Preservation of Reasoning in Primary Progressive Aphasia: Further Differentiation from Alzheimer's Disease and the Behavioral Presentation of Frontotemporal Dementia

Wicklund, Alissa H.; Johnson, Nancy; Weıntraub, Sandra

doi:10.1080/13803390490510077

Cited by 81 publications

(48 citation statements)

References 21 publications

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“…Therefore, the low scores on some nonlanguage tests were attributed to interference from the language impairment. PPA patients showed relatively less impairment in CERAD Word List Recognition, Visual Target Cancellation, JLO, and the Visual-Verbal Test (Wicklund et al, 2004), representing tests of memory, visuospatial functions, and reasoning and executive functions, respectively. Normal controls showed no impairments on any of the neuropsychological tests.…”

Section: Methodsmentioning

confidence: 99%

Altered Effective Connectivity within the Language Network in Primary Progressive Aphasia

Sonty¹,

Mesulam²,

Weıntraub³

et al. 2007

J. Neurosci.

122

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Primary progressive aphasia (PPA) is a neurodegenerative dementia syndrome principally characterized by the gradual dissolution of language functions, especially in the early stages of disorder. In a previous functional neuroimaging study, PPA patients were found to activate core language areas similarly to control subjects when performing semantic and phonological processing tasks (Sonty et al., 2003). In the present study, functional magnetic resonance imaging (fMRI) and dynamic causal modeling (DCM) were used to study multiregional effective connectivity in early-stage PPA (n ϭ 8) and control (n ϭ 8) subjects performing semantic word matching and visual letter matching tasks. fMRI analysis showed semantic task-specific activations in the left inferior frontal (Broca's area) and posterior superior temporal (Wernicke's area) regions, in addition to other language regions, in both groups. Using a model language network consisting of six left hemisphere regions, the DCM analysis demonstrated reduced language-specific effective connectivity between Wernicke's and Broca's areas in the PPA patient group. Furthermore, this decrement in connectivity was predictive of semantic task accuracy. These results demonstrate for the first time that dysfunctional network interactions (effective connectivity), rather than hypoactivity within individual brain regions, may contribute to the emergence of language deficits seen in PPA.

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Section: Methodsmentioning

confidence: 99%

Altered Effective Connectivity within the Language Network in Primary Progressive Aphasia

Sonty¹,

Mesulam²,

Weıntraub³

et al. 2007

J. Neurosci.

122

View full text Add to dashboard Cite

show abstract

“…A greater deficit in naming verbs than naming nouns is associated with nonfluent, agrammatic forms of PPA . Verb processing deficits can also occur in AD, but the deficits are linked to impaired processing of the semantic rather than the syntactic information carried by verbs (Grossman et al 1996;Kim and Thompson 2004).Neuropsychological studies that directly compared patients with clinically diagnosed PPA, bvFTD, and AD have shown that those with PPA have relatively preserved reasoning and episodic memory compared with the other two groups (Wicklund et al 2004(Wicklund et al , 2006. Furthermore, functional ability reflected in activities of daily living (ADL) is better preserved in patients with PPA than in the other two groups when duration of illness is controlled (Wicklund et al 2007).…”

mentioning

confidence: 99%

The Neuropsychological Profile of Alzheimer Disease

Weıntraub

Wicklund²,

Salmon³

2012

Cold Spring Harbor Perspectives in Medicine

467

282

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Neuropsychological assessment has featured prominently over the past 30 years in the characterization of dementia associated with Alzheimer disease (AD). Clinical neuropsychological methods have identified the earliest, most definitive cognitive and behavioral symptoms of illness, contributing to the identification, staging, and tracking of disease. With increasing public awareness of dementia, disease detection has moved to earlier stages of illness, at a time when deficits are both behaviorally and pathologically selective. For reasons that are not well understood, early AD pathology frequently targets large-scale neuroanatomical networks for episodic memory before other networks that subserve language, attention, executive functions, and visuospatial abilities. This chapter reviews the pathognomonic neuropsychological features of AD dementia and how these differ from "normal," age-related cognitive decline and from other neurodegenerative diseases that cause dementia, including cortical Lewy body disease, frontotemporal lobar degeneration, and cerebrovascular disease.O ver the past 30 years, neuropsychological assessment has featured centrally in characterizing the dementia associated with Alzheimer disease (AD), identifying the most salient and earliest cognitive and behavioral symptoms and contributing to the staging and tracking of disease (Flicker et al. 1984;Morris et al. 1989;Storandt and Hill 1989;Storandt 1991;Welsh et al. 1991Welsh et al. , 1992Locascio et al. 1995;Albert 1996;Storandt et al. 1998; see also Salmon and Bondi 2009). As research has increasingly focused on earlier stages of illness, it has become clear that biological markers of AD can precede cognitive and behavioral symptoms by years. It has also become clear that the early symptoms of AD represent the selective targeting by disease of specific, "largescale" neuroanatomical networks, with clinical deficits consistent with the anatomical locus of impact (Weintraub and Mesulam 1993Seeley et al. 2009). In the usual case, AD pathology is initially selective for limbic regions that subserve episodic memory, which leads to a circumscribed memory deficit in the early stages of the disease (Braak and Braak 1991;Jack et al. 1997; de ToledoMorrell et al. 2000). It is only as pathology progresses to other neocortical regions over time (Braak and Braak 1996a,b;Braak et al. 1999;Jack et al. 2000) that additional cognitive symptoms emerge and the full dementia syndrome becomes apparent.These discoveries have prompted a revision of the established research diagnostic criteria for AD dementia that had served so well since 1984 (McKhann et al. 1984). The new criteria define not only the dementia of AD (McKhann et al. 2011) but also incorporate a fuller spectrum of cognitive aging, including an intermediate stage of mild cognitive impairment (MCI) that precedes the dementia (Albert et al. 2011). A third, even earlier, stage of "preclinical AD" has also been identified (Sperling et al. 2011). This prodromal period is characterized by the presence of bi...

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“…It may often be diffi cult to confi rm normal function in other cognitive when signifi cant language defi cits are present. Modifi cation of standard testing paradigms to reduce their dependence on language skills can be useful (Wicklund et al 2004). Defi cits in other cognitive domains eventually emerge after the initial few years, but the language dysfunction remains the most salient feature and advances most rapidly, throughout the course of the illness (Mesulam 2003).…”

Section: Clinical Presentation and Evolutionmentioning

confidence: 99%

A review on primary progressive aphasia

Léger

Johnson²

2008

NDT

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Primary progressive aphasia (PPA) is a neurodegenerative disease of insidious onset presenting with progressive isolated loss of language function, without signifi cant impairment in other cognitive domains. Current diagnostic criteria require the language dysfunction to remain isolated for at least two years, and to remain the salient feature as the disease progresses, usually to involve other domains such as behavior, executive functions, and judgment. Although PPA in its early stages can usually be differentiated from probable Alzheimer's disease (PRAD) and the behavioral variant of frontotemporal lobar degeneration by the absence of signifi cant changes in memory and behavior, and the preservation of activities daily living, progression of the disease often leads to defi cits more consistent with the latter. Underlying etiologies remain heterogeneous: the neuropathological characteristics associated with frontotemporal lobar degeneration, cortocobasal degeneration, and motor neuron disease are usually found. There is a strong genetic susceptibility with affl iction of fi rst-degree relatives with similar disease in up to 40 to 50% in some series. Pathogenic mutations in genes coding for the proteins tau and progranulin have been isolated. These are leading to a better understanding of the neuropathological mechanisms and hopefully targeted disease-modifying therapy. Current therapy is limited to improving mood symptoms and targeting behavior changes as they develop. Referral to specialized centers where speech therapy, counseling, and education for both patient and caregiver are available may be helpful.

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Preservation of Reasoning in Primary Progressive Aphasia: Further Differentiation from Alzheimer's Disease and the Behavioral Presentation of Frontotemporal Dementia

Cited by 81 publications

References 21 publications

Altered Effective Connectivity within the Language Network in Primary Progressive Aphasia

Altered Effective Connectivity within the Language Network in Primary Progressive Aphasia

The Neuropsychological Profile of Alzheimer Disease

A review on primary progressive aphasia

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