Altered topology of the functional speech production network in non-fluent/agrammatic variant of PPA

Mandelli, Maria Luisa; Welch, Ariane E.; Vilaplana, Eduard; Watson, Christa; Battistella, Giovanni; Brown, Jesse A.; Possin, Katherine L.; Hubbard, Heidi; Miller, Zachary A.; Henry, Maya L.; Marx, Gabe; Santos‐Santos, Miguel A.; Bajorek, Lynn; Fortea, Juan; Boxer, Adam L.; Rabinovici, Gil D.; Lee, Suzee; Deleon, Jessica; Rosen, Howard J.; Miller, Bruce L.; Seeley, William W.

doi:10.1016/j.cortex.2018.08.002

Cited by 44 publications

(62 citation statements)

References 99 publications

(125 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Longitudinal brain imaging in semantic variant PPA indicates that there is a gradual shifting in network dynamics in the context of atrophic changes (Canu et al, 2020). In fact, there is evidence of altered network connectivity in all three PPA variants (Agosta et al, 2014;Ranasinghe et al, 2017;Mandelli et al, 2018;Tao et al, 2020). Specifically in lvPPA (relative to HC), increased connectivity in right frontoparietal cortex has been observed using restingstate fMRI (Tao et al, 2020) and resting-state MEG has revealed bilateral changes within delta-theta oscillations, comprising both hypersynchrony between medial frontal and temporoparietal cortex and hyperactivity in the frontal cortex (Ranasinghe et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

Cortical Tracking of the Speech Envelope in Logopenic Variant Primary Progressive Aphasia

Dial

Gnanateja

Tessmer

et al. 2021

Front. Hum. Neurosci.

Self Cite

View full text Add to dashboard Cite

Logopenic variant primary progressive aphasia (lvPPA) is a neurodegenerative language disorder primarily characterized by impaired phonological processing. Sentence repetition and comprehension deficits are observed in lvPPA and linked to impaired phonological working memory, but recent evidence also implicates impaired speech perception. Currently, neural encoding of the speech envelope, which forms the scaffolding for perception, is not clearly understood in lvPPA. We leveraged recent analytical advances in electrophysiology to examine speech envelope encoding in lvPPA. We assessed cortical tracking of the speech envelope and in-task comprehension of two spoken narratives in individuals with lvPPA (n = 10) and age-matched (n = 10) controls. Despite markedly reduced narrative comprehension relative to controls, individuals with lvPPA had increased cortical tracking of the speech envelope in theta oscillations, which track low-level features (e.g., syllables), but not delta oscillations, which track speech units that unfold across a longer time scale (e.g., words, phrases, prosody). This neural signature was highly correlated across narratives. Results indicate an increased reliance on acoustic cues during speech encoding. This may reflect inefficient encoding of bottom-up speech cues, likely as a consequence of dysfunctional temporoparietal cortex.

show abstract

Section: Discussionmentioning

confidence: 99%

Cortical Tracking of the Speech Envelope in Logopenic Variant Primary Progressive Aphasia

Dial

Gnanateja

Tessmer

et al. 2021

Front. Hum. Neurosci.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Thus, while having disorder-specific features, alterations in fronto-temporal circuitry may contribute to abnormal speech development in multiple neurodevelopmental disorders ( Belmonte et al , 2004 ). Of note, several recent studies have documented that transcranial direct current stimulation over left IFG including Broca’s area reduced articulation errors and increased speech output in both individuals with autism spectrum disorder ( Schneider and Hopp, 2011 ) and individuals with chronic aphasia ( Fiori et al , 2011 ; Marangolo et al , 2011 , 2013 ; Mandelli et al , 2018 ). FMR1 KO mice demonstrate altered spectral and temporal properties of and reduced rate of ultrasonic vocalizations compared with wild type ( Roy et al , 2012 ; Hodges et al , 2017 ; Toledo et al , 2019 ), the latter which was rescued following drug treatment with minocycline in a recent study ( Toledo et al , 2019 ).…”

Section: Discussionmentioning

confidence: 99%

A neurophysiological model of speech production deficits in fragile X syndrome

Schmitt

Wang

Pedapati

et al. 2019

Brain Communications

View full text Add to dashboard Cite

Fragile X syndrome is the most common inherited intellectual disability and monogenic cause of autism spectrum disorder. Expressive language deficits, especially in speech production, are nearly ubiquitous among individuals with fragile X, but understanding of the neurological bases for these deficits remains limited. Speech production depends on feedforward control and the synchronization of neural oscillations between speech-related areas of frontal cortex and auditory areas of temporal cortex. Interaction in this circuitry allows the corollary discharge of intended speech generated from an efference copy of speech commands to be compared against actual speech sounds, which is critical for making adaptive adjustments to optimize future speech. We aimed to determine whether alterations in coherence between frontal and temporal cortices prior to speech production are present in individuals with fragile X and whether they relate to expressive language dysfunction. Twenty-one participants with full-mutation fragile X syndrome (aged 7–55 years, eight females) and 20 healthy controls (matched on age and sex) completed a talk/listen paradigm during high-density EEG recordings. During the talk task, participants repeated pronounced short vocalizations of ‘Ah’ every 1–2 s for a total of 180 s. During the listen task, participants passively listened to their recordings from the talk task. We compared pre-speech event-related potential activity, N1 suppression to speech sounds, single trial gamma power and fronto-temporal coherence between groups during these tasks and examined their relation to performance during a naturalistic language task. Prior to speech production, fragile X participants showed reduced pre-speech negativity, reduced fronto-temporal connectivity and greater frontal gamma power compared to controls. N1 suppression during self-generated speech did not differ between groups. Reduced pre-speech activity and increased frontal gamma power prior to speech production were related to less intelligible speech as well as broader social communication deficits in fragile X syndrome. Our findings indicate that coordinated pre-speech activity between frontal and temporal cortices is disrupted in individuals with fragile X in a clinically relevant way and represents a mechanism contributing to prominent speech production problems in the disorder.

show abstract

“…Widespread disruptions in connectivity have been observed throughout frontal, temporal and striatal regions in the left hemisphere 115 . Within the speech-language network, agPPA patients have been shown to have a loss of functional hubs in the left fronto-temporal-parietal area and new nodes in more anterior frontal regions and the right frontal lobe compared to controls 194 , suggesting a reorganization of the speech-language network is occurring in agPPA. In fact, longitudinal progression of atrophy in agPPA has been shown to be spatially related to functional connectivity of the speech-language network, supporting the view that neurodegeneration in agPPA spreads through this network 191 .…”

Section: Agrammatic Primary Progressive Aphasia and Primary Progressimentioning

confidence: 98%

FTD spectrum: Neuroimaging across the FTD spectrum

Whitwell

2019

Progress in Molecular Biology and Translational Science

View full text Add to dashboard Cite

Frontotemporal dementia is a complex and heterogeneous neurodegenerative disease that encompasses many clinical syndromes, pathological diseases, and genetic mutations. Neuroimaging has played a critical role in our understanding of the underlying pathophysiology of frontotemporal dementia and provided biomarkers to aid diagnosis. Early studies defined patterns of neurodegeneration and hypometabolism associated with the clinical, pathological and genetic aspects of frontotemporal dementia, with more recent studies highlighting how the breakdown of structural and functional brain networks define frontotemporal dementia. Molecular positron emission tomography ligands allowing the in vivo imaging of tau proteins have also provided important insights, although more work is needed to understand the biology of the currently available ligands.

show abstract

Altered topology of the functional speech production network in non-fluent/agrammatic variant of PPA

Cited by 44 publications

References 99 publications

Cortical Tracking of the Speech Envelope in Logopenic Variant Primary Progressive Aphasia

Cortical Tracking of the Speech Envelope in Logopenic Variant Primary Progressive Aphasia

A neurophysiological model of speech production deficits in fragile X syndrome

FTD spectrum: Neuroimaging across the FTD spectrum

Contact Info

Product

Resources

About