The effectiveness of transcranial magnetic stimulation for dysphagia in stroke patients: an umbrella review of systematic reviews and meta-analyses.

Numerous studies have explored the use of repetitive Transcranial Magnetic Stimulation (rTMS) intervention in post-stroke dysphagia. The primary aim of this umbrella review was to appraise the methodological quality of systematic reviews (SRs), with and without meta-analyses (MAs), that synthesized the findings of randomized controlled trials (RCTs) exploring the effectiveness of rTMS in the management of dysphagia post-stroke. A secondary aim of was to evaluate the consistency and reliability of translational implications of rTMS for swallowing recovery after stroke across these SRs and MAs. We searched several databases from inception to the 14th of May 2023, to identify SRs and MAs that examined the effectiveness of rTMS in the management of dysphagia post-stroke. The methodological quality of the included studies was evaluated utilizing the AMSTAR 2 (A Measurement Tool to Assess Systematic Reviews) instrument. To investigate the extent of literature overlap among the primary studies included in the SRs, the Graphical Overview of Evidence (GROOVE) was utilized. Of the 19 SRs that were identified, two studies received low quality ratings, while the rest (17) were rated with critically low quality based on the AMSTAR 2 rating. A high literature overlap across the SRs was observed. In all SRs and MAs reviewed, there was a consistent presence of at least some significant evidence supporting the effectiveness of rTMS in enhancing swallowing outcomes for individuals with dysphagia post-stroke, that is, all MAs reported at least a moderate overall effect in favor of rTMS (SMD range = [0.59, 6.23]). While rTMS shows promise for improving dysphagia post-stroke, the current evidence remains limited and inconclusive due to the methodological flaws observed in the published SRs and their respective MAs on the topic so far. Concerning the limitations of our study, language restrictions and methodological shortcomings may affect the generalizability of our findings.

Exploring cerebral laterality of writing and the relationship to handedness: a functional transcranial Doppler ultrasound investigation.

Cerebral lateralization of oral language has been investigated in a plethora of studies and it is well established that the left hemisphere is dominant for production tasks in the majority of individuals. However, few studies have focused on written language and even fewer have sampled left-handers. Writing comprises language and motor components, both of which contribute to cerebral activation, yet previous research has not disentangled. The aim of this study was to disentangle the language and motor components of writing lateralization. This was achieved through the comparison of cerebral activation during (i) written word generation and (ii) letter copying, as assessed by functional Transcranial Doppler (fTCD) ultrasound. We further assessed cerebral laterality of oral language. The sample was balanced for handedness. We preregistered the hypotheses that (i) cerebral lateralization of the linguistic component of writing would be weaker in left-handers compared to right-handers and (ii) oral language and the linguistic component of written language would not be correlated in terms of cerebral lateralization. No compelling evidence for either of our hypotheses was found. Findings highlight the complexity of the processes subserving written and oral language as well as the methodological challenges to isolate the linguistic component of writing.

Causal evidence for the role of the sensory visual cortex in visual short-term memory maintenance.

The role of the sensory visual cortex during visual short-term memory (VSTM) remains controversial. This controversy is possibly due to methodological issues in previous attempts to investigate the effects of transcranial magnetic stimulation (TMS) on VSTM. The aim of this study was to use TMS, while covering previous methodological deficits. Sixty-four young adults were recruited to participate in two experiments (Experiment 1: n = 36; Experiment 2: n = 28) using a VSTM orientation change-detection task under TMS. Monocular vision was ensured using red-blue goggles combined with red-blue stimuli. Double-pulse TMS was delivered at different times (Experiment 1: 0, 200 or 1000 ms; Experiment 2: 200, 1000 ms) during a 2 s maintenance phase, on one side of the occipital hemisphere. In Experiment 2, a sham TMS condition was introduced. Decreased detection sensitivity (d') in the ipsilateral occipital hemisphere to visual hemifield, and in the real TMS (compared with sham TMS) condition indicated inhibitory TMS effects, and thus, a causal involvement of the sensory visual cortex during early (200 ms) and late (1000 ms) maintenance in VSTM. These findings are aligned with sensory recruitment, which proposes that both perceptual and memory processes rely upon the same neural substrates in the sensory visual cortex. The methods used in this study were preregistered and had received in-principle acceptance on 6 June 2022 (Stage 1 protocol can be found in: https://doi.org/10.17605/OSF.IO/EMPDT).

Episodic memory effects of gamma frequency precuneus transcranial magnetic stimulation in Alzheimer's disease: A randomized multiple baseline study.

Episodic memory decline is the prominent neuropsychological feature of typical Alzheimer's Disease (AD), for which current treatments have a limited clinical response. Recently, gamma entrainment therapy has been used as a non-invasive treatment in AD, providing evidence that it may have the potential to alleviate brain pathology and improve cognitive function in AD patients. At the same time, the precuneus (PC) has been recognized as a key area involved in AD related memory deficits and as a key node of the Default Mode Network. This study aimed to investigate the effectiveness of a 40 Hz Transcranial Magnetic Stimulation (TMS) intervention, delivered bilaterally to the precuneus for 10 days, in improving the patients' episodic memory performance. Secondary outcome variables investigated included general cognitive function, semantic and spatial memory, as well as attention and executive function. A concurrent multiple baseline design across five cases was employed. Four patients completed the study. Visual analysis combined with effect size indices were used to evaluate changes across phases. An increase in the average level of immediate recalled words was observed in three out of four patients. Effect size indices indicated significant improvement of attention skills in two patients. No treatment effect was observed for semantic and visual memory, or for executive function. An immediate treatment effect was observed in all patients' general cognitive function as assessed with the Alzheimer's Disease Assessment Scale (mean reduction of 5 points), which was maintained and improved further three months post-treatment. The neuropsychological evaluations indicated improved performance three months post-treatment in immediate and delayed recall, attention, phonological verbal fluency, anxiety, and neuropsychiatric symptoms. This study provides preliminary evidence for the efficacy of a novel non-pharmacological treatment using gamma-band TMS in addressing cognitive dysfunction in AD.

The views of people living with chronic stroke and aphasia on their potential involvement as research partners: a thematic analysis.

BACKGROUND: Patient and Public Involvement (PPI) is the active partnership between researchers, patients and laypeople in the process of creating research. PPI in stroke aphasia research aims to ensure equal opportunities for informed decision-making and guarantee democratic representation of patient partners within the research team. Yet, little is known about the factors that hinder and/or promote the autonomous involvement of people with aphasia in stroke and aphasia PPI projects. This study aimed to explore the views and perspectives of people who live with chronic stroke, with and without aphasia, with experience in research prior to stroke, on their potential involvement as research partners. METHODS: The research team included a PPI partner with chronic stroke-induced aphasia. Semi-structured interviews were conducted online with people with chronic stroke (n = 8), four with aphasia and four without. Interviews were subject to thematic analysis. RESULTS: Inductive thematic analysis generated four themes: (1) the kinds of Restrictions that make involvement in research difficult, (2) the preferred levels and ways of Involvement during the research process, (3) the Support required for active and collaborative involvement, and (4) the Impact of their involvement and how it benefits the study's outcomes. CONCLUSION: People experiencing chronic stroke and aphasia are willing to be involved as PPI partners if the research team provides the necessary support. Recommendations for researchers to consider before commencing co-produced research with people with stroke and aphasia are provided.

Adaptation of The Scenario Test for Greek-speaking people with aphasia: A reliability and validity study.

BACKGROUND: Evidence-based assessments for people with aphasia (PWA) in Greek are predominantly impairment based. Functional communication (FC) is usually underreported and neglected by clinicians. This study explores the adaptation and psychometric testing of the Greek (GR) version of The Scenario Test. The test assesses the everyday FC of PWA in an interactive multimodal communication setting. AIMS: To determine the reliability and validity of The Scenario Test-GR and discuss its clinical value. METHODS & PROCEDURES: The Scenario Test-GR was administered to 54 people with chronic stroke (6+ months post-stroke): 32 PWA and 22 stroke survivors without aphasia. Participants were recruited from Greece and Cyprus. All measures were administered in an interview format. Standard psychometric criteria were applied to evaluate reliability (internal consistency, test-retest, and interrater reliability) and validity (construct and known-groups validity) of The Scenario Test-GR. OUTCOMES & RESULTS: The Scenario Test-GR shows high levels of reliability and validity. High scores of internal consistency (Cronbach's α = 0.95), test-retest reliability (intra-class coefficients (ICC) = 0.99), and interrater reliability (ICC = 0.99) were found. Interrater agreement in scores on individual items ranged from good to excellent levels of agreement. Correlations with a tool measuring language function in aphasia, a measure of FC, two instruments examining the psychosocial impact of aphasia and a tool measuring non-verbal cognitive skills revealed good convergent validity (all ps < 0.05). Results showed good known-groups validity (Mann-Whitney U = 96.5, p < 0.001), with significantly higher scores for participants without aphasia compared with those with aphasia. CONCLUSIONS & IMPLICATIONS: The psychometric qualities of The Scenario Test-GR support the reliability and validity of the tool for the assessment of FC in Greek-speaking PWA. The test can be used to assess multimodal FC, promote aphasia rehabilitation goal-setting at the activity and participation levels, and be used as an outcome measure of everyday communication abilities.