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Djani DM, Liou M, Aravamuthan S, Lau V, Cameron S. A retrospective study of the efficacy of zonisamide in controlling seizures in 57 cats. J Vet Intern Med 2024; 38:1092-1100. [PMID: 38240116 PMCID: PMC10937493 DOI: 10.1111/jvim.16984] [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: 05/17/2023] [Accepted: 12/15/2023] [Indexed: 03/16/2024] Open
Abstract
BACKGROUND Evidence-based recommendations for antiepileptic drug selection in cats beyond phenobarbital are limited, and additional studies are needed for cats where seizures remain inadequately controlled by administration of phenobarbital alone or for cats that cannot safely receive phenobarbital. OBJECTIVE To compare seizure frequency in cats before and after oral administration of zonisamide and describe adverse clinical or clinicopathologic effects in this cohort. ANIMALS Fifty-seven cats with a history of seizures. METHODS Multicenter, retrospective study. Median number of seizures per month and number of seizure days per month were compared before and after administration of zonisamide in all cats, a subgroup of cats with idiopathic epilepsy (IE), and a subgroup of cats receiving zonisamide as sole therapy. Clinical and clinicopathologic adverse effect data were also reported. RESULTS A median decrease of 1 (P = .001, 95% confidence interval (CI) [-1.0, -0.5]) seizure per month, and 1 (P = .003, 95% CI [-1.5, -0.2]) seizure days per month was found across all cats after oral administration of zonisamide. The subgroup with IE showed median decreases of 1 (P = .03, 95% CI [-2.0, -0.5]) and 2 (P = .01, 95% CI [-2.5, -1.0]), respectively. The most common clinical adverse effects were sedation (17%), ataxia (11%), hyporexia (17%), and emesis (5%). One cat developed mild nonregenerative anemia, 2 cats developed mild metabolic acidosis, and 6 cats showed mild increases in ALT and ALP. CONCLUSION Zonisamide was well tolerated and efficacious in controlling seizure activity in most cats.
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Affiliation(s)
- Dylan M. Djani
- School of Veterinary Medicine, Department of Medical SciencesUniversity of Wisconsin—MadisonMadisonWisconsinUSA
| | - Michael Liou
- School of Veterinary Medicine, Department of StatisticsUniversity of Wisconsin—MadisonMadisonWisconsinUSA
| | - Srikanth Aravamuthan
- School of Veterinary Medicine, Department of StatisticsUniversity of Wisconsin—MadisonMadisonWisconsinUSA
| | - Vivian Lau
- SAGE Veterinary CentersRedwood CityCaliforniaUSA
| | - Starr Cameron
- School of Veterinary Medicine, Department of Medical SciencesUniversity of Wisconsin—MadisonMadisonWisconsinUSA
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2
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Mizuno S, Asada R, Yu Y, Hamamoto Y, Hasegawa D. Investigation of the effect and availability of ketamine on electroencephalography in cats with temporal lobe epilepsy. Front Vet Sci 2023; 10:1236275. [PMID: 37559886 PMCID: PMC10407800 DOI: 10.3389/fvets.2023.1236275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 07/10/2023] [Indexed: 08/11/2023] Open
Abstract
In recent years, electroencephalography (EEG) in veterinary medicine has become important not only in the diagnosis of epilepsy, but also in determining the epileptogenic focus. In cats, sedation and immobilization, usually with medetomidine or dexmedetomidine, are necessary to place the electrodes and to obtain stable scalp EEG recordings. In this study, we hypothesized that, for cats with temporal lobe epilepsy (TLE), ketamine, a sedative/anesthetic and N-methyl-D-aspartate (NMDA) antagonist that activates the limbic system and is also used to treat refractory status epilepticus in dogs, would induce sufficient sedation and immobilization for EEG, as well as induce interictal epileptiform discharges (IEDs) that are more pronounced than those induced with medetomidine. We obtained EEG recordings from TLE cats and healthy cats administered either ketamine or medetomidine alone (study 1) or ketamine after medetomidine sedation (study 2). In study 1, the frequency of IEDs showed no statistically significant difference between ketamine and medetomidine in both TLE and healthy cats. Seizures were observed in 75% (9/12) cats of the TLE group with ketamine alone. When ketamine was administered after sedation with medetomidine (study 2), 3/18 cats in the TLE group developed generalized tonic-clonic seizure and 1/18 cats showed subclinical seizure activity. However, no seizures were observed in all healthy cats in both study 1 and study 2. Slow wave activity at 2-4 Hz was observed in many individuals after ketamine administration regardless studies and groups, and quantitative analysis in study 2 showed a trend toward increased delta band activities in both groups. While there was no significant difference in the count of IEDs between medetomidine and ketamine, ketamine caused seizures in cats with TLE similar to their habitual seizure type and with a higher seizure frequency. Our results suggest that ketamine may activate epileptiform discharges during EEG recordings. However, caution should be used for cats with TLE.
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Affiliation(s)
- Satoshi Mizuno
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
| | - Rikako Asada
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yoshihiko Yu
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yuji Hamamoto
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
- Veterinary Medical Teaching Hospital, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Daisuke Hasegawa
- Laboratory of Veterinary Clinical Neurology, Graduate School of Nippon Veterinary and Life Science University, Musashino, Japan
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3
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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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4
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Charalambous M, Fischer A, Potschka H, Walker MC, Raedt R, Vonck K, Boon P, Lohi H, Löscher W, Worrell G, Leeb T, McEvoy A, Striano P, Kluger G, Galanopoulou AS, Volk HA, Bhatti SFM. Translational veterinary epilepsy: A win-win situation for human and veterinary neurology. Vet J 2023; 293:105956. [PMID: 36791876 DOI: 10.1016/j.tvjl.2023.105956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
Epilepsy is a challenging multifactorial disorder with a complex genetic background. Our current understanding of the pathophysiology and treatment of epilepsy has substantially increased due to animal model studies, including canine studies, but additional basic and clinical research is required. Drug-resistant epilepsy is an important problem in both dogs and humans, since seizure freedom is not achieved with the available antiseizure medications. The evaluation and exploration of pharmacological and particularly non-pharmacological therapeutic options need to remain a priority in epilepsy research. Combined efforts and sharing knowledge and expertise between human medical and veterinary neurologists are important for improving the treatment outcomes or even curing epilepsy in dogs. Such interactions could offer an exciting approach to translate the knowledge gained from people and rodents to dogs and vice versa. In this article, a panel of experts discusses the similarities and knowledge gaps in human and animal epileptology, with the aim of establishing a common framework and the basis for future translational epilepsy research.
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Affiliation(s)
- Marios Charalambous
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover 30559, Germany.
| | - Andrea Fischer
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich 80539, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University, Munich 80539, Germany
| | - Matthew C Walker
- Institute of Neurology, University College London, London WC1N 3JD, UK
| | - Robrecht Raedt
- Department of Neurology, 4brain, Ghent University, Ghent 9000, Belgium
| | - Kristl Vonck
- Department of Neurology, 4brain, Ghent University, Ghent 9000, Belgium
| | - Paul Boon
- Department of Neurology, 4brain, Ghent University, Ghent 9000, Belgium
| | - Hannes Lohi
- Department of Veterinary Biosciences, Department of Medical and Clinical Genetics, and Folkhälsan Research Center, University of Helsinki, Helsinki 00014, Finland
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover 30559, Germany
| | | | - Tosso Leeb
- Institute of Genetics, University of Bern, Bern 3001, Switzerland
| | - Andrew McEvoy
- Institute of Neurology, University College London, London WC1N 3JD, UK
| | - Pasquale Striano
- IRCCS 'G. Gaslini', Genova 16147, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Gerhard Kluger
- Research Institute, Rehabilitation, Transition-Palliation', PMU Salzburg, Salzburg 5020, Austria; Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen Clinic Vogtareuth, Vogtareuth 83569, Germany
| | - Aristea S Galanopoulou
- Saul R Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Holger A Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover 30559, Germany
| | - Sofie F M Bhatti
- Faculty of Veterinary Medicine, Small Animal Department, Ghent University, Merelbeke 9820, Belgium
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5
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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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6
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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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7
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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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8
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Tenger M, Van Meervenne S, Varjonen K, Tidholm A, Rohdin C. Epilepsy in British Shorthair cats in Sweden. J Feline Med Surg 2022; 24:550-557. [PMID: 34431738 PMCID: PMC11104252 DOI: 10.1177/1098612x211036795] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The primary objective of this study was to investigate the prevalence of epileptic seizures and of presumed idiopathic epilepsy (PIE, describing epilepsy of unknown origin) in a cohort of British Shorthair (BSH) cats in Sweden. The secondary objective was to describe epileptic seizure characteristics and outcome for cats with PIE. METHODS Owners of BSH cats born between 2006 and 2016 and registered with SVERAK (the Swedish Cat Clubs' National Association) were invited to reply to a questionnaire about their cat's general health. Owners who indicated that their cat had experienced epileptic seizures were invited to participate in an in-depth telephone interview about the epileptic seizures. The clinical characteristics of epileptic seizures in BSH cats were determined from the results of the interview. RESULTS In this population comprising 1645 BSH cats (representing 28% of registered BSHs), the prevalence of epileptic seizures was 0.9% and for PIE it was 0.7%. BSH cats with PIE presented with infrequent but consistent epileptic seizures. Twenty-seven percent of BSH cats with epileptic seizures had cluster seizures but none presented with status epilepticus. None of the BSH cats was treated with antiepileptic drugs, and none of the owners reported epileptic seizure remission in their cat. CONCLUSIONS AND RELEVANCE The prevalence of PIE in this population of BSH cats was 0.7%. The prevalence of epileptic seizures was 0.9%. In general, PIE in the BSH cat displayed a relatively benign phenotype where progression of epileptic seizures was uncommon.
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Affiliation(s)
| | | | | | - Anna Tidholm
- Anicura Albano Small Animal Hospital, Stockholm, Sweden
| | - Cecilia Rohdin
- Anicura Albano Small Animal Hospital, Stockholm, Sweden
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
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9
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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 2022; 24:596-608. [PMID: 34355984 PMCID: PMC11104249 DOI: 10.1177/1098612x211035049] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [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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10
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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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11
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Stafstrom CE. To Not Sleep, Perchance to Seize. Epilepsy Curr 2022; 22:187-189. [DOI: 10.1177/15357597221088413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Carl E. Stafstrom
- Neurology, Johns Hopkins Medicine School of Medicine, Baltimore, MA, USA
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12
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Chambers JK, Iwasaki S, Imamoto S, Nakamoto Y, Uchida K. A case of feline temporal lobe epilepsy with hippocampal sclerosis and dentate gyrus malformation. J Vet Med Sci 2022; 84:634-637. [PMID: 35342145 PMCID: PMC9177400 DOI: 10.1292/jvms.22-0006] [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] [Indexed: 11/30/2022] Open
Abstract
A two-months-old, male, mixed breed cat presented with epileptic seizures. The cat was diagnosed with drug-resistant epilepsy, and died at 3-years of age. No gross lesion was found at
necropsy. Histopathologically, the dentate gyrus granule cell layer of the hippocampus was irregularly arranged. Granule cells were dispersed and ectopic cells were sporadically observed in
the molecular layer. The granule cells had an enlarged cytoplasm and swollen nucleus. Immunohistochemistry for NeuN and GFAP confirmed severe neuronal loss and mild gliosis in CA1.
Binucleation and ischemic change were observed in the remaining pyramidal cells. This report describes a case of feline temporal lobe epilepsy and hippocampal sclerosis associated with
dentate gyrus malformation.
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Affiliation(s)
- James K Chambers
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo
| | - Shinya Iwasaki
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo
| | | | - Yuya Nakamoto
- Neuro Vets Animal Neurology Clinic.,Veterinary Medical Center, Osaka Prefecture University
| | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo
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13
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Gómez Álvarez CM, Soler Arias EA. Feline hyperesthesia syndrome: Epilepsy as possible aetiology in two cats. VETERINARY RECORD CASE REPORTS 2021. [DOI: 10.1002/vrc2.132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
| | - Elber Alberto Soler Arias
- Hospital Escuela Universidad de Buenos Aires Facultad de Ciencias Veterinarias Buenos Aires Argentina
- Endovett Endocrinologia Veterinaria Buenos Aires Argentina
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Hasegawa D, Asada R, Hamamoto Y, Yu Y, Kuwabara T, Mizoguchi S, Chambers JK, Uchida K. Focal Cortical Resection and Hippocampectomy in a Cat With Drug-Resistant Structural Epilepsy. Front Vet Sci 2021; 8:719455. [PMID: 34355038 PMCID: PMC8329420 DOI: 10.3389/fvets.2021.719455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 06/25/2021] [Indexed: 11/13/2022] Open
Abstract
Epilepsy surgery is a common therapeutic option in humans with drug-resistant epilepsy. However, there are few reports of intracranial epilepsy surgery for naturally occurring epilepsy in veterinary medicine. A 12-year-old neutered male domestic shorthair cat with presumed congenital cortical abnormalities (atrophy) in the right temporo-occipital cortex and hippocampus had been affected with epilepsy from 3 months of age. In addition to recurrent epileptic seizures, the cat exhibited cognitive dysfunction, bilateral blindness, and right forebrain signs. Seizures had been partially controlled (approximately 0.3–0.7 seizures per month) by phenobarbital, zonisamide, diazepam, and gabapentin until 10 years of age; however, they gradually became uncontrollable (approximately 2–3 seizures per month). In order to plan epilepsy surgery, presurgical evaluations including advanced structural magnetic resonance imaging and long-term intracranial video-electroencephalography monitoring were conducted to identify the epileptogenic zone. The epileptogenic zone was suspected in the right atrophied temporo-occipital cortex and hippocampus. Two-step surgery was planned, and a focal cortical resection of that area was performed initially. After the first surgery, seizures were not observed for 2 months, but they then recurred. The second surgery was performed to remove the right atrophic hippocampus and extended area of the right cortex, which showed spikes on intraoperative electrocorticography. After the second operation, although epileptogenic spikes remained in the contralateral occipital lobe, which was suspected as the second epileptogenic focus, seizure frequency decreased to <0.3 seizure per month under treatment with antiseizure drugs at 1.5 years after surgery. There were no apparent complications associated with either operation, although the original neurological signs were unchanged. This is the first exploratory study of intracranial epilepsy surgery for naturally occurring epilepsy, with modern electroclinical and imaging evidence, in veterinary medicine. Along with the spread of advanced diagnostic modalities and neurosurgical devices in veterinary medicine, epilepsy surgery may be an alternative treatment option for drug-resistant epilepsy in cats.
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Affiliation(s)
- Daisuke Hasegawa
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan.,The Research Center of Animal Life Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Rikako Asada
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yuji Hamamoto
- Veterinary Medical Teaching Hospital, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yoshihiko Yu
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Takayuki Kuwabara
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Shunta Mizoguchi
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - James K Chambers
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Japan
| | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Japan
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15
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Zilli J, Kressin M, Schänzer A, Kampschulte M, Schmidt MJ. Partial cortico-hippocampectomy in cats, as therapy for refractory temporal epilepsy: A descriptive cadaveric study. PLoS One 2021; 16:e0244892. [PMID: 33449929 PMCID: PMC7810294 DOI: 10.1371/journal.pone.0244892] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Accepted: 12/17/2020] [Indexed: 11/18/2022] Open
Abstract
Cats, similar to humans, are known to be affected by hippocampal sclerosis (HS), potentially causing antiepileptic drug (AED) resistance. HS can occur as a consequence of chronic seizure activity, trauma, inflammation, or even as a primary disease. In humans, temporal lobe resection is the standardized therapy in patients with refractory temporal lobe epilepsy (TLE). The majority of TLE patients are seizure free after surgery. Therefore, the purpose of this prospective cadaveric study is to establish a surgical technique for hippocampal resection in cats as a treatment for AED resistant seizures. Ten cats of different head morphology were examined. Pre-surgical magnetic resonance imaging (MRI) and computed tomography (CT) studies of the animals’ head were carried out to complete 3D reconstruction of the head, brain, and hippocampus. The resected hippocampal specimens and the brains were histologically examined for tissue injury adjacent to the hippocampus. The feasibility of the procedure, as well as the usability of the removed specimen for histopathological examination, was assessed. Moreover, a micro-CT (mCT) examination of the brain of two additional cats was performed in order to assess temporal vasculature as a reason for possible intraoperative complications. In all cats but one, the resection of the temporal cortex and the hippocampus were successful without any evidence of traumatic or vascular lesions in the surrounding neurovascular structures. In one cat, the presence of mechanical damage (a fissure) of the thalamic surface was evident in the histopathologic examination of the brain post-resection. All hippocampal fields and the dentate gyrus were identified in the majority of the cats via histological examination. The study describes a new surgical approach (partial temporal cortico-hippocampectomy) offering a potential treatment for cats with clinical and diagnostic evidence of temporal epilepsy which do not respond adequately to the medical therapy.
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Affiliation(s)
- Jessica Zilli
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Germany
- * E-mail:
| | - Monika Kressin
- Institute for Veterinary Anatomy, Histology and Embryology, Justus-Liebig-University, Giessen, Germany
| | - Anne Schänzer
- Institute of Neuropathology, Justus-Liebig-University, Giessen, Germany
| | | | - Martin J. Schmidt
- Department of Veterinary Clinical Sciences, Small Animal Clinic, Justus-Liebig-University, Giessen, Germany
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16
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Olszewska A, Schmidt MJ, Failing K, Nicpoń J, Podgórski P, Wrzosek MA. Interictal Single-Voxel Proton Magnetic Resonance Spectroscopy of the Temporal Lobe in Dogs With Idiopathic Epilepsy. Front Vet Sci 2020; 7:644. [PMID: 33195502 PMCID: PMC7541947 DOI: 10.3389/fvets.2020.00644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Accepted: 08/10/2020] [Indexed: 11/16/2022] Open
Abstract
Proton magnetic resonance spectroscopy (H1-MRS) could provide insight into the metabolic pathophysiology of the temporal lobe of canine brain after seizure. Currently, there is no evidence-based data available on MRS of temporal lobe in dogs with idiopathic epilepsy (IE). The aim of this prospective, cross-sectional study was to evaluate the interictal metabolic activity of the temporal lobe in IE dogs compared to a control group with the use of H1-MRS. Ten healthy dogs and 27 client-owned dogs with IE underwent 1.5-Tesla magnetic resonance imaging (MRI) and single-voxel H1-MRS. The MRS studies were acquired as spin echoes with a repetition time (TR) of 2,000 ms and an echo time (TE) of 144 ms. A cubic voxel (10 ×10 ×10 mm) was positioned bilaterally into the region of the left and right temporal lobe, including a middle part of the hippocampus and the amygdala. The N-acetylaspartate (NAA)-to-creatine (NAA/Cr), NAA-to-choline (NAA/Cho), choline-to-creatine (Cho/Cr), and choline-to-NAA (Cho/NAA) ratios were determined in both hemispheres and compared to controls. No significant differences in all metabolite ratios between epileptic dogs and the control group could be found. A time-dependent decrease in the NAA/Cho ratio as well as an increase in the Cho/NAA ratio was found with proximity in time to the last seizure. We found no correlation between metabolite ratios and age or sex in this animal group. Time span from the last seizure to the acquisition of MRS significantly correlated with NAA/Cho and Cho/NAA ratio. We conclude that without a time relation, metabolite ratios in dogs with IE do not differ from those of the control group.
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Affiliation(s)
- Agnieszka Olszewska
- Department of Veterinary Clinical Science, Small Animal Clinic, Justus-Liebig-University Giessen, Giessen, Germany
| | - Martin Jürgen Schmidt
- Department of Veterinary Clinical Science, Small Animal Clinic, Justus-Liebig-University Giessen, Giessen, Germany
| | - Klaus Failing
- Unit for Biomathematics and Data Processing, Faculty of Veterinary Medicine, Justus Liebig-University Giessen, Giessen, Germany
| | - Józef Nicpoń
- Department of Internal Diseases With a Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland.,Center of Experimental Diagnostics and Innovative Biomedical Technologies, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
| | - Przemysław Podgórski
- Department of General Radiology and Interventional Radiology and Neuroradiology, Wrocław Medical University, Wrocław, Poland
| | - Marcin Adam Wrzosek
- Department of Internal Diseases With a Clinic for Horses, Dogs and Cats, Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, Wrocław, Poland
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17
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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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18
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Santifort KM, Jurgens B, Grinwis GC, Gielen I, Meij BP, Mandigers PJ. Invasive nasal histiocytic sarcoma as a cause of temporal lobe epilepsy in a cat. JFMS Open Rep 2018; 4:2055116918811179. [PMID: 30450218 PMCID: PMC6236490 DOI: 10.1177/2055116918811179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Case summary A 10-year-old neutered female domestic shorthair cat was presented with an acute onset of neurological signs suggestive of a right-sided forebrain lesion, temporal lobe epilepsy and generalised seizure activity. MRI of the head revealed an expansile soft tissue mass in the caudal nasal passages (both sides but predominantly right-sided) involving the ethmoid bone and extending through the cribriform plate into the cranial vault affecting predominantly the right frontal lobe and temporal lobe. Histopathological examination of the tumour revealed a histiocytic sarcoma. Relevance and novel information This is the first report of a cat with clinical signs of temporal lobe epilepsy due to an invasive, histiocytic sarcoma. Histiocytic sarcoma, although rare, should be included in the list of differential diagnoses for soft tissue masses extending through the cribriform plate. Other differential diagnoses are primary nasal neoplasia (eg, adenocarcinoma, squamous cell carcinoma, chondrosarcoma and other types of sarcomas), lymphoma and olfactory neuroblastoma. Temporal lobe epilepsy in cats can be the consequence of primary pathology of temporal lobe structures, or it can be a consequence of pathology with an effect on these structures (eg, mass effect or disruption of interconnecting neuronal pathways).
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Affiliation(s)
- Koen M Santifort
- Veterinary Referral Practice 'de Pietersberg', Oosterbeek, The Netherlands
| | - Ben Jurgens
- Faculty of Veterinary Medicine, Department of Pathobiology, Utrecht University, The Netherlands
| | - Guy Cm Grinwis
- Faculty of Veterinary Medicine, Department of Pathobiology, Utrecht University, The Netherlands
| | - Ingrid Gielen
- Faculty of Veterinary Medicine, Ghent University, Belgium
| | - Björn P Meij
- Faculty of Veterinary Medicine, Department of Clinical Sciences of Companion Animals, Utrecht University, The Netherlands
| | - Paul Jj Mandigers
- Faculty of Veterinary Medicine, Department of Clinical Sciences of Companion Animals, Utrecht University, The Netherlands
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19
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Hamamoto Y, Hasegawa D, Yu Y, Asada R, Mizoguchi S, Kuwabara T, Wada M, Fujiwara-Igarashi A, Fujita M. Statistical Structural Analysis of Familial Spontaneous Epileptic Cats Using Voxel-Based Morphometry. Front Vet Sci 2018; 5:172. [PMID: 30087902 PMCID: PMC6066542 DOI: 10.3389/fvets.2018.00172] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Accepted: 07/04/2018] [Indexed: 12/29/2022] Open
Abstract
Voxel-based morphometry (VBM) based on high resolution three-dimensional data of magnetic resonance imaging has been developed as a statistical morphometric imaging analysis method to locate brain abnormalities in humans. Recently, VBM has been used for human patients with psychological or neurological disorders such as Alzheimer's disease, Parkinson's disease, and epilepsy. Traditional volumetry using region of interest (ROI) is performed manually and the observer needs detailed knowledge of the neuroanatomy having to trace objects of interest on many slices which can cause artificial errors. In contrast, VBM is an automatic technique that has less observer biases compared to the ROI method. In humans, VBM analysis is performed in patients with epilepsy to detect accurately structural abnormalities. Familial spontaneous epileptic cats (FSECs) have been developed as an animal model of mesial temporal lobe epilepsy. In FSECs, hippocampal asymmetry had been detected using three-dimensional magnetic resonance (MR) volumetry based on the ROI method. In this study, we produced a standard template of the feline brain and compared FSECs and healthy cats using standard VBM analysis. The feline standard template and tissue probability maps were created using 38 scans from 14 healthy cats. Subsequently, the gray matter was compared between FSECs (n = 25) and healthy controls (n = 12) as group analysis and between each FSEC and controls as individual analysis. The feline standard template and tissue probability maps could be created using the VBM tools for humans. There was no significant reduction of GM in the FSEC group compared to the control group. However, 5/25 (20%) FSECs showed significant decreases in the hippocampal and/or amygdaloid regions in individual analysis. Here, we established the feline standard templates of the brain that can be used to determine accurately abnormal zones. Furthermore, like MR volumetry, VBM identified morphometric changes in the hippocampus and/or amygdala in some FSECs.
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Affiliation(s)
- Yuji Hamamoto
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Daisuke Hasegawa
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Yoshihiko Yu
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Rikako Asada
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Shunta Mizoguchi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Takayuki Kuwabara
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Masae Wada
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Aki Fujiwara-Igarashi
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Michio Fujita
- Department of Clinical Veterinary Medicine, Nippon Veterinary and Life Science University, Musashino, Japan
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20
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Abstract
Epilepsy affects all age groups and is one of the most common and most disabling neurological disorders. The accurate diagnosis of seizures is essential as some patients will be misdiagnosed with epilepsy, whereas others will receive an incorrect diagnosis. Indeed, errors in diagnosis are common, and many patients fail to receive the correct treatment, which often has severe consequences. Although many patients have seizure control using a single medication, others require multiple medications, resective surgery, neuromodulation devices or dietary therapies. In addition, one-third of patients will continue to have uncontrolled seizures. Epilepsy can substantially impair quality of life owing to seizures, comorbid mood and psychiatric disorders, cognitive deficits and adverse effects of medications. In addition, seizures can be fatal owing to direct effects on autonomic and arousal functions or owing to indirect effects such as drowning and other accidents. Deciphering the pathophysiology of epilepsy has advanced the understanding of the cellular and molecular events initiated by pathogenetic insults that transform normal circuits into epileptic circuits (epileptogenesis) and the mechanisms that generate seizures (ictogenesis). The discovery of >500 genes associated with epilepsy has led to new animal models, more precise diagnoses and, in some cases, targeted therapies.
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Affiliation(s)
- Orrin Devinsky
- Departments of Neurology, Neuroscience, Neurosurgery and Psychiatry, NYU School of Medicine, New York, NY, USA
| | - Annamaria Vezzani
- Laboratory of Experimental Neurology, Department of Neuroscience, IRCCS 'Mario Negri' Institute for Pharmacological Research, Milan, Italy
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia.,Departments of Neurology and Medicine, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
| | - Nathalie Jette
- Department of Neurology and Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Department of Medicine, Austin Health, The University of Melbourne, Melbourne, Victoria, Australia.,The Florey Institute of Neuroscience and Mental Health, Melbourne, Victoria, Australia.,Department of Paediatrics, The University of Melbourne, and Department of Neurology, The Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Marco de Curtis
- Epilepsy Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Neurology, Alfred Health, Melbourne, Victoria, Australia.,Departments of Neurology and Medicine, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, Victoria, Australia
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21
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Demars F, Clark K, Wyeth MS, Abrams E, Buckmaster PS. A single subconvulsant dose of domoic acid at mid-gestation does not cause temporal lobe epilepsy in mice. Neurotoxicology 2018; 66:128-137. [PMID: 29625197 PMCID: PMC5940543 DOI: 10.1016/j.neuro.2018.04.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Revised: 03/28/2018] [Accepted: 04/02/2018] [Indexed: 11/19/2022]
Abstract
Harmful blooms of domoic acid (DA)-producing algae are a problem in oceans worldwide. DA is a potent glutamate receptor agonist that can cause status epilepticus and in survivors, temporal lobe epilepsy. In mice, one-time low-dose in utero exposure to DA was reported to cause hippocampal damage and epileptiform activity, leading to the hypothesis that unrecognized exposure to DA from contaminated seafood in pregnant women can damage the fetal hippocampus and initiate temporal lobe epileptogenesis. However, development of epilepsy (i.e., spontaneous recurrent seizures) has not been tested. In the present study, long-term seizure monitoring and histology was used to test for temporal lobe epilepsy following prenatal exposure to DA. In Experiment One, the previous study's in utero DA treatment protocol was replicated, including use of the CD-1 mouse strain. Afterward, mice were video-monitored for convulsive seizures from 2 to 6 months old. None of the CD-1 mice treated in utero with vehicle or DA was observed to experience spontaneous convulsive seizures. After seizure monitoring, mice were evaluated for pathological evidence of temporal lobe epilepsy. None of the mice treated in utero with DA displayed the hilar neuron loss that occurs in patients with temporal lobe epilepsy and in the mouse pilocarpine model of temporal lobe epilepsy. In Experiment Two, a higher dose of DA was administered to pregnant FVB mice. FVB mice were tested as a potentially more sensitive strain, because they have a lower seizure threshold, and some females spontaneously develop epilepsy. Female offspring were monitored with continuous video and telemetric bilateral hippocampal local field potential recording at 1-11 months old. A similar proportion of vehicle- and DA-treated female FVB mice spontaneously developed epilepsy, beginning in the fourth month of life. Average seizure frequency and duration were similar in both groups. Seizure frequency was lower than that of positive-control pilocarpine-treated mice, but seizure duration was similar. None of the mice treated in utero with vehicle or DA displayed hilar neuron loss or intense mossy fiber sprouting, a form of aberrant synaptic reorganization that develops in patients with temporal lobe epilepsy and in pilocarpine-treated mice. FVB mice that developed epilepsy (vehicle- and DA-treated) displayed mild mossy fiber sprouting. Results of this study suggest that a single subconvulsive dose of DA at mid-gestation does not cause temporal lobe epilepsy in mice.
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Affiliation(s)
- Fanny Demars
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; VetAgro Sup, School of Veterinary Medicine, Lyon, France; Paris Descartes University, Paris, France
| | - Kristen Clark
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; College of Veterinary Medicine, Oklahoma State University, Stillwater, OK, United States
| | - Megan S Wyeth
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Emily Abrams
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States
| | - Paul S Buckmaster
- Department of Comparative Medicine, School of Medicine, Stanford University, Stanford, CA, United States; Department of Neurology & Neurological Sciences, School of Medicine, Stanford University, Stanford, CA, United States.
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22
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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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