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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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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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Hamamoto Y, Yu Y, Asada R, Mizuno S, Hasegawa D. Age-related brain atrophy in cats without apparent neurological and behavioral signs using voxel-based morphometry. Front Vet Sci 2022; 9:1071002. [PMID: 36504872 PMCID: PMC9729775 DOI: 10.3389/fvets.2022.1071002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2022] [Accepted: 11/02/2022] [Indexed: 11/25/2022] Open
Abstract
Introduction Brain atrophy is observed with aging and may cause cognitive decline or dysfunction. Aging cats may demonstrate behavioral changes related to cognitive dysfunction. In the clinical veterinary field, although the conventional region of interest method by manual or semiauto tracing on magnetic resonance imaging is used to detect atrophy of regional structures, such as the hippocampus, it is difficult to assess atrophy globally. Voxel-based morphometry (VBM) has been developed to detect global and regional abnormalities in humans. The purpose of the present study investigates whether the feline brain volume decreases with aging using VBM analysis. Materials A total of 65 cats, aged 17-200 months, without apparent neurological and behavioral signs were included in the statistical analysis. Results We observed that the gray matter in the bilateral parietal lobes was decreased significantly with aging. The regions that showed decreased volume included the right postcruciate, cingulate gyrus, rostral suprasylvian/ectosylvian gyri, and the left postcruciate gyrus. No significant reduction in white matter was observed. Together, our results show that age-related brain atrophy can be detected using VBM analysis. Discussion The age-related atrophy of the parietal cortex may not cause neurological and behavioral signs in cats. Therefore, veterinarians should consider age when assessing the relation between morphometric and functional abnormalities of the parietal cortex in cats.
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Affiliation(s)
- Yuji Hamamoto
- Veterinary Medical Teaching Hospital, Nippon Veterinary and Life Science University, Musashino, Japan,Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan,The Research Center for Animal Life Science, Nippon Veterinary and Life Science University, Musashino, Japan,*Correspondence: Yuji Hamamoto
| | - Yoshihiko Yu
- Laboratory of Veterinary Radiology, Faculty of Veterinary 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
| | - Satoshi Mizuno
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan
| | - Daisuke Hasegawa
- Laboratory of Veterinary Radiology, Faculty of Veterinary Science, Nippon Veterinary and Life Science University, Musashino, Japan,The Research Center for Animal Life Science, Nippon Veterinary and Life Science University, Musashino, Japan
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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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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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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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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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