scholarly journals Autobiographical Memory and Patterns of Brain Atrophy in Fronto-temporal Lobar Degeneration

2008 ◽  
Vol 20 (10) ◽  
pp. 1839-1853 ◽  
Author(s):  
Margaret C. McKinnon ◽  
Elena I. Nica ◽  
Pheth Sengdy ◽  
Natasa Kovacevic ◽  
Morris Moscovitch ◽  
...  

Autobiographical memory paradigms have been increasingly used to study the behavioral and neuroanatomical correlates of human remote memory. Although there are numerous functional neuroimaging studies on this topic, relatively few studies of patient samples exist, with heterogeneity of results owing to methodological variability. In this study, fronto-temporal lobar degeneration (FTLD), a form of dementia affecting regions crucial to autobiographical memory, was used as a model of autobiographical memory loss. We emphasized the separation of episodic (recollection of specific event, perceptual, and mental state information) from semantic (factual information unspecific in time and place) autobiographical memory, derived from a reliable method for scoring transcribed autobiographical protocols, the Autobiographical Interview [Levine, B., Svoboda, E., Hay, J., Winocur, G., & Moscovitch, M. Aging and autobiographical memory: Dissociating episodic from semantic retrieval. Psychology and Aging, 17, 677–689, 2002]. Patients with the fronto-temporal dementia (FTD) and mixed fronto-temporal and semantic dementia (FTD/SD) variants of FTLD were impaired at reconstructing episodically rich autobiographical memories across the lifespan, with FTD/SD patients generating an excess of generic semantic autobiographical information. Patients with progressive nonfluent aphasia were mildly impaired for episodic autobiographical memory, but this impairment was eliminated with the provision of structured cueing, likely reflecting relatively intact medial-temporal lobe function, whereas the same cueing failed to bolster the FTD and FTD/SD patients' performance relative to that of matched comparison subjects. The pattern of episodic, but not semantic, autobiographical impairment was enhanced with disease progression on 1- to 2-year follow-up testing in a subset of patients, supplementing the cross-sectional evidence for specificity of episodic autobiographical impairment with longitudinal data. This behavioral pattern covaried with volume loss in a distributed left-lateralized posterior network centered on the temporal lobe, consistent with evidence from other patient and functional neuroimaging studies of autobiographical memory. Frontal lobe volumes, however, did not significantly contribute to this network, suggesting that frontal contributions to autobiographical episodic memory may be more complex than previously appreciated.

2008 ◽  
Vol 20 (8) ◽  
pp. 1490-1506 ◽  
Author(s):  
R. Shayna Rosenbaum ◽  
Morris Moscovitch ◽  
Jonathan K. Foster ◽  
David M. Schnyer ◽  
Fuqiang Gao ◽  
...  

The issue of whether the hippocampus and related structures in the medial-temporal lobe (MTL) play a temporary or permanent role in autobiographical episodic memory remains unresolved. One long-standing belief is that autobiographical memory (AM), like semantic memory, is initially dependent on the MTL but ultimately can be retained and recovered independently of it. However, evidence that hippocampal amnesia results in severe loss of episodic memory for a lifetime of personally experienced events suggests otherwise. To test the opposing views, we conducted detailed investigations of autobiographical episodic memory in people with amnesia resulting from MTL lesions of varying extent. By combining precise quantification of MTL and neocortical volumes with sensitive measures of recollection of one's personal past, we show that the severity of episodic, but not semantic, AM loss is best accounted for by the degree of hippocampal damage and less likely related to additional neocortical compromise.


2021 ◽  
Author(s):  
Aubrey Anne Ladd Wank ◽  
Anna Robertson ◽  
Sean C. Thayer ◽  
Mieke Verfaellie ◽  
Steven Z. Rapcsak ◽  
...  

Autobiographical memory consists of distinct memory types varying from highly abstract to episodic. Self trait knowledge, which is considered one of the more abstract types of autobiographical memory, is thought to rely on regions of the autobiographical memory neural network implicated in schema representation, including the medial prefrontal cortex, and critically, not the medial temporal lobes. The current case study introduces an individual who, as a consequence of bilateral posterior cerebral artery strokes, experienced extensive medial temporal lobe damage with sparing of the medial prefrontal cortex. Interestingly, in addition to severe retrograde and anterograde episodic and autobiographical fact amnesia, this individual’s self trait knowledge was impaired for his current and pre-morbid personality traits. Yet, further assessment revealed that this individual had preserved conceptual knowledge for personality traits, could reliably and accurately rate another person’s traits, and could access his own self-concept in a variety of ways. In addition to autobiographical memory loss, he demonstrated impairment on non-personal semantic memory tests, most notably on tests requiring retrieval of unique knowledge. This rare case of amnesia suggests a previously unreported role for the medial temporal lobes in personal trait knowledge, which we propose reflects the critical role of this neural region in the storage and retrieval of personal semantics that are experience-near, meaning autobiographical facts grounded in spatiotemporal contexts.


2006 ◽  
Vol 12 (5) ◽  
pp. 707-735 ◽  
Author(s):  
ELIZABETH W. TWAMLEY ◽  
SUSAN A. LEGENDRE ROPACKI ◽  
MARK W. BONDI

Alzheimer's disease (AD) is a common, devastating form of dementia. With the advent of promising symptomatic treatment, the importance of recognizing AD at its very earliest stages has increased. We review the extant neuropsychological and neuroimaging literature on preclinical AD, focusing on longitudinal studies of initially nondemented individuals and cross-sectional investigations comparing at-risk with normal individuals. We systematically reviewed 91 studies of neuropsychological functioning, structural neuroimaging, or functional neuroimaging in preclinical AD. The neuropsychological studies indicated that preclinical AD might be characterized by subtle deficits in a broad range of neuropsychological domains, particularly in attention, learning and memory, executive functioning, processing speed, and language. Recent findings from neuroimaging research suggest that volume loss and cerebral blood flow or metabolic changes, particularly in the temporal lobe, may be detected before the onset of dementia. There exist several markers of a preclinical period of AD, in which specific cognitive and biochemical changes precede the clinical manifestations. The preclinical indicators of AD reflect early compromise of generalized brain integrity and temporal lobe functioning in particular. (JINS, 2006,12, 707–735.)


2019 ◽  
Vol 15 ◽  
pp. P8-P9
Author(s):  
Laura Wisse ◽  
Long Xie ◽  
Sandhitsu R. Das ◽  
de Flores Robin ◽  
Paul A. Yushkevich ◽  
...  

2002 ◽  
Vol 13 (3-4) ◽  
pp. 123-131 ◽  
Author(s):  
Daniela Montaldi ◽  
Andrew R. Mayes ◽  
Anna Barnes ◽  
Donald M. Hadley ◽  
Jim Patterson ◽  
...  

Brain dedicated single photon emission computed tomography (SPECT) was used to compare the neuroactivation produced by the cued recall of response words in a set of studied word pairs with that produced by the cued retrieval of words semantically related to unstudied stimulus words. Six of the 12 subjects scanned were extensively trained so as to have good memory of the studied pairs and the remaining six were minimally trained so as to have poor memory. When comparing episodic with semantic retrieval, the well-trained subjects showed significant left medial temporal lobe activation, which was also significantly greater than that shown by the poorly trained subjects, who failed to show significant medial temporal lobe activation. In contrast, the poorly trained subjects showed significant bilateral frontal lobe activation, which was significantly greater than that shown by the well-trained subjects who failed to show significant frontal lobe activation. The frontal activations occurred mainly in the dorsolateral region, but extended into the ventrolateral and, to a lesser extent, the frontal polar regions. It is argued that whereas the medial temporal lobe activation increased as the proportion of response words successfully recalled increased, the bilateral frontal lobe activation increased in proportion to retrieval effort, which was greater when learning had been less good.


1994 ◽  
Vol 24 (4) ◽  
pp. 1037-1045 ◽  
Author(s):  
M. D. Kopelman ◽  
R. E. A. Green ◽  
E. M. Green ◽  
P. D. R. Lewis ◽  
N. Stanhope

SynopsisThis paper describes a patient whose amnesia for an offence (fraud) and two fugue episodes occurred against the background of an underlying organic amnesia. The fugue states conformed in their duration and precipitating factors to previous accounts in the literature. The organic, anterograde memory impairment was attributed to multiple small infarcts and a larger infarction in the left medial temporal lobe, which were evident on MRI and PET scans after the patient had developed transient neurological signs. At follow-up, the anterograde amnesia had persisted, and the patient also showed some difficulty in retrieving autobiographical memories of past incidents or events, although other aspects of his retrograde memory were intact (including his knowledge of facts about his past life and his general knowledge of public events). The difficulty in retrieving autobiographical incidents may have resulted from the presence of a moderate degree of frontal lobe dysfunction or, just possibly, from ischaemia in the left anterior temporal lobe. The persistence of the organic memory impairment and the importance of both the clinical history and neuropsychological testing in assessment are discussed, as well as the need to examine for possible organic factors in patients who may initially appear to manifest purely ‘psychogenic’ memory loss.


2021 ◽  
Vol 26 (4) ◽  
pp. 865-867
Author(s):  
Chien-Chung Cheng ◽  
Jia-Ying Sung ◽  
Chih-Shan Huang

Limbic encephalitis is a rare disorder mainly affecting the medial temporal lobe and is classically paraneoplastic. Autoimmune etiologies also exist, such as antibodies against leucine-rich glioma activated 1 (LGI1). Most cases of anti-LGI1 encephalitis are not associated with tumors. Subacute memory loss is the predominant feature, and most patients develop focal seizures, especially faciobrachial dystonic seizures (FBDSs). Immunotherapies usually show a good response, but are less effective in paraneoplastic cases. We report a case of steroid-responsive anti-LGI1 encephalitis with atypical presentations of sensory aphasia during relapse from rectal carcinoma, an atypical site.


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