW 2006, Australia
- Veterinaire Specialisten Vught, Reutsedijk 8a, 5264 Vught, The Netherlands
| | - Mitchell O’Brien
- Transformational Bioinformatics, Health and Biosecurity, Commonwealth Scientific and Industrial Research Organisation (CSIRO), Westmead, NSW 2145, Australia
| | - Claire M. Wade
- Faculty of Science, School of Life and Environmental Sciences Camperdown, The University of Sydney, Sydney, NSW 2006, Australia
- Correspondence:
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9
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Monteiro BP, Lascelles BDX, Murrell J, Robertson S, Steagall PVM, Wright B. 2022
WSAVA
guidelines for the recognition, assessment and treatment of pain. J Small Anim Pract 2022. [DOI: 10.1111/jsap.13566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- B. P. Monteiro
- Department of Clinical Sciences, Faculty of Veterinary Medicine Université de Montréal 3200 rue Sicotte, Saint‐Hyacinthe Quebec Canada
| | - B. D. X. Lascelles
- Comparative Pain Research Laboratory and Surgery Section North Carolina State University 4700 Hillsborough Street Raleigh NC USA
| | - J. Murrell
- Highcroft Veterinary Referrals 615 Wells Rd, Whitchurch Bristol BS149BE UK
| | - S. Robertson
- Senior Medical Director Lap of Love Veterinary Hospice 17804 N US Highway 41 Lutz FL 33549 USA
| | - P. V. M. Steagall
- Department of Clinical Sciences, Faculty of Veterinary Medicine Université de Montréal 3200 rue Sicotte, Saint‐Hyacinthe Quebec Canada
| | - B. Wright
- Mistral Vet 4450 Thompson Pkwy Fort Collins CO 80534 USA
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10
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Mortensen D, Thoefner MS, Agerholm JS, Slumstrup L, Jensen TS, Bjerrum OJ, Berendt M, Nyengaard JR. Dorsal horn volume loss and pain pathway changes in Cavalier King Charles Spaniels with syringomyelia, signs of pain, and phantom scratching. Pain 2022; 163:2365-2379. [PMID: 35353770 DOI: 10.1097/j.pain.0000000000002630] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 02/28/2022] [Indexed: 11/25/2022]
Abstract
ABSTRACT Central neuropathic pain is a core clinical sign of syringomyelia in humans and Cavalier King Charles Spaniel (CKCS) dogs. This histopathological study used spinal cords from CKCS with syringomyelia to investigate: 1) whether specific structural cervical spinal cord entities involved in nociception are affected by loss of neuroparenchyma or other pathological changes in CKCS with pain-related behaviour and phantom scratching, 2) if pain related behaviour or phantom scratching correlated with loss of a specific anatomical entity or upregulation of glia cells, and 3) if syringomyelia-related lesions affected specific functional spinal cord units of nociception.Spinal cord segments C1-C8 from CKCS with MRI-confirmed syringomyelia and clinical signs of pain and phantom scratch (n=8) were compared to CKCS without syringomyelia (n=4). Dogs with unilateral scratching (n=7) had a volume loss (P=0.043) of the dorsal horn laminae I-III in the ipsilateral side compared to the contralateral dorsal horn. A clear pattern of ipsilateral changes in the dorsal root entry zone characterised by deafferentation and reorganization of first-order axons into deeper laminae was found in cases with lateralised scratching. Significant changes in cell number density were not found for astrocytes or microglia, suggesting that the dogs represented cases of end-stage syringomyelia and thus could not reveal astrogliosis and microgliosis, which may be involved in the early phases of syrinx development and phantom scratch.The present relationship between clinical findings and dorsal horn and pain pathway pathology in CKCS suggests that these dogs may be of interest as a supplement to experimental model pain research.
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Affiliation(s)
- Danny Mortensen
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Center for Stochastic Geometry and Advanced Bioimaging
| | - Maria Soendergaard Thoefner
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Joergen Steen Agerholm
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Lasse Slumstrup
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Center for Stochastic Geometry and Advanced Bioimaging
| | | | - Ole Jannik Bjerrum
- Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen
| | - Mette Berendt
- Department of Veterinary Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
| | - Jens Randel Nyengaard
- Core Center for Molecular Morphology, Section for Stereology and Microscopy, Center for Stochastic Geometry and Advanced Bioimaging.,Department of Pathology, Aarhus University Hospital, Denmark
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11
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Donnini EK, Walugembe M, Rothschild MF, Jergens AE, Allenspach K. An initial genome-wide investigation of protein-losing enteropathy in Gordon setters: Exploratory observations. CANADIAN JOURNAL OF VETERINARY RESEARCH = REVUE CANADIENNE DE RECHERCHE VETERINAIRE 2021; 85:51-60. [PMID: 33390653 PMCID: PMC7747665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 06/14/2020] [Indexed: 06/12/2023]
Abstract
The objective of this preliminary study was to identify genomic regions that may predispose Gordon setters from the United Kingdom to familial protein-losing enteropathy (PLE) at a young age. A total of 106 related Gordon setters was used, including 6 affected dogs from an affected litter, 6 case controls from the same litter, 10 related/affected dogs, and 84 related/unaffected dogs. Genomic DNA was collected from each Gordon setter and extracted from buccal mucosal swabs. Genotyping of affected and unaffected dogs was carried out using the Canine Illumina HD SNP array and data generated were analyzed with PLINK software, using fixation index (Fst) and runs of homozygosity (ROH) methods. Pairwise Fst analyses between the affected and unaffected Gordon setter dogs identified various regions of differentiation on chromosomes 10, 18, 21, and 23 that contained several important genes. These regions revealed 5 candidate genes, including RARB, TTC7A, SOCS5, PIGF, and RHOD, that are associated with human inflammatory bowel disease (IBD) and could potentially be associated with PLE in Gordon setters. Run of homozygosity (ROH) analyses revealed additional unique regions on chromosomes 15 and 17. These regions contained genes SYT1, UCN, and FNDC that could also be potential candidates for PLE in Gordon setters. The biological functions of the identified genes provided initial insights into the pathophysiology of PLE. Further large-scale studies are warranted to investigate the possible causality of these genomic regions and any possible genetic markers that could be used in predicting susceptibility to PLE syndrome.
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Affiliation(s)
- Elle K Donnini
- Department of Veterinary Clinical Sciences (Donnini, Jergens, Allenspach), College of Veterinary Medicine, 1809 South Riverside Drive, Iowa State University, Ames, Iowa 50010, USA; Department of Animal Science (Walugembe, Rothschild), College of Agriculture and Life Sciences, 2255 H. Kildee Hall, Iowa State University, Ames, Iowa 20011, USA
| | - Muhammed Walugembe
- Department of Veterinary Clinical Sciences (Donnini, Jergens, Allenspach), College of Veterinary Medicine, 1809 South Riverside Drive, Iowa State University, Ames, Iowa 50010, USA; Department of Animal Science (Walugembe, Rothschild), College of Agriculture and Life Sciences, 2255 H. Kildee Hall, Iowa State University, Ames, Iowa 20011, USA
| | - Max F Rothschild
- Department of Veterinary Clinical Sciences (Donnini, Jergens, Allenspach), College of Veterinary Medicine, 1809 South Riverside Drive, Iowa State University, Ames, Iowa 50010, USA; Department of Animal Science (Walugembe, Rothschild), College of Agriculture and Life Sciences, 2255 H. Kildee Hall, Iowa State University, Ames, Iowa 20011, USA
| | - Albert E Jergens
- Department of Veterinary Clinical Sciences (Donnini, Jergens, Allenspach), College of Veterinary Medicine, 1809 South Riverside Drive, Iowa State University, Ames, Iowa 50010, USA; Department of Animal Science (Walugembe, Rothschild), College of Agriculture and Life Sciences, 2255 H. Kildee Hall, Iowa State University, Ames, Iowa 20011, USA
| | - Karin Allenspach
- Department of Veterinary Clinical Sciences (Donnini, Jergens, Allenspach), College of Veterinary Medicine, 1809 South Riverside Drive, Iowa State University, Ames, Iowa 50010, USA; Department of Animal Science (Walugembe, Rothschild), College of Agriculture and Life Sciences, 2255 H. Kildee Hall, Iowa State University, Ames, Iowa 20011, USA
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12
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Yu Y, Creighton EK, Buckley RM, Lyons LA. A Deletion in GDF7 is Associated with a Heritable Forebrain Commissural Malformation Concurrent with Ventriculomegaly and Interhemispheric Cysts in Cats. Genes (Basel) 2020; 11:E672. [PMID: 32575532 PMCID: PMC7349246 DOI: 10.3390/genes11060672] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 06/10/2020] [Accepted: 06/16/2020] [Indexed: 12/17/2022] Open
Abstract
An inherited neurologic syndrome in a family of mixed-breed Oriental cats has been characterized as forebrain commissural malformation, concurrent with ventriculomegaly and interhemispheric cysts. However, the genetic basis for this autosomal recessive syndrome in cats is unknown. Forty-three cats were genotyped on the Illumina Infinium Feline 63K iSelect DNA Array and used for analyses. Genome-wide association studies, including a sib-transmission disequilibrium test and a case-control association analysis, and homozygosity mapping, identified a critical region on cat chromosome A3. Short-read whole genome sequencing was completed for a cat trio segregating with the syndrome. A homozygous 7 bp deletion in growth differentiation factor 7 (GDF7) (c.221_227delGCCGCGC [p.Arg74Profs]) was identified in affected cats, by comparison to the 99 Lives Cat variant dataset, validated using Sanger sequencing and genotyped by fragment analyses. This variant was not identified in 192 unaffected cats in the 99 Lives dataset. The variant segregated concordantly in an extended pedigree. In mice, GDF7 mRNA is expressed within the roof plate when commissural axons initiate ventrally-directed growth. This finding emphasized the importance of GDF7 in the neurodevelopmental process in the mammalian brain. A genetic test can be developed for use by cat breeders to eradicate this variant.
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Affiliation(s)
- Yoshihiko Yu
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (Y.Y.); (E.K.C.); (R.M.B.)
- Laboratory of Veterinary Radiology, Nippon Veterinary and Life Science University, Musashino, Tokyo 180-8602, Japan
| | - Erica K. Creighton
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (Y.Y.); (E.K.C.); (R.M.B.)
| | - Reuben M. Buckley
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (Y.Y.); (E.K.C.); (R.M.B.)
| | - Leslie A. Lyons
- Department of Veterinary Medicine and Surgery, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (Y.Y.); (E.K.C.); (R.M.B.)
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13
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Bannasch DL, Baes CF, Leeb T. Genetic Variants Affecting Skeletal Morphology in Domestic Dogs. Trends Genet 2020; 36:598-609. [PMID: 32487495 DOI: 10.1016/j.tig.2020.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Revised: 05/12/2020] [Accepted: 05/14/2020] [Indexed: 12/25/2022]
Abstract
Purebred dog breeds provide a powerful resource for the discovery of genetic variants affecting skeletal morphology. Domesticated and subsequently purebred dogs have undergone strong artificial selection for a broad range of skeletal variation, which include both the size and shapes of their bones. While the phenotypic variation between breeds is high, within-breed morphological variation is typically low. Approaches for defining genetic variants associated with canine morphology include quantitative within-breed analyses, as well as across-breed analyses, using breed standards as proxies for individual measurements. The ability to identify variants across the genomes of individual dogs can now be paired with precise measures of morphological variation to define the genetic interactions and the phenotypic effect of variants on skeletal morphology.
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Affiliation(s)
- Danika L Bannasch
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA.
| | - Christine F Baes
- Department of Animal Biosciences, University of Guelph, Guelph, ON N1G 2W1, Canada; Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland
| | - Tosso Leeb
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland
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14
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Capra V, Iacomino M, Accogli A, Pavanello M, Zara F, Cama A, De Marco P. Chiari malformation type I: what information from the genetics? Childs Nerv Syst 2019; 35:1665-1671. [PMID: 31385087 DOI: 10.1007/s00381-019-04322-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/28/2019] [Indexed: 12/21/2022]
Abstract
PURPOSE Chiari malformation type I (CMI), a rare disorder of the craniocerebral junction with an estimated incidence of 1 in 1280, is characterized by the downward herniation of the cerebellar tonsils of at least 5 mm through the foramen magnum, resulting in significant neurologic morbidity. Classical CMI is thought to be caused by an underdeveloped occipital bone, resulting in a posterior cranial fossa which is too small to accommodate the normal-sized cerebellum. In this review, we dissect the lines of evidence supporting a genetic contribution for this disorder. METHODS We present the results of two types of approaches: animal models and human studies encompassing different study designs such as whole genome linkage analysis, case-control association studies, and expression studies. The update of the literature also includes the most recent findings emerged by whole exome sequencing strategy. RESULTS Despite evidence for a genetic component, no major genes have been identified and the genetics of CMI is still very much unknown. One major challenge is the variability of clinical presentation within CMI patient population that reflects an underlying genetic heterogeneity. CONCLUSIONS The identification of the genes that contribute to the etiology of CMI will provide an important step to the understanding of the underlying pathology. The finding of a predisposing gene may lead to the development of simple and accurate diagnostic tests for better prognosis, counseling, and clinical management of patients and their relatives.
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Affiliation(s)
- Valeria Capra
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Michele Iacomino
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy.,UOSD Laboratorio Neurogenetica e Neuroscienze, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Andrea Accogli
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Marco Pavanello
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Federico Zara
- UOSD Laboratorio Neurogenetica e Neuroscienze, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Armando Cama
- UOC Neurochirurgia, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy
| | - Patrizia De Marco
- UOSD Laboratorio Neurogenetica e Neuroscienze, IRCCS Istituto Giannina Gaslini, v. G. Gaslini 5, 16147, Genoa, Italy.
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15
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Knowler SP, Gillstedt L, Mitchell TJ, Jovanovik J, Volk HA, Rusbridge C. Pilot study of head conformation changes over time in the Cavalier King Charles spaniel breed. Vet Rec 2019; 184:122. [PMID: 30635451 PMCID: PMC6589453 DOI: 10.1136/vr.105135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 11/23/2018] [Accepted: 11/23/2018] [Indexed: 11/23/2022]
Abstract
Modern interpretation of head conformation in the Cavalier King Charles spaniel (CKCS) has favoured a smaller, more exaggerated, brachycephalic type than originally described in the 1929 breed standard. Recent research studies identified brachycephaly and reduced hind cranium as two conformational (dysmorphic) features that increase risk for symptomatic Chiari-like malformation and secondary syringomyelia (SM). A prospective pilot study investigated the hypothesis that dysmorphic head features could be assessed visually and correlated with risk of SM. Thirteen CKCS, selected from anonymised photographic evidence, were physically appraised by authorised Kennel Club judges using a head shape checklist. These subjective evaluations were then matched with objective measurements of the cranium (cephalic index and rostrocaudal doming) and their subsequent MRI. A positive correlation (P=0.039) between the judges’ checklist score and rostrocaudal doming (hindskull ratio) and a positive correlation between the cephalic index and hindskull ratio (P=0.042) were identified. Five CKCS had no SM and their status tallied with 62 per cent of the judges’ evaluation. Although the ability of adjudicators to identify differences in head conformation varied, there was sufficient association between the dysmorphic parameters and the risk of SM to cause concern and propose a larger study in CKCS breed.
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Affiliation(s)
- Susan Penelope Knowler
- Faculty of Health and Medical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, UK
| | | | | | | | - Holger Andreas Volk
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, UK
| | - Clare Rusbridge
- Faculty of Health and Medical Sciences, School of Veterinary Medicine, University of Surrey, Guildford, UK.,Neurology Department, Fitzpatrick Referrals, Godalming, UK
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16
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Rusbridge C, Stringer F, Knowler SP. Clinical Application of Diagnostic Imaging of Chiari-Like Malformation and Syringomyelia. Front Vet Sci 2018; 5:280. [PMID: 30547039 PMCID: PMC6279941 DOI: 10.3389/fvets.2018.00280] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2018] [Accepted: 10/22/2018] [Indexed: 12/18/2022] Open
Abstract
Chiari-like malformation (CM) and syringomyelia (SM) is a frequent diagnosis in predisposed brachycephalic toy breeds since increased availability of MRI. However, the relevance of that MRI diagnosis has been questioned as CM, defined as identification of a cerebellar herniation, is ubiquitous in some breeds and SM can be asymptomatic. This article reviews the current knowledge of neuroanatomical changes in symptomatic CM and SM and diagnostic imaging modalities used for the clinical diagnosis of CM-pain or myelopathy related to SM. Although often compared to Chiari type I malformation in humans, canine CM-pain and SM is more comparable to complex craniosynostosis syndromes (i.e., premature fusion of multiple skull sutures) characterized by a short skull (cranial) base, rostrotentorial crowding with rostral forebrain flattening, small, and ventrally orientated olfactory bulbs, displacement of the neural tissue to give increased height of the cranium and further reduction of the functional caudotentorial space with hindbrain herniation. MRI may further reveal changes suggesting raised intracranial pressure such as loss of sulci definition in conjunction with ventriculomegaly. In addition to these brachycephalic changes, dogs with SM are more likely to have craniocervical junction abnormalities including rostral displacement of the axis and atlas with increased odontoid angulation causing craniospinal junction deformation and medulla oblongata elevation. Symptomatic SM is diagnosed on the basis of signs of myelopathy and presence of a large syrinx that is consistent with the neuro-localization. The imaging protocol should establish the longitudinal and transverse extent of the spinal cord involvement by the syrinx. Phantom scratching and cervicotorticollis are associated with large mid-cervical syringes that extend to the superficial dorsal horn. If the cause of CSF channel disruption and syringomyelia is not revealed by anatomical MRI then other imaging modalities may be appropriate with radiography or CT for any associated vertebral abnormalities.
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Affiliation(s)
- Clare Rusbridge
- Fitzpatrick Referrals, Godalming, United Kingdom.,School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
| | | | - Susan P Knowler
- School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, United Kingdom
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17
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Knowler SP, Galea GL, Rusbridge C. Morphogenesis of Canine Chiari Malformation and Secondary Syringomyelia: Disorders of Cerebrospinal Fluid Circulation. Front Vet Sci 2018; 5:171. [PMID: 30101146 PMCID: PMC6074093 DOI: 10.3389/fvets.2018.00171] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Accepted: 07/04/2018] [Indexed: 01/01/2023] Open
Abstract
Chiari-like Malformation (CM) and secondary syringomyelia (SM), as well as their analogous human conditions, is a complex developmental condition associated with pain and accompanying welfare concerns. CM/SM is diagnosed ever more frequently, thanks in part to the increased availability of magnetic resonance imaging in veterinary medicine. Research over the last two decades has focused primarily on its pathophysiology relating to overcrowding of the cranial caudal fossa. More recent characterizations of CM/SM include brachycephaly with osseous reduction and neural parenchymal displacement involving the entire brain and craniocervical junction to include rostral flattening, olfactory bulb rotation, increased height of the cranium, reduced cranial base with spheno-occipital synchondrosis angulation, reduced supraoccipital and interparietal crest and rostral displacement of the axis and atlas with increased odontoid angulation. The most shared manifestation of CM is the development of fluid-filled pockets (syrinx, syringes) in the spinal cord that can be readily quantified. Dogs with symptomatic CM without SM have a reduced basioccipital bone, compensatory increased cranial fossa height with displaced parenchyma whereby the cerebellum is invaginated beneath the occipital lobes but without compromising cerebrospinal fluid channels enough to cause SM. Thus, broadly defined, CM might be described as any distortion of the skull and craniocervical junction which compromises the neural parenchyma and cerebrospinal fluid circulation causing pain and/or SM. The etiology of CM is multifactorial, potentially including genetically-influenced, breed-specific abnormalities in both skeletal and neural components. Since causation between specific morphologic changes and SM or clinical signs is unproven, CM might be more appropriately considered as a brachycephalic obstructive CSF channel syndrome (BOCCS) rather than a single malformation. Understanding the normal development of the brain, skull and craniocervical junction is fundamental to identifying deviations which predispose to CM/SM. Here we review its anatomical, embryological, bio-mechanical, and genetic underpinnings to update the profession's understanding of this condition and meaningfully inform future research to diminish its welfare impact.
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Affiliation(s)
- Susan P Knowler
- Department of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Gabriel L Galea
- Developmental Biology of Birth Defects, Great Ormond Street Institute of Child Health, University College London, London,, United Kingdom
| | - Clare Rusbridge
- Department of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom.,Fitzpatrick Referrals Veterinary Specialist Hospital, Surrey, United Kingdom
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