The role of executive control in post-stroke aphasia treatment

Combining executive function training and anomia therapy in chronic post-stroke aphasia: A preliminary study of multidimensional effects

PURPOSE

The influential relationship between executive functioning and aphasia rehabilitation outcomes has been addressed in a number of studies, but few have studied the effect of adding executive function training to linguistic therapies. The present study aimed to measure the effects of combining, within therapy sessions, executive function training and anomia therapy on naming and discourse abilities in people with chronic aphasia.

METHOD

A single-case experimental design with multiple baselines across participants was used. Four persons with chronic post-stroke aphasia received 12 sessions of a tailored treatment combining executive function training and semantic feature analysis (SFA) therapy. Naming accuracy of treated items was examined over the course of the treatment while control naming scores of untreated items and discourse measures were collected pre-treatment, immediately post-treatment, and 4 weeks post-treatment, in order to investigate the multidimensional effects of the treatment and their maintenance.

RESULT

Naming skills improved in all participants for treated and untreated items, were maintained over time, and were accompanied by improved discourse abilities. Visual and statistical analyses showed a significant treatment effect for naming skills in three out of the four participants.

CONCLUSION

A combination of executive function training and SFA treatment in people with chronic aphasia may improve both naming skills and discourse efficiency. Further studies are needed to substantiate these promising preliminary results.

Reading for Meaning: The Influence of Reader Characteristics on Paragraph Understanding in Aphasia

PURPOSE

The study improves our understanding of the reading comprehension difficulties seen in people with aphasia. It investigates the influence of reader characteristics, including personal demographic variables, and linguistic and wider cognitive skills, on text comprehension.

METHOD

Seventy-five people with aphasia and 87 neurologically typical readers completed a test of paragraph comprehension. People with aphasia also completed background tests of language, attention, recognition memory, and executive functions. The influence of demographic variables (age, gender, and level of education) was analyzed separately in the group of people with aphasia and the typical readers using analyses of variance. In the people with aphasia, the relationship between paragraph comprehension and the language and cognitive tests was explored using correlational analyses.

RESULTS

In the typical readers, there was a significant effect of gender and level of education and a significant three-way interaction. For the people with aphasia, there were no significant effects of demographic variables. Significant positive correlations were found between performance on paragraph comprehension and each of the language tests and with tests of auditory attention, executive functions, and recognition memory for words.

CONCLUSIONS

In people with aphasia, the effects of demographic variables were overshadowed by the effect of their language difficulties. The association seen across language measures reflects the shared semantic representations across single-word, sentence, and text levels, across modalities. The study emphasizes the importance of attention, executive functions, and short-term memory in the comprehension of and memory for what we read. The contribution of both language difficulties and wider cognitive skills needs to be considered when planning intervention.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24695451.

Targeted neurorehabilitation strategies in post-stroke aphasia

BACKGROUND

Aphasia is a debilitating language impairment, affecting millions of people worldwide. About 40% of stroke survivors develop chronic aphasia, resulting in life-long disability.

OBJECTIVE

This review examines extrinsic and intrinsic neuromodulation techniques, aimed at enhancing the effects of speech and language therapies in stroke survivors with aphasia.

METHODS

We discuss the available evidence supporting the use of transcranial direct current stimulation (tDCS), repetitive transcranial magnetic stimulation, and functional MRI (fMRI) real-time neurofeedback in aphasia rehabilitation.

RESULTS

This review systematically evaluates studies focusing on efficacy and implementation of specialized methods for post-treatment outcome optimization and transfer to functional skills. It considers stimulation target determination and various targeting approaches. The translation of neuromodulation interventions to clinical practice is explored, emphasizing generalization and functional communication. The review also covers real-time fMRI neurofeedback, discussing current evidence for efficacy and essential implementation parameters. Finally, we address future directions for neuromodulation research in aphasia.

CONCLUSIONS

This comprehensive review aims to serve as a resource for a broad audience of researchers and clinicians interested in incorporating neuromodulation for advancing aphasia care.

French Phonological Component Analysis and aphasia recovery: A bilingual perspective on behavioral and structural data

Studies show bilingualism entails an advantage in cognitive control tasks. There is evidence of a bilingual advantage in the context of aphasia, resulting in better cognitive outcomes and recovery in bilingual persons with aphasia compared to monolingual peers. This bilingual advantage also results in structural changes in the right hemisphere gray matter. Very few studies have examined the so-called bilingual advantage by reference to specific anomia therapy efficacy. This study aims to compare the effect of French-Phonological Component Analysis (Fr-PCA) in monolinguals and bilingual persons with aphasia, both at the linguistic and cognitive control level, and to examine the structural impact of left hemisphere lesion location and right hemisphere structural data. Eight participants with chronic aphasia received Fr-PCA for a total of 15 h over 5 weeks. The results showed improved accuracy for treated words and generalization to untreated items and discourse in both groups, and improved Flanker task performance for some participants. Bilingual participants improved more than monolinguals for picture-naming tasks and narrative discourse. Damage to the left postcentral gyrus and the middle frontal gyrus was associated with less therapy-induced improvement. Additionally, left hemisphere damage to the inferior parietal gyrus and postcentral gyrus was associated with reduced cognitive control pre-therapy. Undamaged right hemisphere cortical thicknesses were significantly different between groups; the inferior frontal gyrus and the middle frontal gyrus were greater for the bilingual participants and correlated with cognitive control skills. These results suggest a bilingual advantage in anomia recovery following Fr-PCA, potentially resulting from enhanced cognitive control abilities that could be supported by right hemisphere neural reserve.

The efficacy of a directed rhythmic-melodic voice training in the treatment of chronic non-fluent aphasia-Behavioral and imaging results

The main objective of this study was to investigate the efficacy of a directed rhythmic-melodic voice training (SIPARI) compared to language therapy with the focus on improvement in expressive linguistic performance. 20 patients suffering from chronic non-fluent aphasia, allocated by coin tossing to either of the groups, participated in 32 single therapy sessions over a period of 4 months. Before and after therapy, independent testers performed a standardized language test (Aachener Aphasie Test). Behavioral assessments revealed that improvements of patients of the experimental group were clinically significant compared to those of the control group. These improvements concerned the description level articulation and prosody for spontaneous speech and the subtests repetition, naming, and comprehension. Based on these improvements, a significant increase in profile level (effect size (ES) = 2.028, p < 0.001) was assessed, an overall and clinically relevant measure of the severity of aphasia. Additional fMRI examinations yielded activation in the left superior frontal gyrus for the post-minus pre- therapy assessments only for participants of the experimental group. Since this brain region is reported to be particularly involved in executive processing, we assume that the directed procedure of the SIPARI treatment with regard to musical, linguistic, and cognitive function potentially holds the key for successful language rehabilitation. While our imaging results hint at a possible explanation for its efficacy, our behavioral results corroborate the efficacy of this therapy in the treatment of chronic non-fluent aphasia patients. DRKS00026730, 19.10.21, retrospectively registered https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00026730.

Cognitive Training to Enhance Aphasia Therapy (Co-TrEAT): A Feasibility Study

Persons with aphasia (PWA) often have deficits in cognitive domains such as working memory (WM), which are negatively correlated with recovery, and studies have targeted WM deficits in aphasia therapy. To our knowledge, however, no study has examined the efficacy of multi-modal training which includes both WM training and targeted language therapy. This pilot project examined the feasibility and preliminary efficacy of combining WM training and naming therapy to treat post-stroke PWA. Chronic PWA were randomly assigned to either the a) Phonological Components Analysis (PCA) and WM intervention (WMI) condition (i.e., a computerized adaptive dual n-back task), or b) PCA and active control condition (WMC). Participants received face-to-face PCA therapy 3 times/week for 5 weeks, and simultaneously engaged in WM training or the active control condition five times/week, independently at home. Six PWA were enrolled, 3 in each condition. Feasibility metrics were excellent for protocol compliance, retention rate and lack of adverse events. Recruitment was less successful, with insufficient participants for group analyses. Participants in the WMI (but not the WMC) condition demonstrated a clinically significant (i.e., > 5 points) improvement on the Western Aphasia Battery- Aphasia Quotient (WAB-R AQ) and Boston Naming Test after therapy. Given the small sample size, the performance of two individuals, matched on age, education, naming accuracy pre-treatment, WAB-R AQ and WM abilities was compared. Participant WMI-3 demonstrated a notable increase in WM training performance over the course of therapy; WMC-2 was the matched control. After therapy, WMI-3's naming accuracy for the treated words improved from 30 to 90% (compared to 30–50% for WMC-2) with a 7-point WAB-R AQ increase (compared to 3 for WMC-2). Improvements were also found for WMI-3 but not for WMC-2 on ratings of communicative effectiveness, confidence and some conversation parameters in discourse. This feasibility study demonstrated excellent results for most aspects of Co-TrEAT. Recruitment rate, hampered by limited resources, must be addressed in future trials; remotely delivered aphasia therapy may be a possible solution. Although no firm conclusions can be drawn, the case studies suggest that WM training has the potential to improve language and communication outcomes when combined with aphasia therapy.

Sentence Recall in Latent and Anomic Aphasia: An Exploratory Study of Semantics and Syntax

We investigated whether semantic plausibility and syntactic complexity affect immediate sentence recall in people with latent and anomic aphasia. To date, these factors have not been explored in these types of aphasia. As with previous studies of sentence recall, we measured accuracy of verbatim recall and uniquely real-time speech measures. The results showed that accuracy did not distinguish performance between latent aphasia and neurotypical controls. However, some of the real-time speech measures distinguished performance between people with latent aphasia and neurotypical controls. There was some evidence, though not pervasive, that semantic plausibility and syntactic complexity influenced recall performance. There were no interactions between semantic plausibility and syntactic complexity. The speed of preparation of responses was slower in latent aphasia than controls; it was also slower in anomic aphasia than both latent and control groups. It appears that processing speed as indexed by temporal speech measures may be differentially compromised in latent and anomic aphasia. However, semantic plausibility and syntactic complexity did not show clear patterns of performance among the groups. Notwithstanding the absence of interactions, we advance an explanation based on conceptual short-term memory as to why semantically implausible sentences are typically more erroneous and possibly also slower in recall.