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Orciani C, Ballesteros C, Troncy E, Berthome C, Bujold K, Bennamoune N, Sparapani S, Pugsley MK, Paquette D, Boulay E, Authier S. The Spontaneous Incidence of Neurological Clinical Signs in Preclinical Species Using Cage-side Observations or High-definition Video Monitoring: A Retrospective Analysis. Int J Toxicol 2024; 43:123-133. [PMID: 38063479 DOI: 10.1177/10915818231218984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2024]
Abstract
When conducting toxicology studies, the interpretation of drug-related neurological clinical signs such as convulsions, myoclonus/myoclonic jerks, tremors, ataxia, and salivation requires an understanding of the spontaneous incidence of those observations in commonly used laboratory animal species. The spontaneous incidence of central nervous system clinical signs in control animals from a single facility using cage-side observations or high definition video monitoring was retrospectively analyzed. Spontaneous convulsions were observed at low incidence in Beagle dogs and Sprague-Dawley rats but were not identified in cynomolgus monkeys and Göttingen minipigs. Spontaneous myoclonic jerks and muscle twitches were observed at low incidence in Beagle dogs, cynomolgus monkeys, and Sprague-Dawley rats but were not seen in Göttingen minipigs. Spontaneous ataxia/incoordination was identified in all species and generally with a higher incidence when using video monitoring. Salivation and tremors were the two most frequent spontaneous clinical signs and both were observed in all species. Data from the current study unveil potential limitations when using control data obtained from a single study for toxicology interpretation related to low incidence neurological clinical signs while providing historical control data from Beagle dogs, cynomolgus monkeys, Sprague-Dawley rats, and Göttingen minipigs.
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Affiliation(s)
| | | | - Eric Troncy
- GREPAQ, Faculté de Médecine Vétérinaire, Universite de Montreal, Saint Hyacinthe, QC, Canada
| | | | | | | | | | | | - Dominique Paquette
- GREPAQ, Faculté de Médecine Vétérinaire, Universite de Montreal, Saint Hyacinthe, QC, Canada
| | - Emmanuel Boulay
- Charles River, Laval, QC, Canada
- GREPAQ, Faculté de Médecine Vétérinaire, Universite de Montreal, Saint Hyacinthe, QC, Canada
| | - Simon Authier
- Charles River, Laval, QC, Canada
- GREPAQ, Faculté de Médecine Vétérinaire, Universite de Montreal, Saint Hyacinthe, QC, Canada
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Hemmeter L, Bien CG, Bien CI, Tipold A, Neßler J, Bathen‐Nöthen A, Matiasek K, Dahlhoff M, Rusbridge C, Rotter Black C, Rentmeister K, Volk HA, Fischer A. Investigation of the presence of specific neural antibodies in dogs with epilepsy or dyskinesia using murine and human assays. J Vet Intern Med 2023; 37:1409-1417. [PMID: 37232512 PMCID: PMC10365065 DOI: 10.1111/jvim.16744] [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: 09/15/2022] [Accepted: 05/07/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Autoimmune mechanisms represent a novel category for causes of seizures and epilepsies in humans, and LGI1-antibody associated limbic encephalitis occurs in cats. HYPOTHESIS/OBJECTIVES To investigate the presence of neural antibodies in dogs with epilepsy or dyskinesia of unknown cause using human and murine assays modified for use in dogs. ANIMALS Fifty-eight dogs with epilepsy of unknown cause or suspected dyskinesia and 57 control dogs. METHODS Serum and CSF samples were collected prospectively as part of the diagnostic work-up. Clinical data including onset and seizure/episode type were retrieved from the medical records. Screening for neural antibodies was done with cell-based assays transfected with human genes for typical autoimmune encephalitis antigens and tissue-based immunofluorescence assays on mouse hippocampus slices in serum and CSF samples from affected dogs and controls. The commercial human und murine assays were modified with canine-specific secondary antibody. Positive controls were from human samples. RESULTS The commercial assays used in this study did not provide unequivocal evidence for presence of neural antibodies in dogs including one dog with histopathologically proven limbic encephalitis. Low titer IgLON5 antibodies were present in serum from one dog from the epilepsy/dyskinesia group and in one dog from the control group. CONCLUSION AND CLINICAL IMPORTANCE Specific neural antibodies were not detected using mouse and human target antigens in dogs with epilepsy and dyskinesia of unknown origin. These findings emphasize the need for canine-specific assays and the importance of control groups.
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Affiliation(s)
- Lea Hemmeter
- Section of Neurology, Centre for Clinical Veterinary MedicineLMU MunichMunichGermany
| | - Christian G. Bien
- Department of Epileptology (Krankenhaus Mara)Bielefeld University, Medical SchoolBielefeldGermany
- Laboratory KroneBad SalzuflenGermany
| | | | - Andrea Tipold
- Department of Small Animal Medicine and SurgeryUniversity of Veterinary Medicine Hannover FoundationHannoverGermany
| | - Jasmin Neßler
- Department of Small Animal Medicine and SurgeryUniversity of Veterinary Medicine Hannover FoundationHannoverGermany
| | | | - Kaspar Matiasek
- Section of Clinical & Comparative Neuropathology, Centre for Clinical Veterinary MedicineLMU MunichMunichGermany
| | - Maik Dahlhoff
- Institute of In Vivo and In Vitro Models, University of Veterinary Medicine ViennaViennaAustria
| | - Clare Rusbridge
- Fitzpatrick Referrals, Halfway LaneSurreyUK
- School of Veterinary Medicine, Faculty of Health & Medical SciencesUniversity of SurreySurreyUK
| | | | | | - Holger A. Volk
- Department of Small Animal Medicine and SurgeryUniversity of Veterinary Medicine Hannover FoundationHannoverGermany
| | - Andrea Fischer
- Section of Neurology, Centre for Clinical Veterinary MedicineLMU MunichMunichGermany
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Glantschnigg-Eisl U, Klang A, Kneissl S, Lang B, Waters P, Irani SR, Binks SNM, Pakozdy A. A feline model of spontaneously occurring autoimmune limbic encephalitis. Vet J 2023; 296-297:105974. [PMID: 36958405 DOI: 10.1016/j.tvjl.2023.105974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 03/08/2023] [Accepted: 03/20/2023] [Indexed: 03/25/2023]
Abstract
Autoimmune encephalitis (AE) is an important cause of encephalitis in humans and occurs at a similar rate to infectious encephalitis. It is frequently associated with antibodies against the extracellular domain of neuronal proteins. Among human AE, that with antibodies against leucine-rich glioma-inactivated 1 (LGI1) is one of the most prevalent forms, and was recently described in cats with limbic encephalitis (LE). In this study, we describe a large cohort (n = 32) of cats with AE, tested positive for voltage gated potassium channel (VGKC)-antibodies, of which 26 (81%) harboured LGI1-antibodies. We delineate their clinical and paraclinical features as well as long-term outcomes up to 5 years. Similar to human cases, most cats with LGI1-antibodies had a history of focal seizures (83%), clustering in the majority (88%), with interictal behavioural changes (73%). Among feline AE patients, there was no seizure type or other clinical characteristic that could distinguish LGI1-antibody positive from negative cats, unlike the pathognomic faciobrachial dystonic seizures seen in humans. Although six cats were euthanased in the first year for epilepsy-associated reasons, those attaining at least 1-year survival had good seizure control and quality of life with appropriate veterinary care and medication. Acute-phase immunotherapy (prednisolone) was given to the most severely unwell cases and its effect is retrospectively evaluated in 10 cats. Our data show LGI1-antibodies are an important cause of feline encephalitis, sharing many features with human AE. Further research should examine optimal therapeutic management strategies and the cause of LE in seronegative cats, building on paradigms established in the counterpart human disease.
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Affiliation(s)
- U Glantschnigg-Eisl
- Clinic for Small Animals, Internal Medicine, University of Veterinary Medicine Vienna, Austria.
| | - A Klang
- Institute for Pathology and Forensic Veterinary Medicine, Universitiy of Veterinary Medicine Vienna, Austria
| | - S Kneissl
- Diagnostic Imaging, University of Veterinary Medicine Vienna, Austria
| | - B Lang
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, UK
| | - P Waters
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, OX3 9DU, UK
| | - S 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
| | - S N M 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
| | - A Pakozdy
- Clinic for Small Animals, Internal Medicine, University of Veterinary Medicine Vienna, Austria
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Pakozdy A, Halasz P, Klang A, Lörincz BA, Schmidt MJ, Glantschnigg-Eisl U, Binks S. Temporal lobe epilepsy in cats. Vet J 2023; 291:105941. [PMID: 36549606 DOI: 10.1016/j.tvjl.2022.105941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 12/02/2022] [Accepted: 12/16/2022] [Indexed: 12/23/2022]
Abstract
In recent years there has been increased attention to the proposed entity of feline temporal lobe epilepsy (TLE). Epileptic discharges in certain parts of the temporal lobe elicit very similar semiology, which justifies grouping these epilepsies under one name. Furthermore, feline TLE patients tend to have histopathological changes within the temporal lobe, usually in the hippocampus. The initial aetiology is likely to be different but may result in hippocampal necrosis and later hippocampal sclerosis. The aim of this article was not only to summarise the clinical features and the possible aetiology, but also being work to place TLE within the veterinary epilepsy classification. Epilepsies in cats, similar to dogs, are classified based on the aetiology into idiopathic epilepsy, structural epilepsy and unknown cause. TLE seems to be outside of this classification, as it is not an aetiologic category, but a syndrome, associated with a topographic affiliation to a certain anatomical brain structure. Magnetic resonance imaging, histopathologic aspects and current medical therapeutic considerations will be summarised, and emerging surgical options are discussed.
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Affiliation(s)
- Akos Pakozdy
- University Clinic for Small Animals, University of Veterinary Medicine, Vienna, Austria.
| | - Peter Halasz
- Institute of Experimental Medicine, Budapest, Hungary
| | - Andrea Klang
- Institute of Pathology, University of Veterinary Medicine, Austria
| | - Borbala A Lörincz
- Clinic of Diagnostic Imaging, University of Veterinary Medicine Vienna, Austria
| | - Martin J Schmidt
- Department of Veterinary Clinical Sciences, Small Animal Clinic-Neurosurgery, Neuroradiology and Clinical Neurology, Justus-Liebig-University, Germany
| | | | - Sophie Binks
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
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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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Hasegawa D, Kanazono S, Chambers JK, Uchida K. Neurosurgery in feline epilepsy, including clinicopathology of feline epilepsy syndromes. Vet J 2022; 290:105928. [PMID: 36347391 DOI: 10.1016/j.tvjl.2022.105928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 11/04/2022] [Accepted: 11/04/2022] [Indexed: 11/07/2022]
Abstract
Feline epilepsy is treated with antiseizure medications, which achieves fair to good seizure control. However, a small subset of feline patients with drug-resistant epilepsy requires alternative therapies. Furthermore, approximately 50 % of cats with epileptic seizures are diagnosed with structural epilepsy with or without hippocampal abnormality and may respond to surgical intervention. The presence of hippocampal pathology and intracranial tumors is a key point to consider for surgical treatment. This review describes feline epilepsy syndrome and epilepsy-related pathology, and discusses the indications for and availability of neurosurgery, including lesionectomy, temporal lobectomy with hippocampectomy, and corpus callosotomy, for cats with different epilepsy types.
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Affiliation(s)
- Daisuke Hasegawa
- Laboratory of Veterinary Radiology, Nippon Veterinary and Life Science University, 1-7-1 Kyounancho, Musashino, Tokyo 180-8602, Japan; The Research Center for Animal Life Science, Nippon Veterinary and Life Science University, 1-7-1 Kyounancho, Musashino, Tokyo 180-8602, Japan.
| | - Shinichi Kanazono
- Neurology and Neurosurgery Service, Veterinary Specialists and Emergency Center, 815 Ishigami, Kawaguchi, Saitama 333-0823, Japan
| | - James K Chambers
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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7
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Eaton SL, Murdoch F, Rzechorzek NM, Thompson G, Hartley C, Blacklock BT, Proudfoot C, Lillico SG, Tennant P, Ritchie A, Nixon J, Brennan PM, Guido S, Mitchell NL, Palmer DN, Whitelaw CBA, Cooper JD, Wishart TM. Modelling Neurological Diseases in Large Animals: Criteria for Model Selection and Clinical Assessment. Cells 2022; 11:cells11172641. [PMID: 36078049 PMCID: PMC9454934 DOI: 10.3390/cells11172641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 11/16/2022] Open
Abstract
Issue: The impact of neurological disorders is recognised globally, with one in six people affected in their lifetime and few treatments to slow or halt disease progression. This is due in part to the increasing ageing population, and is confounded by the high failure rate of translation from rodent-derived therapeutics to clinically effective human neurological interventions. Improved translation is demonstrated using higher order mammals with more complex/comparable neuroanatomy. These animals effectually span this translational disparity and increase confidence in factors including routes of administration/dosing and ability to scale, such that potential therapeutics will have successful outcomes when moving to patients. Coupled with advancements in genetic engineering to produce genetically tailored models, livestock are increasingly being used to bridge this translational gap. Approach: In order to aid in standardising characterisation of such models, we provide comprehensive neurological assessment protocols designed to inform on neuroanatomical dysfunction and/or lesion(s) for large animal species. We also describe the applicability of these exams in different large animals to help provide a better understanding of the practicalities of cross species neurological disease modelling. Recommendation: We would encourage the use of these assessments as a reference framework to help standardise neurological clinical scoring of large animal models.
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Affiliation(s)
- Samantha L. Eaton
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
- Correspondence: (S.L.E.); (T.M.W.); Tel.: +44-(0)-131-651-9125 (S.L.E.); +44-(0)-131-651-9233 (T.M.W.)
| | - Fraser Murdoch
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Nina M. Rzechorzek
- Medical Research Council Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge CB2 0QH, UK
| | - Gerard Thompson
- Centre for Clinical Brain Sciences, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
- Department of Clinical Neurosciences, NHS Lothian, 50 Little France Crescent, Edinburgh EH16 4TJ, UK
| | - Claudia Hartley
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Benjamin Thomas Blacklock
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Chris Proudfoot
- The Large Animal Research & Imaging Facility, Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Simon G. Lillico
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Peter Tennant
- The Large Animal Research & Imaging Facility, Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Adrian Ritchie
- The Large Animal Research & Imaging Facility, Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - James Nixon
- The Large Animal Research & Imaging Facility, Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Paul M. Brennan
- Translational Neurosurgery, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh EH16 4SB, UK
| | - Stefano Guido
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
- Bioresearch & Veterinary Services, University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh EH16 4SB, UK
| | - Nadia L. Mitchell
- Faculty of Agriculture and Life Sciences, Lincoln University, P.O. Box 85084, Lincoln 7647, New Zealand
| | - David N. Palmer
- Faculty of Agriculture and Life Sciences, Lincoln University, P.O. Box 85084, Lincoln 7647, New Zealand
| | - C. Bruce A. Whitelaw
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
| | - Jonathan D. Cooper
- Departments of Pediatrics, Genetics, and Neurology, Washington University School of Medicine in St. Louis, 660 S Euclid Ave, St. Louis, MO 63110, USA
| | - Thomas M. Wishart
- Royal (Dick) School of Veterinary Studies and Roslin Institute, University of Edinburgh, Easter Bush Campus, Roslin, Midlothian EH25 9RG, UK
- Correspondence: (S.L.E.); (T.M.W.); Tel.: +44-(0)-131-651-9125 (S.L.E.); +44-(0)-131-651-9233 (T.M.W.)
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Huenerfauth EI, Bien CG, Bien C, Volk HA, Meyerhoff N. Case Report: Anti-GABAA Receptor Encephalitis in a Dog. Front Vet Sci 2022; 9:886711. [PMID: 35812851 PMCID: PMC9262380 DOI: 10.3389/fvets.2022.886711] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Accepted: 05/25/2022] [Indexed: 01/21/2023] Open
Abstract
Autoantibodies against neurotransmitter receptors detected in cerebrospinal fluid (CSF) and serum are increasingly recognized in people with human autoimmune encephalitis causing severe neurological deficits, such as seizures and behavioral abnormalities. This case report describes the first encephalitis associated with antibodies against the γ-aminobutyric acid-A receptor (GABAAR) in a dog. A young male intact Cavalier King Charles Spaniel was presented with recent onset of initial multiple generalized tonic-clonic seizures progressing into a status epilepticus. Interictally, he showed alternating stupor and hyperexcitability, ataxia, pleurothotonus and circling behavior to the left side. Magnetic resonance imaging (MRI) of the brain showed breed-specific anatomical abnormalities. Standard CSF analysis was unremarkable. Despite treatment with multiple antiseizure medications (ASMs) seizures and behavior abnormalities sustained. Immunotherapy with dexamethasone was started on the fifth day after disease manifestation. This led to rapid improvement of clinical signs. An extensive antibody search in CSF and serum demonstrated a neuropil staining pattern on a tissue-based assay compatible with GABAAR antibodies. The diagnosis was confirmed by binding of serum and CSF antibodies to GABAAR transfected Human Embryonic Kidney cells. The serum titer was 1:320, the CSF titer 1:2. At the control visit 4.5 weeks after start of immunotherapy, the dog was clinically normal. The GABAAR antibody titer in serum had strongly decreased. The antibodies were no longer detectable in CSF. Based on clinical presentation and testing for GABAAR binding antibodies, this describes the first veterinary patient with an anti-GABAAR encephalitis with a good outcome following ASM and corticosteroid treatment.
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Affiliation(s)
- Enrice I. Huenerfauth
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Foundation, Hannover, Germany
- *Correspondence: Enrice I. Huenerfauth
| | | | | | - Holger A. Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Foundation, Hannover, Germany
| | - Nina Meyerhoff
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Foundation, Hannover, Germany
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Zilli J, Schänzer A, Büttner K, Kressin M, Schmidt MJ. Quantitative and qualitative evaluation of the hippocampal cytoarchitecture in adult cats with regard to the pathological diagnosis of hippocampal sclerosis. PLoS One 2022; 17:e0268010. [PMID: 35560321 PMCID: PMC9106214 DOI: 10.1371/journal.pone.0268010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Accepted: 04/20/2022] [Indexed: 11/18/2022] Open
Abstract
Cats are known to be affected by hippocampal sclerosis, potentially causing antiseizure drug(s) resistance. In order to lay the foundation for a standardized, systematic classification and diagnosis of this pathology in cats, this prospective study aimed at evaluating normal reference values of cellular densities and the cytoarchitecture of the feline hippocampus. Three transverse sections (head, body and tail) of each left hippocampus were obtained from 17 non-epileptic cats of different brachycephalic and mesocephalic breeds and age classes (range: 3–17 years). Histological (hematoxylin and eosin, Nissl) and immunohistochemical (NeuN, GFAP) staining was performed to investigate neuron and astroglial cell populations, as well as the layer thickness of the pyramidal cell layer and granule cell layer. Significant differences in neuronal density (in CA2-CA4 and the granule cell layer) and layer thickness (in CA1-CA3 and the granule cell layer) were evidenced throughout the longitudinal hippocampal axis (p<0.05); on the other hand, the astrocyte density did not differ. Moreover, reference ranges were defined for these parameters in the pyramidal cell layer and in the granule cell layer. The findings did not differ according to breed or age. In veterinary medicine these parameters have not been evaluated in cats so far. As surgical treatment may become a therapeutic option for cats with temporal lobe epilepsy, estimating normal values of the hippocampal cytoarchitecture will help in the standardized histopathological examination of resected hippocampal specimens to reach a diagnosis of hippocampal sclerosis.
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Affiliation(s)
- Jessica Zilli
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Hessen, Germany
- * E-mail:
| | - Anne Schänzer
- Institute of Neuropathology, Justus-Liebig-University, Giessen, Hessen, Germany
| | - Kathrin Büttner
- Institute for Biomathematics, Justus-Liebig-University, Giessen, Hessen, Germany
| | - Monika Kressin
- Institute for Veterinary Anatomy, Histology and Embryology, Justus-Liebig-University, Giessen, Hessen, Germany
| | - Martin J. Schmidt
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Hessen, Germany
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Gill AJ, Venkatesan A. Pathogenic mechanisms in neuronal surface autoantibody-mediated encephalitis. J Neuroimmunol 2022; 368:577867. [DOI: 10.1016/j.jneuroim.2022.577867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 03/22/2022] [Accepted: 04/09/2022] [Indexed: 11/16/2022]
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Riegler E, Pákozdy Á, Klang A, Tichy A, Braunöder B, Prüllage M, Lőrincz BB, Lőrincz BA. [Magnetic resonance imaging findings in 143 epileptic cats]. TIERARZTLICHE PRAXIS. AUSGABE K, KLEINTIERE/HEIMTIERE 2022; 50:13-22. [PMID: 35235959 DOI: 10.1055/a-1697-4729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
OBJECTIVE Epilepsy is one of the more common chronic neurological diseases in cats in which MRI plays a key role in the diagnostic work-up. Hippocampal MRI changes are common in cats, however it is unclear whether these changes represent the reason or the consequence of the disease.The goal of the present study was the retrospective analysis of the MRI findings in a large cohort of epileptic cats. MATERIAL AND METHODS In total, 143 cats of 3 age groups (< 1 year, 1-6 years, and > 6 years) were included in the study. MRI findings were divided into 4 categories: normal, with extrahippocampal lesions, and hippocampal signal alterations with or without contrast enhancement. The prevalence and frequency of these MRI findings in the age groups were examined using chi-quadrat test and nominal regression model. RESULTS In approximately one half of the cats (49 %), MRI displayed normal findings. Extrahippocampal changes occurred in 18 % of the animals. Hippocampal alterations were present in 33 % of the cats. Hippocampal sclerosis was found histopathologically in all four MRI categories. CONCLUSION AND CLINICAL RELEVANCE Brain MRI was normal in approximately 50 % of the epileptic cats. Extrahippocampal changes are expected mostly in cats older than 6 years. The etiology of the hippocampal alterations is unclear in most cases. Further investigations are needed for a better understanding of the hippocampal signal alterations.
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Affiliation(s)
| | - Ákos Pákozdy
- Interne Medizin Kleintiere Veterinärmedizinische Universität Wien
| | - Andrea Klang
- Department für Pathobiologie, Veterinärmedizinische Universität Wien
| | - Alexander Tichy
- Department für Bioinformatik und Biostatistik, Veterinärmedizinische Universität Wien
| | | | - Maria Prüllage
- Bildgebende Diagnostik, Veterinärmedizinische Universität Wien
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Abstract
Limbic encephalitis (LE) is a clinical syndrome defined by subacutely evolving limbic signs and symptoms with structural and functional evidence of mediotemporal damage in the absence of a better explanation than an autoimmune (or paraneoplastic) cause. There are features common to all forms of LE. In recent years, antibody(ab)-defined subtypes have been established. They are distinct regarding underlying pathophysiologic processes, clinical and magnetic resonance imaging courses, cerebrospinal fluid signatures, treatment responsivity, and likelihood of a chronic course. With immunotherapy, LE with abs against surface antigens has a better outcome than LE with abs to intracellular antigens. Diagnostic and treatment challenges are, on the one hand, to avoid overlooking and undertreatment and, on the other hand, to avoid overdiagnoses and overtreatment. LE can be conceptualized as a model disease for the consequences of new onset mediotemporal damage by different mechanisms in adult life. It may be studied as an example of mediotemporal epileptogenesis.
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Affiliation(s)
- Christian G Bien
- Department of Epileptology (Krankenhaus Mara), Bielefeld University, Bielefeld, Germany; Laboratory Krone, Bad Salzuflen, Germany.
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13
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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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14
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Abstract
The realization that autoantibodies can contribute to dysfunction of the brain has brought about a paradigm shift in neurological diseases over the past decade, offering up important novel diagnostic and therapeutic opportunities. Detection of specific autoantibodies to neuronal or glial targets has resulted in a better understanding of central nervous system autoimmunity and in the reclassification of some diseases previously thought to result from infectious, 'idiopathic' or psychogenic causes. The most prominent examples, such as aquaporin 4 autoantibodies in neuromyelitis optica or NMDAR autoantibodies in encephalitis, have stimulated an entire field of clinical and experimental studies on disease mechanisms and immunological abnormalities. Also, these findings inspired the search for additional autoantibodies, which has been very successful to date and has not yet reached its peak. This Review summarizes this rapid development at a point in time where preclinical studies have started delivering fundamental new data for mechanistic understanding, where new technologies are being introduced into this field, and - most importantly - where the first specifically tailored immunotherapeutic approaches are emerging.
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Affiliation(s)
- Harald Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany.
- Department of Neurology and Experimental Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
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15
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Scalia B, Caine A, Pittaway R, Cherubini GB. Feline temporal lobe epilepsy: seven cases of hippocampal and piriform lobe necrosis in England and literature review. J Feline Med Surg 2021; 24:596-608. [PMID: 34355984 DOI: 10.1177/1098612x211035049] [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: 11/17/2022]
Abstract
CASE SERIES SUMMARY Seven cases of feline hippocampal and piriform lobe necrosis (FHN) are described, with particular emphasis on clinical, radiographic and histopathological correlations. FHN is an uncommon acute epileptic condition resembling human autoimmune limbic encephalitis and temporal lobe epilepsy. Seizures are typically focal and feature uni- or bilateral orofacial or head twitching, hypersalivation, lip smacking, mydriasis, vocalisation and motionless staring, with inter-ictal behavioural changes such as unprovoked aggression and rapid running. Emerging evidence supports an autoimmune aetiology, although disruption of hippocampal architecture secondary to brain neoplasia has also been recognised. Most commonly, however, the underlying cause remains unknown. Diagnosis is achieved clinically and with brain MRI; electroencephalography and voltage-gated potassium channel-complex autoantibodies are currently the subject of research. Affected cats are frequently refractory to conventional antiepileptic treatment. RELEVANCE AND NOVEL INFORMATION Following a review of the literature, including potential complicating factors and comparisons with human medicine, the hippocampus and piriform lobe are proposed as the neuroanatomical localisation for focal seizures with orofacial involvement in cats, regardless of aetiology.
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Affiliation(s)
| | - Abby Caine
- Dick White Referrals, Six Mile Bottom, UK
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16
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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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17
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Giannoccaro MP, Wright SK, Vincent A. In vivo Mechanisms of Antibody-Mediated Neurological Disorders: Animal Models and Potential Implications. Front Neurol 2020; 10:1394. [PMID: 32116982 PMCID: PMC7013005 DOI: 10.3389/fneur.2019.01394] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/19/2019] [Indexed: 12/25/2022] Open
Abstract
Over the last two decades, the discovery of antibodies directed against neuronal surface antigens (NSA-Abs) in patients with different forms of encephalitis has provided a basis for immunotherapies in previously undefined disorders. Nevertheless, despite the circumstantial clinical evidence of the pathogenic role of these antibodies in classical autoimmune encephalitis, specific criteria need to be applied in order to establish the autoimmune nature of a disease. A growing number of studies have begun to provide proof of the pathogenicity of NSA-Abs and insights into their pathogenic mechanisms through passive transfer or, more rarely, through active immunization animal models. Moreover, the increasing evidence that NSA-Abs in the maternal circulation can reach the fetal brain parenchyma during gestation, causing long-term effects, has led to models of antibody-induced neurodevelopmental disorders. This review summarizes different methodological approaches and the results of the animal models of N-methyl-d-aspartate receptor (NMDAR), leucine-rich glioma-inactivated 1 (LGI1), contactin-associated protein 2 (CASPR2), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) antibody-mediated disorders and discuss the results and the limitations. We also summarize recent experiments that demonstrate that maternal antibodies to NMDAR and CASPR2 can alter development in the offspring with potential lifelong susceptibility to neurological or psychiatric disorders.
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Affiliation(s)
- Maria Pia Giannoccaro
- Department of Biomedical and Neuromotor Sciences, University of Bologna and IRCCS Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Sukhvir K. Wright
- School of Life and Health Sciences & Aston Neuroscience Institute, Aston University, Birmingham, United Kingdom
- Department of Neurology, Birmingham Children's Hospital, Birmingham, United Kingdom
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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18
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Partridge B, Rossmeisl JH. Companion animal models of neurological disease. J Neurosci Methods 2020; 331:108484. [PMID: 31733285 PMCID: PMC6942211 DOI: 10.1016/j.jneumeth.2019.108484] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2019] [Revised: 10/28/2019] [Accepted: 10/28/2019] [Indexed: 02/07/2023]
Abstract
Clinical translation of novel therapeutics that improve the survival and quality of life of patients with neurological disease remains a challenge, with many investigational drug and device candidates failing in advanced stage clinical trials. Naturally occurring inherited and acquired neurological diseases, such as epilepsy, inborn errors of metabolism, brain tumors, spinal cord injury, and stroke occur frequently in companion animals, and many of these share epidemiologic, pathophysiologic and clinical features with their human counterparts. As companion animals have a relatively abbreviated lifespan and genetic background, are immunocompetent, share their environment with human caregivers, and can be clinically managed using techniques and tools similar to those used in humans, they have tremendous potential for increasing the predictive value of preclinical drug and device studies. Here, we review comparative features of spontaneous neurological diseases in companion animals with an emphasis on neuroimaging methods and features, illustrate their historical use in translational studies, and discuss inherent limitations associated with each disease model. Integration of companion animals with naturally occurring disease into preclinical studies can complement and expand the knowledge gained from studies in other animal models, accelerate or improve the manner in which research is translated to the human clinic, and ultimately generate discoveries that will benefit the health of humans and animals.
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Affiliation(s)
- Brittanie Partridge
- Veterinary and Comparative Neuro-Oncology Laboratory, Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061, USA; Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Medical Center Blvd, NRC 405, Winston Salem, NC, 27157, USA
| | - John H Rossmeisl
- Veterinary and Comparative Neuro-Oncology Laboratory, Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061, USA; Brain Tumor Center of Excellence, Wake Forest University Comprehensive Cancer Center, Medical Center Blvd, NRC 405, Winston Salem, NC, 27157, USA.
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19
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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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20
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Hazenfratz M, Taylor SM. Recurrent seizures in cats: Diagnostic approach - when is it idiopathic epilepsy? J Feline Med Surg 2019; 20:811-823. [PMID: 30139320 DOI: 10.1177/1098612x18791873] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Practical relevance: Seizures are one of the most common neurologic problems recognized in cats, affecting approximately 1-3% of the general population. Treatment options and prognosis are closely related to the underlying cause, so it is important that veterinarians are familiar with the diagnostic approach to cats with seizures and options for medical management. Series outline: This is the first of a two-part article series that reviews the diagnosis and treatment of seizures in cats. Part 1 outlines the classification and terminology used to describe epilepsy and epileptic seizures in cats, and discusses some of the most common and unique causes of recurrent seizures in cats. The diagnostic approach to cats with recurrent seizures is addressed, as are criteria for the diagnosis of idiopathic epilepsy. AUDIENCE This review of recurrent seizures in cats is intended for all veterinarians who are facing the challenges of seizure diagnosis and management in the feline patient. Evidence base: Recommendations for diagnosis and management of feline seizure disorders have historically been extrapolated from the canine and human literature. The information and guidance provided in this two-part series is based on a review of the recent published literature addressing seizure disorders and antiepileptic treatment in cats, as well as the authors' clinical experience.
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Affiliation(s)
- Michal Hazenfratz
- Department of Clinical Studies, Ontario Veterinary College, University of Guelph, Canada
| | - Susan M Taylor
- Department of Small Animal Clinical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, Saskatoon, SK S7N5B4, Canada
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21
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Stafford EG, Kortum A, Castel A, Green L, Lau J, Early PJ, Muñana KR, Mariani CL, Yoder JA, Olby NJ. Presence of cerebrospinal fluid antibodies associated with autoimmune encephalitis of humans in dogs with neurologic disease. J Vet Intern Med 2019; 33:2175-2182. [PMID: 31495976 PMCID: PMC6766506 DOI: 10.1111/jvim.15616] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 08/22/2019] [Indexed: 12/12/2022] Open
Abstract
Background Presumed autoimmune diseases affecting the central nervous system (CNS) of dogs are common. In people, antibodies against neuronal cell surface antigens that are associated with a wide variety of neurological syndromes have been identified. The presence of cerebrospinal fluid (CSF) autoantibodies that target neuronal cell surface proteins has not been reported in dogs with neurologic disorders. Objectives Autoantibodies to neuronal cell surface antigens can be found in the CSF of dogs with inflammatory CNS disease. Our aim was to determine whether 6 neuronal cell surface autoantibodies were present in the CSF of dogs diagnosed with inflammatory and noninflammatory CNS disease. Animals Client‐owned dogs with CNS disease and complete diagnostic evaluation including magnetic resonance imaging and CSF analysis were included. One healthy dog was included as a negative control. Methods Cerebrospinal fluid was tested for 6 antigenic targets with a commercially available indirect immunofluorescence assay test kit. Results There were 32 dogs with neurological disease, 19 diagnosed with inflammatory disease (encephalitis and meningitis), 10 with noninflammatory disease (neoplasia, intervertebral disk disease, degenerative myelopathy, and epilepsy), 2 with no diagnosis, and 1 with neoplasia and meningoencephalitis. Anti‐N‐methyl‐d‐aspartate receptor 1 (NMDAR1) antibodies were detected in 3 dogs (3/32; 9.38%). All 3 dogs responded to treatment of meningoencephalomyelitis of unknown etiology (MUE). Conclusions and Clinical Importance Further evaluation of the prevalence and clinical relevance of CSF and serum antibodies to neuronal cell surface antigens is warranted. Defining antigenic targets associated with encephalitis in dogs might allow diagnostic categorization of MUE antemortem.
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Affiliation(s)
- Emma G Stafford
- Department of Population Health and Pathobiology, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina.,Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Clinical Veterinary Pharmacy, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Amanda Kortum
- Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Aude Castel
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Small Animal Clinical Sciences, University of Tennessee Veterinary Teaching Hospital, College of Veterinary Medicine, Knoxville, Tennessee
| | - Lauren Green
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Jeanie Lau
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Peter J Early
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Karen R Muñana
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Christopher L Mariani
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Jeffrey A Yoder
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Molecular Biomedical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
| | - Natasha J Olby
- Comparative Medicine Institute, North Carolina State University, Raleigh, North Carolina.,Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina
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22
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Devinsky O, Boesch JM, Cerda-Gonzalez S, Coffey B, Davis K, Friedman D, Hainline B, Houpt K, Lieberman D, Perry P, Prüss H, Samuels MA, Small GW, Volk H, Summerfield A, Vite C, Wisniewski T, Natterson-Horowitz B. A cross-species approach to disorders affecting brain and behaviour. Nat Rev Neurol 2019; 14:677-686. [PMID: 30287906 DOI: 10.1038/s41582-018-0074-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Structural and functional elements of biological systems are highly conserved across vertebrates. Many neurological and psychiatric conditions affect both humans and animals. A cross-species approach to the study of brain and behaviour can advance our understanding of human disorders via the identification of unrecognized natural models of spontaneous disorders, thus revealing novel factors that increase vulnerability or resilience, and via the assessment of potential therapies. Moreover, diagnostic and therapeutic advances in human neurology and psychiatry can often be adapted for veterinary patients. However, clinical and research collaborations between physicians and veterinarians remain limited, leaving this wealth of comparative information largely untapped. Here, we review pain, cognitive decline syndromes, epilepsy, anxiety and compulsions, autoimmune and infectious encephalitides and mismatch disorders across a range of animal species, looking for novel insights with translational potential. This comparative perspective can help generate novel hypotheses, expand and improve clinical trials and identify natural animal models of disease resistance and vulnerability.
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Affiliation(s)
- Orrin Devinsky
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA.
| | - Jordyn M Boesch
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | | | - Barbara Coffey
- Department of Child and Adolescent Psychiatry, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kathryn Davis
- Department of Neurology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, USA
| | - Daniel Friedman
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA
| | - Brian Hainline
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA
| | - Katherine Houpt
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Daniel Lieberman
- Department of Human Evolutionary Biology, Harvard University, Cambridge, MA, USA
| | - Pamela Perry
- College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Harald Prüss
- Department of Neurology with Experimental Neurology, Charité University Medicine Berlin, Berlin, Germany, and German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | | | - Gary W Small
- University of California-Los Angeles (UCLA) Brain Research Institute, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Holger Volk
- Veterinary Neurology and Neurosurgery, The Royal Veterinary College, University of London, London, UK
| | - Artur Summerfield
- Institute of Virology and Immunology and Department of Infectious Diseases and Pathobiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
| | - Charles Vite
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas Wisniewski
- Department of Neurology, New York University (NYU) Langone Medical Center and NYU School of Medicine, New York, NY, USA
| | - Barbara Natterson-Horowitz
- Department of Ecology and Evolutionary Biology, Division of Cardiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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23
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Hasegawa D, Ohnishi Y, Koyama E, Matsunaga S, Ohtani S, Nakanishi A, Shiga T, Chambers JK, Uchida K, Yokoi N, Fukata Y, Fukata M. Deleted in colorectal cancer (netrin-1 receptor) antibodies and limbic encephalitis in a cat with hippocampal necrosis. J Vet Intern Med 2019; 33:1440-1445. [PMID: 30942925 PMCID: PMC6524083 DOI: 10.1111/jvim.15492] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 03/19/2019] [Indexed: 12/01/2022] Open
Abstract
A 7‐year‐old neutered female domestic shorthaired cat born in Poland and then moved to Japan presented to the local clinic with recent onset of convulsive cluster seizures and status epilepticus. Magnetic resonance imaging revealed bilateral swelling of the hippocampus with T2 hyperintensity and contrast enhancing image, suggesting hippocampal necrosis. The cat completely recovered after treatment with antiepileptic drugs (AED) and administration of prednisolone (1 mg/kg PO q24h for 4 days and tapered). However, cluster seizures reoccurred and developed into status epilepticus despite increasing doses of AED. Although the convulsions were resolved by other AEDs, stupor and renal failure developed, and the cat was euthanized. Pathological findings were consistent with hippocampal necrosis. Immunological analysis for leucine‐rich glioma inactivated 1 (LGI1) autoantibodies was negative, but antibodies against DCC (deleted in colorectal carcinoma) known as netrin‐1 receptor were found. This report describes a case of feline autoimmune limbic encephalitis and hippocampal necrosis that were presumably associated with DCC autoantibodies.
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Affiliation(s)
- Daisuke Hasegawa
- Department of Veterinary Clinical Medicine, Nippon Veterinary and Life Science University, Tokyo, Japan
| | - Yumi Ohnishi
- Companion Animal Medical Imaging Center, Tokyo, Japan
| | - Eiji Koyama
- Companion Animal Medical Imaging Center, Tokyo, Japan.,Sendai General Animal Hospital, Miyagi, Japan
| | | | | | | | - Takanori Shiga
- Laboratory of Veterinary Pathology, The University of Tokyo, Tokyo, Japan
| | - James K Chambers
- Laboratory of Veterinary Pathology, The University of Tokyo, Tokyo, Japan
| | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, The University of Tokyo, Tokyo, Japan
| | - Norihiko Yokoi
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Science, Aichi, Japan
| | - Yuko Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Science, Aichi, Japan
| | - Masaki Fukata
- Division of Membrane Physiology, Department of Molecular and Cellular Physiology, National Institute for Physiological Sciences, National Institutes of Natural Science, Aichi, Japan
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24
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Yu Y, Hasegawa D, Fujiwara-Igarashi A, Hamamoto Y, Mizoguchi S, Kuwabara T, Fujita M. Molecular cloning and characterization of the family of feline leucine-rich glioma-inactivated (LGI) genes, and mutational analysis in familial spontaneous epileptic cats. BMC Vet Res 2017; 13:389. [PMID: 29237452 PMCID: PMC5729232 DOI: 10.1186/s12917-017-1308-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/28/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Leucine-rich glioma-inactivated (LGI) proteins play a critical role in synaptic transmission. Dysfunction of these genes and encoded proteins is associated with neurological disorders such as genetic epilepsy or autoimmune limbic encephalitis in animals and human. Familial spontaneous epileptic cats (FSECs) are the only feline strain and animal model of familial temporal lobe epilepsy. The seizure semiology of FSECs comprises recurrent limbic seizures with or without evolution into generalized epileptic seizures, while cats with antibodies against voltage-gated potassium channel complexed/LGI1 show limbic encephalitis and recurrent limbic seizures. However, it remains unclear whether the genetics underlying FSECs are associated with LGI family genes. In the present study, we cloned and characterized the feline LGI1-4 genes and examined their association with FSECs. Conventional PCR techniques were performed for cloning and mutational analysis. Characterization was predicted using bioinformatics software. RESULTS The cDNAs of feline LGI1-4 contained 1674-bp, 1650-bp, 1647-bp, and 1617-bp open reading frames, respectively, and encoded proteins comprising 557, 549, 548, and 538 amino acid residues, respectively. The feline LGI1-4 putative protein sequences showed high homology with Homo sapiens, Canis familiaris, Bos taurus, Sus scrofa, and Equus caballus (92%-100%). Mutational analysis in 8 FSECs and 8 controls for LGI family genes revealed 3 non-synonymous and 14 synonymous single nucleotide polymorphisms in the coding region. Only one non-synonymous single nucleotide polymorphism in LGI4 was found in 3 out of 8 FSECs. Using three separate computational tools, this mutation was not predicted to be disease causing. No co-segregation of the disease was found with any variant. CONCLUSIONS We cloned the cDNAs of the four feline LGI genes, analyzed the amino acid sequences, and revealed that epilepsy in FSEC is not a monogenic disorder associated with LGI genes.
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Affiliation(s)
- Yoshihiko Yu
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan.
| | - Daisuke Hasegawa
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan.
| | - Aki Fujiwara-Igarashi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Yuji Hamamoto
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Shunta Mizoguchi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Takayuki Kuwabara
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
| | - Michio Fujita
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, 1-7-1 Kyonan-cho, Musashino-shi, Tokyo, 180-8602, Japan
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Tröscher AR, Klang A, French M, Quemada-Garrido L, Kneissl SM, Bien CG, Pákozdy Á, Bauer J. Selective Limbic Blood-Brain Barrier Breakdown in a Feline Model of Limbic Encephalitis with LGI1 Antibodies. Front Immunol 2017; 8:1364. [PMID: 29093718 PMCID: PMC5651237 DOI: 10.3389/fimmu.2017.01364] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 10/05/2017] [Indexed: 12/30/2022] Open
Abstract
Human leucine-rich glioma-inactivated protein 1 encephalitis (LGI1) is an autoimmune limbic encephalitis in which serum and cerebrospinal fluid contain antibodies targeting LGI1, a protein of the voltage gated potassium channel (VGKC) complex. Recently, we showed that a feline model of limbic encephalitis with LGI1 antibodies, called feline complex partial seizures with orofacial involvement (FEPSO), is highly comparable to human LGI1 encephalitis. In human LGI1 encephalitis, neuropathological investigations are difficult because very little material is available. Taking advantage of this natural animal model to study pathological mechanisms will, therefore, contribute to a better understanding of its human counterpart. Here, we present a brain-wide histopathological analysis of FEPSO. We discovered that blood–brain barrier (BBB) leakage was present not only in all regions of the hippocampus but also in other limbic structures such as the subiculum, amygdale, and piriform lobe. However, in other regions, such as the cerebellum, no leakage was observed. In addition, this brain-region-specific immunoglobulin leakage was associated with the breakdown of endothelial tight junctions. Brain areas affected by BBB dysfunction also revealed immunoglobulin and complement deposition as well as neuronal cell death. These neuropathological findings were supported by magnetic resonance imaging showing signal and volume increase in the amygdala and the piriform lobe. Importantly, we could show that BBB disturbance in LGI1 encephalitis does not depend on T cell infiltrates, which were present brain-wide. This finding points toward another, so far unknown, mechanism of opening the BBB. The limbic predilection sites of immunoglobulin antibody leakage into the brain may explain why most patients with LGI1 antibodies have a limbic phenotype even though LGI1, the target protein, is ubiquitously distributed across the central nervous system.
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Affiliation(s)
- Anna R Tröscher
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Andrea Klang
- Department for Pathobiology, Institute of Pathology and Forensic Veterinary Medicine, University of Veterinary Medicine, Vienna, Austria
| | - Maria French
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Lucía Quemada-Garrido
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
| | - Sibylle Maria Kneissl
- Diagnostic Imaging, Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
| | | | - Ákos Pákozdy
- Clinical Unit of Internal Medicine Small Animals, University of Veterinary Medicine, Vienna, Austria
| | - Jan Bauer
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Vienna, Austria
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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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Hasegawa D, Pakozdy A, Volk HA. Differentiating structural from idiopathic epilepsy in cats. Vet Rec 2017. [DOI: 10.1136/vr.j2896] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Affiliation(s)
- Daisuke Hasegawa
- Department of Clinical Veterinary Science; Nippon Veterinary and Life Science University; Tokyo Japan
| | - Akos Pakozdy
- Clinic for Small Animal Medicine; University of Veterinary Medicine; Vienna Austria
| | - Holger A. Volk
- Department of Clinical Science and Services; Royal Veterinary College; Hatfield UK
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Stanciu GD, Packer RMA, Pakozdy A, Solcan G, Volk HA. Clinical reasoning in feline epilepsy: Which combination of clinical information is useful? Vet J 2017; 225:9-12. [PMID: 28720302 DOI: 10.1016/j.tvjl.2017.04.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 04/01/2017] [Accepted: 04/08/2017] [Indexed: 10/19/2022]
Abstract
We sought to identify the association between clinical risk factors and the diagnosis of idiopathic epilepsy (IE) or structural epilepsy (SE) in cats, using statistical models to identify combinations of discrete parameters from the patient signalment, history and neurological examination findings that could suggest the most likely diagnosis. Data for 138 cats with recurrent seizures were reviewed, of which 110 were valid for inclusion. Seizure aetiology was classified as IE in 57% and SE in 43% of cats. Binomial logistic regression analyses demonstrated that pedigree status, older age at seizure onset (particularly >7years old), abnormal neurological examinations, and ictal vocalisation were associated with a diagnosis of SE compared to IE, and that ictal salivation was more likely to be associated with a diagnosis of IE than SE. These findings support the importance of considering inter-ictal neurological deficits and seizure history in clinical reasoning.
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Affiliation(s)
- Gabriela-Dumitrita Stanciu
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield AL9 7TA, UK; University of Agricultural Sciences and Veterinary Medicine "Ion Ionescu de la Brad", Faculty of Veterinary Medicine, Department of Internal Medicine/Neurology, Iasi, 8 M. Sadoveanu Alley, 700489, Iasi, Romania
| | | | - Akos Pakozdy
- Clinic for Internal Medicine and Infectious Diseases, University of Veterinary Medicine, Neurology Service, Veterinarplatz 1, A-1210 Vienna, Austria
| | - Gheorghe Solcan
- University of Agricultural Sciences and Veterinary Medicine "Ion Ionescu de la Brad", Faculty of Veterinary Medicine, Department of Internal Medicine/Neurology, Iasi, 8 M. Sadoveanu Alley, 700489, Iasi, Romania
| | - Holger Andreas Volk
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield AL9 7TA, UK.
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29
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Epilepsy in Humans and Animals: From Patients to Disease Models. Comp Med 2017. [DOI: 10.1007/978-3-319-47007-8_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Abstract
PURPOSE OF REVIEW Autoimmune epileptic encephalopathy is a potentially treatable neurological syndrome characterized by the coexistence of a neuronal antibody in serum and, often, cerebrospinal fluid. Patients present with combinations of seizures, neuropsychiatric features, movement disorder, and cognitive decline, but some patients have isolated seizures either at first presentation or during their illness. This review summarizes our current understanding of the roles of specific neuronal antibodies in epilepsy-related syndromes and aims to aid the clinician in diagnosis and treatment. RECENT FINDINGS Antigen discovery methods in three neuroimmunology centres independently identified antibodies to different subunits of the γ amino butyric acid-A receptor; high levels of these antibodies were found mainly in patients with severe refractory seizures. These and other antibodies were also found in a proportion (<10%) of children and adults with epilepsy. A clinical study comparing immunotherapy in patients with autoantibodies or without an identified target antigen found neuroinflammatory features were predictive of a therapeutic response. New in-vitro and in-vivo studies, and spontaneous animal models, have confirmed the pathogenicity and epileptogenicity of neuronal antibodies and their relevance to other mammals. SUMMARY Neuronal antibodies are an important cause of autoimmune epileptic encephalopathy, early recognition is important as there may be an underlying tumour, and early treatment is associated with a better outcome. In the absence of an antibody, the clinician should adopt a pragmatic approach and consider a trial of immunotherapy when other causes have been excluded.
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Abstract
In recent years a large number of antibody-associated or antibody-defined encephalitides have been discovered. These conditions are often referred to as autoimmune encephalitides. The clinical features include prominent epileptic seizures, cognitive and psychiatric disturbance. These encephalitides can be divided in those with antibodies against intracellular antigens and those with antibodies against surface antigens. The discovery of new antibodies against targets on the surface of neurons is especially interesting since patients with such antibodies can be successfully treated immunologically. This chapter focuses on the pathology and the pathogenetic mechanisms involved in these encephalitides and discusses some of the questions that are raised in this exciting new field. It is important to realise, however, that because of the use of antibodies to diagnose the patients, and their improvement with treatment, there are relatively few biopsy or postmortem reports, limiting the neuropathological data and conclusions that can be drawn. For this reason we especially focus on the most frequent autoimmune encephalitides, those with antibodies to the NMDA receptor and with antibodies to the known protein components of the VGKC complex. Analysis of these encephalitides show completely different pathogenic mechanisms. In VGKC complex encephalitis, antibodies seem to bind to their target and activate complement, leading to destruction and loss of neurons. On the other hand, in NMDAR encephalitis, complement activation and neuronal degeneration seems to be largely absent. Instead, binding of antibodies leads to a decrease of NMDA receptors resulting in a hypofunction. This hypofunction offers an explanation for some of the clinical features such as psychosis and episodic memory impairment, but not for the frequent seizures. Thus, additional analysis of the few human brain specimens present and the use of specific animal models are needed to further understand the effects of these antibodies in autoimmune encephalitides.
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Affiliation(s)
- Jan Bauer
- Center for Brain Research, Medical University Vienna, Vienna, Austria.
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Bradl M, Lassmann H. Neurologic autoimmunity: mechanisms revealed by animal models. HANDBOOK OF CLINICAL NEUROLOGY 2016; 133:121-43. [PMID: 27112675 DOI: 10.1016/b978-0-444-63432-0.00008-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Over the last decade, neurologic autoimmunity has become a major consideration in the diagnosis and management of patients with many neurologic presentations. The nature of the associated antibodies and their targets has led to appreciation of the importance of the accessibility of the target antigen to antibodies, and a partial understanding of the different mechanisms that can follow antibody binding. This chapter will first describe the basic principles of autoimmune inflammation and tissue damage in the central and peripheral nervous system, and will then demonstrate what has been learnt about neurologic autoimmunity from circumstantial clinical evidence and from passive, active, and occasionally spontaneous or genetic animal models. It will cover neurologic autoimmune diseases ranging from disorders of neuromuscular transmission, peripheral and ganglionic neuropathy, to diseases of the central nervous system, where autoantibodies are either pathogenic and cause destruction or changes in function of their targets, where they are harmless bystanders of T-cell-mediated tissue damage, or are not involved at all. Finally, this chapter will summarize the relevance of current animal models for studying the different neurologic autoimmune diseases, and it will identify aspects where future animal models need to be improved to better reflect the disease reality experienced by affected patients, e.g., the chronicity or the relapsing/remitting nature of their disease.
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Affiliation(s)
- Monika Bradl
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria.
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University Vienna, Vienna, Austria
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Matiasek K, Pumarola I Batlle M, Rosati M, Fernández-Flores F, Fischer A, Wagner E, Berendt M, Bhatti SFM, De Risio L, Farquhar RG, Long S, Muñana K, Patterson EE, Pakozdy A, Penderis J, Platt S, Podell M, Potschka H, Rusbridge C, Stein VM, Tipold A, Volk HA. International veterinary epilepsy task force recommendations for systematic sampling and processing of brains from epileptic dogs and cats. BMC Vet Res 2015; 11:216. [PMID: 26324339 PMCID: PMC4595046 DOI: 10.1186/s12917-015-0467-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/29/2015] [Indexed: 01/06/2023] Open
Abstract
Traditionally, histological investigations of the epileptic brain are required to identify epileptogenic brain lesions, to evaluate the impact of seizure activity, to search for mechanisms of drug-resistance and to look for comorbidities. For many instances, however, neuropathological studies fail to add substantial data on patients with complete clinical work-up. This may be due to sparse training in epilepsy pathology and or due to lack of neuropathological guidelines for companion animals.The protocols introduced herein shall facilitate systematic sampling and processing of epileptic brains and therefore increase the efficacy, reliability and reproducibility of morphological studies in animals suffering from seizures.Brain dissection protocols of two neuropathological centres with research focus in epilepsy have been optimised with regards to their diagnostic yield and accuracy, their practicability and their feasibility concerning clinical research requirements.The recommended guidelines allow for easy, standardised and ubiquitous collection of brain regions, relevant for seizure generation. Tissues harvested the prescribed way will increase the diagnostic efficacy and provide reliable material for scientific investigations.
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Affiliation(s)
- Kaspar Matiasek
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Martí Pumarola I Batlle
- Department of Animal Medicine and Surgery, Veterinary Faculty, Universitat Autònoma de Barcelona, Campus UAB Bellaterra, 08193, Barcelona, Spain.
| | - Marco Rosati
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Francisco Fernández-Flores
- Department of Animal Medicine and Surgery, Veterinary Faculty, Universitat Autònoma de Barcelona, Campus UAB Bellaterra, 08193, Barcelona, Spain.
| | - Andrea Fischer
- Department of Animal and Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
| | - Eva Wagner
- Section of Clinical and Comparative Neuropathology, Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University, Veterinärstr. 13, 80539, Munich, Germany.
| | - Mette Berendt
- Department of Animal and Clinical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, Denmark.
| | - Sofie F M Bhatti
- Department of Small Animal Medicine and Clinical Biology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, 9820, Belgium.
| | - Luisa De Risio
- Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, Suffolk, UK.
| | - Robyn G Farquhar
- Fernside Veterinary Centre, 205 Shenley Road, Borehamwood, SG9 0TH, Hertfordshire, UK.
| | - Sam Long
- University of Melbourne, 250 Princes Highway, Weibee, 3015, VIC, Australia.
| | - Karen Muñana
- North Carolina State University, 1052 William Moore Drive, Raleigh, NC, 27607, USA.
| | - Edward E Patterson
- University of Minnesota College of Veterinary Medicine, D426 Veterinary Medical Center, 1352 Boyd Avenue, St. Paul, MN, 55108, USA.
| | - Akos Pakozdy
- Clinical Unit of Internal Medicine Small Animals, University of Veterinary Medicine, Veterinärplatz 1, 1210, Vienna, Austria.
| | - Jacques Penderis
- Vet Extra Neurology, Broadleys Veterinary Hospital, Craig Leith Road, Stirling, FK7 7LE, Stirlingshire, UK.
| | - Simon Platt
- College of Veterinary Medicine, University of Georgia, 501 DW Brooks Drive, Athens, GA, 30602, USA.
| | - Michael Podell
- Chicago Veterinary Neurology and Neurosurgery, 3123 N. Clybourn Avenue, Chicago, IL, 60618, USA.
| | - Heidrun Potschka
- Department of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximillians-University, Königinstr. 16, 80539, Munich, Germany.
| | - Clare Rusbridge
- Fitzpatrick Referrals, Halfway Lane, Eashing, Godalming, GU7 2QQ, Surrey, UK. .,School of Veterinary Medicine, Faculty of Health and Medical Sciences, University of Surrey, Guildford, GU2 7TE, Surrey, UK.
| | - Veronika M Stein
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Bünteweg 9, 30559, Hannover, Germany.
| | - Holger A Volk
- Department of Clinical Science and Services, Royal Veterinary College, Hatfield, AL9 7TA, Hertfordshire, UK.
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Prüss H, Leubner J, Wenke NK, Czirják GÁ, Szentiks CA, Greenwood AD. Anti-NMDA Receptor Encephalitis in the Polar Bear (Ursus maritimus) Knut. Sci Rep 2015; 5:12805. [PMID: 26313569 PMCID: PMC4551079 DOI: 10.1038/srep12805] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 07/06/2015] [Indexed: 12/31/2022] Open
Abstract
Knut the polar bear of the Berlin Zoological Garden drowned in 2011 following seizures and was diagnosed as having suffered encephalitis of unknown etiology after exhaustive pathogen screening. Using the diagnostic criteria applied to human patients, we demonstrate that Knut’s encephalitis is almost identical to anti-NMDA receptor encephalitis which is a severe autoimmune disease representing the most common non-infectious encephalitis in humans. High concentrations of antibodies specific against the NR1 subunit of the NMDA receptor were detected in Knut’s cerebrospinal fluid. Histological examination demonstrated very similar patterns of plasma cell infiltration and minimal neuronal loss in affected brain areas. We conclude that Knut suffered anti-NMDA receptor encephalitis making his the first reported non-human case of this treatable disease. The results suggest that anti-NMDA receptor encephalitis may be a disease of broad relevance to mammals that until now has remained undiagnosed.
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Affiliation(s)
- H Prüss
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Germany.,Department of Neurology, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - J Leubner
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Germany
| | - N K Wenke
- German Center for Neurodegenerative Diseases (DZNE) Berlin, Germany
| | - G Á Czirják
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - C A Szentiks
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
| | - A D Greenwood
- Department of Wildlife Diseases, Leibniz Institute for Zoo and Wildlife Research, Berlin, Germany
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35
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Fors S, Van Meervenne S, Jeserevics J, Rakauskas M, Cizinauskas S. Feline hippocampal and piriform lobe necrosis as a consequence of severe cluster seizures in two cats in Finland. Acta Vet Scand 2015. [PMID: 26215252 PMCID: PMC4515920 DOI: 10.1186/s13028-015-0127-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Feline hippocampal and piriform lobe necrosis (FHN) has been reported from several countries worldwide and is considered an important aetiology for feline epileptic seizures. The aetiology of FHN remains unclear, however it is suspected that FHN might occur secondary to intense epileptic activity as described in humans and dogs although this has not yet been documented in cats. The purpose of our report is to describe the first cases of FHN in Finland diagnosed by magnetic resonance imaging (MRI) and histopathology. The two cases we describe had a well documented history of pre-existing seizures with normal brain MRI at the onset of cluster seizures but MRI done when the cats exhibited clinical deterioration secondary to severe seizure activity, revealed lesions in the hippocampus and piriform lobes typical of FHN. Our report confirms that feline hippocampus and piriform lobe necrosis does occur in the Finnish cat population and should therefore be considered as a differential diagnosis in cats with seizures. In addition, the presentation, clinical findings, results of MRI and/or histopathology shows that cats may develop FHN secondary to severe seizure activity.
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36
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Pakozdy A, Patzl M, Zimmermann L, Jokinen TS, Glantschnigg U, Kelemen A, Hasegawa D. LGI Proteins and Epilepsy in Human and Animals. J Vet Intern Med 2015; 29:997-1005. [PMID: 26032921 PMCID: PMC4895363 DOI: 10.1111/jvim.12610] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 03/23/2015] [Accepted: 04/11/2015] [Indexed: 12/16/2022] Open
Abstract
Leucine‐rich glioma‐inactivated (LGI) protein was first thought to have a suppressor effect in the formation of some cancers. Developments in physiology and medicine made it possible to characterize the function of the LGI protein family and its crucial role in different conditions more precisely. These proteins play an important role in synaptic transmission, and dysfunction may cause hyperexcitability. Genetic mutation of LGI1was confirmed to be the cause of autosomal dominant lateral temporal lobe epilepsy in humans. The LGI2 mutation was identified in benign familial juvenile epilepsy in Lagotto Romagnolo (LR) dogs. Cats with familial spontaneous temporal lobe epilepsy have been reported, and the etiology might be associated with LGI protein family dysfunction. In addition, an autoimmune reaction against LGI1 was detected in humans and cats with limbic encephalitis. These advances prompted a review of LGI protein function and its role in different seizure disorders.
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Affiliation(s)
- A Pakozdy
- University Clinic of Small Animals, University of Veterinary Medicine, Vienna, Austria
| | - M Patzl
- Institute of Immunology, University of Veterinary Medicine, Vienna, Austria
| | - L Zimmermann
- Unit of Physiology and Biophysics, University of Veterinary Medicine, Vienna, Austria
| | - T S Jokinen
- Department of Equine and Small Animal Medicine, University of Helsinki, Helsinki, Finland
| | - U Glantschnigg
- University Clinic of Small Animals, University of Veterinary Medicine, Vienna, Austria
| | - A Kelemen
- Epilepsy Center, National Institute of Clinical Neurosciences, Budapest, Hungary
| | - D Hasegawa
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashinoshi, Tokyo, Japan
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Wagner E, Rosati M, Molin J, Foitzik U, Wahle AM, Fischer A, Matiasek LA, Reese S, Flegel T, Matiasek K. Hippocampal sclerosis in feline epilepsy. Brain Pathol 2014; 24:607-19. [PMID: 24698012 PMCID: PMC8029488 DOI: 10.1111/bpa.12147] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 03/31/2014] [Indexed: 01/01/2023] Open
Abstract
Hippocampal sclerosis (HS) refers to loss of hippocampal neurons and astrogliosis. In temporal lobe epilepsy (TLE), HS is a key factor for pharmacoresistance, even though the mechanisms are not quite understood. While experimental TLE models are available, there is lack of models reflecting the natural HS development. Among domestic animals, cats may present with TLE-like seizures in natural and experimental settings. With this study on the prevalence, segmental pattern and clinicopathological correlates of feline HS, we evaluated the translational value for human research. Evaluation schemes for human brains were applied to epileptic cats. The loss of neurons was morphometrically assessed and the degree of gliosis was recorded. Hippocampal changes resembling human HS were seen in about one third of epileptic cats. Most of these were associated with infiltrative diseases such as limbic encephalitis. Irrespective of the etiology and semiology of seizures, total hippocampal sclerosis was the most prevalent form seen in epileptic animals. Other HS types also occur at varying frequencies. Segmental differences to human HS can be explained by species-specific synaptic connectivities and a different spectrum of etiologies. All these variables require consideration when translating results from feline studies regarding seizure-associated changes of the temporal lobe and especially HS.
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Affiliation(s)
- Eva Wagner
- Section of Clinical & Comparative NeuropathologyInstitute of Veterinary PathologyCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Marco Rosati
- Section of Clinical & Comparative NeuropathologyInstitute of Veterinary PathologyCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Jessica Molin
- Section of Clinical & Comparative NeuropathologyInstitute of Veterinary PathologyCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Ulrike Foitzik
- Section of Clinical & Comparative NeuropathologyInstitute of Veterinary PathologyCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Andrea M. Wahle
- Section of NeurologySmall Animal Medical ClinicCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Andrea Fischer
- Section of NeurologySmall Animal Medical ClinicCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Lara A. Matiasek
- Section of NeurologySmall Animal Medical ClinicCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
| | - Sven Reese
- Institute of Veterinary AnatomyDepartment of Veterinary SciencesLudwig Maximilians University of MunichMunichGermany
| | - Thomas Flegel
- Neurology ServiceDepartment of Small Animal MedicineUniversity of LeipzigLeipzigGermany
| | - Kaspar Matiasek
- Section of Clinical & Comparative NeuropathologyInstitute of Veterinary PathologyCentre for Clinical Veterinary MedicineLudwig Maximilians University of MunichMunichGermany
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Moore SA. Seizures and epilepsy in cats. VETERINARY MEDICINE-RESEARCH AND REPORTS 2014; 5:41-47. [PMID: 32670845 PMCID: PMC7337200 DOI: 10.2147/vmrr.s62077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Accepted: 04/23/2014] [Indexed: 11/23/2022]
Abstract
Seizures are a common presenting complaint in cats, although causes and options for the treatment of seizures in this species have been historically poorly described in the veterinary literature. Seizure manifestation in cats may be different than what is typically seen in dogs, but the underlying causes of seizure activity are the same. These include primary epilepsies, structural epilepsies, and reactive seizures. Although primary epilepsy was once believed to be rare in cats, we now commonly appreciate this syndrome, albeit at a lower frequency than in dogs. Because of this, a complete diagnostic work-up is recommended for all cats presenting for initial evaluation of seizures. Symptomatic treatment of seizures in cats is similar to dogs, with only a few limitations related to species-specific antiepileptic drug toxicities. The goal of this review is to summarize the recent veterinary literature related to feline seizures, with a focus on seizure classification, clinical manifestation, diagnostic evaluation, and treatment options.
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Affiliation(s)
- Sarah A Moore
- Department of Veterinary Clinical Sciences, The Ohio State University, Columbus, OH, USA
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IgG and complement deposition and neuronal loss in cats and humans with epilepsy and voltage-gated potassium channel complex antibodies. J Neuropathol Exp Neurol 2014; 73:403-13. [PMID: 24709680 DOI: 10.1097/nen.0000000000000063] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Voltage-gated potassium channel complex (VGKC-complex) antibody (Ab) encephalitis is a well-recognized form of limbic encephalitis in humans, usually occurring in the absence of an underlying tumor. The patients have a subacute onset of seizures, magnetic resonance imaging findings suggestive of hippocampal inflammation, and high serum titers of Abs against proteins of the VGKC-complex, particularly leucine-rich, glioma-inactivated 1 (LGI1). Most patients are diagnosed promptly and recover substantially with immunotherapies; consequently, neuropathological data are limited. We have recently shown that feline complex partial cluster seizures with orofacial involvement (FEPSO) in cats can also be associated with Abs against VGKC-complexes/LGI1. Here we examined the brains of cats with FEPSO and compared the neuropathological findings with those in a human with VGKC-complex-Ab limbic encephalitis. Similar to humans, cats with VGKC-complex-Ab and FEPSO have hippocampal lesions with only moderate T-cell infiltrates but with marked IgG infiltration and complement C9neo deposition on hippocampal neurons, associated with neuronal loss. These findings provide further evidence that FEPSO is a feline form of VGKC-complex-Ab limbic encephalitis and provide a model for increasing understanding of the human disease.
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Abstract
In patients with immune-associated disorders of the gray central nervous system matter (including recurrent seizures), antibodies against intracellular antigens have been discovered since the 1980s/1990s. In recent years, new antibodies against surface antigens have also been discovered. In two respects, these antibodies are even more interesting than the ones to intracellular antigens as, first, they promise a better response to immunotherapy; and, second, these antibodies contribute greatly to the understanding of the disease mechanisms. Whereas in encephalitides with antibodies against intracellular antigens, a cytotoxic T-cell-mediated response seems to be responsible for neuronal cell loss, in encephalitides with autoantibodies against surface antigens these antibodies are probably the relevant pathogenic agents in the associated disease conditions. On the one hand, antibodies to the NR1 subunit of N-methyl-D-aspartate receptors have been suggested to cause internalization and loss of these receptors without any cell destruction. This mechanism can explain the reversible functional effects caused by these antibodies. On the other hand, antibody- and complement-mediated destructive, and the irreversible effects of antibodies against the voltage-gated potassium channel antigens have been noted. These emerging findings make it plausible that immunological therapies, preferably early after characterization of the antibodies, offer opportunities to restore the health of affected patients.
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Affiliation(s)
| | - Jan Bauer
- />Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
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Pakozdy A, Halasz P, Klang A. Epilepsy in cats: theory and practice. J Vet Intern Med 2014; 28:255-63. [PMID: 24438024 PMCID: PMC4857998 DOI: 10.1111/jvim.12297] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Revised: 11/14/2013] [Accepted: 12/04/2013] [Indexed: 11/29/2022] Open
Abstract
The veterinary literature on epilepsy in cats is less extensive than that for dogs. The present review summarizes the most important human definitions related to epilepsy and discusses the difficulties in applying them in daily veterinary practice. Epileptic seizures can have a wide range of clinical signs and are not necessarily typical in all cases. Whether a seizure event is epileptic can only be suspected based on clinical, laboratory, and neuroimaging findings as electroencephalography diagnostic techniques have not yet been developed to a sufficiently accurate level in veterinary medicine. In addition, the present review aims to describe other diagnoses and nonepileptic conditions that might be mistaken for epileptic seizures. Seizures associated with hippocampal lesions are described and discussed extensively, as they seem to be a special entity only recognized in the past few years. Furthermore, we focus on clinical work‐up and on treatment that can be recommended based on the literature and summarize the limited data available relating to the outcome. Critical commentary is provided as most studies are based on very weak evidence.
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Affiliation(s)
- A Pakozdy
- University Clinic for Small Animals, Clinical Department for Companion Animals and Horses, University of Veterinary Medicine, Vienna, Austria
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Wahle AM, Brühschwein A, Matiasek K, Putschbach K, Wagner E, Mueller RS, Fischer A. Clinical characterization of epilepsy of unknown cause in cats. J Vet Intern Med 2013; 28:182-8. [PMID: 24237601 PMCID: PMC4895554 DOI: 10.1111/jvim.12250] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 09/15/2013] [Accepted: 10/08/2013] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND The diagnosis of feline epilepsy of unknown cause (EUC) requires a thorough diagnostic evaluation, otherwise the prevalence of EUC could be overestimated. HYPOTHESIS Feline EUC is a clinically defined disease entity, which differs from feline hippocampal necrosis by the absence of magnetic resonance imaging (MRI) signal alteration of the hippocampus. The objectives of this study were (1) to evaluate the prevalence of EUC in a hospital population of cats by applying well-defined inclusion criteria, and (2) to describe the clinical course of EUC. ANIMALS Eighty-one cats with recurrent seizures. METHODS Retrospective study--medical records were reviewed for cats presented for evaluation of recurrent seizures (2005-2010). Inclusion criteria were a defined diagnosis based on laboratory data, and either MRI or histopathology. Final outcome was confirmed by telephone interview with the owner. Magnetic resonance images were reviewed to evaluate hippocampal morphology and signal alterations. RESULTS Epilepsy of unknown cause was diagnosed in 22% of cats with epilepsy. Physical, neurologic, and laboratory examinations, and either 1.5 T MRI and cerebrospinal fluid analysis or postmortem examination failed to identify an underlying cause. Cats with EUC had a higher survival rate (P < .05) and seizure remission occurred frequently (44.4%). CONCLUSION AND CLINICAL IMPORTANCE A detailed clinical evaluation and diagnostic imaging with MRI is recommended in any cat with recurrent seizures. The prognosis of cats with normal MRI findings and a clinical diagnosis of EUC are good. Standardized imaging guidelines should be established to assess the hippocampus in cats.
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Affiliation(s)
- A M Wahle
- Clinic of Small Animal Medicine, Ludwig-Maximilians University, Munich, Germany
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[Pathophysiology of antibody-associated diseases of the central nervous system]. DER NERVENARZT 2013; 84:466-70. [PMID: 23568168 DOI: 10.1007/s00115-012-3606-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Antibodies against intracellular antigens have been known since the 1980s and 1990s but in recent years antibodies against surface antigens have also been discovered. These are "more interesting" than those to intracellular targets in two respects: they result in a better response to immunotherapy and are probably directly pathogenic, which helps to understand the disease mechanisms. There are the destructive and irreversible effects of the antibodies to antigens that are complexed with voltage-gated potassium channels (VGKC complex antibodies), especially antibodies to leucine-rich glioma inactivated 1 (LGI1) on the one hand. On the other hand, antibodies may have reversible functional effects, such as antibodies against the N-methyl-D-aspartate receptor, which cause an internalization of these receptors but do not lead to cell destruction: LGI1 antibodies also seem to have functional, in this case epileptogenic effects. These emerging findings make plausible why antibody-reducing therapies provide opportunities for the restoration of health in affected patients.
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Myokymia and neuromyotonia in veterinary medicine: a comparison with peripheral nerve hyperexcitability syndrome in humans. Vet J 2013; 197:153-62. [PMID: 23583699 DOI: 10.1016/j.tvjl.2013.03.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Revised: 01/12/2013] [Accepted: 03/04/2013] [Indexed: 01/17/2023]
Abstract
Involuntary muscle hyperactivity can result from muscle or peripheral nerve hyperexcitability or central nervous system dysfunction. In humans, diseases causing hyperexcitability of peripheral nerves are grouped together under the term 'peripheral nerve hyperexcitability' (PNH). Hyperexcitability of the peripheral motor nerve can result into five different phenotypic main variants, i.e. fasciculations, myokymia, neuromyotonia, cramps and tetany, each with their own clinical and electromyographic characteristics. This review focuses on the most commonly described expressions of PNH in veterinary medicine, i.e. myokymia and neuromyotonia, in particular in young Jack Russell terriers. Data from 58 veterinary cases with generalized myokymia and neuromyotonia were analyzed, including unpublished treatment and follow-up data on eight Jack Russell terriers from a previous study and seven additional Jack Russell terriers. A dysfunction of the potassium channel or its associated proteins has been found in many human syndromes characterized by PNH, in particular in generalized myokymia and neuromyotonia, and is suspected to occur in veterinary medicine. Potential pathomechanisms of potassium channel dysfunction leading to signs of PNH are broad and include genetic mutations, antibody-mediated attack or ion channel maldistribution due to axonal degeneration or demyelination. A more accurate classification of the different PNH syndromes will facilitate a more rapid diagnosis and guide further research into natural occurring PNH in animals.
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