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Rivera-Lares K, Baddeley A, Della Sala S. Influence of degree of learning on rate of forgetting of tonal sequences. Mem Cognit 2024:10.3758/s13421-024-01597-6. [PMID: 39020063 DOI: 10.3758/s13421-024-01597-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/19/2024] [Indexed: 07/19/2024]
Abstract
Initial performance is frequently equated in studies that compare forgetting rates across groups. However, since the encoding capacity of different groups can be different, some procedures to match initial degree of learning need to be implemented, adding confounding variables such as longer exposures to the material, which would create memories of a different age. Slamecka and McElree Journal of Experimental Psychology: Learning, Memory, and Cognition, 9, 384-397, (1983) and our previous work found that the rate of forgetting was independent from initial degree of learning using verbal material. The present study seeks to determine whether this pattern holds true when undertaken with nonverbal material. In two experiments, we manipulate initial degree of learning by varying the number of presentations of the material and studying the effect on the forgetting rates. A set of 30 tonal sequences were presented to young, healthy participants either once or three times. Forgetting was evaluated in a yes/no recognition paradigm immediately and 1 hour or 24 hours after the study phase. A different subset of 10 sequences was tested along with 10 nontargets at each retention interval. The results of these experiments showed that initial acquisition was modulated by the number of repetitions. However, the forgetting rates were independent of initial degree of learning. These results are in keeping with the pattern found by Slamecka and McElree, and in our own previous studies. They suggest that the pattern of parallel forgetting after different levels of initial learning is not limited to verbal material.
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Affiliation(s)
- Karim Rivera-Lares
- Human Cognitive Neuroscience, Psychology Department, University of Edinburgh, Edinburgh, UK.
| | - Alan Baddeley
- Department of Psychology, University of York, Heslington, York, UK
| | - Sergio Della Sala
- Human Cognitive Neuroscience, Psychology Department, University of Edinburgh, Edinburgh, UK.
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2
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Studer M, Guggisberg AG, Gyger N, Gutbrod K, Henke K, Heinemann D. Accelerated long-term forgetting in patients with acquired brain injury. Brain Inj 2024; 38:377-389. [PMID: 38385560 DOI: 10.1080/02699052.2024.2311349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 01/24/2024] [Indexed: 02/23/2024]
Abstract
OBJECTIVE Recent research suggests that patients with neurological disorders without overt seizures may also experience accelerated long-term forgetting (ALF). This term describes unimpaired learning and memory performance after standard retention intervals, but an excessive rate of forgetting over delays of days or weeks. The objective of this retrospective study was to investigate ALF in patients with an acquired brain injury (ABI) and to associate memory performance with executive functions. METHODS Verbal memory performance (short-term recall, 30-min recall, 1-week recall) was assessed in 34 adult patients with ABI and compared to a healthy control group (n = 54) using an auditory word learning and memory test. RESULTS Repeated measure analysis showed significant effects of time and group as well as interaction effects between time and group regarding recall and recognition performance. Patients with ABI had a significantly impaired 1-week recall and recognition performance compared to the healthy control group. Correlations between recall performance and executive functions were nonsignificant. DISCUSSION Our results demonstrate that non-epileptic patients with ABI, especially patients with frontal and fronto-temporal lesions, are prone to ALF. Additionally, our data support the assumption that ALF results from a consolidation impairment since verbal recall and recognition were impaired in patients with ABI.
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Affiliation(s)
- M Studer
- Department of Pediatric Neurology and Developmental Medicine, University Children's Hospital Basel (UKBB), Basel, Switzerland
- Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - A G Guggisberg
- Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - N Gyger
- Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
| | - K Gutbrod
- Neurozentrum Bern, Bern, Switzerland
| | - K Henke
- Institute of Psychology, University of Bern, Bern, Switzerland
| | - D Heinemann
- Department of Neurology, Inselspital, Bern University Hospital, and University of Bern, Bern, Switzerland
- Department of Neurology, Cantonal Hospital Aarau, Aarau, Switzerland
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3
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Transient epileptic amnesia is significantly associated with discrete CA1-located hippocampal calcifications but not with atrophic changes on brain imaging. Epilepsy Res 2021; 176:106736. [PMID: 34403990 DOI: 10.1016/j.eplepsyres.2021.106736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 07/17/2021] [Accepted: 08/05/2021] [Indexed: 11/24/2022]
Abstract
BACKGROUND The exact etiology of transient epileptic amnesia (TEA) is currently unknown. In older individuals, common neurodegenerative dementias and small-vessel diseases (SVDs) could be major contributors. We examined these hypotheses on the basis of imaging analysis. METHODS In total, 36 TEA patients were compared with 25 healthy controls for (1) cortical atrophic changes (in the mesial temporal, frontal, anterior temporal, and parietal regions) using four established MRI-based visual rating scales, and for (2) SVD evidence using two MRI-based visual rating scales (Fazekas and MARS scores). In 24 TEAs cases, there were also brain CT scans available that were compared with 57 controls for the presence of hippocampal calcifications (HCs). RESULTS We did not find significant differences in cortical atrophy between TEAs and controls, nor did we observe a different SVD brain load on MRI. However, TEAs were significantly associated (p < 0.01) with uni- or bilateral CA1-located HCs in half of the patients compared with the controls (less than 20 %). CONCLUSIONS This study argues in favor of a hippocampal-restricted SVD (as indicated by HCs) as one of the major etiologies of TEA, while neurodegenerative dementias are probably minor causes. It furthermore highlights the pivotal role of the CA1 hippocampal subfield in the pathophysiology of this syndrome.
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4
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Accelerated forgetting in temporal lobe epilepsy: When does it occur? Cortex 2021; 141:190-200. [PMID: 34058619 DOI: 10.1016/j.cortex.2021.03.035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 02/24/2021] [Accepted: 03/30/2021] [Indexed: 11/21/2022]
Abstract
OBJECTIVE The main goal of the study was to analyse differences in the forgetting rates of Temporal Lobe Epilepsy (TLE) patients at different intervals (30 sec, 10 min, 1 day and 1 week) compared with those of healthy controls. A secondary aim of this research was to provide an assessment of the relationship between clinical epilepsy-related variables and forgetting rates in TLE patients. METHOD The sample was composed of 14 TLE patients and 14 healthy matched controls. All participants underwent a full standardised neuropsychological assessment including general intelligence, executive functioning, memory, language and other variables, such as depression, anxiety or everyday memory failures. Two specific memory tasks, consisting of cued recall of 4 short stories and 4 routes, were carried out at four different intervals. RESULTS There was a significant difference between groups at 10-min interval on the stories task, with the TLE group displaying greater forgetting than healthy controls. None of the other intervals on either task showed significant group differences. No differences were found when controlling for clinical epilepsy-related variables. CONCLUSION Forgetting of verbal information at 10 min was greater in patients with TLE compared with controls, but accelerated longer term forgetting was not found. This study suggests that a late consolidation process is not necessarily impaired in TLE patients.
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5
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Baker J, Savage S, Milton F, Butler C, Kapur N, Hodges J, Zeman A. The syndrome of transient epileptic amnesia: a combined series of 115 cases and literature review. Brain Commun 2021; 3:fcab038. [PMID: 33884371 PMCID: PMC8047097 DOI: 10.1093/braincomms/fcab038] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/26/2021] [Accepted: 01/28/2021] [Indexed: 12/24/2022] Open
Abstract
The term transient epileptic amnesia was coined in 1990 to describe a form of epilepsy causing predominantly amnestic seizures which could be confused with episodes of Transient Global Amnesia. Subsequent descriptions have highlighted its association with ‘atypical’ forms of memory disturbance including accelerated long-term forgetting, disproportionate autobiographical amnesia and topographical amnesia. However, this highly treatment-responsive condition remains under-recognized and undertreated. We describe the clinical and neuropsychological features in 65 consecutive cases of transient epileptic amnesia referred to our study, comparing these to our previous cohort of 50 patients and to those reported in 102 literature cases described since our 2008 review. Findings in our two cohorts are substantially consistent: The onset of transient epileptic amnesia occurs at an average age of 62 years, giving rise to amnestic episodes at a frequency of around 1/month, typically lasting 15–30 min and often occurring on waking. Amnesia is the only manifestation of epilepsy in 24% of patients; olfactory hallucinations occur in 43%, motor automatisms in 41%, brief unresponsiveness in 39%. The majority of patients describe at least one of the atypical forms of memory disturbance mentioned above; easily provoked tearfulness is a common accompanying feature. There is a male predominance (85:30). Epileptiform changes were present in 35% of cases, while suspected causative magnetic resonance imaging abnormalities were detected in only 5%. Seizures ceased with anticonvulsant treatment in 93% of cases. Some clinical features were detected more commonly in the second series than the first, probably as a result of heightened awareness. Neuropsychological testing and comparison to two age and IQ-matched control groups (n = 24 and 22) revealed consistent findings across the two cohorts, namely elevated mean IQ, preserved executive function, mild impairment at the group level on standard measures of memory, with additional evidence for accelerated long-term forgetting and autobiographical amnesia, particularly affecting episodic recollection. Review of the literature cases revealed broadly consistent features except that topographical amnesia, olfactory hallucinations and emotionality have been reported rarely to date by other researchers. We conclude that transient epileptic amnesia is a distinctive syndrome of late-onset limbic epilepsy of unknown cause, typically occurring in late middle age. It is an important, treatable cause of memory loss in older people, often mistaken for dementia, cerebrovascular disease and functional amnesia. Its aetiology, the monthly occurrence of seizures in some patients and the mechanisms and interrelationships of the interictal features—amnestic and affective—all warrant further study.
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Affiliation(s)
- John Baker
- Cognitive & Behavioural Neurology, University of Exeter Medical School, College House, St Luke's Campus, Exeter EX1 2LU, UK
| | - Sharon Savage
- Cognitive & Behavioural Neurology, University of Exeter Medical School, College House, St Luke's Campus, Exeter EX1 2LU, UK.,School of Psychology, University of Newcastle, New South Wales 2308, Australia
| | - Fraser Milton
- Discipline of Psychology, University of Exeter, Washington Singer Laboratories, Exeter EX4 4QG, UK
| | - Christopher Butler
- Nuffield Department of Clinical Neurosciences, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DU, UK.,Department of Brain Sciences, Imperial College, London W12 0NN, UK.,Departamento de Neurología, Pontificia Universidad Católica de Chile, Santiago 833007, Chile
| | - Narinder Kapur
- Research Department of Clinical, Educational and Health Psychology, University College London, London WC1E 6BT, UK
| | - John Hodges
- Brain and Mind Centre, University of Sydney, Sydney 2050, Australia
| | - Adam Zeman
- Cognitive & Behavioural Neurology, University of Exeter Medical School, College House, St Luke's Campus, Exeter EX1 2LU, UK
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6
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Lambert I, Tramoni-Negre E, Lagarde S, Pizzo F, Trebuchon-Da Fonseca A, Bartolomei F, Felician O. Accelerated long-term forgetting in focal epilepsy: Do interictal spikes during sleep matter? Epilepsia 2021; 62:563-569. [PMID: 33476422 DOI: 10.1111/epi.16823] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 12/19/2020] [Accepted: 01/05/2021] [Indexed: 12/21/2022]
Abstract
Accelerated long-term forgetting (ALF) is a particular form of amnesia mostly encountered in focal epilepsy, particularly in temporal lobe epilepsy. This type of memory loss is characterized by an impairment of long-term consolidation of declarative memory, and its mechanisms remain poorly understood. In particular, the respective contribution of lesion, seizures, interictal epileptic discharges, and sleep is still debated. Here, we provide an overview of the relationships intertwining epilepsy, sleep, and memory consolidation and, based on recent findings from intracranial electroencephalographic recordings, we propose a model of ALF pathophysiology that integrates the differential role of interictal spikes during wakefulness and sleep. This model provides a framework to account for the different timescales at which ALF may occur.
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Affiliation(s)
- Isabelle Lambert
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Epileptology and Clinical Neurophysiology Department, Timone Hospital, Marseille, France
| | - Eve Tramoni-Negre
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Neurology and Neuropsychology Department, Timone Hospital, Marseille, France
| | - Stanislas Lagarde
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Epileptology and Clinical Neurophysiology Department, Timone Hospital, Marseille, France
| | - Francesca Pizzo
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Epileptology and Clinical Neurophysiology Department, Timone Hospital, Marseille, France
| | - Agnès Trebuchon-Da Fonseca
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Epileptology and Clinical Neurophysiology Department, Timone Hospital, Marseille, France
| | - Fabrice Bartolomei
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Epileptology and Clinical Neurophysiology Department, Timone Hospital, Marseille, France
| | - Olivier Felician
- System Neurosciences Institute, Aix Marseille University, INSERM, INS, Marseille, France.,Neurology and Neuropsychology Department, Timone Hospital, Marseille, France
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7
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A Review of Accelerated Long-Term Forgetting in Epilepsy. Brain Sci 2020; 10:brainsci10120945. [PMID: 33297371 PMCID: PMC7762289 DOI: 10.3390/brainsci10120945] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 11/30/2020] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
Accelerated long-term forgetting (ALF) is a memory disorder that manifests by a distinct pattern of normal memory for up to an hour after learning, but an increased rate of forgetting during the subsequent hours and days. The topic of ALF has gained much attention in group studies with epilepsy patients and the phenomenon has been shown to have contradictory associations with seizures, epileptiform activity, imaging data, sleep, and antiepileptic medication. The aim of this review was to explore how clinical and imaging data could help determine the topographic and physiological substrate of ALF, and what is the possible use of this information in the clinical setting. We have reviewed 51 group studies in English to provide a synthesis of the existing findings concerning ALF in epilepsy. Analysis of recently reported data among patients with temporal lobe epilepsy, transient epileptic amnesia, and generalized and extratemporal epilepsies provided further indication that ALF is likely a disorder of late memory consolidation. The spatial substrate of ALF might be located along the parts of the hippocampal-neocortical network and novel studies reveal the increasingly possible importance of damage in extrahippocampal sites. Further research is needed to explore the mechanisms of cellular impairment in ALF and to develop effective methods of care for patients with the disorder.
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8
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Lee A, Lah S, Joplin S, Haroutonian C, Pye J, Mowszowski L, Duffy SL, Naismith SL. Actigraphy-recorded sleep efficiency and hippocampal volume are related to visual and verbal rate of forgetting in older adults. AGING NEUROPSYCHOLOGY AND COGNITION 2020; 28:936-958. [PMID: 33141652 DOI: 10.1080/13825585.2020.1842849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
This study aimed to determine if older adults "at-risk" for dementia (those with MCI or SMC) exhibit accelerated long-term forgetting (ALF) and whether rate of forgetting (RoF) is associated with sleep efficiency, hippocampal volume and demographic/clinical features. Forty-nine "at-risk" participants and eighteen controls underwent examination. Memory was assessed using the Scene Memory Task (SMT) and WMS-III Logical Memory (LM) subtest. Tests were administered at baseline, 24 hours and 2 weeks. While our study did not find ALF in those "at-risk" for dementia, on the SMT, RoF over 24 hours and 2 weeks was negatively correlated with sleep efficiency. For LM, RoF at 2 weeks was moderately associated with left hippocampal volume. Neither visual or verbal RoF was correlated with demographic or clinical variables (age, MMSE, IQ, GDS-15). While ALF was not observed in this sample, our results suggest that visual and verbal forgetting have differential predictors.
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Affiliation(s)
- Alessandra Lee
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Suncica Lah
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia
| | - Samantha Joplin
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Carla Haroutonian
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia.,Neurosleep, Australian National Health and Medical Research Council Centre of Research Excellence, Sydney, Australia
| | - Jonathon Pye
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia
| | - Loren Mowszowski
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia.,Neurosleep, Australian National Health and Medical Research Council Centre of Research Excellence, Sydney, Australia
| | - Shantel L Duffy
- Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia.,Neurosleep, Australian National Health and Medical Research Council Centre of Research Excellence, Sydney, Australia
| | - Sharon L Naismith
- School of Psychology, The University of Sydney, Camperdown, NSW, Australia.,Healthy Brain Ageing Program, Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Brain and Mind Centre, The University of Sydney, Camperdown, NSW, Australia.,Charles Perkins Centre, The University of Sydney, Camperdown, NSW, Australia.,Neurosleep, Australian National Health and Medical Research Council Centre of Research Excellence, Sydney, Australia
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9
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Baxendale S, Heaney D. Memory complaints in the epilepsy clinic. Pract Neurol 2020:practneurol-2020-002523. [PMID: 32950961 DOI: 10.1136/practneurol-2020-002523] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/03/2020] [Indexed: 11/04/2022]
Abstract
Cognitive complaints in people with epilepsy are usually multifactorial in their nature and origin. While antiepileptic medications are an important consideration, we explore other ways in which neurologists can address cognitive problems in this population. It is never too early to ask about cognitive impairment, and the answers can have diagnostic significance. Understanding and accepting that cognitive problems may result, at least in part, from the same pathological process that generates seizures is an important part of the rehabilitation process. Patients referred for neurorehabilitation for cognitive difficulties who have realistic expectations and goals tend to benefit more from the intervention than those expecting a cure. Developing an understanding of this and managing patient expectations should start in the neurology clinic. Although we focus primarily on memory function, the principles we discuss in this paper apply to the broad spectrum of cognitive and neurobehavioral problems that accompany the many diagnoses of epilepsy.
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Affiliation(s)
- Sallie Baxendale
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Dominic Heaney
- National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Foundation Trust, London, UK
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10
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Chiba T, Henmi N, Neshige S, Takada K, Ikeda A, Takahashi R, Yokoe M. [Ictal EEG pattern of transient epileptic amnesia in acute phase of non-herpetic limbic encephalitis]. Rinsho Shinkeigaku 2020; 60:446-451. [PMID: 32435050 DOI: 10.5692/clinicalneurol.60.cn-001414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
A 60-year-old, right-handed woman was admitted to our hospital for amnesia as the only neurological abnormal findings following the autonomic symptoms and transient episodes of loss of awareness. EEG during the amnesia showed rhythmic alpha activity arising from the left mid-temporal region. Although this ictal activity showed evolution in the frequency and amplitude, the location was limited in the bilateral temporal areas. After the EEG evaluation, her amnesia was resolved immediately, suggesting that her presentation was transient epileptic amnesia (TEA). Meanwhile, given the clinical course and MRI findings (high intensity in the bilateral mesial temporal areas, more on the left), she was diagnosed with non-herpetic limbic encephalitis and treated with steroid and anti-epileptic drugs, leading to the positive outcome. The ictal EEG findings during TEA as the one of the presentation in acute phase of non-herpetic limbic encephalitis may contribute to further investigation of underlying mechanism of TEA.
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Affiliation(s)
- Tomoya Chiba
- Department of Neurology, Japan Community Health care Organization, Hoshigaoka Medical Centre.,Department of Neurology, Osaka University Graduate School of Medicine
| | - Namiko Henmi
- Department of Neurology, Japan Community Health care Organization, Hoshigaoka Medical Centre.,Department of Neurology, Kyoto University Graduate School of Medicine
| | - Shuichiro Neshige
- Department of Neurology, Kyoto University Graduate School of Medicine.,Department of Clinical Neuroscience and Therapeutics, Hiroshima University Graduate School of Biochemical and Health Sciences
| | - Kazushiro Takada
- Department of Neurology, Japan Community Health care Organization, Hoshigaoka Medical Centre
| | - Akio Ikeda
- Department of Epilepsy, Movement Disorders and Physiology, Kyoto University Graduate School of Medicine
| | - Ryosuke Takahashi
- Department of Neurology, Kyoto University Graduate School of Medicine
| | - Masaru Yokoe
- Department of Neurology, Japan Community Health care Organization, Hoshigaoka Medical Centre
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11
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Polat B, Yılmaz NH, Mantar N, Cadirci F, Sitrava S, Ozmansur EN, Uzan M, Özkara C, Hanoglu L. Accelerated long-term forgetting after amygdalohippocampectomy in temporal lobe epilepsy. J Clin Neurosci 2020; 72:43-49. [PMID: 31956086 DOI: 10.1016/j.jocn.2020.01.038] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2019] [Accepted: 01/05/2020] [Indexed: 10/25/2022]
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12
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Accelerated long-term forgetting in resected and seizure-free temporal lobe epilepsy patients. Cortex 2019; 110:80-91. [DOI: 10.1016/j.cortex.2018.02.017] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Revised: 01/17/2018] [Accepted: 02/27/2018] [Indexed: 11/19/2022]
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13
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Zeman A, Byruck M, Tallis P, Vossel K, Tranel D. Touching the void – First and third person perspectives in two cases of autobiographical amnesia linked to temporal lobe epilepsy. Neuropsychologia 2018; 110:55-64. [DOI: 10.1016/j.neuropsychologia.2017.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2017] [Revised: 06/07/2017] [Accepted: 07/09/2017] [Indexed: 10/19/2022]
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14
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Contador I, Sánchez A, Kopelman MD, González de la Aleja J. Long-term forgetting in temporal lobe epilepsy: Is this phenomenon a norm? Epilepsy Behav 2017; 77:30-32. [PMID: 29080418 DOI: 10.1016/j.yebeh.2017.09.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Revised: 09/19/2017] [Accepted: 09/22/2017] [Indexed: 11/19/2022]
Abstract
OBJECTIVES This research investigated forgetting rates of patients with temporal lobe epilepsy (TLE) at brief and longer intervals. METHODS The sample is formed by 5 patients with TLE and 10 healthy individuals. One of the patients received the diagnosis of transient epileptic amnesia (TEA). All patients underwent a standardized clinical protocol for diagnosis including a comprehensive neuropsychological assessment. In addition, two experimental tasks were used to assess the forgetting rates at 4 intervals (30s, 10min, 1day, and 1week): a story task to evaluate verbal cued recall and a route task to assess visuospatial cued recall. RESULTS There were no significant differences between groups in forgetting rates. CONCLUSIONS These findings suggest that forgetting patterns in patients with TLE may be heterogeneous, and the presence of accelerated long-term forgetting is not universal.
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Affiliation(s)
- Israel Contador
- Department of Basic Psychology, Psychobiology and Methodology of Behavioral Science, University of Salamanca, Salamanca, Spain.
| | - Abraham Sánchez
- Department of Basic Psychology, Psychobiology and Methodology of Behavioral Science, University of Salamanca, Salamanca, Spain
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15
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The evolution of accelerated long-term forgetting: Evidence from the TIME study. Cortex 2017; 110:16-36. [PMID: 29122206 PMCID: PMC6330058 DOI: 10.1016/j.cortex.2017.09.007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Revised: 08/10/2017] [Accepted: 09/09/2017] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Accelerated long-term forgetting (ALF) occurs when newly learned information decays faster than normal over extended delays. It has been recognised most frequently in temporal lobe epilepsy, including Transient Epileptic Amnesia (TEA), but can also be drug-induced. Little is known about the evolution of ALF over time and its impacts upon other memory functions, such as autobiographical memory (ABM). Here we investigate the long-term outcome of ALF and ABM in a group of patients with TEA and a single case of baclofen-induced ALF. METHODS Study 1 involved a longitudinal follow-up of 14 patients with TEA over a 10-year period. Patients repeated a neuropsychological battery, three ALF measures (with free recall probed at 30-min and 1-week), and a modified Autobiographical Memory Interview (MAMI). Performance was compared with a group of healthy age-matched controls. In Study 2, patient CS, who previously experienced baclofen-induced ALF, was followed over 4 years, and re-tested now, 18 months after ceasing baclofen. CS repeated a neuropsychological battery, three ALF experimental tasks (each probed after 30 min and 1 week), and a modified autobiographical interview (AI). Her performance was compared with healthy age-matched controls. RESULTS On ALF measures, the TEA group performed significantly below controls, but when analysed individually, 4 of the 7 patients who originally showed ALF no longer did so. In two, this was accompanied by improvements in ABM for recent but not remote memory. Patient CS no longer demonstrated ALF on standard lab-based tests and now appeared to retain new episodic autobiographical events with a similar degree of episodic richness as controls. CONCLUSION Long-term follow up suggests that ALF can resolve, with improvements translating to recent ABM in some cases.
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Lemesle B, Planton M, Pagès B, Pariente J. Accelerated long-term forgetting and autobiographical memory disorders in temporal lobe epilepsy: One entity or two? Rev Neurol (Paris) 2017; 173:498-505. [PMID: 28843413 DOI: 10.1016/j.neurol.2017.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Revised: 06/28/2017] [Accepted: 07/04/2017] [Indexed: 11/16/2022]
Abstract
Temporal lobe epilepsy (TLE) is a type of epilepsy that often has a negative impact on patients' memory. Despite the importance of patients' complaints in this regard, the difficulties described by these patients are often not easy to demonstrate through a standard neuropsychological assessment. Accelerated long-term forgetting and autobiographical memory disorders are the two main memory impairments reported in the literature in patients with TLE. However, the methods used by different authors to evaluate long-term memory and autobiographical memory are heterogeneous. This heterogeneity can lead to differences in the observed results as well as how they are interpreted. Yet, despite the methodological differences, objectification of such memory deficits appears to be both specific and robust within this patient population. Analysis of the literature shows that accelerated long-term forgetting and autobiographical memory disorders share the same clinical characteristics. This leads to the assumption that they are, in fact, only one entity and that their evaluation may be done through a single procedure. Our proposal is to place this evaluation within the context of memory consolidation disorders. With such a perspective, evaluation of accelerated forgetting in autobiographical memory should consist of identifying a disorder in the formation and/or recovery of new memory traces.
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Affiliation(s)
- B Lemesle
- Department of neurology, Toulouse university hospital, place du Dr-Baylac, 31059 Toulouse cedex, France; Toulouse neuroimaging center, université de Toulouse, Inserm, UPS, place du Dr-Baylac, 31059 Toulouse cedex, France.
| | - M Planton
- Department of neurology, Toulouse university hospital, place du Dr-Baylac, 31059 Toulouse cedex, France; Toulouse neuroimaging center, université de Toulouse, Inserm, UPS, place du Dr-Baylac, 31059 Toulouse cedex, France
| | - B Pagès
- Department of neurology, Toulouse university hospital, place du Dr-Baylac, 31059 Toulouse cedex, France; Toulouse neuroimaging center, université de Toulouse, Inserm, UPS, place du Dr-Baylac, 31059 Toulouse cedex, France
| | - J Pariente
- Department of neurology, Toulouse university hospital, place du Dr-Baylac, 31059 Toulouse cedex, France; Toulouse neuroimaging center, université de Toulouse, Inserm, UPS, place du Dr-Baylac, 31059 Toulouse cedex, France
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Tramoni-Negre E, Lambert I, Bartolomei F, Felician O. Long-term memory deficits in temporal lobe epilepsy. Rev Neurol (Paris) 2017; 173:490-497. [DOI: 10.1016/j.neurol.2017.06.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2017] [Accepted: 06/15/2017] [Indexed: 11/25/2022]
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18
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Ge T, Yang W, Fan J, Li B. Preclinical evidence of ghrelin as a therapeutic target in epilepsy. Oncotarget 2017; 8:59929-59939. [PMID: 28938694 PMCID: PMC5601790 DOI: 10.18632/oncotarget.18349] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2017] [Accepted: 05/22/2017] [Indexed: 12/17/2022] Open
Abstract
Ghrelin, an orexigenic peptide synthesized by endocrine cells of the gastric mucosa, plays a major role in inhibiting seizures. However, the underlying mechanism of ghrelin's anticonvulsant action is still unclear. Nowadays, there are considerable evidences showing that ghrelin is implicated in various neurophysiological processes, including learning and memory, neuroprotection, neurogenesis, and inflammatory effects. In this review, we will summarize the effects of ghrelin on epilepsy. It may provide a comprehensive picture of the role of ghrelin in epilepsy.
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Affiliation(s)
- Tongtong Ge
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Wei Yang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Jie Fan
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
| | - Bingjin Li
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetics, The Second Hospital of Jilin University, Changchun 130041, PR China
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Abstract
Transient epileptic amnesia (TEA) is a sub-type of mesial temporal lobe epilepsy, with amnesic seizures. TEA is characterized by recurrent episodes of amnesia. Diagnostic criteria are available for TEA, and these memory disturbances should not be misdiagnosed with transient global amnesia. The neuropsychological evaluation is normal, however, autobiographical memory impairment is present in 70% of the cases and accelerated long term forgetting in 44%. When a patient complains of memory disturbances, especially autobiographical memory, TEA must be considered especially if there was an amnesic episode and symptoms that suggest temporal epilepsia. Video electroencephalography monitoring of sleep is a precious diagnostic tool, as epileptiform activities are found during sleep in 83% cases. TEA is pharmaco-sensitive, with full treatment response in 73 to 96% of the cases.
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20
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Atherton KE, Nobre AC, Lazar AS, Wulff K, Whittaker RG, Dhawan V, Lazar ZI, Zeman AZ, Butler CR. Slow wave sleep and accelerated forgetting. Cortex 2016; 84:80-89. [PMID: 27710778 PMCID: PMC5084685 DOI: 10.1016/j.cortex.2016.08.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 07/04/2016] [Accepted: 08/29/2016] [Indexed: 12/12/2022]
Abstract
We investigated whether the benefit of slow wave sleep (SWS) for memory consolidation typically observed in healthy individuals is disrupted in people with accelerated long-term forgetting (ALF) due to epilepsy. SWS is thought to play an active role in declarative memory in healthy individuals and, furthermore, electrographic epileptiform activity is often more prevalent during SWS than during wakefulness or other sleep stages. We studied the relationship between SWS and the benefit of sleep for memory retention using a word-pair associates task. In both the ALF and the healthy control groups, sleep conferred a memory benefit. However, the relationship between the amount of SWS and sleep-related memory benefits differed significantly between the groups. In healthy participants, the amount of SWS correlated positively with sleep-related memory benefits. In stark contrast, the more SWS, the smaller the sleep-related memory benefit in the ALF group. Therefore, contrary to its role in healthy people, SWS-associated brain activity appears to be deleterious for memory in patients with ALF.
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Affiliation(s)
- Kathryn E Atherton
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Anna C Nobre
- Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK
| | - Alpar S Lazar
- John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, UK
| | - Katharina Wulff
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | | | - Vandana Dhawan
- Institute of Neuroscience, Newcastle University, Newcastle, UK
| | - Zsolt I Lazar
- Department of Physics, Babes-Bolyai University, Cluj-Napoca, Romania
| | - Adam Z Zeman
- Cognitive and Behavioural Neurology, Peninsular Medical School, University of Exeter, UK
| | - Christopher R Butler
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
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21
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Zeman A, Hoefeijzers S, Milton F, Dewar M, Carr M, Streatfield C. The GABAB receptor agonist, baclofen, contributes to three distinct varieties of amnesia in the human brain – A detailed case report. Cortex 2016; 74:9-19. [DOI: 10.1016/j.cortex.2015.10.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 09/13/2015] [Accepted: 10/08/2015] [Indexed: 02/06/2023]
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22
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Huijgen J, Samson S. The hippocampus: A central node in a large-scale brain network for memory. Rev Neurol (Paris) 2015; 171:204-16. [DOI: 10.1016/j.neurol.2015.01.557] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 01/22/2015] [Accepted: 01/29/2015] [Indexed: 11/25/2022]
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Dewar M, Hoefeijzers S, Zeman A, Butler C, Della Sala S. Impaired picture recognition in transient epileptic amnesia. Epilepsy Behav 2015; 42:107-16. [PMID: 25506793 DOI: 10.1016/j.yebeh.2014.10.032] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Revised: 10/06/2014] [Accepted: 10/28/2014] [Indexed: 11/29/2022]
Abstract
Transient epileptic amnesia (TEA) is an epileptic syndrome characterized by recurrent, brief episodes of amnesia. Transient epileptic amnesia is often associated with the rapid decline in recall of new information over hours to days (accelerated long-term forgetting - 'ALF'). It remains unknown how recognition memory is affected in TEA over time. Here, we report a systematic study of picture recognition in patients with TEA over the course of one week. Sixteen patients with TEA and 16 matched controls were presented with 300 photos of everyday life scenes. Yes/no picture recognition was tested 5min, 2.5h, 7.5h, 24h, and 1week after picture presentation using a subset of target pictures as well as similar and different foils. Picture recognition was impaired in the patient group at all test times, including the 5-minute test, but it declined normally over the course of 1week. This impairment was associated predominantly with an increased false alarm rate, especially for similar foils. High performance on a control test indicates that this impairment was not associated with perceptual or discrimination deficits. Our findings suggest that, at least in some TEA patients with ALF in verbal recall, picture recognition does not decline more rapidly than in controls over 1week. However, our findings of an early picture recognition deficit suggest that new visual memories are impoverished after minutes in TEA. This could be the result of deficient encoding or impaired early consolidation. The early picture recognition deficit observed could reflect either the early stages of the process that leads to ALF or a separable deficit of anterograde memory in TEA. Lastly, our study suggests that at least some patients with TEA are prone to falsely recognizing new everyday visual information that they have not in fact seen previously. This deficit, alongside their ALF in free recall, likely affects everyday memory performance.
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Affiliation(s)
- Michaela Dewar
- Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK; Psychology, School of Life Sciences, Heriot-Watt University, Edinburgh, UK.
| | - Serge Hoefeijzers
- Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK
| | - Adam Zeman
- Cognitive and Behavioural Neurology, University of Exeter Medical School, Exeter, UK
| | - Christopher Butler
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Sergio Della Sala
- Human Cognitive Neuroscience, Psychology, University of Edinburgh, Edinburgh, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, Psychology, University of Edinburgh, Edinburgh, UK
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24
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Riccio CA, Pliego JA, Cohen MJ, Park Y. Executive Function Performance for Children With Epilepsy Localized to the Frontal or Temporal Lobes. APPLIED NEUROPSYCHOLOGY-CHILD 2014; 4:277-84. [DOI: 10.1080/21622965.2014.923774] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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25
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Left dominance of EEG abnormalities in patients with transient global amnesia. Seizure 2014; 23:825-9. [DOI: 10.1016/j.seizure.2014.06.014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Revised: 06/22/2014] [Accepted: 06/25/2014] [Indexed: 11/20/2022] Open
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26
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Hoefeijzers S, Dewar M, Della Sala S, Butler C, Zeman A. Accelerated long-term forgetting can become apparent within 3-8 hours of wakefulness in patients with transient epileptic amnesia. Neuropsychology 2014; 29:117-25. [PMID: 25089646 PMCID: PMC4296931 DOI: 10.1037/neu0000114] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Objective: Accelerated long-term forgetting (ALF) is typically defined as a memory disorder in which information that is learned and retained normally over standard intervals (∼30 min) is forgotten at an abnormally rapid rate thereafter. ALF has been reported, in particular, among patients with transient epileptic amnesia (TEA). Previous work in TEA has revealed ALF 24 hr - 1 week after initial memory acquisition. It is unclear, however, if ALF observed 24 hr after acquisition reflects (a) an impairment of sleep consolidation processes taking place during the first night’s sleep, or (b) an impairment of daytime consolidation processes taking place during the day of acquisition. Here we focus on the daytime-forgetting hypothesis of ALF in TEA by tracking in detail the time course of ALF over the day of acquisition, as well as over 24 hr and 1 week. Method: Eleven TEA patients who showed ALF at 1 week and 16 matched controls learned 4 categorical word lists on the morning of the day of acquisition. We subsequently probed word-list retention 30 min, 3 hr, and 8 hr postacquisition (i.e., over the day of acquisition), as well as 24-hr and 1-week post acquisition. Results: ALF became apparent in the TEA group over the course of the day of acquisition 3–8 hr after learning. No further forgetting was observed over the first night in either group. Conclusions: The results of this study show that ALF in TEA can result from a deficit in memory consolidation occurring within hours of learning without a requirement for intervening sleep.
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Affiliation(s)
- Serge Hoefeijzers
- Human Cognitive Neuroscience, Department of Psychology, University of Edinburgh
| | - Michaela Dewar
- Human Cognitive Neuroscience, Department of Psychology, University of Edinburgh
| | - Sergio Della Sala
- Human Cognitive Neuroscience, Department of Psychology, University of Edinburgh
| | | | - Adam Zeman
- Cognitive and Behavioural Neurology, University of Exeter Medical School
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27
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Lapenta L, Brunetti V, Losurdo A, Testani E, Giannantoni NM, Quaranta D, Di Lazzaro V, Della Marca G. Transient epileptic amnesia: clinical report of a cohort of patients. Clin EEG Neurosci 2014; 45:179-83. [PMID: 24214286 DOI: 10.1177/1550059413495201] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Transient epileptic amnesia is a seizure disorder, usually with onset in the middle-elderly and good response to low dosages of antiepileptic drugs. We describe the clinical, electroencephalography (EEG), and neuroimaging features of 11 patients with a temporal lobe epilepsy characterized by amnesic seizures as the sole or the main symptom. We outline the relevance of a detailed clinical history to recognize amnesic seizures and to avoid the more frequent misdiagnoses. Moreover, the response to monotherapy was usually good, although the epileptic disorder was symptomatic of acquired lesions in the majority of patients.
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MESH Headings
- Adult
- Aged
- Amnesia, Transient Global/diagnosis
- Amnesia, Transient Global/drug therapy
- Amnesia, Transient Global/physiopathology
- Anticonvulsants/administration & dosage
- Diagnosis, Differential
- Dose-Response Relationship, Drug
- Electroencephalography
- Epilepsy, Temporal Lobe/diagnosis
- Epilepsy, Temporal Lobe/drug therapy
- Epilepsy, Temporal Lobe/physiopathology
- Evoked Potentials/physiology
- Female
- Frontal Lobe/drug effects
- Frontal Lobe/pathology
- Frontal Lobe/physiopathology
- Humans
- Magnetic Resonance Imaging
- Male
- Middle Aged
- Monitoring, Ambulatory
- Signal Processing, Computer-Assisted
- Temporal Lobe/drug effects
- Temporal Lobe/pathology
- Temporal Lobe/physiopathology
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28
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Atherton KE, Nobre AC, Zeman AZ, Butler CR. Sleep-dependent memory consolidation and accelerated forgetting. Cortex 2014; 54:92-105. [PMID: 24657478 PMCID: PMC4007033 DOI: 10.1016/j.cortex.2014.02.009] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 01/28/2014] [Accepted: 02/10/2014] [Indexed: 11/26/2022]
Abstract
Accelerated long-term forgetting (ALF) is a form of memory impairment in which learning and initial retention of information appear normal but subsequent forgetting is excessively rapid. ALF is most commonly associated with epilepsy and, in particular, a form of late-onset epilepsy called transient epileptic amnesia (TEA). ALF provides a novel opportunity to investigate post-encoding memory processes, such as consolidation. Sleep is implicated in the consolidation of memory in healthy people and a deficit in sleep-dependent memory consolidation has been proposed as an explanation for ALF. If this proposal were correct, then sleep would not benefit memory retention in people with ALF as much as in healthy people, and ALF might only be apparent when the retention interval contains sleep. To test this theory, we compared performance on a sleep-sensitive memory task over a night of sleep and a day of wakefulness. We found, contrary to the hypothesis, that sleep benefits memory retention in TEA patients with ALF and that this benefit is no smaller in magnitude than that seen in healthy controls. Indeed, the patients performed significantly more poorly than the controls only in the wake condition and not the sleep condition. Patients were matched to controls on learning rate, initial retention, and the effect of time of day on cognitive performance. These results indicate that ALF is not caused by a disruption of sleep-dependent memory consolidation. Instead, ALF may be due to an encoding abnormality that goes undetected on behavioural assessments of learning, or by a deficit in memory consolidation processes that are not sleep-dependent.
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Affiliation(s)
- Kathryn E Atherton
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK.
| | - Anna C Nobre
- Department of Experimental Psychology, University of Oxford, Oxford, UK; Oxford Centre for Human Brain Activity, University of Oxford, Oxford, UK
| | - Adam Z Zeman
- Cognitive and Behavioural Neurology Research Group, University of Exeter Medical School, UK
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29
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Elliott G, Isaac CL, Muhlert N. Measuring forgetting: a critical review of accelerated long-term forgetting studies. Cortex 2014; 54:16-32. [PMID: 24631847 PMCID: PMC4007031 DOI: 10.1016/j.cortex.2014.02.001] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 12/09/2013] [Accepted: 02/03/2014] [Indexed: 12/31/2022]
Abstract
Accelerated long-term forgetting (ALF) refers to abnormal forgetting over hours to weeks despite normal acquisition or initial consolidation. Since standardised assessments of memory typically only test at delays of up to 40-minutes, ALF may go undetected in clinical practice. The memory difficulties associated with ALF can however cause considerable distress to patients. It is important therefore that clinicians are aware that ALF may represent a distinct phenomenon that will require additional and careful assessment to aid patients' understanding of the condition and assist in developing strategies to address its effects. At the same time, ALF may also provide insight into long-term memory processes. Studies of ALF in patients with epilepsy have so far demonstrated mixed results, which may reflect differences in methodology. This review explores the methodological issues that can affect forgetting, such as the effects of age, general cognitive function, test sensitivity and initial learning. It then evaluates the extent to which existing studies have considered these key issues. We outline the points to consider when designing ALF studies that can be used to help improve their validity. These issues can also help to explain some of the mixed findings in studies of ALF and inform the design of standardised tests for assessing ALF in clinical practice.
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Affiliation(s)
- Gemma Elliott
- Clinical Neuropsychology Services, Royal Hallamshire Hospital, Sheffield, UK; Department of Psychology, University of Sheffield, Sheffield, UK
| | - Claire L Isaac
- Clinical Neuropsychology Services, Royal Hallamshire Hospital, Sheffield, UK; Neuropsychology Department, Lincolnshire Partnership NHS Foundation Trust, Lincoln, UK
| | - Nils Muhlert
- Neuropsychology Department, Lincolnshire Partnership NHS Foundation Trust, Lincoln, UK; Cognitive Neuroscience, School of Psychology, Cardiff University, Cardiff, UK.
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30
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Abstract
Diagnostically, headache is the easy part of migraine. It is the surrounds of migraine--the aura, prodrome and postdrome--that can be most challenging, and confused with other pathologies. This article examines the definition and variants of migraine; alternative diagnoses for which migraine may be mistaken (mimics); conditions that lie between migraine and other diagnoses (borderlands) and the possible presentations of migraine posing as other conditions (chameleons). The focus is on adults, with only passing reference to children. Migraine is more often a chameleon than a mimic; and it is the careful history that usually makes the distinction. Given migraine's prevalence of 10-15%, relatively uncommon features of migraine occur quite often, in comparison with frequent manifestations of less common diseases. Thus, even rare or under-recognised presentations of migraine come into the differential diagnosis of many presentations.
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31
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Clinical features of late-onset partial cryptogenic epilepsy: toward an idiopathic temporal epilepsy? Epilepsy Behav 2013; 28:168-71. [PMID: 23747501 DOI: 10.1016/j.yebeh.2013.05.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/24/2013] [Revised: 05/01/2013] [Accepted: 05/02/2013] [Indexed: 11/23/2022]
Abstract
Adult-onset epilepsy is commonly thought to be secondary to a brain lesion. However, the etiology of adult-onset epilepsy remains unknown in approximately 25% of patients, despite progress in medical and diagnostic tools. In the present study, we investigated whether late-onset partial cryptogenic epilepsies could be subgrouped based on seizure semiology and clinical characteristics. A total of 41 patients with late-onset cryptogenic epilepsy were included, and the corresponding clinical and electrophysiological data were analyzed. The following three clinical subgroups were identified: 1) a group that fulfilled the diagnostic criteria of transient epileptic amnesia (TEA); 2) a group with late-onset cryptogenic epilepsies with a temporal seizure semiology; and 3) a cryptogenic extratemporal group, which was consistent with the categorization of cryptogenic epilepsies, i.e., epilepsies involving unknown lesions. The temporal group showed homogeneous clinical characteristics, especially a rapid evolution and a greater tendency toward generalization and pharmacoresistance compared with the other two groups. Transient epileptic amnesia was associated with a higher frequency of sleep disorders than either of the other groups. Our findings argue for the clinical identification of a subgroup of late-onset temporal epilepsy that might constitute an idiopathic form. The association between TEA and sleep disorders would suggest a possible pathophysiological role of sleep apnea syndromes in TEA.
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32
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Milton F, Butler CR, Benattayallah A, Zeman AZJ. The neural basis of autobiographical memory deficits in transient epileptic amnesia. Neuropsychologia 2012; 50:3528-41. [PMID: 23036282 DOI: 10.1016/j.neuropsychologia.2012.09.027] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Revised: 09/13/2012] [Accepted: 09/15/2012] [Indexed: 12/11/2022]
Abstract
Transient epileptic amnesia (TEA) is a recently recognized form of temporal lobe epilepsy which is often associated with persistent interictal impairment of autobiographical memory. We used fMRI to investigate the neural basis of this deficit. Eleven patients with TEA, who had no significant deficits on standard tests of anterograde memory, and 17 age and IQ matched healthy controls retrieved memories from across the lifespan. Both groups engaged the autobiographical memory network, but activation in patients was less extensive than in controls. Direct comparison revealed hypoactivation of regions in the right hemisphere. Specifically, patients showed reduced activation of the posterior parahippocampal gyrus (pPHG), especially for mid-life and recent memories, with decreased engagement of the right temporoparietal junction and the cerebellum. In addition, we found reduced effective connectivity in patients between the right pPHG and the right middle temporal gyrus. Our results are consistent with other evidence that TEA is a syndrome of medial temporal lobe epilepsy and indicate that it affects the function and connectivity of regions within the autobiographical memory network.
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Affiliation(s)
- Fraser Milton
- Discipline of Psychology, University of Exeter, Exeter, UK.
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