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Karoly PJ, Rao VR, Gregg NM, Worrell GA, Bernard C, Cook MJ, Baud MO. Cycles in epilepsy. Nat Rev Neurol 2021; 17:267-284. [PMID: 33723459 DOI: 10.1038/s41582-021-00464-1] [Citation(s) in RCA: 115] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/19/2021] [Indexed: 01/31/2023]
Abstract
Epilepsy is among the most dynamic disorders in neurology. A canonical view holds that seizures, the characteristic sign of epilepsy, occur at random, but, for centuries, humans have looked for patterns of temporal organization in seizure occurrence. Observations that seizures are cyclical date back to antiquity, but recent technological advances have, for the first time, enabled cycles of seizure occurrence to be quantitatively characterized with direct brain recordings. Chronic recordings of brain activity in humans and in animals have yielded converging evidence for the existence of cycles of epileptic brain activity that operate over diverse timescales: daily (circadian), multi-day (multidien) and yearly (circannual). Here, we review this evidence, synthesizing data from historical observational studies, modern implanted devices, electronic seizure diaries and laboratory-based animal neurophysiology. We discuss advances in our understanding of the mechanistic underpinnings of these cycles and highlight the knowledge gaps that remain. The potential clinical applications of a knowledge of cycles in epilepsy, including seizure forecasting and chronotherapy, are discussed in the context of the emerging concept of seizure risk. In essence, this Review addresses the broad question of why seizures occur when they occur.
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Affiliation(s)
- Philippa J Karoly
- Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria, Australia.
| | - Vikram R Rao
- Department of Neurology, University of California, San Francisco, CA, USA.,Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
| | - Nicholas M Gregg
- Bioelectronics, Neurophysiology and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Gregory A Worrell
- Bioelectronics, Neurophysiology and Engineering Laboratory, Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Christophe Bernard
- Aix Marseille University, Inserm, Institut de Neurosciences des Systèmes, Marseille, France
| | - Mark J Cook
- Graeme Clark Institute, The University of Melbourne, Melbourne, Victoria, Australia
| | - Maxime O Baud
- Sleep-Wake-Epilepsy Center, Department of Neurology, Inselspital Bern, University Hospital, University of Bern, Bern, Switzerland. .,Center for Experimental Neurology, Department of Neurology, Inselspital Bern, University Hospital, University of Bern, Bern, Switzerland.
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Bernard C. Circadian/multidien Molecular Oscillations and Rhythmicity of Epilepsy (MORE). Epilepsia 2020; 62 Suppl 1:S49-S68. [PMID: 33063860 DOI: 10.1111/epi.16716] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/15/2020] [Accepted: 09/15/2020] [Indexed: 12/26/2022]
Abstract
The occurrence of seizures at specific times of the day has been consistently observed for centuries in individuals with epilepsy. Electrophysiological recordings provide evidence that seizures have a higher probability of occurring at a given time during the night and day cycle in individuals with epilepsy here referred to as the seizure rush hour. Which mechanisms underlie such circadian rhythmicity of seizures? Why don't they occur every day at the same time? Which mechanisms may underlie their occurrence outside the rush hour? In this commentary, I present a hypothesis: MORE - Molecular Oscillations and Rhythmicity of Epilepsy, a conceptual framework to study and understand the mechanisms underlying the circadian rhythmicity of seizures and their probabilistic nature. The core of the hypothesis is the existence of ~24-hour oscillations of gene and protein expression throughout the body in different cells and organs. The orchestrated molecular oscillations control the rhythmicity of numerous body events, such as feeding and sleep. The concept developed here is that molecular oscillations may favor seizure genesis at preferred times, generating the condition for a seizure rush hour. However, the condition is not sufficient, as other factors are necessary for a seizure to occur. Studying these molecular oscillations may help us understand seizure genesis mechanisms and find new therapeutic targets and predictive biomarkers. The MORE hypothesis can be generalized to comorbidities and the slower multidien (week/month period) rhythmicity of seizures, a phenomenon addressed in another article in this issue of Epilepsia.
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Affiliation(s)
- Christophe Bernard
- Inserm, INS, Institut de Neurosciences des Systèmes, Aix Marseille Univ, Marseille, France
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Leite Góes Gitai D, de Andrade TG, Dos Santos YDR, Attaluri S, Shetty AK. Chronobiology of limbic seizures: Potential mechanisms and prospects of chronotherapy for mesial temporal lobe epilepsy. Neurosci Biobehav Rev 2019; 98:122-134. [PMID: 30629979 PMCID: PMC7023906 DOI: 10.1016/j.neubiorev.2019.01.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2018] [Revised: 12/20/2018] [Accepted: 01/06/2019] [Indexed: 12/11/2022]
Abstract
Mesial Temporal Lobe Epilepsy (mTLE) characterized by progressive development of complex partial seizures originating from the hippocampus is the most prevalent and refractory type of epilepsy. One of the remarkable features of mTLE is the rhythmic pattern of occurrence of spontaneous seizures, implying a dependence on the endogenous clock system for seizure threshold. Conversely, circadian rhythms are affected by epilepsy too. Comprehending how the circadian system and seizures interact with each other is essential for understanding the pathophysiology of epilepsy as well as for developing innovative therapies that are efficacious for better seizure control. In this review, we confer how the temporal dysregulation of the circadian clock in the hippocampus combined with multiple uncoupled oscillators could lead to periodic seizure occurrences and comorbidities. Unraveling these associations with additional research would help in developing chronotherapy for mTLE, based on the chronobiology of spontaneous seizures. Notably, differential dosing of antiepileptic drugs over the circadian period and/or strategies that resynchronize biological rhythms may substantially improve the management of seizures in mTLE patients.
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Affiliation(s)
- Daniel Leite Góes Gitai
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas, USA; Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Alagoas, Brazil
| | | | | | - Sahithi Attaluri
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas, USA
| | - Ashok K Shetty
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M University, College Station, Texas, USA; Research Service, Olin E. Teague Veterans' Medical Center, Central Texas Veterans Health Care System, Temple, Texas, USA.
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Reddy DS, Chuang SH, Hunn D, Crepeau AZ, Maganti R. Neuroendocrine aspects of improving sleep in epilepsy. Epilepsy Res 2018; 147:32-41. [PMID: 30212766 PMCID: PMC6192845 DOI: 10.1016/j.eplepsyres.2018.08.013] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 08/27/2018] [Accepted: 08/30/2018] [Indexed: 12/15/2022]
Abstract
Sleep plays an intricate role in epilepsy and can affect the frequency and occurrence of seizures. With nearly 35% of U.S. adults failing to obtain the recommended 7 h of sleep every night, understanding the complex relationship between sleep and epilepsy is of utmost relevance. Sleep deprivation is a common trigger of seizures in many persons with epilepsy and sleep patterns play a role in the occurrence of seizures. Some patients have their first seizure or repeated seizures after an "all-nighter" at college or after a long period of chronic sleep deprivation. The strength of the relationship between sleep and seizures varies between patients, but improving sleep and optimizing seizure control can have significant positive effects on the quality of life for all these patients. Research has shown that the changes in the brain's electrical and hormonal activity occurring during normal sleep-wake cycles can be linked to both sleep and seizure patterns. Many questions remain to be answered about sleep and epilepsy. How can sleep deprivation trigger an epileptic seizure? How do circadian and hormonal changes influence sleep pattern and seizure occurrence? Can hormones or sleeping pills help with sleep in epilepsy? In this article we discuss these and many other questions on sleep in epilepsy, with an emphasis on sleep architecture, hormone changes, mechanistic factors, and possible prevention strategies.
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Affiliation(s)
- Doodipala Samba Reddy
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX 77807, USA.
| | - Shu-Hui Chuang
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX 77807, USA
| | - Dayton Hunn
- Department of Neuroscience and Experimental Therapeutics, Texas A&M University Health Science Center College of Medicine, Bryan, TX 77807, USA
| | - Amy Z Crepeau
- Department of Neurology, Mayo Clinic Hospital, Phoenix, AZ 85054, USA
| | - Rama Maganti
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, WI 53705, USA
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5
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Matos HDC, Koike BDV, Pereira WDS, de Andrade TG, Castro OW, Duzzioni M, Kodali M, Leite JP, Shetty AK, Gitaí DLG. Rhythms of Core Clock Genes and Spontaneous Locomotor Activity in Post- Status Epilepticus Model of Mesial Temporal Lobe Epilepsy. Front Neurol 2018; 9:632. [PMID: 30116220 PMCID: PMC6082935 DOI: 10.3389/fneur.2018.00632] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 07/12/2018] [Indexed: 12/16/2022] Open
Abstract
The interaction of Mesial Temporal Lobe Epilepsy (mTLE) with the circadian system control is apparent from an oscillatory pattern of limbic seizures, daytime's effect on seizure onset and the efficacy of antiepileptic drugs. Moreover, seizures per se can interfere with the biological rhythm output, including circadian oscillation of body temperature, locomotor activity, EEG pattern as well as the transcriptome. However, the molecular mechanisms underlying this cross-talk remain unclear. In this study, we systematically evaluated the temporal expression of seven core circadian transcripts (Bmal1, Clock, Cry1, Cry2, Per1, Per2, and Per3) and the spontaneous locomotor activity (SLA) in post-status epilepticus (SE) model of mTLE. Twenty-four hour oscillating SLA remained intact in post-SE groups although the circadian phase and the amount and intensity of activity were changed in early post-SE and epileptic phases. The acrophase of the SLA rhythm was delayed during epileptogenesis, a fragmented 24 h rhythmicity and extended active phase length appeared in the epileptic phase. The temporal expression of circadian transcripts Bmal1, Cry1, Cry2, Per1, Per2, and Per3 was also substantially altered. The oscillatory expression of Bmal1 was maintained in rats imperiled to SE, but with lower amplitude (A = 0.2) and an advanced acrophase in the epileptic phase. The diurnal rhythm of Cry1 and Cry2 was absent in the early post-SE but was recovered in the epileptic phase. Per1 and Per2 rhythmic expression were disrupted in post-SE groups while Per3 presented an arrhythmic profile in the epileptic phase, only. The expression of Clock did not display rhythmic pattern in any condition. These oscillating patterns of core clock genes may contribute to hippocampal 24 h cycling and, consequently to seizure periodicity. Furthermore, by using a pool of samples collected at 6 different Zeitgeber Times (ZT), we found that all clock transcripts were significantly dysregulated after SE induction, except Per3 and Per2. Collectively, altered SLA rhythm in early post-SE and epileptic phases implies a possible role for seizure as a nonphotic cue, which is likely linked to activation of hippocampal–accumbens pathway. On the other hand, altered temporal expression of the clock genes after SE suggests their involvement in the MTLE.
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Affiliation(s)
- Heloisa de Carvalho Matos
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Brazil
| | | | - Wanessa Dos Santos Pereira
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Brazil
| | - Tiago G de Andrade
- Laboratory of Molecular Chronobiology, Federal University of Alagoas, Arapiraca, Brazil.,Department of Physiology and Pharmacology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Brazil
| | - Olagide W Castro
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, TX, United States
| | - Marcelo Duzzioni
- Institute for Regenerative Medicine, Department of Molecular and Cellular Medicine, Texas A&M Health Science Center College of Medicine, College Station, TX, United States
| | - Maheedhar Kodali
- Division of Neurology, Department of Neurosciences and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil
| | - Joao P Leite
- Faculty of Medicine, Federal University of Alagoas, Maceio, Brazil
| | - Ashok K Shetty
- Division of Neurology, Department of Neurosciences and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil
| | - Daniel L G Gitaí
- Department of Cellular and Molecular Biology, Institute of Biological Sciences and Health, Federal University of Alagoas, Maceio, Brazil.,Division of Neurology, Department of Neurosciences and Behavioral Sciences, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirão Preto, Brazil
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6
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Wallace E, Wright S, Schoenike B, Roopra A, Rho JM, Maganti RK. Altered circadian rhythms and oscillation of clock genes and sirtuin 1 in a model of sudden unexpected death in epilepsy. Epilepsia 2018; 59:1527-1539. [DOI: 10.1111/epi.14513] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Eli Wallace
- Cellular and Molecular Pathology Graduate Program; University of Wisconsin School of Medicine and Public Health; Madison WI USA
- Department of Neuroscience; University of Wisconsin School of Medicine and Public Health; Madison WI USA
- Department of Neurology; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Samantha Wright
- Department of Neurology; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Barry Schoenike
- Department of Neuroscience; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Avtar Roopra
- Department of Neuroscience; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Jong M. Rho
- Departments of Pediatrics, Clinical Neurosciences, and Physiology & Pharmacology; Alberta Children's Hospital Research Institute; Cumming School of Medicine; University of Calgary; Calgary Alberta Canada
| | - Rama K. Maganti
- Department of Neurology; University of Wisconsin School of Medicine and Public Health; Madison WI USA
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7
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Mahoney EC, Zeng A, Yu W, Rowe M, Sahai S, Feustel PJ, Ramirez-Zamora A, Pilitsis JG, Shin DS. Ventral pallidum deep brain stimulation attenuates acute partial, generalized and tonic-clonic seizures in two rat models. Epilepsy Res 2018; 142:36-44. [DOI: 10.1016/j.eplepsyres.2018.03.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Revised: 02/17/2018] [Accepted: 03/08/2018] [Indexed: 11/29/2022]
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Pitsch J, Becker AJ, Schoch S, Müller JA, de Curtis M, Gnatkovsky V. Circadian clustering of spontaneous epileptic seizures emerges after pilocarpine-induced status epilepticus. Epilepsia 2017; 58:1159-1171. [DOI: 10.1111/epi.13795] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/12/2017] [Indexed: 01/02/2023]
Affiliation(s)
- Julika Pitsch
- Section for Translational Epilepsy Research; Department of Neuropathology; University of Bonn; Bonn Germany
| | - Albert J. Becker
- Section for Translational Epilepsy Research; Department of Neuropathology; University of Bonn; Bonn Germany
| | - Susanne Schoch
- Section for Translational Epilepsy Research; Department of Neuropathology; University of Bonn; Bonn Germany
| | - Johannes Alexander Müller
- Section for Translational Epilepsy Research; Department of Neuropathology; University of Bonn; Bonn Germany
| | - Marco de Curtis
- Unit of Epileptology and Experimental Neurophysiology; Fondazione Istituto Neurologico Carlo Besta; Milan Italy
| | - Vadym Gnatkovsky
- Unit of Epileptology and Experimental Neurophysiology; Fondazione Istituto Neurologico Carlo Besta; Milan Italy
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Tchekalarova J, Petkova Z, Pechlivanova D, Moyanova S, Kortenska L, Mitreva R, Lozanov V, Atanasova D, Lazarov N, Stoynev A. Prophylactic treatment with melatonin after status epilepticus: effects on epileptogenesis, neuronal damage, and behavioral changes in a kainate model of temporal lobe epilepsy. Epilepsy Behav 2013; 27:174-87. [PMID: 23435277 DOI: 10.1016/j.yebeh.2013.01.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Revised: 01/07/2013] [Accepted: 01/10/2013] [Indexed: 10/27/2022]
Abstract
Melatonin is a potent antioxidant which showed anticonvulsant activities both in experimental and clinical studies. In the present study, we examined the effect of melatonin treatment (10mg/kg/day, diluted in drinking water, 8 weeks) during epileptogenesis on the consequences of a kainate (KA)-induced status epilepticus (SE) in rats. Melatonin increased the latency in the appearance of spontaneous recurrent seizures (SRSs) and decreased their frequency only during the treatment period. The behavioral alterations associated with hyperactivity, depression-like behavior during the light phase, and deficits in hippocampus-dependent working memory were positively affected by melatonin treatment in rats with epilepsy. Melatonin reduced the neuronal damage in the CA1 area of the hippocampus and piriform cortex and recovered the decrease of hippocampal serotonin (5-HT) level in rats with epilepsy. Taken together, long-term melatonin treatment after SE was unable to suppress the development of epileptogenesis. However, it showed a potential in reducing some of the deleterious alterations that develop during the chronic epileptic state in a diurnal phase-dependent mode.
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Affiliation(s)
- Jana Tchekalarova
- Institute of Neurobiology, Acad G Bonchev Str, Bl 23, Bulgarian Academy of Sciences, Sofia 1113, Bulgaria.
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Mirzoev A, Bercovici E, Stewart LS, Cortez MA, Snead OC, Desrocher M. Circadian profiles of focal epileptic seizures: a need for reappraisal. Seizure 2012; 21:412-6. [PMID: 22537415 DOI: 10.1016/j.seizure.2012.03.014] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Revised: 03/27/2012] [Accepted: 03/27/2012] [Indexed: 11/25/2022] Open
Abstract
Circadian rhythm of seizure is underestimated in the study of focal epilepsies. A review of the current literature revealed a clear correlation between cortical epileptogenic focus and the circadian phase of seizure peak occurrence in adult patients. A single diurnal peak at 19:00 was found in seizures originating from the occipital lobe, between 5:00 and 7:00 in frontal lobe seizures, and between 16:00 and 17:00 h in temporal lobe seizures. Two diurnal peaks, between 5:00 and 7:00, and at 23:00 are reported in seizures from the parietal lobe, and between 7:00 to 8:00 and 16:00 to 17:00 in mesial temporal onset seizures. This circadian character of seizure occurrence in focal epilepsies may not be unique to partial seizures since recent clinical and experimental data indicate that generalized seizures also demonstrate circadian effects. The clinical evidence on generalized seizures and epilepsies is not recent, but a formal integration of circadian rhythmicity in our understanding and clinical management of epilepsies may be warranted.
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Fenoglio-Simeone KA, Wilke JC, Milligan HL, Allen CN, Rho JM, Maganti RK. Ketogenic diet treatment abolishes seizure periodicity and improves diurnal rhythmicity in epileptic Kcna1-null mice. Epilepsia 2009; 50:2027-34. [PMID: 19490051 DOI: 10.1111/j.1528-1167.2009.02163.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION Seizures are known to perturb circadian rhythms in humans as well as in animal models of epilepsy. However, it is unknown whether treatment of the underlying epilepsy restores normal biologic rhythms. We asked whether: (1) seizure activity is characterized by diurnal rhythmicity, (2) chronically epileptic mice exhibit impaired rest-activity rhythms, and (3) treatment with the anticonvulsant ketogenic diet (KD) improves such perturbations. METHODS Chronically epileptic Kcna1-null mice were fed either a standard diet (SD) or KD for 4 weeks and subjected to continuous video-EEG (electroencephalography) and actigraphy monitoring for 3-5 days to assess seizure activity and rest-activity cycles. RESULTS Seizure activity in Kcna1-null mice demonstrated diurnal rhythmicity, peaking at zeitgeber (ZT)2.30 +/- 1.52. Rest-activity rhythms of epileptic mice were significantly disrupted. Whereas locomotor activity for wild-type mice peaked at ZT15.45 +/- 0.28 (ZT14:26-ZT16:51), peak activity of epileptic mice was more unpredictable, occurring over a 12.4 h range (ZT06:33-ZT18:57). In six of nine epileptic mice, peak activity was delayed to ZT17.42 +/- 0.38, whereas peak activity was advanced to ZT10.00 +/- 1.26 in the remaining mice. Treatment with the KD abolished seizure periodicity and restored the rest-activity rhythm to values resembling those of wild-type mice (i.e., activity peaking at ZT16.73 +/- 0.67). CONCLUSIONS Kcna1-null mice experience seizures with 24-h periodicity and impaired circadian behavior. KD reduces the number and periodicity of seizures and restores normal behavioral rhythms, suggesting that this nonpharmacologic therapy may benefit biologic rhythm disturbances in epileptic patients.
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Affiliation(s)
- Kristina A Fenoglio-Simeone
- Barrow Neurological Institute and St. Joseph's Medical Center, Neurology Research, Phoenix, Arizona 85013, USA
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Tahsili-Fahadan P, Yahyavi-Firouz-Abadi N, Riazi K, Ghahremani MH, Dehpour AR. Effect of acute and chronic photoperiod modulation on pentylenetetrazole-induced clonic seizure threshold in mice. Epilepsy Res 2008; 82:64-69. [DOI: 10.1016/j.eplepsyres.2008.07.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 07/10/2008] [Accepted: 07/11/2008] [Indexed: 11/30/2022]
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Stewart LS, Nylen KJ, Persinger MA, Cortez MA, Gibson KM, Snead OC. Circadian distribution of generalized tonic-clonic seizures associated with murine succinic semialdehyde dehydrogenase deficiency, a disorder of GABA metabolism. Epilepsy Behav 2008; 13:290-4. [PMID: 18514581 PMCID: PMC2574901 DOI: 10.1016/j.yebeh.2008.04.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2008] [Revised: 04/17/2008] [Accepted: 04/18/2008] [Indexed: 11/29/2022]
Abstract
Human succinic semialdehyde dehydrogenase (SSADH) deficiency is an autosomal recessive disorder of GABA metabolism associated with motor impairment and epileptic seizures. Similarly, mice with targeted deletion of the Aldh5a1 gene (Aldh5a1(-/-)) exhibit SSADH deficiency and seizures early in life. These seizures begin as absence seizures the second week of life, but evolve into generalized convulsive seizures that increase in severity and become lethal during the fourth postnatal week. The seizures are alleviated and survival is prolonged when the mutant animals are weaned onto a ketogenic diet (KD). The persistence of spontaneous, recurrent, generalized tonic-clonic seizures in KD-treated adult Aldh5a1(-/-) mice allowed us to quantify their daily (circadian) distribution using a novel behavioral method based on the detection of changes in movement velocity. Adult KD-treated Aldh5a1(-/-) mice exhibited a seizure phenotype characterized by fits of wild running clonus accompanied by jumping and bouncing. These hypermotor seizures were largely spontaneous and occurred daily in a nonrandom pattern. The seizure rhythm showed a peak shortly after dark phase onset (2008 hours) with near-24-hour periodicity. Age-matched wild-type littermates showed no evidence of abnormal motor behavior. These new data suggest that generalized tonic-clonic seizures in Aldh5a1(-/-) mice are more frequent during a specific time of day and will provide useful information to clinicians for the treatment of seizures associated with human SSADH deficiency.
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Affiliation(s)
- Lee S. Stewart
- Neurosciences and Mental Health Research Program, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8
| | - Kirk J. Nylen
- Neurosciences and Mental Health Research Program, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8
| | - Michael A. Persinger
- Behavioral Neuroscience Program, Department of Psychology, Laurentian University, Sudbury ON, Canada P3E 2C6
| | - Miguel A. Cortez
- Neurosciences and Mental Health Research Program, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8, Division of Neurology, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8, Department of Pediatrics, Faculty of Medicine, University of Toronto, 190 Elizabeth Street, Toronto ON, Canada M5G 2C4
| | - K. Michael Gibson
- Division of Medical Genetics, Departments of Pediatrics and Pathology, University of Pittsburgh School of Medicine, Rangos Research Center, 3460 Fifth Avenue, Pittsburgh PA 15213, USA
| | - O. Carter Snead
- Neurosciences and Mental Health Research Program, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8, Division of Neurology, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8, Department of Pediatrics, Faculty of Medicine, University of Toronto, 190 Elizabeth Street, Toronto ON, Canada M5G 2C4, Corresponding author. Address: Neurosciences and Mental Health Research Program, The Hospital for Sick Children, 555 University Avenue, Toronto ON, Canada M5G 1X8. Fax: +1 416 813 6334. E-mail address: (O.C. Snead, III)
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14
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Stewart LS, Bercovici E, Shukla R, Serbanescu I, Persad V, Mistry N, Cortez MA, Snead OC. Daily rhythms of seizure activity and behavior in a model of atypical absence epilepsy. Epilepsy Behav 2006; 9:564-72. [PMID: 17030024 DOI: 10.1016/j.yebeh.2006.08.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Revised: 08/28/2006] [Accepted: 08/29/2006] [Indexed: 10/24/2022]
Abstract
We studied daily rhythms of chronic seizure activity and behavior in adult rats and mice treated with the cholesterol biosynthesis inhibitor AY-9944 (AY) during early postnatal development. Chronic atypical absence seizures were verified in the AY-treated animals by the presence of spontaneous 5- to 6-Hz slow spike-wave discharges (SSWDs) in the neocortex. General behavioral activity, as measured by total movements (TM), movement time (MT), ambulatory movement time (AMT), time spent in center of arena (CT), jumps (JFP), and rotational behavior (TURNS), were continuously recorded under a 12-hour light:12-hour dark photocycle. The average SSWD duration in AY-treated rats varied daily, with two peaks occurring at approximately dark phase and light phase onset. Mice treated with AY exhibited significant increases in all behavioral measures during the light and dark phases, with the exception of light-phase CT, which did not differ from that of controls. Consequently, the daily rhythm of total behavioral activity (TM) exhibited a significantly higher mean oscillation (mesor) and amplitude without evidence of phase shift compared with the TM rhythm of controls. The occurrence of SSWD activity in the AY model appears to be subject to regulation by biological timing mechanisms and, furthermore, associated with motor hyperactivity that does not alter the timing of behavioral rhythmicity.
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Affiliation(s)
- Lee S Stewart
- Brain and Behavior Research Program, The Hospital for Sick Children, Toronto, Ont., Canada
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15
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Abstract
PURPOSE The pineal hormone melatonin has been shown to enhance hippocampal excitability. We therefore investigated whether inactivation of hippocampal melatonin receptors affects behavioral seizures. METHODS Intrahippocampal infusions were performed in rats to study the effect of different melatonin receptor antagonists on behavioral activity, EEG, and seizure susceptibility. Experiments were conducted at 2 times of the day that coincided with the peak and trough of the daily melatonin rhythm. RESULTS Local infusion of the Mel(1b) receptor antagonist 4-phenyl-2-propionamidotetralin (4-P-PDOT) into the hippocampus, but not the overlying neocortex, significantly increased seizure latency and in some cases provided complete protection against seizure development. In addition, 4-P-PDOT suppressed open field activity and hippocampal EEG amplitude. The mixed Mel(1a)/Mel(1b) receptor antagonist luzindole also increased seizure latency but to a lesser degree than 4-P-PDOT. The behavioral effects of Mel(1b) receptor inhibition were comparable to those of the gamma-aminobutyric acid (GABA)(A) receptor agonist muscimol and were observed during the dark phase (2400-0200 h) but not the light phase (1200-1400 h) of the daily photocycle. The anticonvulsant effect of intrahippocampal infusion of 4P-P-DOT was blocked by coadministration of the GABA(A) antagonist bicuculline. CONCLUSIONS Our results suggest that nocturnal activation of hippocampal Mel(1b) receptors depresses GABA(A) receptor function in the hippocampus and enhances seizure susceptibility.
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Affiliation(s)
- Lee S Stewart
- Program in Neuroscience, Department of Physiology & Pharmacology, The University of Western Ontario, London, Ontario, Canada.
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McKay BE, Persinger MA. Lithium ion "cyclotron resonance" magnetic fields decrease seizure onset times in lithium-pilocarpine seized rats. Int J Neurosci 2005; 114:1035-45. [PMID: 15527207 DOI: 10.1080/00207450490461350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
The cyclotron resonance equation predicts that the frequency of an applied magnetic field that might optimally interact with a single ion species may be computed as a function of the charge-to-mass ratio of the ion and the strength of the background static magnetic field. The present study was undertaken to discern the applicability of this equation for optimizing lithium ion utilization in the rat, as inferred by the predicted magnetic "ion resonance "field-induced shift of lithium's dose-dependent curve for seizure onset times (SOTs) when combined with the cholinergic agent pilocarpine. Groups of rats were administered 1.5 thru 3 mEq/kg lithium chloride (in 0.5 mEq/kg increments) and exposed to reference conditions or to one of three intensities (70 nanoTesla, 0.8 microTesla, or 25 microTesla) of a 85 Hz magnetic field calculated to resonate with lithium ions given the background static geomagnetic field of approximately 38,000 nanoTesla (0.38 Gauss). A statistically significant quadratic relationship for SOT as a function of magnetic field intensity (irrespective of lithium dose) was noted: this U-shaped function was characterized by equal SOTs for the reference and 25 microTesla groups, with a trend toward shorter SOTs for the 70 nanoTesla and 0.8 microTesla groups. Although not predicted by the equations, this report extends other findings suggestive of discrete intensity windows for which magnetic field frequencies derived from the cyclotron ion resonance equation may affect ion activity.
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Affiliation(s)
- B E McKay
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada
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17
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Persinger MA, Dupont MJ. Emergence of spontaneous seizures during the year following lithium/pilocarpine-induced epilepsy and neuronal loss within the right temporal cortices. Epilepsy Behav 2004; 5:440-5. [PMID: 15256179 DOI: 10.1016/j.yebeh.2004.03.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2003] [Revised: 03/22/2004] [Accepted: 03/23/2004] [Indexed: 11/22/2022]
Abstract
Thirty days after the induction of seizures in 16 rats with lithium (3 mEq/kg) and pilocarpine (30 mg/kg), the numbers of episodes of motor seizures (rapid forelimb clonus) during daily 10-minute observational periods were recorded for 11 months. The proportions of neuronal loss were ranked using two methods by light microscopy for all structures between the posterior and anterior commissures. Amounts of damage within the dentate gyrus, hilus (CA4), and CA3 field were most strongly correlated with numbers of seizures per month about 6 months before the brains were removed. The strongest correlations occurred between the amounts of damage within the right temporal cortices, even after the variance associated with damage within the dentate gyrus had been removed, and the numbers of seizures during the last 2 months. These results may explain the greater proportion of spontaneous seizures that begin with left side forelimb clonus and suggest a particular sensitivity of the right side of the brain to either their initiation or their consequences.
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Affiliation(s)
- M A Persinger
- Behavioral Neuroscience Program, Laurentian University, Sudbury Ont., Canada, P3E 2C6.
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18
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McKay BE, Persinger MA. Normal spatial and contextual learning for ketamine-treated rats in the pilocarpine epilepsy model. Pharmacol Biochem Behav 2004; 78:111-9. [PMID: 15159140 DOI: 10.1016/j.pbb.2004.02.019] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2003] [Revised: 12/05/2003] [Accepted: 02/27/2004] [Indexed: 11/18/2022]
Abstract
Cognitive impairments frequently accompany epileptic disorders. Here, we examine two neuroprotective agents, the noncompetitive NMDA antagonist ketamine and the dopaminergic antagonist acepromazine, for their efficacy in attenuating cognitive impairments in the lithium-pilocarpine (LI-PILO) model of rat limbic epilepsy. Declarative-like cognitive behaviors were assessed in a Morris water maze task that consisted successively of spatial and nonspatial (cued platform) training. Whereas the ketamine-treated (Ket) LI-PILO rats performed equally in all respects to nonseized control rats for the spatial and nonspatial components of the water maze task, the acepromazine-treated (Ace) LI-PILO rats failed to demonstrate learning in either the hidden or cued platform variants of the task and did not demonstrate any place learning in the platform-removed probe trials. We further assessed nondeclarative (associative) cognitive behaviors with a standard contextual fear-conditioning protocol. LI-PILO rats treated with acepromazine failed to learn the Pavlovian relationship; Ket LI-PILO rats performed equivalently to nonseized controls. Cumulatively, these data suggest robust cognitive sparing for LI-PILO rats with pharmacological NMDA receptor antagonism following induction of status epilepticus (SE). This cognitive sparing occurs despite earlier findings that the mean amount of total brain damage with LI-PILO is equivalent for Ket and Ace rats.
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Affiliation(s)
- B E McKay
- Behavioral Neuroscience Laboratory, Laurentian University, Sudbury, Ontario, Canada P3E 2C6.
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