Epilepsy as a ''natural laboratory'' for the study of human memory

Brain and Cognition (Impact Factor: 2.68). 11/1997; 35(1):1-4. DOI: 10.1006/brcg.1997.0924
Source: PubMed
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    ABSTRACT: Episodic autobiographical memory (AM) allows one, through the recollection of sensory-perceptual details, thoughts and feelings, to become aware of an event as belonging to one's own past as well as being able to project into one's future. Because AM provides a sense of self-continuity, contributes to the integrity of the self, and helps predicting future experiences, any deficit of AM may have debilitating consequences for everyday life functioning. Understanding AM failure and the underlying neural mechanisms has the potential to shed light on brain reorganization mechanisms and engagement of compensatory processes. Functional magnetic resonance imaging (fMRI) provides the most promising imaging method to tackle these issues. We reviewed evidence from the few studies that used fMRI to investigate the functionality of the residual tissue, the neural reorganization and compensatory mechanisms in patients with neurological conditions due to impaired medial temporal lobe. Overall, these studies highlight the importance of the left hippocampus, which when atrophied and not functional leads to AM deficits but its residual functionality may support relatively normal AM recollection. When damaged hippocampal tissue is not functional, other brain regions (e.g., the medial prefrontal cortex) may be involved to compensate impairment, but they appear generally ineffective to support detailed episodic recollection.
    04/2014; 6(4):93-105. DOI:10.4329/wjr.v6.i4.93
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    ABSTRACT: Transient Epileptic Amnesia (TEA) is a recently defined subtype of temporal lobe epilepsy, principally affecting people in middle age with a male predominance. Its key manifestation is the occurrence of recurring episodes of transient amnesia, usually lasting less than an hour and often occurring on waking. One-third of patients have exclusively amnestic attacks, while in two-thirds, at least some attacks are accompanied by other manifestations of epilepsy, especially olfactory hallucinations. Several lines of evidence point to a seizure focus in the medial temporal lobes. Transient Epileptic Amnesia is accompanied by a striking loss of autobiographical memories in two-thirds of sufferers, accelerated loss of memories which had been acquired successfully in around one half, and topographical amnesia in around one-third. This paper reviews the findings of the TIME project (The Impairment of Memory in Epilepsy - in relation to TEA, accelerated long-term forgetting, and remote memory impairment. This article is part of a Special Issue entitled Translational Epilepsy Research.
    Epilepsy & Behavior 11/2012; DOI:10.1016/j.yebeh.2012.09.030 · 2.06 Impact Factor
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    ABSTRACT: Impaired memory is a common and often debilitating complaint in patients with epilepsy. Overlapping variables such as seizure control, attentional dysfunction, and mood disorders further complicate diagnosis and management. Direct therapy for memory deficits associated with epilepsy is rarely attempted. The varied pharmacological (AED selection, cholinesterase inhibitors, stimulants, antidepressants, and herbal supplements) and nonpharmacological approaches to cognitive remediation in epilepsy patients are reviewed.
    Epilepsy & Behavior 11/2002; 3(5S):30-34. DOI:10.1016/S1525-5050(02)00509-7 · 2.06 Impact Factor