Why are patients with progressive nonfluent aphasia nonfluent?

Gunawardena, Delani; Ash, Sharon; McMillan, Corey T.; Avants, Brian B.; Gee, James C.; Grossman, Murray

doi:10.1212/wnl.0b013e3181ed9c7d

Cited by 88 publications

(116 citation statements)

References 36 publications

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“…Different letters indicate that values are significant different at P<0.05 sudangrass seedlings with EDTA application under Cu stress (Székely et al 2011). In this study, the increase in Cu translocation from root to shoot might be due to chelating effects of EDTA (Gunawardena et al 2010). In the present study, increase in transpiration with EDTA application (Fig.…”

Section: Edta Mitigates the Cu Toxicity In B Napusmentioning

confidence: 64%

EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

Habiba

Ali²,

Farid³

et al. 2014

Environ Sci Pollut Res

239

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Copper (Cu) is an essential micronutrient for normal plant growth and development, but in excess, it is also toxic to plants. The present study investigated the influence of ethylenediaminetetraacetic acid (EDTA) in enhancing Cu uptake and tolerance as well as the morphological and physiological responses of Brassica napus L. seedlings under Cu stress. Four-week-old seedlings were transferred to hydroponics containing Hoagland's nutrient solution. After 2 weeks of transplanting, three levels (0, 50, and 100 μM) of Cu were applied with or without application of 2.5 mM EDTA and plants were further grown for 8 weeks in culture media. Results showed that Cu alone significantly decreased plant growth, biomass, photosynthetic pigments, and gas exchange characteristics. Cu stress also reduced the activities of antioxidants, such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and catalase (CAT) along with protein contents. Cu toxicity increased the concentration of reactive oxygen species (ROS) as indicated by the increased production of malondialdehyde (MDA) and hydrogen peroxide (H2O2) in both leaves and roots. The application of EDTA significantly alleviated Cu-induced toxic effects in B. napus, showing remarkable improvement in all these parameters. EDTA amendment increased the activity of antioxidant enzymes by decreasing the concentrations of MDA and H2O2 both in leaves and roots of B. napus. Although, EDTA amendment with Cu significantly increased Cu uptake in roots, stems, and leaves in decreasing order of concentration but increased the growth, photosynthetic parameters, and antioxidant enzymes. These results showed that the application of EDTA can be a useful strategy for phytoextraction of Cu by B. napus from contaminated soils.

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Section: Edta Mitigates the Cu Toxicity In B Napusmentioning

confidence: 64%

EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

Habiba

Ali²,

Farid³

et al. 2014

Environ Sci Pollut Res

239

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“…A detailed analysis of a lengthy, semi-structured speech sample in naPPA reveals significant simplification of grammatical forms. There is also a significantly greater number of grammatical errors and omissions compared to controls and other PPA patients [35][36][37] . These characteristics results ina significantly abbreviatedmean length of utterance.…”

Section: Speech and Language Deficits In Nappamentioning

confidence: 80%

“…In one study, only difficulty associated with grammatical processing overlaps areas of cortical atrophy related to non-fluent speech, and this is evident in left inferior frontal and anterior superior temporal regions 37 . Another study associates AoS with left inferior frontal atrophy 41 , although the operational definition of AoS included both phonetic errors consistent with AoS and phonologic errors resulting from an impairment of the linguistic system responsible for processing the abstract rules governing speech sounds.…”

Section: Structure-function Relationships In Nappamentioning

confidence: 95%

The non-fluent/agrammatic variant of primary progressive aphasia

Grossman¹

2016

The Behavioral Neurology of Dementia

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In an era of disease-modifying treatments, the non-fluent/agrammatic variant of primary progressive aphasia (naPPA) may help screen for a specific cause of neurodegenerative disease. However, there are controversies surrounding the identification of naPPA. This review describes the characteristic features associated with this discrete, young-onset neurodegenerative condition. Patients with naPPA have a distinct limitation in language emphasizingtheir poor grammatical comprehension and expression, as well as a disorder of speech sound production. Imaging studies associate an impairment of this uniquely human language capacity with disruption of a large-scale neural network centered in left inferior frontal and anterior-superior temporal regions. This corresponds to thepathologic burden of disease anatomically focused in left inferior frontal and anterior-superior temporal regions. A review of the histopathology underlying naPPA relates this condition to frontotemporal lobar degeneration spectrum pathology involving the microtubuleassociated protein tau in a majority of cases. While much work remains to be done, these observations point to unique clinical-pathological correlations that can advance care for an important class of diseases while supplementing our knowledge of human cognitive neuroscience.

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“…Grammatical expression deficits have been related to this anatomic distribution of disease 5. However, studies directly relating sentence comprehension to regional GM atrophy in naPPA have been very rare.…”

Section: Discussionmentioning

confidence: 99%

Grammatical comprehension deficits in non-fluent/agrammatic primary progressive aphasia

Charles

Olm

Powers

et al. 2013

Journal of Neurology, Neurosurgery & Psychiatry

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Importance Grammatical comprehension difficulty is an essential supporting feature of the non-fluent/agrammatic variant of primary progressive aphasia (naPPA), but well-controlled clinical measures of grammatical comprehension are unavailable. Objective To develop a measure of grammatical comprehension and examine this comparatively in PPA variants and behavioural-variant frontotemporal degeneration (bvFTD) and to assess the neuroanatomic basis for these deficits with volumetric grey matter atrophy and whole-brain fractional anisotropy (FA) in white matter tracts. Design Case–control study. Setting Academic medical centre. Participants 39 patients with variants of PPA (naPPA=12, lvPPA=15 and svPPA=12), 27 bvFTD patients without aphasia and 12 healthy controls. Main outcome measure Grammatical comprehension accuracy. Results Patients with naPPA had selective difficulty understanding cleft sentence structures, while all PPA variants and patients with bvFTD were impaired with sentences containing a centre-embedded subordinate clause. Patients with bvFTD were also impaired understanding sentences involving short-term memory. Linear regressions related grammatical comprehension difficulty in naPPA to left anterior-superior temporal atrophy and reduced FA in corpus callosum and inferior frontal-occipital fasciculus. Difficulty with centre-embedded sentences in other PPA variants was related to other brain regions. Conclusions and relevance These findings emphasise a distinct grammatical comprehension deficit in naPPA and associate this with interruption of a frontal-temporal neural network.

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Why are patients with progressive nonfluent aphasia nonfluent?

Abstract: Objective: To investigate the cognitive and neural basis for nonfluent speech in progressive nonfluent aphasia (PNFA).Background: Nonfluent speech is the hallmark feature of PNFA, and this has been attributed to

Cited by 88 publications

References 36 publications

EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

EDTA enhanced plant growth, antioxidant defense system, and phytoextraction of copper by Brassica napus L.

The non-fluent/agrammatic variant of primary progressive aphasia

Grammatical comprehension deficits in non-fluent/agrammatic primary progressive aphasia

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