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Binks SNM, Al-Diwani A, Handel AE, Bajorek T, Manohar S, Husain M, Irani SR, Koychev I. LGI1-antibody encephalitis: how to approach this highly treatable dementia mimic in memory and mental health services. Br J Psychiatry 2024; 224:252-257. [PMID: 38699852 PMCID: PMC7615977 DOI: 10.1192/bjp.2024.72] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/05/2024]
Abstract
Leucine-rich glioma-inactivated 1-antibody-encephalitis is a treatable and potentially reversible cause of cognitive and psychiatric presentations, and may mimic cognitive decline, rapidly progressive dementia and complex psychosis in older patients. This aetiology is of immediate relevance given the alternative treatment pathway required, compared with other conditions presenting with cognitive deficits.
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Affiliation(s)
- Sophie N M Binks
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
| | - Adam Al-Diwani
- University Department of Psychiatry, University of Oxford, UK
- Department of Psychological Medicine, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
- Oxford Community Psychological Medicine Service, Oxford Health NHS Foundation Trust, Oxford, UK
| | - Adam E Handel
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
- Department of Psychological Medicine, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
- Oxford Community Psychological Medicine Service, Oxford Health NHS Foundation Trust, Oxford, UK
| | - Tomasz Bajorek
- Department of Psychological Medicine, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
| | - Sanjay Manohar
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
- Department of Experimental Psychology, University of Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Masud Husain
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
- Department of Experimental Psychology, University of Oxford, UK
- Nuffield Department of Clinical Neurosciences, University of Oxford, UK
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical Neurosciences, University of Oxford, UK
- Department of Neurology, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
| | - Ivan Koychev
- University Department of Psychiatry, University of Oxford, UK; and Department of Psychological Medicine, John Radcliffe Hospital, Oxford University Hospital NHS Foundation Trust, Oxford, UK
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Mazzacane F, Ferrari F, Malvaso A, Mottese Y, Gastaldi M, Costa A, Pichiecchio A, Cavallini A. Acute amnestic syndrome in fornix lesions: a systematic review of reported cases with a focus on differential diagnosis. Front Neurol 2024; 15:1338291. [PMID: 38333604 PMCID: PMC10850356 DOI: 10.3389/fneur.2024.1338291] [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: 11/15/2023] [Accepted: 01/09/2024] [Indexed: 02/10/2024] Open
Abstract
Introduction Acute amnestic syndrome is an uncommon clinical presentation of neurological disease. Differential diagnosis encompasses several syndromes including Wernicke-Korsakoff and transient global amnesia (TGA). Structural lesions of the fornix account for a minority of cases of acute amnestic syndromes. Etiology varies from iatrogenic injury to ischemic, inflammatory, or neoplastic lesions. A prompt diagnosis of the underlying pathology is essential but challenging. The aim of this review is to systematically review the existing literature regarding cases of acute amnestic syndrome associated with non-iatrogenic lesions of the fornix. Methods We performed a systematic literature search on PubMed, Scopus, and Web of Science up to September 2023 to identify case reports and case series of patients with amnestic syndrome due to fornix lesions. The systematic review was conducted according to PRISMA guidelines. The research was limited to articles written in English. Cases of fornix damage directly ascribable to a surgical procedure were excluded. Results A total of 52 publications reporting 55 cases were included in the review. Focusing on acute/subacute onset, vascular etiology was highly prevalent, being responsible for 78% of cases, 40/55 (74%) of which were due to acute ischemic stroke. The amnestic syndrome was characterized by anterograde amnesia in all patients, associated with retrograde amnesia in 27% of cases. Amnesia was an isolated presentation in most cases. Up to two thirds of patients had persistent memory deficits of any severity at follow-up. Discussion Acute amnestic syndrome can be rarely caused by fornix lesions. In most cases of acute/subacute presentation, the etiology is ischemic stroke, mainly caused by strokes involving the subcallosal artery territory. The differential diagnosis is challenging and a distinction from common mimics is often difficult on a clinical basis. A high index of suspicion should be maintained to avoid misdiagnosis and provide adequate acute treatment to patients with time-dependent disease, also employing advanced neuroimaging. More research is needed to better understand the outcome and identify prognostic factors in patients with amnestic syndrome due to fornix lesions.
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Affiliation(s)
- F. Mazzacane
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Department of Emergency Neurology and Stroke Unit, IRCCS Fondazione Mondino, Pavia, Italy
- Unit of Behavioral Neurology, Mondino Foundation, Pavia, Italy
| | - F. Ferrari
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Department of Emergency Neurology and Stroke Unit, IRCCS Fondazione Mondino, Pavia, Italy
| | - A. Malvaso
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Neuroimmunology Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Y. Mottese
- Department of Neuroradiology, IRCCS Mondino Foundation, Pavia, Italy
| | - M. Gastaldi
- Neuroimmunology Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - A. Costa
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Unit of Behavioral Neurology, Mondino Foundation, Pavia, Italy
| | - A. Pichiecchio
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Department of Neuroradiology, IRCCS Mondino Foundation, Pavia, Italy
| | - A. Cavallini
- Department of Emergency Neurology and Stroke Unit, IRCCS Fondazione Mondino, Pavia, Italy
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Moscovitch M, Gilboa A. Has the concept of systems consolidation outlived its usefulness? Identification and evaluation of premises underlying systems consolidation. Fac Rev 2022; 11:33. [PMID: 36532709 PMCID: PMC9720899 DOI: 10.12703/r/11-33] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023] Open
Abstract
Systems consolidation has mostly been treated as a neural construct defined by the time-dependent change in memory representation from the hippocampus (HPC) to other structures, primarily the neocortex. Here, we identify and evaluate the explicit and implicit premises that underlie traditional or standard models and theories of systems consolidation based on evidence from research on humans and other animals. We use the principle that changes in neural representation over time and experience are accompanied by corresponding changes in psychological representations, and vice versa, to argue that each of the premises underlying traditional or standard models and theories of systems consolidation is found wanting. One solution is to modify or abandon the premises or theories and models. This is reflected in moderated models of systems consolidation that emphasize the early role of the HPC in training neocortical memories until they stabilize. The fault, however, may lie in the very concept of systems consolidation and its defining feature. We propose that the concept be replaced by one of memory systems reorganization, which does not carry the theoretical baggage of systems consolidation and is flexible enough to capture the dynamic nature of memory from inception to very long-term retention and retrieval at a psychological and neural level. The term "memory system reorganization" implies that memory traces are not fixed, even after they are presumably consolidated. Memories can continue to change as a result of experience and interactions among memory systems across the lifetime. As will become clear, hippocampal training of neocortical memories is only one type of such interaction, and not always the most important one, even at inception. We end by suggesting some principles of memory reorganization that can help guide research on dynamic memory processes that capture corresponding changes in memory at the psychological and neural levels.
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Affiliation(s)
- Morris Moscovitch
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Rotman Research Institute, Baycrest, Toronto, ON, Canada
| | - Asaf Gilboa
- Department of Psychology, University of Toronto, Toronto, ON, Canada
- Rotman Research Institute, Baycrest, Toronto, ON, Canada
- Toronto Rehabilitation Institute, University Health Network, Toronto, ON, Canada
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4
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Chan F, O'Gorman C, Swayne A, Gillis D, Blum S, Warren N. Voltage-gated potassium channel blanket testing in first-episode psychosis: Diagnostic nihilism? Aust N Z J Psychiatry 2021; 55:817-823. [PMID: 33423505 DOI: 10.1177/0004867420983454] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Voltage-gated potassium channel antibodies are implicated in limbic encephalitis and currently included in first-episode psychosis organic screening guidelines. Individuals with high-positive voltage-gated potassium channel titres most commonly present with neurological symptoms as well as sleep, cognitive, behaviour, psychosis and mood disturbance. The significance of low-positive voltage-gated potassium channel antibody titres in psychiatric patients is unclear and has not been previously examined. We aim to describe a statewide cohort of psychiatric patients with low- and high-positive voltage-gated potassium channel titres and explore if this finding influenced clinical management and patient outcomes. METHODS A retrospective review of all voltage-gated potassium channel antibodies testing performed in public psychiatric services in Queensland, Australia, with comparison of the clinical presentation and long-term outcomes of low- and high-positive voltage-gated potassium channel titre cases. Specific antigen targets (leucine-rich glioma-inactivated protein 1 and contactin-associated protein 2 antibodies) were also assessed. RESULTS The overall prevalence of voltage-gated potassium channel antibody positivity in Queensland, public, psychiatric service testing was 0.3% (14/4098), with 12 cases of low-positive voltage-gated potassium channel titre, 2 cases of high-positive (leucine-rich glioma-inactivated protein 1 antibody positive) cases and a voltage-gated potassium channel negative contactin-associated protein 2 antibody positive case. No low-positive case developed neurological abnormalities or had abnormal paraclinical investigations. In comparison, both high-positive voltage-gated potassium channel/leucine-rich glioma-inactivated protein 1 cases and the contactin-associated protein 2 antibody positive case rapidly developed neurological symptoms, had abnormal paraclinical testing and improved only with immunotherapy. There was no later development of encephalitic symptoms in the low-positive cases over an average of 1067 days follow-up. CONCLUSION Voltage-gated potassium channel antibody-associated limbic encephalitis was rare, and always associated with high antibody titres. Low-positive titres were not associated with the development of encephalitis over a long period of follow-up. The value of universal voltage-gated potassium channel antibody screening is unclear, and further prospective studies in first-episode psychosis populations are required.
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Affiliation(s)
- Fiona Chan
- Department of Neurology, Princess Alexandra Hospital, Brisbane, QLD, Australia
| | - Cullen O'Gorman
- Department of Neurology, Princess Alexandra Hospital, Brisbane, QLD, Australia.,Mater Centre for Neurosciences, Mater Hospital Brisbane, Brisbane, QLD, Australia.,School of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Andrew Swayne
- Mater Centre for Neurosciences, Mater Hospital Brisbane, Brisbane, QLD, Australia.,School of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - David Gillis
- Queensland Pathology, Brisbane, QLD, Australia.,Immunology Department, Sunshine Coast University Hospital, Birtinya, QLD, Australia
| | - Stefan Blum
- Department of Neurology, Princess Alexandra Hospital, Brisbane, QLD, Australia.,Mater Centre for Neurosciences, Mater Hospital Brisbane, Brisbane, QLD, Australia.,School of Medicine, The University of Queensland, Brisbane, QLD, Australia
| | - Nicola Warren
- School of Medicine, The University of Queensland, Brisbane, QLD, Australia.,Metro South Addiction and Mental Health, Princess Alexandra Hospital, Brisbane, QLD, Australia
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5
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Neuropsychological Evaluations in Limbic Encephalitis. Brain Sci 2021; 11:brainsci11050576. [PMID: 33947002 PMCID: PMC8145692 DOI: 10.3390/brainsci11050576] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 04/27/2021] [Accepted: 04/27/2021] [Indexed: 12/20/2022] Open
Abstract
Limbic encephalitis (LE) can cause dynamic and permanent impairment of cognition and behavior. In clinical practice, the question arises as to which cognitive and behavioral domains are affected by LE and which assessment is suited to monitor the disease progress and the success of treatment. Current findings on cognition and behavior in LE are reviewed and discussed based on current guidelines and consensus papers. In addition, we outline approaches for the neuropsychological monitoring of LE and its treatment. Dependent on disease acuity and severity, LE leads to episodic long-term memory dysfunction in different variants (e.g., anterograde memory impairment, accelerated long-term forgetting, and affection of autobiographical memory) and executive deficits. In addition, affective disorders are very common. More severe psychiatric symptoms may occur as well. In the course of the disease, dynamic phases with functional recovery must be differentiated from residual defect states. Evidence-based neuropsychological diagnostics should be conducted ideally before treatment initiation and reassessments are indicated when any progress is suggested, and when decisive anti-seizure or immunomodulatory treatment changes are made. Cognition and behavior may but must not run in synchrony with seizures, MRI pathology, or immune parameters. Cognitive and behavioral problems are integral aspects of LE and represent important biomarkers of disease acuity, progress, and therapy response beyond and in addition to parameters of immunology, neurological symptoms, and brain imaging. Thus, evidence-based neuropsychological assessments are essential for the diagnostic workup of patients with suspected or diagnosed limbic encephalitis, for treatment decisions, and disease and treatment monitoring.
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6
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Argyropoulos GPD, Butler CR. Does hippocampal atrophy explain anterograde and retrograde amnesia following autoimmune limbic encephalitis? Hippocampus 2020; 30:1013-1017. [PMID: 32320116 DOI: 10.1002/hipo.23208] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Revised: 03/26/2020] [Accepted: 03/31/2020] [Indexed: 11/09/2022]
Affiliation(s)
- Georgios P D Argyropoulos
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Division of Psychology, Faculty of Natural Sciences, University of Stirling, Stirling, UK
| | - Christopher R Butler
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Brain Sciences, Imperial College London, London, UK.,Departamento de Neurología, Pontificia Universidad Católica de Chile, Santiago, Chile
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7
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Argyropoulos GPD, Loane C, Roca-Fernandez A, Lage-Martinez C, Gurau O, Irani SR, Butler CR. Network-wide abnormalities explain memory variability in hippocampal amnesia. eLife 2019; 8:e46156. [PMID: 31282861 PMCID: PMC6639076 DOI: 10.7554/elife.46156] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Accepted: 07/05/2019] [Indexed: 01/11/2023] Open
Abstract
Patients with hippocampal amnesia play a central role in memory neuroscience but the neural underpinnings of amnesia are hotly debated. We hypothesized that focal hippocampal damage is associated with changes across the extended hippocampal system and that these, rather than hippocampal atrophy per se, would explain variability in memory between patients. We assessed this hypothesis in a uniquely large cohort of patients (n = 38) after autoimmune limbic encephalitis, a syndrome associated with focal structural hippocampal pathology. These patients showed impaired recall, recognition and maintenance of new information, and remote autobiographical amnesia. Besides hippocampal atrophy, we observed correlatively reduced thalamic and entorhinal cortical volume, resting-state inter-hippocampal connectivity and activity in posteromedial cortex. Associations of hippocampal volume with recall, recognition, and remote memory were fully mediated by wider network abnormalities, and were only direct in forgetting. Network abnormalities may explain the variability across studies of amnesia and speak to debates in memory neuroscience.
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Affiliation(s)
- Georgios PD Argyropoulos
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Clare Loane
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Institute of Cognitive NeuroscienceUniversity College LondonLondonUnited Kingdom
| | - Adriana Roca-Fernandez
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Carmen Lage-Martinez
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
- Valdecilla Biomedical Research InstituteUniversity Hospital Marqués de ValdecillaSantanderSpain
| | - Oana Gurau
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Sarosh R Irani
- Oxford Autoimmune Neurology Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
| | - Christopher R Butler
- Memory Research Group, Nuffield Department of Clinical NeurosciencesUniversity of OxfordOxfordUnited Kingdom
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8
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Zangrandi A, Gasparini F, Marti A, Bhalla R, Napoli M, Angelini D, Ghidoni E, Rizzi R. A 9-year neuropsychological report of a patient with LGI1-associated limbic encephalitis. J Clin Exp Neuropsychol 2019; 41:749-759. [PMID: 31142216 DOI: 10.1080/13803395.2019.1617836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Introduction: Anti-leucine-rich glioma-inactivated 1 limbic encephalitis (LGI1-LE) is an autoimmune disorder associated with antibodies to voltage-gated potassium channels (VGKC). It is a non-paraneoplastic and partially reversible encephalitis that can be diagnosed via serological testing. Untreated LGI1-LE can be associated with neurocognitive as well as neuropsychiatric sequelae. Here we report the neuropsychological and clinical profile of a patient with LGI1-LE following three different treatment approaches: plasmapheresis (PA), intravenous immunoglobulin (IVIG), and corticosteroids (CO). Method: We investigated our patient with 10 neuropsychological evaluations obtained over a 9-year follow-up period. Multiple MRI scans, EEG recordings, neurological examinations, and serum tests were also obtained. Results: The neurocognitive profile of our patient was characterized by long-term memory impairment (verbal and visual-spatial), and deficits in aspects of executive functioning and language. Neuropsychiatric symptoms of depression and anxiety were noted intermittently. Conclusions: Non-specific treatment prior to diagnosis had marginal effects on neurocognitive profile, neuropsychiatric symptoms, or control of epileptic seizure. In contrast, specific treatments for LGI1-LE following diagnosis resulted in neurocognitive improvement and epileptic control. Among the three treatments, IVIG and CO had the most beneficial impact on neurocognitive status, likely due to the continuity of administration.
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Affiliation(s)
- Andrea Zangrandi
- a Clinical Neuropsychology, Cognitive Disorders and Dyslexia Unit, Department of Neuro-Motor Diseases , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
| | - Federico Gasparini
- a Clinical Neuropsychology, Cognitive Disorders and Dyslexia Unit, Department of Neuro-Motor Diseases , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
| | - Alessandro Marti
- a Clinical Neuropsychology, Cognitive Disorders and Dyslexia Unit, Department of Neuro-Motor Diseases , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
| | - Rishi Bhalla
- b Department of Psychiatry , University of British Columbia , Vancouver , Canada
| | - Manuela Napoli
- c Neuroradiology Unit, Department of Diagnostic Imaging , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
| | - Damiano Angelini
- a Clinical Neuropsychology, Cognitive Disorders and Dyslexia Unit, Department of Neuro-Motor Diseases , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
| | - Enrico Ghidoni
- a Clinical Neuropsychology, Cognitive Disorders and Dyslexia Unit, Department of Neuro-Motor Diseases , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
| | - Romana Rizzi
- d Neurology Unit, Department of Neuro-Motor Diseases , Azienda Unità Sanitaria Locale - IRCCS Reggio Emilia , Reggio Emilia , Italy
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Helmstaedter C, Winter B, Melzer N, Lohmann H, Witt JA. Accelerated long-term forgetting in focal epilepsies with special consideration given to patients with diagnosed and suspected limbic encephalitis. Cortex 2019; 110:58-68. [DOI: 10.1016/j.cortex.2018.01.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Revised: 07/13/2017] [Accepted: 01/05/2018] [Indexed: 02/04/2023]
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Miller TD, Chong TTJ, Aimola Davies AM, Ng TWC, Johnson MR, Irani SR, Vincent A, Husain M, Jacob S, Maddison P, Kennard C, Gowland PA, Rosenthal CR. Focal CA3 hippocampal subfield atrophy following LGI1 VGKC-complex antibody limbic encephalitis. Brain 2017; 140:1212-1219. [PMID: 28369215 PMCID: PMC5405234 DOI: 10.1093/brain/awx070] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 01/29/2017] [Indexed: 12/16/2022] Open
Abstract
Magnetic resonance imaging has linked chronic voltage-gated potassium channel (VGKC) complex antibody-mediated limbic encephalitis with generalized hippocampal atrophy. However, autoantibodies bind to specific rodent hippocampal subfields. Here, human hippocampal subfield (subiculum, cornu ammonis 1-3, and dentate gyrus) targets of immunomodulation-treated LGI1 VGKC-complex antibody-mediated limbic encephalitis were investigated using in vivo ultra-high resolution (0.39 × 0.39 × 1.0 mm3) 7.0 T magnetic resonance imaging [n = 18 patients, 17 patients (94%) positive for LGI1 antibody and one patient negative for LGI1/CASPR2 but positive for VGKC-complex antibodies, mean age: 64.0 ± 2.55 years, median 4 years post-limbic encephalitis onset; n = 18 controls]. First, hippocampal subfield quantitative morphometry indicated significant volume loss confined to bilateral CA3 [F(1,34) = 16.87, P < 0.0001], despite hyperintense signal evident in 5 of 18 patients on presentation. Second, early and later intervention (<3 versus >3 months from symptom onset) were associated with CA3 atrophy. Third, whole-brain voxel-by-voxel morphometry revealed no significant grey matter loss. Fourth, CA3 subfield atrophy was associated with severe episodic but not semantic amnesia for postmorbid autobiographical events that was predicted by variability in CA3 volume. The results raise important questions about the links with histopathology, the impact of the observed focal atrophy on other CA3-mediated reconstructive and episodic mechanisms, and the role of potential antibody-mediated pathogenicity as part of the pathophysiology cascade in humans.
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Affiliation(s)
- Thomas D Miller
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,National Hospital for Neurology and Neurosurgery, London, London, UK
| | - Trevor T-J Chong
- Monash Institute of Cognitive and Clinical Neurosciences, Monash University, Clayton, Victoria 3800, Australia
| | - Anne M Aimola Davies
- Department of Experimental Psychology, University of Oxford, Oxford, UK.,Australian National University, Research School of Psychology, Canberra, ACT, AUS
| | - Tammy W C Ng
- Centre for Anaesthesia, Critical Care and Pain Medicine, University College London Hospital, London UK
| | - Michael R Johnson
- Division of Brain Sciences, Charing Cross Campus, Imperial College London, London UK
| | - Sarosh R Irani
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Angela Vincent
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Masud Husain
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.,Department of Experimental Psychology, University of Oxford, Oxford, UK
| | - Saiju Jacob
- Neurology Department, Queen Elizabeth Neuroscience Centre, University Hospitals of Birmingham, Birmingham, UK
| | - Paul Maddison
- Neurology Department, Queen's Medical Centre, Nottingham, UK
| | - Christopher Kennard
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Penny A Gowland
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Clive R Rosenthal
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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11
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Prüss H, Lennox BR. Emerging psychiatric syndromes associated with antivoltage-gated potassium channel complex antibodies. J Neurol Neurosurg Psychiatry 2016; 87:1242-1247. [PMID: 27435086 DOI: 10.1136/jnnp-2015-313000] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Accepted: 07/02/2016] [Indexed: 01/17/2023]
Abstract
Antibodies against the voltage-gated potassium channel (VGKC) were first recognised as having a potential pathogenic role in disorders of the central nervous system in 2001, with VGKC antibodies described in patients with limbic encephalitis, and the subsequent seminal paper describing the clinical phenotype and immunotherapy treatment responsiveness in 13 patients with VGKC antibodies and limbic encephalitis in 2004. These initial case descriptions were of a progressive neuropsychiatric syndrome with abnormalities of mood, sleep and cognition recognised alongside the neurological symptoms of seizures and autonomic instability. The clinical syndromes associated with VGKC complex (VGKCC) antibodies have broadened considerably over the last 15 years, with multiple cases of more restricted 'formes fruste' presentations associated with VGKCC antibodies being described. However, the relevance of antibodies in these cases has remained controversial. The understanding of the pathogenic nature of VGKC antibodies has further advanced since 2010 with the discovery that VGKC antibodies are not usually antibodies against the VGKC subunits themselves, but instead to proteins that are complexed with the potassium channel, in particular leucine-rich, glioma-inactivated protein 1 (LGI1) and contactin-associated protein 2 (Caspr2). Antibodies against these proteins have been associated with particular, although overlapping, clinical phenotypes, each also including neuropsychiatric features. Our aim is to critically review the association between VGKCC, LGI1 and Caspr2 antibodies with isolated psychiatric presentations-with a focus on cognitive impairment, mood disorders and psychosis. We recommend that screening for VGKCC, LGI1 and Caspr2 antibodies be considered for those with neuropsychiatric presentations.
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Affiliation(s)
- Harald Prüss
- Department of Neurology, Charité University Medicine Berlin, German Center for Neurodegenerative Diseases (DZNE) Berlin, Berlin, Germany
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12
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Dodich A, Cerami C, Iannaccone S, Marcone A, Alongi P, Crespi C, Canessa N, Andreetta F, Falini A, Cappa SF, Perani D. Neuropsychological and FDG-PET profiles in VGKC autoimmune limbic encephalitis. Brain Cogn 2016; 108:81-7. [DOI: 10.1016/j.bandc.2016.07.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/26/2016] [Accepted: 07/26/2016] [Indexed: 02/08/2023]
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13
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Rossor M, Collinge J, Fox N, Mead S, Mummery C, Rohrer J, Schott J, Warren J. Dementia and Cognitive Impairment. Neurology 2016. [DOI: 10.1002/9781118486160.ch8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
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Abstract
In recent years a large number of antibody-associated or antibody-defined encephalitides have been discovered. These conditions are often referred to as autoimmune encephalitides. The clinical features include prominent epileptic seizures, cognitive and psychiatric disturbance. These encephalitides can be divided in those with antibodies against intracellular antigens and those with antibodies against surface antigens. The discovery of new antibodies against targets on the surface of neurons is especially interesting since patients with such antibodies can be successfully treated immunologically. This chapter focuses on the pathology and the pathogenetic mechanisms involved in these encephalitides and discusses some of the questions that are raised in this exciting new field. It is important to realise, however, that because of the use of antibodies to diagnose the patients, and their improvement with treatment, there are relatively few biopsy or postmortem reports, limiting the neuropathological data and conclusions that can be drawn. For this reason we especially focus on the most frequent autoimmune encephalitides, those with antibodies to the NMDA receptor and with antibodies to the known protein components of the VGKC complex. Analysis of these encephalitides show completely different pathogenic mechanisms. In VGKC complex encephalitis, antibodies seem to bind to their target and activate complement, leading to destruction and loss of neurons. On the other hand, in NMDAR encephalitis, complement activation and neuronal degeneration seems to be largely absent. Instead, binding of antibodies leads to a decrease of NMDA receptors resulting in a hypofunction. This hypofunction offers an explanation for some of the clinical features such as psychosis and episodic memory impairment, but not for the frequent seizures. Thus, additional analysis of the few human brain specimens present and the use of specific animal models are needed to further understand the effects of these antibodies in autoimmune encephalitides.
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Affiliation(s)
- Jan Bauer
- Center for Brain Research, Medical University Vienna, Vienna, Austria.
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15
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Abstract
This review reports the available evidence on the activation of the innate and adaptive branches of the immune system and the related inflammatory processes in epileptic disorders and the putative pathogenic role of inflammatory processes developing in the brain, as indicated by evidence from experimental and clinical research. Indeed, there is increasing knowledge supporting a role of specific inflammatory mediators and immune cells in the generation and recurrence of epileptic seizures, as well as in the associated neuropathology and comorbidities. Major challenges in this field remain: a better understanding of the key inflammatory pathogenic pathways activated in chronic epilepsy and during epileptogenesis, and how to counteract them efficiently without altering the homeostatic tissue repair function of inflammation. The relevance of this information for developing novel therapies will be highlighted.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, IRCSS-Istituto di Ricerche Farmacologiche "Mario Negri," 20156 Milano, Italy
| | - Bethan Lang
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Oxford OX3 9DU, United Kingdom
| | - Eleonora Aronica
- Department of (Neuro)Pathology, Academic Medical Center, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands Department of (Neuro)Pathology, Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, 1105 AZ Amsterdam, The Netherlands SEIN-Stichting Epilepsie Instellingen Nederland, Heemstede 2103 SW, The Netherlands
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16
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Witt JA, Vogt VL, Widman G, Langen KJ, Elger CE, Helmstaedter C. Loss of Autonoetic Awareness of Recent Autobiographical Episodes and Accelerated Long-Term Forgetting in a Patient with Previously Unrecognized Glutamic Acid Decarboxylase Antibody Related Limbic Encephalitis. Front Neurol 2015; 6:130. [PMID: 26106363 PMCID: PMC4460811 DOI: 10.3389/fneur.2015.00130] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2015] [Accepted: 05/19/2015] [Indexed: 01/16/2023] Open
Abstract
We describe a 35-year-old male patient presenting with depressed mood and emotional instability, who complained about severe anterograde and retrograde memory deficits characterized by accelerated long-term forgetting and loss of autonoetic awareness regarding autobiographical memories of the last 3 years. Months before he had experienced two breakdowns of unknown etiology giving rise to the differential diagnosis of epileptic seizures after various practitioners and clinics had suggested different etiologies such as a psychosomatic condition, burnout, depression, or dissociative amnesia. Neuropsychological assessment indicated selectively impaired figural memory performance. Extended diagnostics confirmed accelerated forgetting of previously learned and retrievable verbal material. Structural imaging showed bilateral swelling and signal alterations of temporomesial structures (left >right). Video-EEG monitoring revealed a left temporal epileptic focus and subclincal seizure, but no overt seizures. Antibody tests in serum and liquor were positive for glutamic acid decarboxylase antibodies. These findings led to the diagnosis of glutamic acid decarboxylase antibody related limbic encephalitis. Monthly steroid pulses over 6 months led to recovery of subjective memory and to intermediate improvement but subsequent worsening of objective memory performance. During the course of treatment, the patient reported de novo paroxysmal non-responsive states. Thus, antiepileptic treatment was started and the patient finally became seizure free. At the last visit, vocational reintegration was successfully in progress. In conclusion, amygdala swelling, retrograde biographic memory impairment, accelerated long-term forgetting, and emotional instability may serve as indicators of limbic encephalitis, even in the absence of overt epileptic seizures. The monitoring of such patients calls for a standardized and concerted multilevel diagnostic approach with repeated assessments.
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Affiliation(s)
| | - Viola Lara Vogt
- Department of Epileptology, University of Bonn , Bonn , Germany
| | - Guido Widman
- Department of Epileptology, University of Bonn , Bonn , Germany
| | - Karl-Josef Langen
- Institute of Neuroscience and Medicine, Forschungszentrum Jülich , Jülich , Germany
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17
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Abstract
We evaluated two different perspectives about the function of the human hippocampus--one that emphasizes the importance of memory and another that emphasizes the importance of spatial processing and scene construction. We gave tests of boundary extension, scene construction, and memory to patients with lesions limited to the hippocampus or large lesions of the medial temporal lobe. The patients were intact on all of the spatial tasks and impaired on all of the memory tasks. We discuss earlier studies that associated performance on these spatial tasks to hippocampal function. Our results demonstrate the importance of medial temporal lobe structures for memory and raise doubts about the idea that these structures have a prominent role in spatial cognition.
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18
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Bettcher BM, Gelfand JM, Irani SR, Neuhaus J, Forner S, Hess CP, Geschwind MD. More than memory impairment in voltage-gated potassium channel complex encephalopathy. Eur J Neurol 2014; 21:1301-10. [PMID: 24981998 DOI: 10.1111/ene.12482] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 05/05/2014] [Indexed: 12/13/2022]
Abstract
BACKGROUND AND PURPOSE Autoimmune encephalopathies (AEs) are a heterogeneous group of neurological disorders that affect cognition. Although memory difficulties are commonly endorsed, few reports of AEs inclusively assess all cognitive domains in detail. Our aim was to perform an unbiased cognitive evaluation of AE patients with voltage-gated potassium channel complex antibodies (VGKCC -Abs) in order to delineate cognitive strengths and weaknesses. METHODS Serial VGKCC -Ab AE subjects (n = 12) were assessed with a comprehensive evaluation of memory, executive functions, visuospatial skills and language. Clinical magnetic resonance imaging (MRI) (n = 10/12) was evaluated. Five subjects had serial cognitive testing available, permitting descriptive analysis of change. RESULTS Subjects demonstrated mild to moderate impairment in memory (mean Z = -1.9) and executive functions (mean Z = -1.5), with variable impairments in language and sparing of visuospatial skills. MRI findings showed T2 hyperintensities in medial temporal lobe (10/10) and basal ganglia (2/10). Serial cognitive examination revealed heterogeneity in cognitive function; whereas most patients improved in one or more domains, residual impairments were observed in some patients. CONCLUSIONS This study augments previous neuropsychological analyses in VGKCC -Ab AE by identifying not only memory and executive function deficits but also language impairments, with preservation of visuospatial functioning. The study further highlights the importance of domain-specific testing to parse out the complex cognitive phenotypes of VGKCC -Ab AE.
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Affiliation(s)
- B M Bettcher
- Department of Neurology, Memory and Aging Center, UCSF, San Francisco, CA, USA
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19
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Butler CR, Miller TD, Kaur MS, Baker IW, Boothroyd GD, Illman NA, Rosenthal CR, Vincent A, Buckley CJ. Persistent anterograde amnesia following limbic encephalitis associated with antibodies to the voltage-gated potassium channel complex. J Neurol Neurosurg Psychiatry 2014; 85:387-91. [PMID: 24403282 DOI: 10.1136/jnnp-2013-306724] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
OBJECTIVE Limbic encephalitis (LE) associated with antibodies to the voltage-gated potassium channel complex (VGKC) is a potentially reversible cause of cognitive impairment. Despite the prominence of cognitive dysfunction in this syndrome, little is known about patients' neuropsychological profile at presentation or their long-term cognitive outcome. METHODS We used a comprehensive neuropsychological test battery to evaluate cognitive function longitudinally in 19 patients with VGKC-LE. RESULTS Before immunotherapy, the group had significant impairment of memory, processing speed and executive function, whereas language and perceptual organisation were intact. At follow-up, cognitive impairment was restricted to the memory domain, with processing speed and executive function having returned to the normal range. Residual memory function was predicted by the antibody titre at presentation. CONCLUSIONS The results show that, despite broad cognitive dysfunction in the acute phase, patients with VGKC-LE often make a substantial recovery with immunotherapy but may be left with permanent anterograde amnesia.
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Affiliation(s)
- Christopher R Butler
- Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, , Oxford, UK
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20
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Abstract
In patients with immune-associated disorders of the gray central nervous system matter (including recurrent seizures), antibodies against intracellular antigens have been discovered since the 1980s/1990s. In recent years, new antibodies against surface antigens have also been discovered. In two respects, these antibodies are even more interesting than the ones to intracellular antigens as, first, they promise a better response to immunotherapy; and, second, these antibodies contribute greatly to the understanding of the disease mechanisms. Whereas in encephalitides with antibodies against intracellular antigens, a cytotoxic T-cell-mediated response seems to be responsible for neuronal cell loss, in encephalitides with autoantibodies against surface antigens these antibodies are probably the relevant pathogenic agents in the associated disease conditions. On the one hand, antibodies to the NR1 subunit of N-methyl-D-aspartate receptors have been suggested to cause internalization and loss of these receptors without any cell destruction. This mechanism can explain the reversible functional effects caused by these antibodies. On the other hand, antibody- and complement-mediated destructive, and the irreversible effects of antibodies against the voltage-gated potassium channel antigens have been noted. These emerging findings make it plausible that immunological therapies, preferably early after characterization of the antibodies, offer opportunities to restore the health of affected patients.
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Affiliation(s)
| | - Jan Bauer
- />Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, Spitalgasse 4, 1090 Vienna, Austria
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21
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Irani SR, Stagg CJ, Schott JM, Rosenthal CR, Schneider SA, Pettingill P, Pettingill R, Waters P, Thomas A, Voets NL, Cardoso MJ, Cash DM, Manning EN, Lang B, Smith SJM, Vincent A, Johnson MR. Faciobrachial dystonic seizures: the influence of immunotherapy on seizure control and prevention of cognitive impairment in a broadening phenotype. ACTA ACUST UNITED AC 2013; 136:3151-62. [PMID: 24014519 DOI: 10.1093/brain/awt212] [Citation(s) in RCA: 287] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Voltage-gated potassium channel complex antibodies, particularly those directed against leucine-rich glioma inactivated 1, are associated with a common form of limbic encephalitis that presents with cognitive impairment and seizures. Faciobrachial dystonic seizures have recently been reported as immunotherapy-responsive, brief, frequent events that often predate the cognitive impairment associated with this limbic encephalitis. However, these observations were made from a retrospective study without serial cognitive assessments. Here, we undertook the first prospective study of faciobrachial dystonic seizures with serial assessments of seizure frequencies, cognition and antibodies in 10 cases identified over 20 months. We hypothesized that (i) faciobrachial dystonic seizures would show a differential response to anti-epileptic drugs and immunotherapy; and that (ii) effective treatment of faciobrachial dystonic seizures would accelerate recovery and prevent the development of cognitive impairment. The 10 cases expand both the known age at onset (28 to 92 years, median 68) and clinical features, with events of longer duration, simultaneously bilateral events, prominent automatisms, sensory aura, and post-ictal fear and speech arrest. Ictal epileptiform electroencephalographic changes were present in three cases. All 10 cases were positive for voltage-gated potassium channel-complex antibodies (346-4515 pM): nine showed specificity for leucine-rich glioma inactivated 1. Seven cases had normal clinical magnetic resonance imaging, and the cerebrospinal fluid examination was unremarkable in all seven tested. Faciobrachial dystonic seizures were controlled more effectively with immunotherapy than anti-epileptic drugs (P = 0.006). Strikingly, in the nine cases who remained anti-epileptic drug refractory for a median of 30 days (range 11-200), the addition of corticosteroids was associated with cessation of faciobrachial dystonic seizures within 1 week in three and within 2 months in six cases. Voltage-gated potassium channel-complex antibodies persisted in the four cases with relapses of faciobrachial dystonic seizures during corticosteroid withdrawal. Time to recovery of baseline function was positively correlated with time to immunotherapy (r = 0.74; P = 0.03) but not time to anti-epileptic drug administration (r = 0.55; P = 0.10). Of 10 cases, the eight cases who received anti-epileptic drugs (n = 3) or no treatment (n = 5) all developed cognitive impairment. By contrast, the two who did not develop cognitive impairment received immunotherapy to treat their faciobrachial dystonic seizures (P = 0.02). In eight cases without clinical magnetic resonance imaging evidence of hippocampal signal change, cross-sectional volumetric magnetic resonance imaging post-recovery, after accounting for age and head size, revealed cases (n = 8) had smaller brain volumes than healthy controls (n = 13) (P < 0.001). In conclusion, faciobrachial dystonic seizures can be prospectively identified as a form of epilepsy with an expanding phenotype. Immunotherapy is associated with excellent control of the frequently anti-epileptic drug refractory seizures, hastens time to recovery, and may prevent the subsequent development of cognitive impairment observed in this study.
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Affiliation(s)
- Sarosh R Irani
- 1 Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
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22
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Pertzov Y, Miller TD, Gorgoraptis N, Caine D, Schott JM, Butler C, Husain M. Binding deficits in memory following medial temporal lobe damage in patients with voltage-gated potassium channel complex antibody-associated limbic encephalitis. ACTA ACUST UNITED AC 2013; 136:2474-85. [PMID: 23757763 PMCID: PMC3722347 DOI: 10.1093/brain/awt129] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Some prominent studies have claimed that the medial temporal lobe is not involved in retention of information over brief intervals of just a few seconds. However, in the last decade several investigations have reported that patients with medial temporal lobe damage exhibit an abnormally large number of errors when required to remember visual information over brief intervals. But the nature of the deficit and the type of error associated with medial temporal lobe lesions remains to be fully established. Voltage-gated potassium channel complex antibody-associated limbic encephalitis has recently been recognized as a form of treatable autoimmune encephalitis, frequently associated with imaging changes in the medial temporal lobe. Here, we tested a group of these patients using two newly developed visual short-term memory tasks with a sensitive, continuous measure of report. These tests enabled us to study the nature of reporting errors, rather than only their frequency. On both paradigms, voltage-gated potassium channel complex antibody patients exhibited larger errors specifically when several items had to be remembered, but not for a single item. Crucially, their errors were strongly associated with an increased tendency to report the property of the wrong item stored in memory, rather than simple degradation of memory precision. Thus, memory for isolated aspects of items was normal, but patients were impaired at binding together the different properties belonging to an item, e.g. spatial location and object identity, or colour and orientation. This occurred regardless of whether objects were shown simultaneously or sequentially. Binding errors support the view that the medial temporal lobe is involved in linking together different types of information, potentially represented in different parts of the brain, regardless of memory duration. Our novel behavioural measures also have the potential to assist in monitoring response to treatment in patients with memory disorders, such as those with voltage-gated potassium channel complex antibody limbic encephalitis.
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Affiliation(s)
- Yoni Pertzov
- Institute of Neurology, University College London, London, UK.
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23
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Frisch C, Malter MP, Elger CE, Helmstaedter C. Neuropsychological course of voltage-gated potassium channel and glutamic acid decarboxylase antibody related limbic encephalitis. Eur J Neurol 2013; 20:1297-304. [PMID: 23678940 DOI: 10.1111/ene.12186] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/08/2013] [Indexed: 01/30/2023]
Abstract
BACKGROUND AND PURPOSE Autoantibodies (abs) to glutamic acid decarboxylase (GAD) and to voltage-gated potassium channels (VGKC) induce distinct courses of limbic encephalitis, related to MRI findings, seizure outcome and cognition. METHODS A detailed analysis of the cognitive course of the two forms is presented, spanning a median time interval of 28 months, including parameters of attention, learning and memory in 15 VGKC-ab-positive and 16 GAD-ab-positive patients. RESULTS In both groups, the initially significantly impaired attention performance recovered to a putatively premorbid level. In VGKC patients the partially severely impaired learning and memory performance improved under treatment but remained subnormal at last follow-up. By contrast, GAD-ab-positive patients had initially less impaired learning and memory scores but did not show an improvement under treatment. CONCLUSIONS The results provide evidence of distinct relations between inductive processes and cognitive outcome in VGKC-ab-positive and GAD-ab-positive subforms of limbic encephalitis, which possibly depend on differences in pathogenic molecular mechanisms and affected cerebral loci.
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Affiliation(s)
- C Frisch
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.
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24
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Bauer J, Vezzani A, Bien CG. Epileptic encephalitis: the role of the innate and adaptive immune system. Brain Pathol 2012; 22:412-21. [PMID: 22497613 PMCID: PMC8029258 DOI: 10.1111/j.1750-3639.2012.00580.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2012] [Accepted: 02/07/2012] [Indexed: 12/31/2022] Open
Abstract
Seizures are a prominent clinical feature of encephalitis. Recent data suggest the adaptive as well as innate immune system to be involved directly in the pathomechanism of epileptogenesis. Cytotoxic T-cells and antibody-mediated complement activation are major components of the adaptive immune system, which can induce neurodegeneration, thereby probably contributing to epileptic encephalitis. The innate immune system operates via interleukin-1 and toll-like receptor-associated mechanisms and was shown to play a direct role in epileptogenesis. Here, we review neuropathology hallmarks of various encephalitis conditions such as Rasmussen encephalitis (RE) but also introduce the more recently discovered antibody-associated voltage-gated potassium channel complex (VGKC), N-methyl-D-aspartate receptor (NMDAR) or glutamic acid decarboxylase (GAD) 65 encephalitides. Neuropathological investigations are used to determine specific cellular components and molecular mechanisms used by the immune system to provoke neurodegeneration and to promote epileptogenesis. Based on recent findings, we propose concepts for the stratification of epileptic encephalitis. Knowledge of the role of the innate immunity has already translated into clinical treatment strategies and may help to discover novel drug targets for these epileptic disorders.
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Affiliation(s)
- Jan Bauer
- Department of Neuroimmunology, Center for Brain Research, Vienna, Austria.
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25
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Addis DR, Schacter DL. The hippocampus and imagining the future: where do we stand? Front Hum Neurosci 2012; 5:173. [PMID: 22291625 PMCID: PMC3251274 DOI: 10.3389/fnhum.2011.00173] [Citation(s) in RCA: 176] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2011] [Accepted: 12/12/2011] [Indexed: 11/27/2022] Open
Abstract
Recent neuroimaging work has demonstrated that the hippocampus is engaged when imagining the future, in some cases more than when remembering the past. It is possible that this hippocampal activation reflects recombining details into coherent scenarios and/or the encoding of these scenarios into memory for later use. However, inconsistent findings have emerged from recent studies of future simulation in patients with memory loss and hippocampal damage. Thus, it remains an open question as to whether the hippocampus is necessary for future simulation. In this review, we consider the findings from patient studies and the neuroimaging literature with respect to a new framework that highlights three component processes of simulation: accessing episodic details, recombining details, and encoding simulations. We attempt to reconcile these discrepancies between neuroimaging and patient studies by suggesting that different component processes of future simulation may be differentially affected by hippocampal damage.
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Affiliation(s)
- Donna Rose Addis
- Australian Research Council Centre of Excellence in Cognition and its Disorders Sydney, NSW, Australia
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26
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Abstract
With time and experience, memories undergo a process of reorganization that involves different neuronal networks, known as systems consolidation. The traditional view, as articulated in standard consolidation theory (SCT), is that (episodic and semantic) memories initially depend on the hippocampus, but eventually become consolidated in their original forms in other brain regions. In this study, we review the main principles of SCT and report evidence from the neuropsychological literature that would not be predicted by this theory. By comparison, the evidence supports an alternative account, the transformation hypothesis, whose central premise is that changes in neural representation in systems consolidation are accompanied by corresponding changes in the nature of the memory. According to this view, hippocampally dependent, episodic, or context-specific memories transform into semantic or gist-like versions that are represented in extra-hippocampal structures. To the extent that episodic memories are retained, they will continue to require the hippocampus, but the hippocampus is not needed for the retrieval of semantic memories. The transformation hypothesis emphasizes the dynamic nature of memory, as well as the underlying functional and neural interactions that must be taken into account in a comprehensive theory of memory.
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27
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Autoantibodies associated with diseases of the CNS: new developments and future challenges. Lancet Neurol 2011; 10:759-72. [PMID: 21777830 DOI: 10.1016/s1474-4422(11)70096-5] [Citation(s) in RCA: 351] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
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28
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Unusual amnesia in a patient with VGKC-Ab limbic encephalitis: A case study. Cortex 2011; 47:451-9. [DOI: 10.1016/j.cortex.2010.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2009] [Revised: 11/23/2009] [Accepted: 01/21/2010] [Indexed: 11/22/2022]
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29
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Reply to Maguire and Hassabis: Autobiographical memory and future imagining. Proc Natl Acad Sci U S A 2011. [DOI: 10.1073/pnas.1019643108] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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30
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Andelman F, Hoofien D, Goldberg I, Aizenstein O, Neufeld MY. Bilateral hippocampal lesion and a selective impairment of the ability for mental time travel. Neurocase 2010; 16:426-35. [PMID: 20401802 DOI: 10.1080/13554791003623318] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Mental time travel allows individuals to mentally project themselves backwards and forwards in subjective time. This case report describes a young woman suddenly rendered amnesic as a result of bilateral hippocampal damage following an epileptic seizure and brain anoxia. Her neuropsychological profile was characterized by a high-average general level of cognitive functioning, selective deficit in episodic memory of past events and a significant difficulty to envisage her personal future. This case provides clinical support for the concept of mental time travel with its retrospective and prospective components and for the hippocampus being its critical neural substrate.
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Affiliation(s)
- Fani Andelman
- Functional Neurosurgery Unit, Tel-Aviv Sourasky Medical Center, Tel Aviv, Israel
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31
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Winocur G, Moscovitch M, Bontempi B. Memory formation and long-term retention in humans and animals: convergence towards a transformation account of hippocampal-neocortical interactions. Neuropsychologia 2010; 48:2339-56. [PMID: 20430044 DOI: 10.1016/j.neuropsychologia.2010.04.016] [Citation(s) in RCA: 292] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2009] [Revised: 04/13/2010] [Accepted: 04/19/2010] [Indexed: 01/10/2023]
Abstract
Historically, the hippocampus has been viewed as a temporary memory structure. Consistent with the central premise of standard consolidation theory (SCT), a memory is initially hippocampus-dependent but, over time, it undergoes a consolidation process and eventually becoming represented in a distributed cortical network independent of the hippocampus. In this paper, we review evidence that is incompatible with each of the following essential features of SCT that are derived from its central premise: (1) Hippocampal damage reliably produces temporally graded retrograde amnesia, (2) all declarative explicit memories are equivalent with respect to consolidation, (3) consolidation entails a process of duplication in which a particular cortically based memory is identical to the hippocampus-dependent memory from which it derived, (4) consolidated memories are permanent and immutable. We propose an alternative hypothesis that assumes a transformation process and changes in the memory over time. Building on multiple trace theory (Nadel & Moscovitch, 1997), the transformation hypothesis contains three key elements that differentiate it from SCT: (1) An initially formed memory, which is assumed to be episodic and context-bound, remains dependent on the hippocampus for as long as it is available, (2) with time and experience, a hippocampal memory supports the development, in neocortex, of a less integrated, schematic version, which retains the gist of the original memory, but few of its contextual details, (3) there is a dynamic interplay between the two types of memory such that one or another may be dominant, depending on the circumstances at retrieval. Evidence is provided in support of the transformation hypothesis, which is advanced as a framework for unifying the seemingly disparate results of studies of anterograde and retrograde memory in the animal and human literatures.
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Affiliation(s)
- Gordon Winocur
- Rotman Research Institute, Baycrest Centre, Toronto, Canada.
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32
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Kano O, Arasaki K, Ikeda K, Aoyagi J, Shiraishi H, Motomura M, Iwasaki Y. Limbic encephalitis associated with systemic lupus erythematosus. Lupus 2009; 18:1316-9. [DOI: 10.1177/0961203309106829] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A 34-year-old woman with systemic lupus erythematosus (SLE) presented with general fatigue, seizures and memory loss. Magnetic resonance imaging of the brain showed a high signal area in the mesial temporal lobe bilaterally. Computed tomography scan of the chest and abdomen and ultrasound of pelvis detected no malignancy and tumour marker, antibodies to antineuronal antibodies (anti-Hu, anti-Ta and anti-Ma) and antibodies to voltage-gated potassium channels were all negative. The present case is limbic encephalitis (LE) associated with SLE and the pathogenesis may include autoimmunity shared. Our experience indicates that the immunologic spectrum of LE will expand to include additional immune mechanisms. Lupus (2009) 18, 1316—1319.
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Affiliation(s)
- O. Kano
- Department of Neurology, Methodist Neurological Institute, Houston, Texas, USA, , Department of Neurology, Aikawa Hospital, Japan
| | - K. Arasaki
- Department of Neurology, Aikawa Hospital, Japan
| | - K. Ikeda
- Department of Neurology, Toho University Omori Medical Center, Tokyo, Japan
| | - J. Aoyagi
- Department of Neurology, Toho University Omori Medical Center, Tokyo, Japan
| | - H. Shiraishi
- First Department of Internal Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - M. Motomura
- First Department of Internal Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan
| | - Y. Iwasaki
- Department of Neurology, Toho University Omori Medical Center, Tokyo, Japan
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33
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Butler CR, Zeman AZ. Recent insights into the impairment of memory in epilepsy: transient epileptic amnesia, accelerated long-term forgetting and remote memory impairment. Brain 2008; 131:2243-63. [DOI: 10.1093/brain/awn127] [Citation(s) in RCA: 230] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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Abstract
Humans devote much time to the exchange of memories within the context of shared general and personal semantic knowledge. Our hypothesis was that functional imaging in normal subjects would demonstrate the convergence of speech comprehension and production on high-order heteromodal and amodal cortical areas implicated in declarative memory functions. Activity independent of speech phase (that is, comprehension and production) was most evident in the left and right lateral anterior temporal cortex. Significant activity was also observed in the posterior cortex, ventral to the angular gyri. The left and right hippocampus and adjacent inferior temporal cortex were active during speech comprehension, compatible with mnemonic encoding of narrative information, but activity was significantly less during the overt memory retrieval associated with speech production. Therefore, although clinical studies suggest that hippocampal function is necessary for the retrieval as well as the encoding of memories, the former appears to depend on much less net synaptic activity. In contrast, the retrosplenial/posterior cingulate cortex and the parahippocampal area, which are closely associated anatomically with the hippocampus, were equally active during both speech comprehension and production. The results demonstrate why a severe and persistent inability both to understand and produce meaningful speech in the absence of an impairment to process linguistic forms is usually only observed after bilateral, and particularly anterior, destruction of the temporal lobes, and emphasize the importance of retrosplenial/posterior cingulate cortex, an area known to be affected early in the course of Alzheimer's disease, in the processing of memories during communication.
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