Precision rehabilitation for aphasia by patient age, sex, aphasia severity, and time since stroke? A prespecified, systematic review-based, individual participant data, network, subgroup meta-analysis.

BACKGROUND: Stroke rehabilitation interventions are routinely personalized to address individuals' needs, goals, and challenges based on evidence from aggregated randomized controlled trials (RCT) data and meta-syntheses. Individual participant data (IPD) meta-analyses may better inform the development of precision rehabilitation approaches, quantifying treatment responses while adjusting for confounders and reducing ecological bias. AIM: We explored associations between speech and language therapy (SLT) interventions frequency (days/week), intensity (h/week), and dosage (total SLT-hours) and language outcomes for different age, sex, aphasia severity, and chronicity subgroups by undertaking prespecified subgroup network meta-analyses of the RELEASE database. METHODS: MEDLINE, EMBASE, and trial registrations were systematically searched (inception-Sept2015) for RCTs, including ⩾ 10 IPD on stroke-related aphasia. We extracted demographic, stroke, aphasia, SLT, and risk of bias data. Overall-language ability, auditory comprehension, and functional communication outcomes were standardized. A one-stage, random effects, network meta-analysis approach filtered IPD into a single optimal model, examining SLT regimen and language recovery from baseline to first post-intervention follow-up, adjusting for covariates identified a-priori. Data were dichotomized by age (⩽/> 65 years), aphasia severity (mild-moderate/ moderate-severe based on language outcomes' median value), chronicity (⩽/> 3 months), and sex subgroups. We reported estimates of means and 95% confidence intervals. Where relative variance was high (> 50%), results were reported for completeness. RESULTS: 959 IPD (25 RCTs) were analyzed. For working-age participants, greatest language gains from baseline occurred alongside moderate to high-intensity SLT (functional communication 3-to-4 h/week; overall-language and comprehension > 9 h/week); older participants' greatest gains occurred alongside low-intensity SLT (⩽ 2 h/week) except for auditory comprehension (> 9 h/week). For both age-groups, SLT-frequency and dosage associated with best language gains were similar. Participants ⩽ 3 months post-onset demonstrated greatest overall-language gains for SLT at low intensity/moderate dosage (⩽ 2 SLT-h/week; 20-to-50 h); for those > 3 months, post-stroke greatest gains were associated with moderate-intensity/high-dosage SLT (3-4 SLT-h/week; ⩾ 50 hours). For moderate-severe participants, 4 SLT-days/week conferred the greatest language gains across outcomes, with auditory comprehension gains only observed for ⩾ 4 SLT-days/week; mild-moderate participants' greatest functional communication gains were associated with similar frequency (⩾ 4 SLT-days/week) and greatest overall-language gains with higher frequency SLT (⩾ 6 days/weekly). Males' greatest gains were associated with SLT of moderate (functional communication; 3-to-4 h/weekly) or high intensity (overall-language and auditory comprehension; (> 9 h/weekly) compared to females for whom the greatest gains were associated with lower-intensity SLT (< 2 SLT-h/weekly). Consistencies across subgroups were also evident; greatest overall-language gains were associated with 20-to-50 SLT-h in total; auditory comprehension gains were generally observed when SLT > 9 h over ⩾ 4 days/week. CONCLUSIONS: We observed a treatment response in most subgroups' overall-language, auditory comprehension, and functional communication language gains. For some, the maximum treatment response varied in association with different SLT-frequency, intensity, and dosage. Where differences were observed, working-aged, chronic, mild-moderate, and male subgroups experienced their greatest language gains alongside high-frequency/intensity SLT. In contrast, older, moderate-severely impaired, and female subgroups within 3 months of aphasia onset made their greatest gains for lower-intensity SLT. The acceptability, clinical, and cost effectiveness of precision aphasia rehabilitation approaches based on age, sex, aphasia severity, and chronicity should be evaluated in future clinical RCTs.

RELEASE: a protocol for a systematic review based, individual participant data, meta- and network meta-analysis, of complex speech-language therapy interventions for stroke-related aphasia.

Background: Speech and language therapy (SLT) benefits people with aphasia following stroke. Group level summary statistics from randomised controlled trials hinder exploration of highly complex SLT interventions and a clinically relevant heterogeneous population. Creating a database of individual participant data (IPD) for people with aphasia aims to allow exploration of individual and therapy-related predictors of recovery and prognosis. Aim: To explore the contribution that individual participant characteristics (including stroke and aphasia profiles) and SLT intervention components make to language recovery following stroke. Methods and procedures: We will identify eligible IPD datasets (including randomised controlled trials, non-randomised comparison studies, observational studies and registries) and invite their contribution to the database. Where possible, we will use meta- and network meta-analysis to explore language performance after stroke and predictors of recovery as it relates to participants who had no SLT, historical SLT or SLT in the primary research study. We will also examine the components of effective SLT interventions. Outcomes and results: Outcomes include changes in measures of functional communication, overall severity of language impairment, auditory comprehension, spoken language (including naming), reading and writing from baseline. Data captured on assessment tools will be collated and transformed to a standardised measure for each of the outcome domains. Conclusion: Our planned systematic-review-based IPD meta- and network meta-analysis is a large scale, international, multidisciplinary and methodologically complex endeavour. It will enable hypotheses to be generated and tested to optimise and inform development of interventions for people with aphasia after stroke. Systematic review registration: The protocol has been registered at the International Prospective Register of Systematic Reviews (PROSPERO; registration number: CRD42018110947).

Predicting the outcome of anomia therapy for people with aphasia post CVA: both language and cognitive status are key predictors.

The aim of this study was to determine whether it was possible to predict therapy gain from participants' performance on background tests of language and cognitive ability. To do this, we amalgamated the assessment and therapy results from 33 people with aphasia following cerebral vascular accident (CVA), all of whom had received the same anomia therapy (based on progressive phonemic and orthographic cueing). Previous studies with smaller numbers of participants had found a possible relationship between anomia therapy performance and some language and cognitive assessments. Because this study had access to a larger data set than previous studies, we were able to replicate the previous findings and also to verify two overarching factors which were predictive of therapy gain: a cognitive factor and a phonological factor. The status of these two domains was able to predict both immediate and longer-term therapy gain. Pre-treatment naming ability also predicted gain after the anomia therapy. When combined, both cognitive and language (naming or phonological) skills were found to be independent predictors of therapy outcome.

The treatment of anomia using errorless learning.

In the contemporary literature, errorless learning is thought to have benefits over more traditional trial-and-error methods. The most prominent investigations of errorless learning are those designed for rehabilitation of severe memory impairments, including numerous demonstrations of effective amelioration of word-finding difficulties (Baddeley & Wilson, 1994; Clare, Wilson, Breen, & Hodges, 1999; Clare et al., 2000; Evans et al., 2000). Despite this, there are very few reports on the application of purely errorless learning to people with aphasia (Fillingham, Hodgson, Sage, & Lambon Ralph, 2003). The aim of this study was to compare directly the efficacy of errorless and errorful learning in a case series of 11 aphasic people with pronounced word-finding difficulties. Previous studies of errorless learning and, more recently, studies of rehabilitation have suggested that cognition is an important factor for determining outcome (Helm-Estabrooks, 2002; Robertson & Murre, 1999). Therefore, a thorough language and neuropsychological assessment battery was completed with each participant. Naming therapy was carried out to contrast errorless and errorful therapy in a case series analysis. Errorless learning proved to be as effective as the more traditional, errorful approach in the majority of cases in terms of both immediate improvement and at follow up assessment. Without exception, the patients preferred the errorless learning therapy. Strikingly, it was found that language skill did not predict therapy outcome. Participants who responded better overall, had better recognition memory, executive/problem solving skills and monitoring ability. This replicates recent findings that frontal executive skills are crucial for rehabilitation (Robertson & Murre, 1999). Also, participants who did better at errorful treatment were those with the best working and recall memory, and attention. It is probable that these factors are essential cognitive components for providing effective monitoring and feedback systems to a more general learning mechanism.

Treatment of anomia using errorless versus errorful learning: are frontal executive skills and feedback important?

BACKGROUND: Studies from the amnesia literature suggest that errorless learning can produce superior results to errorful learning. However, it was found in a previous investigation by the present authors that errorless and errorful therapy produced equivalent results for patients with aphasic word-finding difficulties. A study in the academic literature of phoneme discrimination learning found that errorful learning produced equivalent results to errorless learning when feedback was given. In the authors' previous study, feedback was available to the participants in the errorful therapy. It is possible, therefore, that this feedback may have improved the results from errorless learning -- thereby reducing an underlying difference between the two techniques. Generally, feedback is thought to aid learning, however, there is little information in the speech therapy literature about this factor. AIMS: The present investigation was conducted as a follow-up to authors' original study to compare errorless and errorful therapy for the amelioration of aphasic word-finding difficulties. The second aim was to replicate key findings from the original study: namely, that recognition memory, executive/problem-solving skills and monitoring ability predict immediate and long-term naming improvements but not the participants' remaining language ability. METHODS & PROCEDURES: Seven of the original 11 participants took part in a multiple baseline, crossover, case series design. OUTCOMES & RESULTS: The previous results were replicated: errorless and errorful therapy produced equivalent results immediately post-therapy and at follow-up. There was no effect of omitting feedback - the participants learnt equally well without therapist's feedback about whether or not their response was correct. In addition, executive/problem-solving skills and monitoring ability again predicted immediate naming improvements not language ability. CONCLUSIONS: The findings support the view that cognitive abilities and in particular executive function are important contributors to rehabilitation.

The application of errorless learning to aphasic disorders: A review of theory and practice.

Recently, there has been great interest in errorless learning as a new intervention technique. This may be because there are data from both basic neuroscience and clinical application that suggest it is superior to more traditional trial and error methods. In the contemporary literature the most prominent investigations of errorless learning are those designed for rehabilitation of memory impairments. These studies include numerous demonstrations of effective amelioration of word finding difficulties using errorless intervention. The aphasic literature contains no examples of purely errorless learning methods, however, some studies have successfully treated anomia using error reducing techniques. This suggests that errorless learning could be advantageous for treating aphasic disorders, in particular anomia. To explore this idea, we discuss previous research and review two current theories of errorless learning. We provide our own framework for thinking about errorless and errorful learning. In addition, a review of the anomia treatment literature (from 1985 to the present) is presented and conclusions drawn on the methods of treating the word finding difficulties of patients with aphasia.