scholarly journals Selective Functional Network Changes Following tDCS-Augmented Language Treatment in Primary Progressive Aphasia

2021 ◽  
Vol 13 ◽  
Author(s):  
Yuan Tao ◽  
Bronte Ficek ◽  
Zeyi Wang ◽  
Brenda Rapp ◽  
Kyrana Tsapkini
Keyword(s):  
Lexical Processing ◽  
Inferior Frontal Gyrus ◽  
Primary Progressive Aphasia ◽  
Functional Network ◽  
Processing Efficiency ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Language System ◽  
Before And After ◽  
Global Connectivity

ObjectiveTranscranial direct current stimulation (tDCS) has shown promising results when used as an adjunct to behavioral training in neurodegenerative diseases. However, the underlying neural mechanisms are not understood and neuroimaging evidence from pre/post treatment has been sparse. In this study, we examined tDCS-induced neural changes in a language intervention study for primary progressive aphasia (PPA), a neurodegenerative syndrome with language impairment as the primary clinical presentation. Anodal tDCS was applied to the left inferior frontal gyrus (LIFG). To evaluate the hypothesis that tDCS promotes system segregation, analysis focused on understanding tDCS-induced changes in the brain-wide functional network connectivity of the targeted LIFG.MethodsResting-state fMRI data were obtained from 32 participants with PPA before and after receiving a written naming therapy, accompanied either by tDCS or sham stimulation. We focused on evaluating changes in the global connectivity of the stimulated LIFG-triangularis (LIFG-tri) region given its important role in lexical processing. Global connectivity was indexed by the graph-theoretic measure participation coefficient (PC) which quantifies a region’s level of system segregation. The values before and after treatment were compared for each condition (tDCS or Sham) as well as with age-matched healthy controls (n = 19).ResultsHigher global connectivity of the LIFG-tri before treatment was associated with greater dementia severity. After treatment, the tDCS group showed a significant decrease in global connectivity whereas the Sham group’s did not change, suggesting specific neural effects induced by tDCS. Further examination revealed that the decrease was driven by reduced connectivity between the LIFG-tri and regions outside the perisylvian language area, consistent with the hypothesis that tDCS enhances the segregation of the language system and improves processing efficiency. Additionally, we found that these effects were specific to the LIFG-tri and not observed in other control regions.ConclusionTDCS-augmented language therapy in PPA increased the functional segregation of the language system, a normalization of the hyper-connectivity observed before treatment. These findings add to our understanding of the nature of tDCS-induced neural changes in disease treatment and have applications for validating treatment efficacy and designing future tDCS and other non-invasive brain stimulation (NIBS) treatments.

scholarly journals Selective Functional Network Changes following tDCS-augmented 2 Language Treatment in Primary Progressive Aphasia

2021 ◽  
Author(s):  
Yuan Tao
Keyword(s):  
Lexical Processing ◽  
Inferior Frontal Gyrus ◽  
Primary Progressive Aphasia ◽  
Functional Network ◽  
Processing Efficiency ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Language System ◽  
Before And After ◽  
Global Connectivity

Objective Transcranial direct current stimulation (tDCS) has shown promising results when used as an adjunct to behavioral training in neurodegenerative diseases. However, the underlying neural mechanisms are not understood and neuroimaging evidence from pre/post treatment has been sparse. In this study, we examined tDCS-induced neural changes in a language intervention study for primary progressive aphasia (PPA), a neurodegenerative syndrome with language impairment as the primary clinical presentation. Anodal tDCS was applied to the left inferior frontal gyrus (LIFG). To evaluate the hypothesis that tDCS promotes system segregation, analysis focused on understanding tDCS-induced changes in the brain-wide functional network connectivity of the targeted LIFG MethodsResting-state fMRI data were obtained from 32 participants with PPA before and after receiving a written naming therapy, accompanied either by tDCS or sham stimulation. We focused on evaluating changes in the global connectivity of the stimulated LIFG-triangularis (LIFG-tri) region given its important role in lexical processing. Global connectivity was indexed by the graph-theoretic measure participation coefficient (PC) which quantifies a region’s level of system segregation. The values before and after treatment were compared for each condition (tDCS or Sham) as well as with age-matched healthy controls (n=19).Results Higher global connectivity of the LIFG-tri before treatment was associated with greater dementia severity. After treatment, the tDCS group showed a significant decrease in global connectivity whereas the Sham group’s did not change, suggesting specific neural effects induced by tDCS. Further examination revealed that the decrease was driven by reduced connectivity between the LIFG-tri and regions outside the perisylvian language area, consistent with the hypothesis that tDCS enhances the segregation of the language system and improves processing efficiency. Additionally, we found that these effects were specific to the LIFG-tri and not observed in other control regions.ConclusionsTDCS-augmented language therapy in PPA increased the functional segregation of the language system, a normalization of the hyper-connectivity observed before treatment. These findings add to our understanding of the nature of tDCS-induced neural changes in disease treatment and have applications for validating treatment efficacy and designing future tDCS and other non-invasive brain stimulation (NIBS) treatments.

Sleep as a predictor of tDCS and language therapy outcomes

SLEEP ◽  
2021 ◽  
Author(s):  
Olivia Herrmann ◽  
Bronte Ficek ◽  
Kimberly T Webster ◽  
Constantine Frangakis ◽  
Adam P Spira ◽  
...  
Keyword(s):  
Inferior Frontal Gyrus ◽  
Primary Progressive Aphasia ◽  
Sleep Time ◽  
Sleep Efficiency ◽  
Language Therapy ◽  
Double Blind ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Time In Bed ◽  
Sham Condition

Abstract Study Objectives To determine whether sleep at baseline (before therapy) predicted improvements in language following either language therapy alone or coupled with transcranial direct current stimulation (tDCS) in individuals with primary progressive aphasia (PPA). Methods Twenty-three participants with PPA (mean age 68.13 ± 6.21) received written naming/spelling therapy coupled with either anodal tDCS over the left inferior frontal gyrus (IFG) or sham condition in a crossover, sham-controlled, double-blind design (ClinicalTrials.gov identifier: NCT02606422). The outcome measure was percent of letters spelled correctly for trained and untrained words retrieved in a naming/spelling task. Given its particular importance as a sleep parameter in older adults, we calculated sleep efficiency (total sleep time/time in bed x100) based on subjective responses on the Pittsburgh Sleep Quality Index (PSQI). We grouped individuals based on a median split: high versus low sleep efficiency. Results Participants with high sleep efficiency benefited more from written naming/spelling therapy than participants with low sleep efficiency in learning therapy materials (trained words). There was no effect of sleep efficiency in generalization of therapy materials to untrained words. Among participants with high sleep efficiency, those who received tDCS benefitted more from therapy than those who received sham condition. There was no additional benefit from tDCS in participants with low sleep efficiency. Conclusion Sleep efficiency modified the effects of language therapy and tDCS on language in participants with PPA. These results suggest sleep is a determinant of neuromodulation effects. Clinical Trial: tDCS Intervention in Primary Progressive Aphasia https://clinicaltrials.gov/ct2/show/NCT02606422

scholarly journals Effects of tDCS on Sound Duration in Patients with Apraxia of Speech in Primary Progressive Aphasia

2021 ◽  
Vol 11 (3) ◽  
pp. 335
Author(s):  
Charalambos Themistocleous ◽  
Kimberly Webster ◽  
Kyrana Tsapkini
Keyword(s):  
Speech Therapy ◽  
Inferior Frontal Gyrus ◽  
Primary Progressive Aphasia ◽  
Motor Disorder ◽  
Apraxia Of Speech ◽  
Post Intervention ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Post Stroke ◽  
Sound Duration

Transcranial direct current stimulation (tDCS) over the left inferior frontal gyrus (IFG) was found to improve oral and written naming in post-stroke and primary progressive aphasia (PPA), speech fluency in stuttering, a developmental speech-motor disorder, and apraxia of speech (AOS) symptoms in post-stroke aphasia. This paper addressed the question of whether tDCS over the left IFG coupled with speech therapy may improve sound duration in patients with apraxia of speech (AOS) symptoms in non-fluent PPA (nfvPPA/AOS) more than sham. Eight patients with non-fluent PPA/AOS received either active or sham tDCS, along with speech therapy for 15 sessions. Speech therapy involved repeating words of increasing syllable-length. Evaluations took place before, immediately after, and two months post-intervention. Words were segmented into vowels and consonants and the duration of each vowel and consonant was measured. Segmental duration was significantly shorter after tDCS compared to sham and tDCS gains generalized to untrained words. The effects of tDCS sustained over two months post-treatment in trained and untrained sounds. Taken together, these results demonstrate that tDCS over the left IFG may facilitate speech production by reducing segmental duration. The results provide preliminary evidence that tDCS may maximize efficacy of speech therapy in patients with nfvPPA/AOS.

scholarly journals White Matter Integrity Predicts Electrical Stimulation (tDCS) and Language Therapy Effects in Primary Progressive Aphasia

2020 ◽  
Vol 35 (1) ◽  
pp. 44-57
Author(s):  
Yi Zhao ◽  
Bronte Ficek ◽  
Kimberly Webster ◽  
Constantine Frangakis ◽  
Brian Caffo ◽  
...  
Keyword(s):  
White Matter ◽  
Diffusion Tensor ◽  
Inferior Frontal Gyrus ◽  
Mean Diffusivity ◽  
Primary Progressive Aphasia ◽  
White Matter Integrity ◽  
Language Therapy ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Language Pathways

Background Transcranial direct current stimulation (tDCS), in conjunction with language therapy, improves language therapy outcomes in primary progressive aphasia (PPA). However, no studies show whether white matter integrity predicts language therapy or tDCS effects in PPA. Objective We aimed to determine whether white matter integrity, measured by diffusion tensor imaging (DTI), predicts written naming/spelling language therapy effects (letter accuracy on trained and untrained words) with and without tDCS over the left inferior frontal gyrus (IFG) in PPA. Methods Thirty-nine participants with PPA were randomly assigned to tDCS or sham condition, coupled with language therapy for 15 daily sessions. White matter integrity was measured by mean diffusivity (MD) and fractional anisotropy (FA) in DTI scans before therapy. Written naming outcomes were evaluated before, immediately after, 2 weeks, and 2 months posttherapy. To assess tDCS treatment effect, we used a mixed-effects model with treatment evaluation and time interaction. We considered a forward model selection approach to identify brain regions/fasciculi of which white matter integrity can predict improvement in performance of word naming. Results Both sham and tDCS groups significantly improved in trained items immediately after and at 2 months posttherapy. Improvement in the tDCS group was greater and generalized to untrained words. White matter integrity of ventral language pathways predicted tDCS effects in trained items whereas white matter integrity of dorsal language pathways predicted tDCS effects in untrained items. Conclusions White matter integrity influences both language therapy and tDCS effects. Thus, it holds promise as a biomarker for deciding which patients will benefit from language therapy and tDCS.

P1-531: LEXICAL PROCESSING IN SEMANTIC VARIANT PRIMARY PROGRESSIVE APHASIA

2006 ◽  
Vol 14 (7S_Part_9) ◽  
pp. P535-P536
Author(s):  
Macarena Martínez-Cuitiño ◽  
Federico Gonzalo Soriano ◽  
Jesica Formoso ◽  
Geraldine Borovinsky ◽  
Jesica Ferrari ◽  
...  
Keyword(s):  
Lexical Processing ◽  
Primary Progressive Aphasia ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Semantic Variant

scholarly journals Primary Progressive Aphasia Education and Support Groups: A Clinical Evaluation

2020 ◽  
Vol 35 ◽  
pp. 153331751989563
Author(s):  
Cathleen Taylor-Rubin ◽  
Lisa Azizi ◽  
Karen Croot ◽  
Lyndsey Nickels
Keyword(s):  
Support Groups ◽  
Support Group ◽  
Primary Progressive Aphasia ◽  
Well Being ◽  
Clinical Psychologist ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Before And After ◽  
Speech Pathologist

Objectives: To evaluate the benefits of a primary progressive aphasia (PPA) education and support session for people with PPA (pwPPA) and their caregivers. Method: Thirty-eight individuals (20 pwPPA, 18 caregivers) were invited to participate in the study. Twenty-five individuals (12 pwPPA, 13 caregivers) completed questionnaires before and after an education and support group session provided by a speech pathologist and a clinical psychologist. Seven individuals (2 pwPPA, 5 caregivers) participated in follow-up interviews. Results: After one attendance, caregivers reported significant improvement in knowledge of PPA, strategies to manage worry and low mood, and opportunities to meet peers. Themes at interview were reduced feelings of isolation, increased feelings of support, increased knowledge of coping strategies, and improved understanding of PPA. Caregivers who had attended previous sessions reported increased feelings of well-being and support. Implications: Primary progressive aphasia education and support group sessions in the postdiagnostic period constitute a valuable component of comprehensive care for PPA.

scholarly journals Longitudinal anatomic, functional, and molecular characterization of Pick disease phenotypes

Neurology ◽  
2020 ◽  
Vol 95 (24) ◽  
pp. e3190-e3202
Author(s):  
Jennifer L. Whitwell ◽  
Nirubol Tosakulwong ◽  
Christopher C. Schwarz ◽  
Matthew L. Senjem ◽  
Anthony J. Spychalla ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Parietal Lobe ◽  
Inferior Frontal Gyrus ◽  
Gray Matter Volume ◽  
Primary Progressive Aphasia ◽  
Progressive Aphasia ◽  
Primary Progressive ◽  
Β Amyloid ◽  
Pick Disease ◽  
Over Time

ObjectiveTo characterize longitudinal MRI and PET abnormalities in autopsy-confirmed Pick disease (PiD) and determine how patterns of neurodegeneration differ with respect to clinical syndrome.MethodsSeventeen patients with PiD were identified who had antemortem MRI (8 with behavioral variant frontotemporal dementia [bvFTD-PiD], 6 with nonfluent/agrammatic primary progressive aphasia [naPPA-PiD], 1 with semantic primary progressive aphasia, 1 with unclassified primary progressive aphasia, and 1 with corticobasal syndrome). Thirteen patients had serial MRI for a total of 56 MRIs, 7 had [18F]fluorodeoxyglucose PET, 4 had Pittsburgh compound B (PiB) PET, and 1 patient had [18F]flortaucipir PET. Cross-sectional and longitudinal comparisons of gray matter volume and metabolism were performed between bvFTD-PiD, naPPA-PiD, and controls. Cortical PiB summaries were calculated to determine β-amyloid positivity.ResultsThe bvFTD-PiD and naPPA-PiD groups showed different foci of volume loss and hypometabolism early in the disease, with bvFTD-PiD involving bilateral prefrontal and anterior temporal cortices and naPPA-PiD involving left inferior frontal gyrus, insula, and orbitofrontal cortex. However, patterns merged over time, with progressive spread into prefrontal and anterior temporal lobe in naPPA-PiD, and eventual involvement of posterior temporal lobe, motor cortex, and parietal lobe in both groups. Rates of frontotemporal atrophy were faster in bvFTD-PiD than naPPA-PiD. One patient was β-amyloid–positive on PET with low Alzheimer neuropathologic changes at autopsy. Flortaucipir PET showed elevated uptake in frontotemporal white matter.ConclusionPatterns of atrophy and hypometabolism differ in PiD according to presenting syndrome, although patterns of neurodegeneration appear to converge over time.

scholarly journals The left inferior frontal gyrus is causally involved in selective semantic retrieval: Evidence from tDCS in primary progressive aphasia

2020 ◽  
Author(s):  
Zeyi Wang ◽  
Bronte N Ficek ◽  
Kimberly T Webster ◽  
Chiadi U Onyike ◽  
John E Desmond ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Inferior Frontal Gyrus ◽  
Primary Progressive Aphasia ◽  
Superior Temporal Gyrus ◽  
Semantic Fluency ◽  
Semantic Retrieval ◽  
Left Inferior Frontal Gyrus ◽  
Progressive Aphasia ◽  
Temporal Lobes ◽  
Primary Progressive

Lesion and imaging studies have shown that the left inferior frontal gyrus (IFG) is involved in selective semantic retrieval of information from the temporal lobes. However, causal, i.e., interventional, evidence is sparse. In the present study we addressed this question by testing whether transcranial direct current stimulation (tDCS) over the left IFG in a group of individuals with primary progressive aphasia may improve semantic fluency, a task that relies to selective semantic retrieval. Semantic fluency improved significantly more in the tDCS vs. sham condition immediately post-treatment and improvement lasted up to 2 months. We further addressed the question of who will benefit most from such an intervention by testing possible demographic, clinical and functional connectivity variables that may predict the behavioral tDCS effect. We found that patients with stronger baseline functional connectivity between the subareas of the left IFG opercularis and triangularis, and between the middle temporal pole and superior temporal gyrus. were the most likely to benefit from tDCS over the left IFG. We thus provided causal evidence that the left IFG is the neural substrate of selective semantic retrieval and tDCS over the left IFG may improve semantic fluency in individuals with stronger baseline functional connectivity.

Sign in / Sign up

Export Citation Format

Share Document