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Céré C, Curcio V, Dorez H, Debreuque M, Franconi F, Rousseau D. Quantitative MRI for brain lesion diagnosis in dogs and cats: A comprehensive overview. Vet Radiol Ultrasound 2024. [PMID: 39329277 DOI: 10.1111/vru.13434] [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: 01/15/2024] [Revised: 07/26/2024] [Accepted: 09/08/2024] [Indexed: 09/28/2024] Open
Abstract
MRI is widely used for the detection and characterization of brain lesions. There is a growing interest in the potential benefits of quantitative MRI (qMRI) in veterinary brain lesion diagnosis. Yet, the use of data processing tools in the veterinary field is not as democratized as for the diagnosis of human brain pathologies. Several reviews have addressed the characterization of brain lesions in cats and dogs. None of them is specifically focused on quantitative MRI data processing techniques for the diagnosis of brain lesions in the veterinary field. This paper aims to provide an overview of the evolution of qMRI on cats and dogs both in the clinical and preclinical fields. We analyze the achievements in the field as well as the remaining challenges in the diffusion of data processing tools for veterinary brain lesions characterization.
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Affiliation(s)
- Cassandra Céré
- Hawkcell, Lyon, France
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS), University of Angers, Angers, France
| | | | | | - Maud Debreuque
- Neurology Department, Veterinary Hospital Center Saint Martin, Allonzier-la-Caille, France
| | - Florence Franconi
- Plateforme de Recherche en Imagerie et Spectroscopie Multimodales (PRISM), University of Angers, Angers, France
- Micro et Nanomédecines Translationnelles (MINT), Inserm, CNRS, SFR ICAT, University of Angers, Angers, France
| | - David Rousseau
- Laboratoire Angevin de Recherche en Ingénierie des Systèmes (LARIS), University of Angers, Angers, France
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Banasik A, Wrzosek M, Drobot P, Owsińska-Schmidt K, Brewińska L, Zimny A, Podgórski P. Correlation between semiautomated magnetic resonance imaging volumetry of the cingulate gyrus and interictal epileptiform discharge lateralization in dogs with idiopathic epilepsy. J Vet Intern Med 2024; 38:2590-2602. [PMID: 39189832 PMCID: PMC11423450 DOI: 10.1111/jvim.17178] [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: 03/15/2024] [Accepted: 08/06/2024] [Indexed: 08/28/2024] Open
Abstract
BACKGROUND Brain imaging suggests the involvement of the limbic system, particularly the cingulate gyrus (GC), in dogs with idiopathic epilepsy (IE). HYPOTHESIS A correlation exists between the side of interictal epileptiform discharges (IEDs) and the volume of the ipsilateral GC (GCe) in dogs with IE. ANIMALS Dogs admitted to the neurological consultation (32 with epileptic seizures and 13 control) were included. METHODS This retrospective, blinded study followed the International Veterinary Epilepsy Task Force recommendations for diagnosing IE at the Tier III confidence level. The IE group included 18 and 14 dogs with IEDs in the left and right hemispheres, respectively (median age: 36 months, median weight: 19.5 kg), whereas the control group included 13 dogs (median age: 32 months, median weight: 20 kg). Whole-brain and GC-volumetric assessments were performed by a semiautomated method. RESULTS In the control group, the volume of the GC was: left, from 743.63 to 1001.61 mm3, right, from 789.35 to 1015.86 mm3. In the study group, the volume of the GC was: left, from 720.88 to 1054.9 mm3 and right, from 566.29 to 987.77 mm3. In dogs with IE, GCe volume was significantly lower than the mean volume of the GC in the control group relative to total intracranial volume (TIV; P = .00044). CONCLUSIONS AND CLINICAL IMPORTANCE Alterations in the volume of the GC provide insights into structural changes during IE. The use of semiautomatic volumetry provides an advantage by reducing the potential for human error.
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Affiliation(s)
- Aleksandra Banasik
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Marcin Wrzosek
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
- NeuroTeam Specialist Veterinary Clinic, Wrocław, Poland
| | - Paulina Drobot
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Karolina Owsińska-Schmidt
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Laura Brewińska
- Department of Internal Medicine and Clinic of Diseases of Horses, Dogs and Cats, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Anna Zimny
- Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
| | - Przemysław Podgórski
- Department of General and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
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Foss KD, Billhymer AC. Magnetic resonance imaging in canine idiopathic epilepsy: a mini-review. Front Vet Sci 2024; 11:1427403. [PMID: 39021411 PMCID: PMC11251927 DOI: 10.3389/fvets.2024.1427403] [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: 05/03/2024] [Accepted: 06/19/2024] [Indexed: 07/20/2024] Open
Abstract
Magnetic resonance imaging (MRI) in an integral part of the diagnostic workup in canines with idiopathic epilepsy (IE). While highly sensitive and specific in identifying structural lesions, conventional MRI is unable to detect changes at the microscopic level. Utilizing more advanced neuroimaging techniques may provide further information on changes at the neuronal level in the brain of canines with IE, thus providing crucial information on the pathogenesis of canine epilepsy. Additionally, earlier detection of these changes may aid clinicians in the development of improved and targeted therapies. Advances in MRI techniques are being developed which can assess metabolic, cellular, architectural, and functional alterations; as well alterations in neuronal tissue mechanical properties, some of which are currently being applied in research on canine IE. This mini-review focuses on novel MRI techniques being utilized to better understand canine epilepsy, which include magnetic resonance spectroscopy, diffusion-weighted imaging, diffusion tensor imaging, perfusion-weighted imaging, voxel based morphometry, and functional MRI; as well as techniques applied in human medicine and their potential use in veterinary species.
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Affiliation(s)
- Kari D. Foss
- Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana-Champaign, Urbana, IL, United States
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Beckmann KM, Wang-Leandro A, Steffen F, Richter H, Dennler M, Bektas R, Carrera I, Haller S. Diffusion tensor-based analysis of white matter in dogs with idiopathic epilepsy. Front Vet Sci 2023; 10:1325521. [PMID: 38192722 PMCID: PMC10773822 DOI: 10.3389/fvets.2023.1325521] [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: 10/21/2023] [Accepted: 11/23/2023] [Indexed: 01/10/2024] Open
Abstract
Introduction The understanding of epileptic seizure pathogenesis has evolved over time, and it is now generally accepted that not only are cortical and subcortical areas involved but also the connection of these regions in the white matter (WM). Recent human neuroimaging studies confirmed the involvement of the WM in several epilepsy syndromes. Neuroimaging studies investigating WM integrity with diffusion tensor imaging (DTI) in canine idiopathic epilepsy are lacking. This study aimed to test the hypothesis that WM diffusion changes can be found in dogs affected by idiopathic epilepsy. Method Twenty-six dogs with idiopathic epilepsy (15 Border Collies and 11 Greater Swiss Mountain dogs) and 24 healthy controls (11 Beagle dogs, 5 Border Collies, and 8 Greater Swiss Mountain dogs) were prospectively enrolled. Most dogs with idiopathic epilepsy (17/26) were enrolled within 3 months after seizure onset. Diffusion tensor imaging of the brain with 32 diffusion directions (low b value = 0 s/mm2; maximal b value = 800 s/mm2) was performed in a 3 Tesla scanner. Tract-based spatial statistics (TBSS), a voxel-based approach, was used to investigate changes in fractional anisotropy (FA) and mean diffusivity (MD) in the idiopathic epilepsy group compared to the healthy control group. Additionally, FA and MD were investigated in the region of corpus callosum and cingulate white matter in both groups. Results We observed subtle changes in WM DTI between the idiopathic epilepsy group and the healthy control group limited to cingulate WM, with a significantly lower FA in the idiopathic epilepsy group compared to the healthy control group in the region of interest (ROI) approach (p = 0.027). No significant changes were found between the idiopathic epilepsy group and the healthy control group in the TBSS analysis and in the corpus callosum in the ROI approach. Conclusion This study supports the cingulate area as a target structure in canine epilepsy. The subtle changes only might be explained by the short duration of epilepsy, small sample sizes, and the higher variability in canine brain anatomy. Furthermore, all included dogs showed generalized tonic-clonic seizures, possibly affected by generalized epilepsy syndrome, which are also associated with less pronounced DTI changes in humans than focal epilepsy syndromes.
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Affiliation(s)
- Katrin M. Beckmann
- Section of Neurology, Department of Small Animals, Vetsuisse Faculty Zurich, University of Zurich, Zurich, Switzerland
- Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Adriano Wang-Leandro
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Frank Steffen
- Section of Neurology, Department of Small Animals, Vetsuisse Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Henning Richter
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Dennler
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Rima Bektas
- Section of Anaesthesiology, Department of Clinical Diagnostics and Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Ines Carrera
- Vet Oracle Teleradiology, Norfolk, United Kingdom
| | - Sven Haller
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden
- Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Schmidt T, Meller S, Meyerhoff N, Twele F, Zanghi B, Volk HA. A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial design to investigate the potential of psychobiotics on seizure semiology and comorbidities in canine epilepsy: study protocol. BMC Vet Res 2023; 19:57. [PMID: 36864510 PMCID: PMC9983181 DOI: 10.1186/s12917-023-03609-0] [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: 09/21/2022] [Accepted: 02/16/2023] [Indexed: 03/04/2023] Open
Abstract
BACKGROUND Epilepsy is the most common chronic neurological disease in dogs. More than two-thirds of these patients suffer from associated behavioural comorbidities. The latter could have their origin in partially overlapping pathomechanisms, with the intestinal microbiome as a potential key link between them. The current arsenal of drugs for epilepsy management remains limited. Most canine patients continue to have seizures despite treatment and the occurrence of comorbidities is not sufficiently addressed, limiting quality of life of affected dogs and owners. Therefore, novel additional epilepsy management options are urgently needed. The microbiome-gut-brain axis may serve as a new target for the development of innovative multimodal therapeutic approaches to overcome current shortcomings in epilepsy management. METHODS A six-month prospective, randomised, double-blinded, placebo-controlled, crossover, dietary trial was designed to investigate the potential of the psychobiotic Bifidobacterium longum on behavioural comorbidities in canine epilepsy. Seizure semiology will be evaluated as a secondary outcome measure. Thirty-four privately owned dogs are planned to be included in the ongoing study meeting the following inclusion criteria: Dogs displaying increased anxiety/fear behaviour since the start of the idiopathic epilepsy. Tier II confidence level of the International Veterinary Epilepsy Task Force for the diagnosis of idiopathic epilepsy, with a maximum seizure interval of 3 month and a minimum of three generalised seizures within that period and chronically treated with at least one antiseizure drug without improvement in seizure frequency Each dog will receive the allocated supplement (probiotic vs. placebo) alongside its normal diet for a 3-month period. After a three-week wash out period, the second phase starts by administering the respective other supplement for another 3 months. DISCUSSION The current study considers modern high-quality standards for epilepsy medication trials. Common biasing effects should be limited to a possible minimum (regression-to-the mean effect, placebo effect, observer effect), ensuring a high validity and accuracy of the acquired results, thus enabling a representative nature of the efficacy of Bifidobacterium longum as add-on supplement for dogs suffering from epilepsy and its comorbidities. This publication should provide a description of the study procedure and data acquisition methods, including prognosed statistical analysis.
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Affiliation(s)
- Teresa Schmidt
- grid.412970.90000 0001 0126 6191Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Sebastian Meller
- grid.412970.90000 0001 0126 6191Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Nina Meyerhoff
- grid.412970.90000 0001 0126 6191Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Friederike Twele
- grid.412970.90000 0001 0126 6191Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Brian Zanghi
- Research and Development, Nestlé Purina PetCare, St. Louis, MO USA
| | - Holger Andreas Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany. .,Centre for Systems Neuroscience, University of Veterinary Medicine Hannover, Hannover, Germany.
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Binks S, Lamquet S, Crawford AH, Meurs A, Irani SR, Pakozdy A. Parallel roles of neuroinflammation in feline and human epilepsies. Vet J 2022; 290:105912. [PMID: 36209994 PMCID: PMC10912827 DOI: 10.1016/j.tvjl.2022.105912] [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: 01/22/2022] [Revised: 09/28/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022]
Abstract
Autoimmune encephalitis refers to a group of disorders characterised by a non-infectious encephalitis, often with prominent seizures and surface neuronal autoantibodies. AE is an important cause of new-onset refractory status epilepticus in humans and is frequently responsive to immunotherapies including corticosteroids, plasma exchange, intravenous immunoglobulin G and rituximab. Recent research suggests that parallel autoantibodies can be detected in non-human mammalian species. The best documented example is leucine-rich glioma-inactivated 1 (LGI1)-antibodies in domestic cats with limbic encephalitis (LE). In this review, we discuss the role of neuroinflammation and autoantibodies in human and feline epilepsy and LE.
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Affiliation(s)
- Sophie Binks
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, UK; Department of Neurology, John Radcliffe Hospital, Oxford University Hospitals Foundation Trust, Oxford OX3 9DU, UK.
| | - Simon Lamquet
- Department of Neurology, Ghent University Hospital, Ghent, Belgium
| | - Abbe H Crawford
- Clinical Science and Services, The Royal Veterinary College, Hertfordshire AL9 7TA, UK
| | - Alfred Meurs
- Department of Neurology, Ghent University Hospital, Ghent, Belgium
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, UK; Department of Neurology, John Radcliffe Hospital, Oxford University Hospitals Foundation Trust, Oxford OX3 9DU, UK
| | - Akos Pakozdy
- University Clinic for Small Animals, University of Veterinary Medicine Vienna, Austria
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Yu Y, Hasegawa D, Kanazono S, Saito M. Clinical characterization of epileptic seizures in Pomeranians with idiopathic epilepsy or epilepsy of unknown cause. Vet Med (Auckl) 2022; 36:2113-2122. [DOI: 10.1111/jvim.16578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 10/14/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Yoshihiko Yu
- Laboratory of Veterinary Radiology Nippon Veterinary and Life Science University Tokyo Japan
| | - Daisuke Hasegawa
- Laboratory of Veterinary Radiology Nippon Veterinary and Life Science University Tokyo Japan
- The Research Center for Animal Life Science Nippon Veterinary and Life Science University Tokyo Japan
| | - Shinichi Kanazono
- Neurology and Neurosurgery Service Veterinary Specialists & Emergency Center Saitama Japan
| | - Miyoko Saito
- Laboratory of Small Animal Surgery (Neurology), School of Veterinary Medicine Azabu University Kanagawa Japan
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Mauri N, Richter H, Steffen F, Zölch N, Beckmann KM. Single-Voxel Proton Magnetic Resonance Spectroscopy of the Thalamus in Idiopathic Epileptic Dogs and in Healthy Control Dogs. Front Vet Sci 2022; 9:885044. [PMID: 35873693 PMCID: PMC9302964 DOI: 10.3389/fvets.2022.885044] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Accepted: 06/14/2022] [Indexed: 11/26/2022] Open
Abstract
The role of magnetic resonance spectroscopy (MRS) in the investigation of brain metabolites in epileptic syndromes in dogs has not been explored systematically to date. The aim of this study was to investigate metabolites in the thalamus in dogs affected by idiopathic epilepsy (IE) with and without antiepileptic drug treatment (AEDT) and to compare them to unaffected controls. Our hypothesis is that similar to humans with generalized epilepsy and loss of consciousness, N-acetyl aspartate (NAA) would be reduced, and glutamate–glutamine (Glx) would be increased in treated and untreated IE in comparison with the control group. In this prospective case–control study, Border Collie (BC) and Greater Swiss Mountain dog (GSMD) were divided into three groups: (1) healthy controls, IE with generalized tonic–clonic seizures with (2) and without (3) AEDT. A total of 41 BC and GSMD were included using 3 Tesla single-voxel proton MRS of the thalamus (PRESS localization, shortest TE, TR = 2000 ms, NSA = 240). After exclusion of 11 dogs, 30 dogs (18 IE and 12 healthy controls) remained available for analysis. Metabolite concentrations were estimated with LCModel using creatine as reference and compared using Kruskal–Wallis and Wilcoxon rank-sum tests. The Kruskal–Wallis test revealed significant differences in the NAA-to-creatine (p = 0.04) and Glx-to-creatine (p = 0.03) ratios between the three groups. The Wilcoxon rank-sum test further showed significant reduction in the NAA/creatine ratio in idiopathic epileptic dogs under AEDT compared to epileptic dogs without AEDT (p = 0.03) and compared to healthy controls (p = 0.03). In opposite to humans, Glx/creatine ratio was significantly reduced in dogs with IE under AEDT compared to epileptic dogs without AEDT (p = 0.03) and controls (p = 0.02). IE without AEDT and healthy controls did not show significant difference, neither in NAA/creatine (p = 0.60), nor in Glx-to-creatine (p = 0.55) ratio. In conclusion, MRS showed changes in dogs with IE and generalized seizures under AEDT, but not in those without AEDT. Based upon these results, MRS can be considered a useful advanced imaging technique for the evaluation of dogs with IE in the clinical and research settings.
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Affiliation(s)
- Nico Mauri
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
- Vetimage Diagnostik GmbH, Oberentfelden, Switzerland
| | - Henning Richter
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Frank Steffen
- Section of Neurology and Neurosurgery, Small Animal Clinic, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Niklaus Zölch
- Department of Forensic Medicine and Imaging, Institute of Forensic Medicine, University of Zurich, Zurich, Switzerland
| | - Katrin M. Beckmann
- Section of Neurology and Neurosurgery, Small Animal Clinic, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
- *Correspondence: Katrin M. Beckmann
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Kneissl S. Grand Challenge in Veterinary Imaging: Nothing Is More Constant Than Change. Front Vet Sci 2022; 9:936754. [PMID: 35812874 PMCID: PMC9263969 DOI: 10.3389/fvets.2022.936754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
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Del Signore F, Vignoli M, Della Salda L, Tamburro R, Paolini A, Cerasoli I, Chincarini M, Rossi E, Ferri N, Romanucci M, Falerno I, de Pasquale F. A Magnetic Resonance-Relaxometry-Based Technique to Identify Blood Products in Brain Parenchyma: An Experimental Study on a Rabbit Model. Front Vet Sci 2022; 9:802272. [PMID: 35711807 PMCID: PMC9195168 DOI: 10.3389/fvets.2022.802272] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 04/11/2022] [Indexed: 11/13/2022] Open
Abstract
Magnetic resonance relaxometry is a quantitative technique that estimates T1/T2 tissue relaxation times. This has been proven to increase MRI diagnostic accuracy of brain disorders in human medicine. However, literature in the veterinary field is scarce. In this work, a T1 and T2-based relaxometry approach has been developed. The aim is to investigate its performance in characterizing subtle brain lesions obtained with autologous blood injections in rabbits. This study was performed with a low-field scanner, typically present in veterinary clinics. The approach consisted of a semi-automatic hierarchical classification of different regions, selected from a T2 map. The classification was driven according to the relaxometry properties extracted from a set of regions selected by the radiologist to compare the suspected lesion with the healthy parenchyma. Histopathological analyses were performed to estimate the performance of the proposed classifier through receiver operating characteristic curve analyses. The classifier resulted in moderate accuracy in terms of lesion characterization.
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Affiliation(s)
- Francesca Del Signore
- Veterinary Faculty, University of Teramo, Teramo, Italy
- *Correspondence: Francesca Del Signore
| | | | | | | | | | | | | | - Emanuela Rossi
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise Giuseppe Caporale, Teramo, Italy
| | - Nicola Ferri
- Istituto Zooprofilattico Sperimentale dell'Abruzzo e del Molise Giuseppe Caporale, Teramo, Italy
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Maeso C, Sánchez-Masian D, Ródenas S, Font C, Morales C, Domínguez E, Puig J, Arévalo-Serrano J, Montoliu P. Prevalence, distribution, and clinical associations of suspected postictal changes on brain magnetic resonance imaging in epileptic dogs. J Am Vet Med Assoc 2022; 260:71-81. [PMID: 34793322 DOI: 10.2460/javma.21.02.0088] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OBJECTIVE To determine the prevalence of presumed postictal changes (PC) on brain MRI in epileptic dogs, describe their distribution, and recognize possible correlations with different epilepsy features. ANIMALS 540 client-owned dogs with epilepsy and a complete medical record that underwent brain MRI at 4 veterinary referral hospitals between 2016 and 2019. PROCEDURES Data were collected regarding signalment, seizure type, seizure severity, time between last seizure and MRI, and etiological classification of epilepsy. Postictal changes were considered when solitary or multiple intraparenchymal hyperintense lesions were observed on T2-weighted and fluid-attenuated inversion recovery images and were hypointense or isointense on T1-weighted sequences, which were not confined to a vascular territory and showed no to mild mass effect and no to mild contrast enhancement. RESULTS Sixty-seven dogs (12.4%) showed MRI features consistent with PC. The most common brain sites affected were the piriform lobe, hippocampus, temporal neocortex, and cingulate gyrus. Dogs having suffered cluster seizures or status epilepticus were associated with a higher probability of occurrence of PC, compared to dogs with self-limiting seizures (OR 2.39; 95% confidence interval, 1.33 to 4.30). Suspected PC were detected both in dogs with idiopathic epilepsy and in those with structural epilepsy. Dogs with unknown-origin epilepsy were more likely to have presumed PC than were dogs with structural (OR 0.15; 95% confidence interval, 0.06 to 0.33) or idiopathic epilepsy (OR 0.42; 95% confidence interval, 0.20 to 0.87). Time between last seizure and MRI was significantly shorter in dogs with PC. CLINICAL RELEVANCE MRI lesions consistent with PC were common in epileptic dogs, and the brain distribution of these lesions varied. Occurrence of cluster seizures or status epilepticus, diagnosis of unknown origin epilepsy, and lower time from last seizure to MRI are predictors of suspected PC.
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Affiliation(s)
| | | | | | | | | | | | - Jordi Puig
- Anicura Ars Veterinaria, Barcelona, Spain
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12
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Beckmann KM, Wang-Leandro A, Richter H, Bektas RN, Steffen F, Dennler M, Carrera I, Haller S. Increased resting state connectivity in the anterior default mode network of idiopathic epileptic dogs. Sci Rep 2021; 11:23854. [PMID: 34903807 PMCID: PMC8668945 DOI: 10.1038/s41598-021-03349-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2021] [Accepted: 11/30/2021] [Indexed: 12/11/2022] Open
Abstract
Epilepsy is one of the most common chronic, neurological diseases in humans and dogs and considered to be a network disease. In human epilepsy altered functional connectivity in different large-scale networks have been identified with functional resting state magnetic resonance imaging. Since large-scale resting state networks have been consistently identified in anesthetised dogs’ application of this technique became promising in canine epilepsy research. The aim of the present study was to investigate differences in large-scale resting state networks in epileptic dogs compared to healthy controls. Our hypothesis was, that large-scale networks differ between epileptic dogs and healthy control dogs. A group of 17 dogs (Border Collies and Greater Swiss Mountain Dogs) with idiopathic epilepsy was compared to 20 healthy control dogs under a standardized sevoflurane anaesthesia protocol. Group level independent component analysis with dimensionality of 20 components, dual regression and two-sample t test were performed and revealed significantly increased functional connectivity in the anterior default mode network of idiopathic epileptic dogs compared to healthy control dogs (p = 0.00060). This group level differences between epileptic dogs and healthy control dogs identified using a rather simple data driven approach could serve as a starting point for more advanced resting state network analysis in epileptic dogs.
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Affiliation(s)
- Katrin M Beckmann
- Section of Neurology, Department of Small Animals, Vetsuisse Faculty Zurich, University of Zurich, Zurich, Switzerland.
| | - Adriano Wang-Leandro
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Henning Richter
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland.,Clinic for Neuroradiology, University Hospital Bonn, Bonn, Germany
| | - Rima N Bektas
- Section of Anaesthesiology, Department of Diagnostics and Clinical Services, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Frank Steffen
- Section of Neurology, Department of Small Animals, Vetsuisse Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Dennler
- Clinic for Diagnostic Imaging, Department of Diagnostics and Clinical Services, Vetsuisse-Faculty Zurich, University of Zurich, Zurich, Switzerland
| | - Ines Carrera
- Willows Veterinary Centre and Referral Service, Highlands Road, Shirley, UK
| | - Sven Haller
- Department of Surgical Sciences, Radiology, Uppsala University, Uppsala, Sweden.,Faculty of Medicine, University of Geneva, Geneva, Switzerland
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Hirashima J, Saito M, Igarashi H, Takagi S, Hasegawa D. Case Report: 1-Year Follow-Up of Vagus Nerve Stimulation in a Dog With Drug-Resistant Epilepsy. Front Vet Sci 2021; 8:708407. [PMID: 34355037 PMCID: PMC8330973 DOI: 10.3389/fvets.2021.708407] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/11/2021] [Indexed: 12/02/2022] Open
Abstract
A vagus nerve stimulation (VNS) system was surgically implanted to treat drug-resistant epilepsy in a 5-year-old male Shetland Sheepdog. At regular visits during a 1-year follow-up, treatment efficacy and adverse effects were assessed, and programmable stimulation parameters were adjusted to optimize stimulation intensity while avoiding adverse effects. The frequency of generalized tonic–clonic seizures was reduced by 87% after the initiation of VNS. The owner reported that the dog regained his personality, and the quality of life of both the dog and owner improved. The only adverse effect of VNS was a cough that was controlled by adjusting stimulation parameters. There were no surgical complications or other issues with the VNS device. This is the first long-term evaluation of VNS therapy in a dog, and the results obtained suggest that gradual adjustments of VNS parameters facilitate optimum VNS dosing.
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Affiliation(s)
- Junya Hirashima
- Laboratory of Small Animal Surgery (Neurology), School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Miyoko Saito
- Laboratory of Small Animal Surgery (Neurology), School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Hirotaka Igarashi
- Laboratory of Small Animal Internal Medicine, School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Satoshi Takagi
- Laboratory of Small Animal Surgery (Soft Tissue Surgery and Surgical Oncology), School of Veterinary Medicine, Azabu University, Sagamihara, Japan
| | - Daisuke Hasegawa
- Laboratory of Veterinary Radiology, Nippon Veterinary and Life Science University, Musashino, Japan.,The Research Center for Animal Life Science, Nippon Veterinary and Life Science University, Musashino, Japan
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Canine Lafora Disease: An Unstable Repeat Expansion Disorder. Life (Basel) 2021; 11:life11070689. [PMID: 34357061 PMCID: PMC8304204 DOI: 10.3390/life11070689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Revised: 07/11/2021] [Accepted: 07/12/2021] [Indexed: 11/17/2022] Open
Abstract
Canine Lafora disease is a recessively inherited, rapidly progressing neurodegenerative disease caused by the accumulation of abnormally constructed insoluble glycogen Lafora bodies in the brain and other tissues due to the loss of NHL repeat containing E3 ubiquitin protein ligase 1 (NHLRC1). Dogs have a dodecamer repeat sequence within the NHLRC1 gene, which is prone to unstable (dynamic) expansion and loss of function. Progressive signs of Lafora disease include hypnic jerks, reflex and spontaneous myoclonus, seizures, vision loss, ataxia and decreased cognitive function. We studied five dogs (one Chihuahua, two French Bulldogs, one Griffon Bruxellois, one mixed breed) with clinical signs associated with canine Lafora disease. Identification of polyglucosan bodies (Lafora bodies) in myocytes supported diagnosis in the French Bulldogs; muscle areas close to the myotendinous junction and the myofascial union segment had the highest yield of inclusions. Postmortem examination of one of the French Bulldogs revealed brain Lafora bodies. Genetic testing for the known canine NHLRC1 mutation confirmed the presence of a homozygous mutation associated with canine Lafora disease. Our results show that Lafora disease extends beyond previous known breeds to the French Bulldog, Griffon Bruxellois and even mixed-breed dogs, emphasizing the likely species-wide nature of this genetic problem. It also establishes these breeds as animal models for the devastating human disease. Genetic testing should be used when designing breeding strategies to determine the frequency of the NHLRC1 mutation in affected breeds. Lafora diseases should be suspected in any older dog presenting with myoclonus, hypnic jerks or photoconvulsions.
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Lőrincz BA, Anson A, Handschuh S, Tichy A, Rowan C, Lőrincz BB, Garamvölgyi R. Hippocampal size did not differ between epileptic and non-epileptic dogs using volumetric and subjective methods. Acta Vet Hung 2021; 69:1-8. [PMID: 33835940 DOI: 10.1556/004.2021.00006] [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: 03/22/2020] [Accepted: 02/22/2021] [Indexed: 11/19/2022]
Abstract
Hippocampal changes in epilepsy may manifest as hippocampal atrophy/sclerosis. A recent human study suggests that the demonstration of hippocampal volume loss is more reliable using quantitative evaluation methods. The aim of the present study was to obtain volumetric data in both epileptic and healthy dogs, to compare hippocampal volumes in both groups, and to compare subjective and volumetric assessment. Volumetric measurements of the hippocampi, lateral ventricles and hemispheria were performed in 31 epileptic and 15 control dogs. There was a positive association between the body weight and the hemispheric volume, as well as between the hemispheric volume and the ipsilateral hippocampal volume. There was no significant correlation between age and the volume of any measured brain structures. There was no statistically significant difference between the hippocampal volumes of the control group and the epileptic group. A statistically significant difference between the two groups for hippocampus/hemispherium ratio or hippocampal asymmetric ratio was not identified. An extrapolated hippocampal volume based on body weight was not possible in this study population.
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Affiliation(s)
- Borbála A. Lőrincz
- 1Veterinary University Vienna, Diagnostic Imaging, Veterinärplatz 1, A-1210 Vienna, Austria
- 2Medicopus Nonprofit Ltd, Guba S. u. 40, H-7400 Kaposvár, Hungary
| | - Agustina Anson
- 1Veterinary University Vienna, Diagnostic Imaging, Veterinärplatz 1, A-1210 Vienna, Austria
- 3Department of Clinical Sciences, Diagnostic Imaging Service, Cummings School of Veterinary Medicine at Tufts University, Boston, USA
| | - Stephan Handschuh
- 1Veterinary University Vienna, Diagnostic Imaging, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Alexander Tichy
- 1Veterinary University Vienna, Diagnostic Imaging, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Conor Rowan
- 1Veterinary University Vienna, Diagnostic Imaging, Veterinärplatz 1, A-1210 Vienna, Austria
| | - Balázs B. Lőrincz
- 4Department of Head and Neck for ENT and Oncologic/Reconstructive/Endocrine and Robotic-assisted Head and Neck Surgery, Agaplesion Bethanien and Markus Hospitals, Frankfurt am Main, Germany
| | - Rita Garamvölgyi
- 2Medicopus Nonprofit Ltd, Guba S. u. 40, H-7400 Kaposvár, Hungary
- 5Auvet Pharma Ltd, Kaposvár, Hungary
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16
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Watson F, Coppi AA, Volk HA, Packer RMA, Tauro A, Rusbridge C. Comparison of volume of the forebrain, subarachnoid space and lateral ventricles between dogs with idiopathic epilepsy and controls using a stereological approach: Cavalieri's principle. Canine Med Genet 2021; 8:3. [PMID: 33691781 PMCID: PMC7944915 DOI: 10.1186/s40575-021-00101-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/25/2021] [Indexed: 11/18/2022] Open
Abstract
Background Canine idiopathic epilepsy (IE) is the most common chronic neurological brain disease in dogs, yet it can only be diagnosed by exclusion of all other potential causes. In people, epilepsy has been associated with a reduction in brain volume. The objective was to estimate the volume of the forebrain (FB), subarachnoid space (SAS) and lateral ventricles (LV) in dogs with IE compared to controls using Cavalieri’s principle. MRI scans of case and control dogs were identified from two neurology referral hospital databases. Eight breeds with increased odds of having IE were included: Golden Retriever, Labrador Retriever, Cocker Spaniel, Border terrier, German Shepherd dog, Parson Jack Russell terrier, Boxer, and Border Collie. Five dogs of each breed with IE and up to five controls were systematically and uniformly randomly sampled (SURS). The volume of the FB, SAS and LV were estimated from MRI scans by one blinded observer using Cavalieri’s principle. Results One hundred-two dogs were identified; 56 were diagnosed with IE and 46 were controls. There was no statistically significant difference in FB, SAS and LV volume between dogs with IE and controls. Dogs with a history of status epilepticus had significantly larger FB than those without (p = 0.05). There was a border-line trend for LV volume to increase with increasing length of seizure history in the IE group (p = 0.055). Conclusion The volumes of the FB, SAS and LV are not different between dogs with IE and controls, so IE remains a diagnosis of exclusion with no specific neuroanatomical biomarkers identified. This is the first time FB and SAS volume has been compared in dogs with IE. Unfortunately, we have shown that the results reporting significantly larger FBs in dogs with status epilepticus and LV volume increase with length of seizure history were likely confounded by breed and should be interpreted cautiously. Whilst these associations are interesting and clinically relevant, further investigation with breed-specific or larger, breed-diverse populations are required to permit strong conclusions. The Cavalieri principle provided an effective estimation of FB, SAS and LV volumes on MRI, but may be too time-intensive for use in clinical practice.
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Affiliation(s)
- Fraje Watson
- Royal Veterinary College, Hawkshead Lane, Hertfordshire, Hatfield, AL9 7TA, UK. .,Present Address: University College London, Division of Surgery & Interventional Science, Aspire CREATe, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK.
| | - A Augusto Coppi
- School of Animal, Rural and Environmental Sciences, Nottingham Trent University, Nottingham, NG25 0QF, UK
| | - Holger A Volk
- Royal Veterinary College, Hawkshead Lane, Hertfordshire, Hatfield, AL9 7TA, UK.,Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg, 30559, Hanover, Germany
| | - Rowena M A Packer
- Royal Veterinary College, Hawkshead Lane, Hertfordshire, Hatfield, AL9 7TA, UK
| | - Anna Tauro
- Chestergates Veterinary Specialists, Telford Court, Units E and F, Gates Lane, Chester, CH1 6LT, UK
| | - Clare Rusbridge
- Present Address: University College London, Division of Surgery & Interventional Science, Aspire CREATe, Royal National Orthopaedic Hospital, Brockley Hill, Stanmore, Middlesex, HA7 4LP, UK.,School of Veterinary Medicine, Faculty of Healthy & Medical Sciences, University of Surrey, Main Academic Building (VSM), Daphne Jackson Road, Guildford, Surrey, GU2 7AL, UK
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17
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Cook PF, Hoard VA, Dolui S, Frederick BD, Redfern R, Dennison SE, Halaska B, Bloom J, Kruse-Elliott KT, Whitmer ER, Trumbull EJ, Berns GS, Detre JA, D'Esposito M, Gulland FMD, Reichmuth C, Johnson SP, Field CL, Inglis BA. An MRI protocol for anatomical and functional evaluation of the California sea lion brain. J Neurosci Methods 2021; 353:109097. [PMID: 33581216 DOI: 10.1016/j.jneumeth.2021.109097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 01/29/2021] [Accepted: 02/04/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND Domoic acid (DOM) is a neurotoxin produced by some harmful algae blooms in coastal waters. California sea lions (Zalophus californianus) exposed to DOM often strand on beaches where they exhibit a variety of symptoms, including seizures. These animals typically show hippocampal atrophy on MRI scans. NEW METHOD We describe an MRI protocol for comprehensive evaluation of DOM toxicosis in the sea lion brain. We intend to study brain development in pups exposed in utero. The protocol depicts the hippocampal formation as the primary region of interest. We include scans for quantitative morphometry, functional and structural connectivity, and a cerebral blood flow map. RESULTS High-resolution 3D anatomical scans facilitate post hoc slicing in arbitrary planes and accurate morphometry. We demonstrate the first cerebral blood flow map using MRI, and the first structural tractography from a live sea lion brain. COMPARISON WITH EXISTING METHODS Scans were compared to prior anatomical and functional studies in live sea lions, and structural connectivity in post mortem specimens. Hippocampal volumes were broadly in line with prior studies, with differences likely attributable to the 3D approach used here. Functional connectivity of the dorsal left hippocampus matched that found in a prior study conducted at a lower magnetic field, while structural connectivity in the live brain agreed with findings observed in post mortem studies. CONCLUSIONS Our protocol provides a comprehensive, longitudinal view of the functional and anatomical changes expected to result from DOM toxicosis. It can also screen for other common neurological pathologies and is suitable for any pinniped that can fit inside an MRI scanner.
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Affiliation(s)
- Peter F Cook
- Department of Biopsychology, New College of Florida, 5800 Bay Shore Road, Sarasota, FL, 34243, USA
| | - Vanessa A Hoard
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Sudipto Dolui
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA
| | - Blaise deB Frederick
- Department of Psychiatry, Harvard University Medical School, 25 Shattuck St, Boston, MA, 02115, USA; McLean Hospital Brain Imaging Center, 115 Mill St., Belmont, MA, 02478, USA
| | - Richard Redfern
- Henry H. Wheeler, Jr. Brain Imaging Center, 188 Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, CA, 94720, USA
| | | | - Barbie Halaska
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Josh Bloom
- AnimalScan Advanced Veterinary Imaging, 934 Charter St, Redwood City, CA, 94063, USA
| | - Kris T Kruse-Elliott
- AnimalScan Advanced Veterinary Imaging, 934 Charter St, Redwood City, CA, 94063, USA
| | - Emily R Whitmer
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Emily J Trumbull
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Gregory S Berns
- Psychology Department, Emory University, 36 Eagle Row, Atlanta, GA, 30322, USA
| | - John A Detre
- Department of Radiology, University of Pennsylvania Perelman School of Medicine, 3400 Spruce Street, Philadelphia, PA, 19104, USA; Department of Neurology, University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA
| | - Mark D'Esposito
- Henry H. Wheeler, Jr. Brain Imaging Center, 188 Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, CA, 94720, USA; Helen Wills Neuroscience Institute, University of California, 132 Barker Hall, Berkeley, CA, 94720, USA
| | - Frances M D Gulland
- School of Veterinary Medicine Wildlife Health Center, University of California at Davis, 1089 Veterinary Medicine Dr, Davis, CA, 95616, USA
| | - Colleen Reichmuth
- Long Marine Laboratory, Institute of Marine Sciences, University of California at Santa Cruz, 115 McAllister Way, Santa Cruz, CA, 95060, USA
| | - Shawn P Johnson
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Cara L Field
- The Marine Mammal Center, 2000 Bunker Road, Sausalito, CA, 94965, USA
| | - Ben A Inglis
- Henry H. Wheeler, Jr. Brain Imaging Center, 188 Li Ka Shing Center for Biomedical and Health Sciences, University of California, Berkeley, CA, 94720, USA.
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18
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Zilli J, Kressin M, Schänzer A, Kampschulte M, Schmidt MJ. Partial cortico-hippocampectomy in cats, as therapy for refractory temporal epilepsy: A descriptive cadaveric study. PLoS One 2021; 16:e0244892. [PMID: 33449929 PMCID: PMC7810294 DOI: 10.1371/journal.pone.0244892] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/17/2020] [Indexed: 11/18/2022] Open
Abstract
Cats, similar to humans, are known to be affected by hippocampal sclerosis (HS), potentially causing antiepileptic drug (AED) resistance. HS can occur as a consequence of chronic seizure activity, trauma, inflammation, or even as a primary disease. In humans, temporal lobe resection is the standardized therapy in patients with refractory temporal lobe epilepsy (TLE). The majority of TLE patients are seizure free after surgery. Therefore, the purpose of this prospective cadaveric study is to establish a surgical technique for hippocampal resection in cats as a treatment for AED resistant seizures. Ten cats of different head morphology were examined. Pre-surgical magnetic resonance imaging (MRI) and computed tomography (CT) studies of the animals’ head were carried out to complete 3D reconstruction of the head, brain, and hippocampus. The resected hippocampal specimens and the brains were histologically examined for tissue injury adjacent to the hippocampus. The feasibility of the procedure, as well as the usability of the removed specimen for histopathological examination, was assessed. Moreover, a micro-CT (mCT) examination of the brain of two additional cats was performed in order to assess temporal vasculature as a reason for possible intraoperative complications. In all cats but one, the resection of the temporal cortex and the hippocampus were successful without any evidence of traumatic or vascular lesions in the surrounding neurovascular structures. In one cat, the presence of mechanical damage (a fissure) of the thalamic surface was evident in the histopathologic examination of the brain post-resection. All hippocampal fields and the dentate gyrus were identified in the majority of the cats via histological examination. The study describes a new surgical approach (partial temporal cortico-hippocampectomy) offering a potential treatment for cats with clinical and diagnostic evidence of temporal epilepsy which do not respond adequately to the medical therapy.
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Affiliation(s)
- Jessica Zilli
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Germany
- * E-mail:
| | - Monika Kressin
- Institute for Veterinary Anatomy, Histology and Embryology, Justus-Liebig-University, Giessen, Germany
| | - Anne Schänzer
- Institute of Neuropathology, Justus-Liebig-University, Giessen, Germany
| | | | - Martin J. Schmidt
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Germany
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19
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Huaijantug S, Yatmark P, Chinnabrut P, Rueangsawat N, Wongkumlue A, Teerapan W, Chatchaisak D. Quantitative brain histogram of canine epilepsy using magnetic resonance imaging. Acta Radiol 2021; 62:93-101. [PMID: 32295389 DOI: 10.1177/0284185120914031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Quantitative magnetic resonance imaging (MRI) is used to study the anatomy of the brain in dogs with idiopathic epilepsy. PURPOSE To quantitate MRI images in terms of volumetric ratios and histogram analyses of the following regions of interest (ROI) in dogs with idiopathic epilepsy: frontal; parietal; temporal; piriform; thalamic; and hippocampal regions. MATERIAL AND METHODS Nine dogs with epilepsy and four healthy controls were evaluated. We examined the volumetric ratios and histogram analyses of six ROIs in all dogs. RESULTS MR images, in T1-weighted, T2-weighted, FLAIR, diffusion-weighted imaging, and apparent diffusion coefficient sequences detected changes in 4/9 (44%) epileptic dogs found in 5/6 regions: frontal; parietal; temporal; piriform; and hippocampal regions. However, no such changes were observed in the thalamic region. Interestingly, the frontal and piriform volumetric ratios of epileptic dogs were significantly lower than those of control dogs. The histogram analyses in 4/6 regions were significantly increased in epileptic dogs. CONCLUSION Our results demonstrated MRI finding abnormalities in several regions of the brain in several sequences including T1-weighted, T2-weighted, FLAIR, diffusion-weighted imaging, and apparent diffusion coefficient in epileptic dogs. In several regions of the brain, atrophy may exist, and hyperintensity may be present on MR images in epileptic dogs. These findings suggest that the diagnostic yield of MRI, which is an advanced neuroimaging technique, is high in epileptic dogs and has good reliability and sensitivity in detecting abnormal areas in patients.
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Affiliation(s)
- Somkiat Huaijantug
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Paranee Yatmark
- Department of Pre-Clinical and Apply Animal Science, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | | | | | - Avirut Wongkumlue
- Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
| | - Wuttiwong Teerapan
- Department of Companion Animals Clinical Sciences, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Duangthip Chatchaisak
- Department of Clinical Sciences and Public Health, Faculty of Veterinary Science, Mahidol University, Nakhon Pathom, Thailand
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20
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Bitschi ML, Bagó Z, Rosati M, Reese S, Goehring LS, Matiasek K. A Systematic Approach to Dissection of the Equine Brain-Evaluation of a Species-Adapted Protocol for Beginners and Experts. Front Neuroanat 2020; 14:614929. [PMID: 33390909 PMCID: PMC7775367 DOI: 10.3389/fnana.2020.614929] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/25/2020] [Indexed: 12/13/2022] Open
Abstract
Introduction of new imaging modalities for the equine brain have refocused attention on the horse as a natural model for ethological, neuroanatomical, and neuroscientific investigations. As opposed to imaging studies, strategies for equine neurodissection still lack a structured approach, standardization and reproducibility. In contrast to other species, where adapted protocols for sampling have been published, no comparable guideline is currently available for equids. Hence, we developed a species-specific slice protocol for whole brain vs. hemispheric dissection and tested its applicability and practicability in the field, as well as its neuroanatomical accuracy and reproducibility. Dissection steps are concisely described and depicted by schematic illustrations, photographs and instructional videos. Care was taken to show the brain in relation to the raters' hands, cutting devices and bench surface. Guidance is based on a minimum of external anatomical landmarks followed by geometric instructions that led to procurement of 14 targeted slabs. The protocol was performed on 55 formalin-fixed brains by three groups of investigators with different neuroanatomical skills. Validation of brain dissection outcomes addressed the aptitude of slabs for neuroanatomical studies as opposed to simplified routine diagnostic purposes. Across all raters, as much as 95.2% of slabs were appropriate for neuroanatomical studies, and 100% of slabs qualified for a routine diagnostic setting. Neither autolysis nor subfixation significantly affected neuroanatomical accuracy score, while a significant negative effect was observed with brain extraction artifacts. Procedure times ranged from 14 to 66 min and reached a mean duration of 23.25 ± 7.93 min in the last of five trials in inexperienced raters vs. 16 ± 2.83 min in experts, while acceleration of the dissection did not negatively impact neuroanatomical accuracy. This protocol, derived analogously to the consensus report of the International Veterinary Epilepsy Task Force in dogs and cats, allows for systematic, quick and easy dissection of the equine brain, even for inexperienced investigators. Obtained slabs feature virtually all functional subcompartments at suitable planes for both diagnostic and neuroscientific investigations and complement the data obtained from imaging studies. The instructive protocol and brain dissection videos are available in Supplementary Material.
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Affiliation(s)
- Maya-Lena Bitschi
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig Maximilians University, Munich, Germany
| | - Zoltán Bagó
- Austrian Agency for Health and Food Safety Ltd. (AGES), Institute for Veterinary Disease Control, Mödling, Austria
| | - Marco Rosati
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig Maximilians University, Munich, Germany
| | - Sven Reese
- Department of Veterinary Sciences, Institute of Anatomy, Histology & Embryology, Ludwig Maximilians University, Munich, Germany
| | - Lutz S Goehring
- Division of Medicine and Reproduction, Centre for Clinical Veterinary Medicine, Equine Hospital, Ludwig Maximilians University, Munich, Germany
| | - Kaspar Matiasek
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig Maximilians University, Munich, Germany
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21
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Olszewska A, Schmidt MJ, Failing K, Nicpoń J, Podgórski P, Wrzosek MA. Interictal Single-Voxel Proton Magnetic Resonance Spectroscopy of the Temporal Lobe in Dogs With Idiopathic Epilepsy. Front Vet Sci 2020; 7:644. [PMID: 33195502 PMCID: PMC7541947 DOI: 10.3389/fvets.2020.00644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/10/2020] [Indexed: 11/16/2022] Open
Abstract
Proton magnetic resonance spectroscopy (H1-MRS) could provide insight into the metabolic pathophysiology of the temporal lobe of canine brain after seizure. Currently, there is no evidence-based data available on MRS of temporal lobe in dogs with idiopathic epilepsy (IE). The aim of this prospective, cross-sectional study was to evaluate the interictal metabolic activity of the temporal lobe in IE dogs compared to a control group with the use of H1-MRS. Ten healthy dogs and 27 client-owned dogs with IE underwent 1.5-Tesla magnetic resonance imaging (MRI) and single-voxel H1-MRS. The MRS studies were acquired as spin echoes with a repetition time (TR) of 2,000 ms and an echo time (TE) of 144 ms. A cubic voxel (10 ×10 ×10 mm) was positioned bilaterally into the region of the left and right temporal lobe, including a middle part of the hippocampus and the amygdala. The N-acetylaspartate (NAA)-to-creatine (NAA/Cr), NAA-to-choline (NAA/Cho), choline-to-creatine (Cho/Cr), and choline-to-NAA (Cho/NAA) ratios were determined in both hemispheres and compared to controls. No significant differences in all metabolite ratios between epileptic dogs and the control group could be found. A time-dependent decrease in the NAA/Cho ratio as well as an increase in the Cho/NAA ratio was found with proximity in time to the last seizure. We found no correlation between metabolite ratios and age or sex in this animal group. Time span from the last seizure to the acquisition of MRS significantly correlated with NAA/Cho and Cho/NAA ratio. We conclude that without a time relation, metabolite ratios in dogs with IE do not differ from those of the control group.
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Affiliation(s)
- Agnieszka Olszewska
- Department of Veterinary Clinical Science, Small Animal Clinic, Justus-Liebig-University Giessen, Giessen, Germany
| | - Martin Jürgen Schmidt
- Department of Veterinary Clinical Science, Small Animal Clinic, Justus-Liebig-University Giessen, Giessen, Germany
| | - Klaus Failing
- Unit for Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus Liebig-University Giessen, Giessen, Germany
| | - Józef Nicpoń
- Department of Internal Diseases With a Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.,Center of Experimental Diagnostics and Innovative Biomedical Technologies, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Przemysław Podgórski
- Department of General Radiology and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
| | - Marcin Adam Wrzosek
- Department of Internal Diseases With a Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
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22
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Rusbridge C. Neurobehavioral Disorders: The Corticolimbic System in Health and Disease. Vet Clin North Am Small Anim Pract 2020; 50:1157-1181. [PMID: 32680665 DOI: 10.1016/j.cvsm.2020.06.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The corticolimbic system (prefrontal cortices, amygdala, and hippocampus) integrates emotion with cognition and produces a behavioral output that is flexible based on the environmental circumstances. It also modulates pain, being implicated in pathophysiology of maladaptive pain. Because of the anatomic and function overlap between corticolimbic circuitry for pain and emotion, the pathophysiology for maladaptive pain conditions is extremely complex. Addressing environmental needs and underlying triggers is more important than pharmacotherapy when dealing with feline orofacial pain syndrome or feline hyperesthesia syndrome. By contrast, autoimmune limbic encephalitis requires prompt diagnosis and management with immunosuppression and seizure control.
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Affiliation(s)
- Clare Rusbridge
- Fitzpatrick Referrals, Godalming, Surrey GU7 2QQ, UK; School of Veterinary Medicine, Faculty of Health & Medical Sciences, University of Surrey, Guildford, Surrey GU2 7AL, UK.
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Swain CE, Cherubini GB, Mantis P. Low Field MRI Measurements of the Normal Canine Trigeminal Nerve. Front Vet Sci 2020; 7:274. [PMID: 32509809 PMCID: PMC7249853 DOI: 10.3389/fvets.2020.00274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 04/23/2020] [Indexed: 11/13/2022] Open
Abstract
There is no available measuring protocol and reference range for the normal canine trigeminal nerve. This can be problematic in cases of suspected bilateral trigeminal neuropathy since contralateral nerves cannot be a usefully compared. Trigeminal nerves and brain measurements were retrospectively assessed via multiplanar reconstruction (MPR) of 3DT1 post-contrast MR sequences from 137 dogs with no signs or diagnosis of trigeminal disease. Direct measurements of vertical brain height (BH), trigeminal nerves transverse height (TTH) and trigeminal nerves width in dorsal reconstruction (TDW) were made in a plane immediately caudal to the foramen ovale and used to derive trigeminal nerve-to-brain (NB) ratios, including height-to-brain ratio (HBR) and width-to-brain ratio (WBR). HBR (0.09, IQR = 0.08-0.09) and WBR (0.10, IQR = 0.09-0.11) maintained more consistent values across the study population compared to direct measurements of TTH (3.72, IQR = 3.42-4.07) and TDW (4.35 +/− 0.63). Calculated normal reference intervals for HBR and WBR were 0.07-0.11 and 0.08-0.13, respectively and the largest NB ratios recorded in normal dogs were 0.13 and 0.14 for HBR and WBR, respectively. All measurements varied proportionally with weight, including HBR (r = 0.41, p < 0.0001) and small dogs had a significantly smaller HBRs compared to medium (p = 0.0294), large (p < 0.0049) and giant dogs (p < 0.0044). Median HBR was the same across skull types (0.09), however post-hoc analysis detected significantly smaller HBRs in brachycephalic compared to mesaticephalic dogs (p = 0.0494). In conclusion, trigeminal NB ratios may allow for accurate, objective assessment of the canine trigeminal nerves on MRI but further quantification of the effects of weight and skull type on suggested reference intervals is needed.
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Kaczmarska A, José-López R, Czopowicz M, Lazzerini K, Leblond G, Stalin C, Gutierrez-Quintana R. Postencephalitic epilepsy in dogs with meningoencephalitis of unknown origin: Clinical features, risk factors, and long-term outcome. J Vet Intern Med 2020; 34:808-820. [PMID: 31990104 PMCID: PMC7096646 DOI: 10.1111/jvim.15687] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Accepted: 12/10/2019] [Indexed: 12/27/2022] Open
Abstract
Background Although the presence of seizures in dogs with meningoencephalitis of unknown origin (MUO) has been associated with shorter survival times, data regarding the prevalence and risk factors for postencephalitic epilepsy (PEE) is lacking. Objectives To describe the clinical features, prevalence, risk factors, and long‐term outcome of PEE in dogs with MUO. Animals Sixty‐one dogs with presumptive diagnosis of MUO based on the clinicopathological and diagnostic imaging findings. Methods Retrospective study. Cases were identified by search of hospital medical records for dogs with suspected or confirmed MUO. Medical records of dogs meeting inclusion criteria were reviewed. Signalment, seizure history, clinicopathologic, and magnetic resonance imaging (MRI) findings were recorded. Results Among 61 dogs at risk of PEE, 14 (23%) dogs developed PEE. Three of 14 dogs with PEE (21%) developed drug‐resistant epilepsy. Dogs with PEE were younger (P = .03; ORadjusted = 0.75; 95% confidence interval [CI], 0.58‐0.98) and had significantly shorter survival times (log‐rank test P = .04) when compared to dogs that did not develop epilepsy. The risk factors associated with the development of PEE were the presence of acute symptomatic seizures (ASS; P = .04; ORadjusted = 4.76; 95% CI, 1.11‐20.4) and MRI lesions in the hippocampus (P = .04; ORadjusted = 4.75; 95% CI, 1.07‐21.0). Conclusions and Clinical Importance Dogs with MUO and seizures at the early stage of the disease (ASS) seem to be at a higher risk of developing PEE.
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Affiliation(s)
- Adriana Kaczmarska
- Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Roberto José-López
- Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Michał Czopowicz
- Laboratory of Veterinary Epidemiology and Economics, Faculty of Veterinary Medicine, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | - Kali Lazzerini
- Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Guillaume Leblond
- Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
| | - Catherine Stalin
- Small Animal Hospital, School of Veterinary Medicine, University of Glasgow, Glasgow, United Kingdom
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Portero M, Martínez de Merlo E, Pérez C, Benito M, Daza MA, Fragio C. Cerebrospinal fluid and blood lactate concentrations as prognostic biomarkers in dogs with meningoencephalitis of unknown origin. Vet J 2019; 254:105395. [PMID: 31836169 DOI: 10.1016/j.tvjl.2019.105395] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 10/09/2019] [Accepted: 10/10/2019] [Indexed: 12/22/2022]
Abstract
Meningoencephalitis of unknown origin (MUO) is a common inflammatory disease of the central nervous system. Several studies investigated finding prognostic factors, but results are contradictory. The aim of this study was to determine the concentrations of blood lactate (Blood-L) and cerebrospinal fluid lactate (CSF-L) in dogs with MUO for prognostic purposes. A total of 45 dogs with MUO (MUO group) and 11 with idiopathic epilepsy (IE group) were included. In the MUO group, 22 dogs were treated with prednisolone + cytosine arabinoside, 17 with prednisolone ± cyclosporine, and six received no treatment. In the MUO group, there was a strong-moderate positive correlation between Blood-L and CSF-L (ρ = 0.63557; P < 0.0001), a strong-moderate negative correlation between survival and CSF-L (ρ= -0.50210; P < 0.0004), and a weak negative correlation between survival and Blood-L (ρ= -0.35685; P < 0.0220). Dogs with a favourable response to treatment at 1 month had lower initial concentrations of Blood-L and CSF-L (P < 0.0010; P < 0.0037), and those with a worse response had higher values (P < 0.0497; P < 0.0004). Dogs that remained stable with treatment showed lower CSF-L concentrations (P < 0.0013). Dogs with Blood-L>4 mmol/L (P < 0.03) and/or CSF-L> 4 mmol/L (P < 0.009) had lower survival rates with the latter also showing more severe signs, probably indicating severe neuronal damage. These findings suggest that concentrations of CSF-L and Blood-L in dogs with MUO could be used as prognostic indicators.
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Affiliation(s)
- M Portero
- Department of Small Animal Medicine and Surgery, Hospital Clinico Veterinario Complutense, Universidad Complutense, Madrid, Avenida Puerta de Hierro s/n, 28040, Spain.
| | - E Martínez de Merlo
- Department of Small Animal Medicine and Surgery, Hospital Clinico Veterinario Complutense, Universidad Complutense, Madrid, Avenida Puerta de Hierro s/n, 28040, Spain
| | - C Pérez
- Department of Small Animal Medicine and Surgery, Hospital Clinico Veterinario Complutense, Universidad Complutense, Madrid, Avenida Puerta de Hierro s/n, 28040, Spain
| | - M Benito
- Department of Small Animal Medicine and Surgery, Hospital Clinico Veterinario Complutense, Universidad Complutense, Madrid, Avenida Puerta de Hierro s/n, 28040, Spain
| | - M A Daza
- Department of Small Animal Medicine and Surgery, Hospital Clinico Veterinario Complutense, Universidad Complutense, Madrid, Avenida Puerta de Hierro s/n, 28040, Spain
| | - C Fragio
- Department of Small Animal Medicine and Surgery, Hospital Clinico Veterinario Complutense, Universidad Complutense, Madrid, Avenida Puerta de Hierro s/n, 28040, Spain
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Gruber I, Kneissl S, Probst A, Pakozdy A. Delineation of the Feline Hippocampal Formation: A Comparison of Magnetic Resonance Images With Anatomic Slices. Front Vet Sci 2019; 6:358. [PMID: 31781578 PMCID: PMC6857121 DOI: 10.3389/fvets.2019.00358] [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: 05/24/2019] [Accepted: 09/30/2019] [Indexed: 11/13/2022] Open
Abstract
The hippocampal formation (HF) is a relevant brain structure that is involved in several neurological and psychiatric diseases. In cats, structural changes of the HF are associated with epilepsy. The knowledge of a detailed anatomy of this brain region may lead to the accurate diagnosis and development of better therapies. There are, however, discrepancies among the research findings, which may be due to different definitions being used, according to anatomical guidelines and boundaries, as well as different magnetic resonance (MR) protocols. The aim of this study is to evaluate the anatomical borders of the HF on transverse MR images and the correlated anatomic sections in three cats. The boundaries of the HF were mostly visible in the formalin fixed anatomic sections, except in the areas where the hippocampus proper exchanges into the subicular complex. Also, the delineation of the anteroventral part and the latero-caudal borders of the HF were not clearly defined. Based on our preliminary results these problems are reinforced on MR images, and further histological and anatomical research must be done to find a way to delineate these neurological structures accurately.
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Affiliation(s)
- Isabella Gruber
- Internal Medicine Small Animals, University of Veterinary Medicine, Vienna, Austria
| | - Sibylle Kneissl
- Diagnostic Imaging, University of Veterinary Medicine, Vienna, Austria
| | - Alexander Probst
- Institute of Topographic Anatomy, University of Veterinary Medicine, Vienna, Austria
| | - Akos Pakozdy
- Internal Medicine Small Animals, University of Veterinary Medicine, Vienna, Austria
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Gardini A, Taeymans O, Cherubini GB, de Stefani A, Targett M, Vettorato E. Linear magnetic resonance imaging measurements of the hippocampal formation differ in young versus old dogs. Vet Rec 2019; 185:306. [PMID: 31308154 PMCID: PMC6817983 DOI: 10.1136/vr.105243] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 06/11/2019] [Accepted: 06/23/2019] [Indexed: 12/13/2022]
Abstract
Age-related hippocampal formation (HF) atrophy has been documented on MRI studies using volumetric analysis and visual rating scales. This retrospective cross-sectional study aimed to compare linear MRI measurements of the HF between young (1–3 years) and old (>10 years) non-brachycephalic dogs, with normal brain anatomy and cerebrospinal fluid (CSF) analysis. Right and left hippocampal formation height (HFH), height of the brain (HB) and mean HFH/HB ratio were measured by two observers on a transverse T2 fluid-attenuated inversion recovery sequence containing rostral colliculi and mesencephalic aqueduct.119 MRI studies were enrolled: 75 young and 44 old dogs. Left and right HFH were greater (p<0.0001) in young, while HB was greater in old dogs (p=0.024). Mean HFH/HB ratio was 15.66 per cent and 18.30 per cent in old and young dogs (p<0.0001). No differences were found comparing measurements between epileptic and non-epileptic dogs. Old dogs have a greater HB; this may represent the different study populations or a statistical phenomenon. Ageing affects HF linear measurements. A reduction of mean HFH/HB ratio between 18.30 per cent and 15.66 per cent should be considered a physiological age-related process of the canine lifespan. The use of mean HFH/HB ratio could be considered for quantifying brain atrophy in elderly dogs.
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Affiliation(s)
- Anna Gardini
- Department of Neurology and Neurosurgery, Dick White Referrals, Six Mile Bottom, UK
| | - Olivier Taeymans
- Department of Diagnostic Imaging, Dick White Referrals, Six Mile Bottom, UK
| | | | - Alberta de Stefani
- Department of Neurology and Neurosurgery, Royal Veterinary College, London, UK
| | - Mike Targett
- Department of Neurology and Neurosurgery, University of Nottingham, Loughborough, UK
| | - Enzo Vettorato
- Department of Anaesthesia and Analgesia, Dick White Referrals, Six Mile Bottom, UK
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Czerwik A, Płonek M, Podgórski P, Wrzosek M. Comparison of electroencephalographic findings with hippocampal magnetic resonance imaging volumetry in dogs with idiopathic epilepsy. J Vet Intern Med 2018; 32:2037-2044. [PMID: 30325068 PMCID: PMC6271325 DOI: 10.1111/jvim.15323] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 07/13/2018] [Accepted: 08/15/2018] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND In humans, temporal lobe epilepsy (TLE), is a type of focal epilepsy occurring mainly in the mesial TLE (mTLE), commonly associated with hippocampal sclerosis (HS). OBJECTIVES According to recent studies, TLE might also occur in dogs and could be associated with hippocampal atrophy (HA)/HS. To date, hippocampal lesions have not been correlated with electroencephalographic (EEG) findings in epileptic dogs. ANIMALS An EEG examination, brain magnetic resonance imaging, and volumetric assessment of the hippocampus were performed in 16 nonepileptic and 41 epileptic dogs. METHODS In this retrospective study, the presence and localization of EEG-defined epileptiform discharges (EDs) was blindly evaluated. The hippocampus was measured and assessed for unilateral atrophy. The results of EEG and volumetric findings were correlated to determine whether the functional epileptic focus is equivalent to structural changes. RESULTS The median hippocampal asymmetric ratio (AR) in epileptic dogs was significantly greater than in the control group (P < .001). Using a cut-off threshold AR of >6%, 56% (23/41) of the dogs were characterized with unilateral HA. Of those animals, 35% (8/23) had EDs in the temporal leads and 26% (6/23) had no EDs. In 88% (7/8) of dogs with EDs in the temporal leads that had unilateral HA, the EDs correlated with the side of the decreased hippocampal volume. CONCLUSIONS AND CLINICAL IMPORTANCE The results indicate an association between the presence of EDs detectable on EEG and a decrease in the unilateral hippocampal volume in some cases of canine idiopathic epilepsy that might reflect features of human mTLE.
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Affiliation(s)
- Adriana Czerwik
- Department of Internal Medicine and Clinic for Horses, Dogs and Cats, The Faculty of Veterinary MedicineWrocław University of Environmental and Life SciencesWrocławPoland
| | - Marta Płonek
- Center of Experimental Diagnostics and Innovative Biomedical Technologies, The Faculty of Veterinary MedicineWrocław University of Environmental and Life SciencesWrocławPoland
| | - Przemyslaw Podgórski
- Department of General Radiology, Interventional Radiology and NeuroradiologyWrocław Medical UniversityWrocławPoland
| | - Marcin Wrzosek
- Department of Internal Medicine and Clinic for Horses, Dogs and Cats, The Faculty of Veterinary MedicineWrocław University of Environmental and Life SciencesWrocławPoland
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Packer RA, Rossmeisl JH, Kent MS, Griffin JF, Mazcko C, LeBlanc AK. Consensus recommendations on standardized magnetic resonance imaging protocols for multicenter canine brain tumor clinical trials. Vet Radiol Ultrasound 2018. [PMID: 29522650 DOI: 10.1111/vru.12608] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The National Cancer Institute Comparative Brain Tumor Consortium, Patient Outcomes Working Group, propose a consensus document in support of standardized magnetic resonance imaging protocols for canine brain tumor clinical trials. The intent of this manuscript is to address the widely acknowledged need to ensure canine brain tumor imaging protocols are relevant and have sufficient equivalency to translate to human studies such that: (1) multi-institutional studies can be performed with minimal inter-institutional variation, and (2) imaging protocols are consistent with human consensus recommendations to permit reliable translation of imaging data to human clinical trials. Consensus recommendations include pre- and postcontrast three-dimensional T1-weighted images, T2-weighted turbo spin echo in all three planes, T2*-weighted gradient recalled echo, T2-weighted fluid attenuated inversion recovery, and diffusion weighted imaging/diffusion tensor imaging in transverse plane; field of view of ≤150 mm; slice thickness of ≤2 mm, matrix ≥ 256 for two-dimensional images, and 150 or 256 for three-dimensional images.
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Affiliation(s)
- Rebecca A Packer
- Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, 80523-1678
| | - John H Rossmeisl
- Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Blacksburg, VA, 24061
| | - Michael S Kent
- Department of Surgical and Radiological Sciences, University of California Davis, School of Veterinary Medicine, Davis, CA, 95616
| | - John F Griffin
- Department of Large Animal Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843
| | - Christina Mazcko
- Comparative Oncology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892
| | - Amy K LeBlanc
- Comparative Oncology Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, 20892
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Frank L, Lüpke M, Kostic D, Löscher W, Tipold A. Grey matter volume in healthy and epileptic beagles using voxel-based morphometry - a pilot study. BMC Vet Res 2018; 14:50. [PMID: 29463250 PMCID: PMC5819682 DOI: 10.1186/s12917-018-1373-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Accepted: 02/14/2018] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND One of the most common chronic neurological disorders in dogs is idiopathic epilepsy (IE) diagnosed as epilepsy without structural changes in the brain. In the current study the hypothesis should be proven that subtle grey matter changes occur in epileptic dogs. Therefore, magnetic resonance (MR) images of one dog breed (Beagles) were used to obtain an approximately uniform brain shape. Local differences in grey matter volume (GMV) were compared between 5 healthy Beagles and 10 Beagles with spontaneously recurrent seizures (5 dogs with IE and 5 dogs with structural epilepsy (SE)), using voxel-based morphometry (VBM). T1W images of all dogs were prepared using Amira 6.3.0 for brain extraction, FSL 4.1.8 for registration and SPM12 for realignment. After creation of tissue probability maps of cerebrospinal fluid, grey and white matter from control images to segment all extracted brains, GM templates for each group were constructed to normalize brain images for parametric statistical analysis, which was achieved using SPM12. RESULTS Epileptic Beagles (IE and SE Beagles) displayed statistically significant reduced GMV in olfactory bulb, cingulate gyrus, hippocampus and cortex, especially in temporal and occipital lobes. Beagles with IE showed statistically significant decreased GMV in olfactory bulb, cortex of parietal and temporal lobe, hippocampus and cingulate gyrus, Beagles with SE mild statistically significant GMV reduction in temporal lobe (p < 0.05; family- wise error correction). CONCLUSION These results suggest that, as reported in epileptic humans, focal reduction in GMV also occurs in epileptic dogs. Furthermore, the current study shows that VBM analysis represents an excellent method to detect GMV differences of the brain between a healthy dog group and dogs with epileptic syndrome, when MR images of one breed are used.
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Affiliation(s)
- Lisa Frank
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany.
| | - Matthias Lüpke
- Department of General Radiology and Medical Physics, University of Veterinary Medicine, Hannover, Germany
| | - Draginja Kostic
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine, Hannover, Germany
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Raimondi F, Shihab N, Gutierrez-Quintana R, Smith A, Trevail R, Sanchez-Masian D, Smith PM. Magnetic resonance imaging findings in epileptic cats with a normal interictal neurological examination: 188 cases. Vet Rec 2017; 180:610. [DOI: 10.1136/vr.104142] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/13/2017] [Indexed: 12/25/2022]
Affiliation(s)
- F. Raimondi
- Southern Counties Veterinary Specialists (SCVS); 6 Forest Corner Farm, Ringwood Hampshire BH24 3JW UK
| | - N. Shihab
- Southern Counties Veterinary Specialists (SCVS); 6 Forest Corner Farm, Ringwood Hampshire BH24 3JW UK
| | | | - A. Smith
- Langford Small Animal Referral Hospital; Langford Road Bristol BS40 5DU UK
| | - R. Trevail
- Southern Counties Veterinary Specialists (SCVS); 6 Forest Corner Farm, Ringwood Hampshire BH24 3JW UK
| | | | - P. M. Smith
- Davies Veterinary Specialists, Manor Farm Business Park; Higham Gobion Hitchin SG5 3HR UK
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Hamamoto Y, Hasegawa D, Mizoguchi S, Yu Y, Wada M, Kuwabara T, Fujiwara-Igarashi A, Fujita M. Retrospective epidemiological study of canine epilepsy in Japan using the International Veterinary Epilepsy Task Force classification 2015 (2003-2013): etiological distribution, risk factors, survival time, and lifespan. BMC Vet Res 2016; 12:248. [PMID: 27829458 PMCID: PMC5103468 DOI: 10.1186/s12917-016-0877-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 11/02/2016] [Indexed: 02/07/2023] Open
Abstract
Background Epilepsy is the most common neurological disease in veterinary practice. However, contrary to human medicine, epilepsy classification in veterinary medicine had not been clearly defined until recently. A number of reports on canine epilepsy have been published, reflecting in part updated proposals from the human epilepsy organization, the International League Against Epilepsy. In 2015, the International Veterinary Epilepsy Task Force (IVETF) published a consensus report on the classification and definition of canine epilepsy. The purpose of this retrospective study was to investigate the etiological distribution, survival time of dogs with idiopathic epilepsy (IdE) and structural epilepsy (StE), and risk factors for survival time, according to the recently published IVETF classification. We investigated canine cases with epilepsy that were referred to our teaching hospital in Japan during the past 10 years, and which encompassed a different breed population from Western countries. Results A total of 358 dogs with epilepsy satisfied our etiological study criteria. Of these, 172 dogs (48 %) were classified as IdE and 76 dogs (21 %) as StE. Of these dogs, 100 dogs (consisting of 65 with IdE and 35 with StE) were included in our survival study. Median survival time from the initial epileptic seizure in dogs with IdE and StE was 10.4 and 4.5 years, respectively. Median lifespan of dogs with IdE and StE was 13.5 and 10.9 years, respectively. Multivariable analysis demonstrated that risk factors for survival time in IdE were high seizure frequency (≥0.3 seizures/month) and focal epileptic seizures. Conclusions Focal epileptic seizures were identified as a risk factor for survival time in IdE. Clinicians should carefully differentiate seizure type as it is difficult to identify focal epileptic seizures. With good seizure control, dogs with IdE can survive for nearly the same lifespan as the general dog population. Our results using the IVETF classification are similar to previous studies, although some features were noted in our Japanese canine population (which was composed of mainly small-breed dogs), including a longer lifespan in dogs with epilepsy and a larger percentage of meningoencephalomyelitis of unknown origin in dogs with StE.
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Affiliation(s)
- Yuji Hamamoto
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
| | - Daisuke Hasegawa
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan.
| | - Shunta Mizoguchi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
| | - Yoshihiko Yu
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
| | - Masae Wada
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
| | - Takayuki Kuwabara
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
| | - Aki Fujiwara-Igarashi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
| | - Michio Fujita
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, 180-8602, Tokyo, Japan
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Diagnostic techniques to detect the epileptogenic zone: Pathophysiological and presurgical analysis of epilepsy in dogs and cats. Vet J 2016; 215:64-75. [DOI: 10.1016/j.tvjl.2016.03.005] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 02/24/2016] [Accepted: 03/05/2016] [Indexed: 12/17/2022]
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Claßen AC, Kneissl S, Lang J, Tichy A, Pakozdy A. Magnetic resonance features of the feline hippocampus in epileptic and non-epileptic cats: a blinded, retrospective, multi-observer study. BMC Vet Res 2016; 12:165. [PMID: 27515840 PMCID: PMC4982318 DOI: 10.1186/s12917-016-0788-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/03/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Hippocampal necrosis in cats has been reported to be associated with epileptic seizures. Magnetic resonance imaging (MRI) features of temporal lobe (TL) abnormalities in epileptic cats have been described but MR images from epileptic and non-epileptic individuals have not yet been systematically compared. TL abnormalities are highly variable in shape, size and signal, and therefore may lead to varying evaluations by different specialists. The aim of this study was to investigate whether there were differences in the appearance of the TL between epileptic and non-epileptic cats, and whether there were any relationships between TL abnormalities and seizure semiologies or other clinical findings. We also investigated interobserver agreement among three specialists. METHODS The MR images of 46 cats were reviewed independently by three observers, who were blinded to patient data, examination findings and the review of the other observers. Images were evaluated using a multiparametric scoring system developed for this study. Mann-Whitney U-tests and chi-square were used to analyse the differences between observers' evaluations. The kappa coefficient (k) and Fleiss' kappa coefficient were used to quantify interobserver agreement. RESULTS The overall interobserver agreement was moderate to good (k =0.405 to 0.615). The MR scores between epileptic and non-epileptic cats did not differ significantly. However, there was a significant difference between the MR scores of epileptic cats with and without orofacial involvement according to all three observers. Likewise, MR scores of cats with cluster seizures were higher than those of cats without clusters. CONCLUSION Cats presenting with recurrent epileptic seizures with orofacial involvement are more likely to have hippocampal pathologies, which suggests that TL abnormalities are not merely unspecific epileptic findings, but are associated with a certain type of epilepsy. TL signal alterations are more likely to be detected on FLAIR sequences. In contrast to severe changes in the TL which were described similarly among specialists, mild TL abnormalities may be difficult to interpret, thus leading to different assessments among observers.
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Affiliation(s)
| | - Sibylle Kneissl
- Clinical Unit of Diagnostic Imaging, University of Veterinary Medicine, A 1210, Vienna, Austria
| | - Johann Lang
- Division of Clinical Radiology, Vetsuisse Faculty, University of Bern, CH 3012, Bern, Switzerland
| | - Alexander Tichy
- Department of Biomedical Sciences, University of Veterinary Medicine, A 1210, Vienna, Austria
| | - Akos Pakozdy
- Clinic for Internal Medicine, University of Veterinary Medicine, A 1210, Vienna, Austria
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Podell M, Volk HA, Berendt M, Löscher W, Muñana K, Patterson EE, Platt SR. 2015 ACVIM Small Animal Consensus Statement on Seizure Management in Dogs. J Vet Intern Med 2016; 30:477-90. [PMID: 26899355 PMCID: PMC4913615 DOI: 10.1111/jvim.13841] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 01/18/2016] [Accepted: 01/18/2016] [Indexed: 11/27/2022] Open
Abstract
This report represents a scientific and working clinical consensus statement on seizure management in dogs based on current literature and clinical expertise. The goal was to establish guidelines for a predetermined, concise, and logical sequential approach to chronic seizure management starting with seizure identification and diagnosis (not included in this report), reviewing decision‐making, treatment strategies, focusing on issues related to chronic antiepileptic drug treatment response and monitoring, and guidelines to enhance patient response and quality of life. Ultimately, we hope to provide a foundation for ongoing and future clinical epilepsy research in veterinary medicine.
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Affiliation(s)
- M Podell
- Medvet Chicago, Medical and Cancer Centers for Pets, Chicago, IL.,Department of Neurosurgery, Pritzker School of Medicine, The University of Chicago, Chicago, IL
| | - H A Volk
- Department of Clinical Sciences and Services, Small Animal Medicine and Surgery Group, The Royal Veterinary College, Hatfield, Hertfordshire, UK
| | - M Berendt
- Department of Veterinary and Clinical Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - W Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - K Muñana
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC
| | - E E Patterson
- Department of Veterinary Clinical Sciences, University of Minnesota College of Veterinary Medicine, St. Paul, MN
| | - S R Platt
- Department of Small Animal Medicine & Surgery, College of Veterinary Medicine, University of Georgia, Athens, GA
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