Evidence-based cognitive rehabilitation: Recommendations for clinical practice

Background
Aphasia is an acquired language impairment following brain damage that affects some or all language modalities: expression and understanding of speech, reading, and writing. Approximately one third of people who have a stroke experience aphasia.

Objectives
To assess the effects of speech and language therapy (SLT) for aphasia following stroke.

Search methods
We searched the Cochrane Stroke Group Trials Register (last searched 9 September 2015), CENTRAL (2015, Issue 5) and other Cochrane Library Databases (CDSR, DARE, HTA, to 22 September 2015), MEDLINE (1946 to September 2015), EMBASE (1980 to September 2015), CINAHL (1982 to September 2015), AMED (1985 to September 2015), LLBA (1973 to September 2015), and SpeechBITE (2008 to September 2015). We also searched major trials registers for ongoing trials including ClinicalTrials.gov (to 21 September 2015), the Stroke Trials Registry (to 21 September 2015), Current Controlled Trials (to 22 September 2015), and WHO ICTRP (to 22 September 2015). In an effort to identify further published, unpublished, and ongoing trials we also handsearched the International Journal of Language and Communication Disorders (1969 to 2005) and reference lists of relevant articles, and we contacted academic institutions and other researchers. There were no language restrictions.

Selection criteria
Randomised controlled trials (RCTs) comparing SLT (a formal intervention that aims to improve language and communication abilities, activity and participation) versus no SLT; social support or stimulation (an intervention that provides social support and communication stimulation but does not include targeted therapeutic interventions); or another SLT intervention (differing in duration, intensity, frequency, intervention methodology or theoretical approach).

Data collection and analysis
We independently extracted the data and assessed the quality of included trials. We sought missing data from investigators.

Main results
We included 57 RCTs (74 randomised comparisons) involving 3002 participants in this review (some appearing in more than one comparison). Twenty-seven randomised comparisons (1620 participants) assessed SLT versus no SLT; SLT resulted in clinically and statistically significant benefits to patients' functional communication (standardised mean difference (SMD) 0.28, 95% confidence interval (CI) 0.06 to 0.49, P = 0.01), reading, writing, and expressive language, but (based on smaller numbers) benefits were not evident at follow-up. Nine randomised comparisons (447 participants) assessed SLT with social support and stimulation; meta-analyses found no evidence of a difference in functional communication, but more participants withdrew from social support interventions than SLT. Thirty-eight randomised comparisons (1242 participants) assessed two approaches to SLT. Functional communication was significantly better in people with aphasia that received therapy at a high intensity, high dose, or over a long duration compared to those that received therapy at a lower intensity, lower dose, or over a shorter period of time. The benefits of a high intensity or a high dose of SLT were confounded by a significantly higher dropout rate in these intervention groups. Generally, trials randomised small numbers of participants across a range of characteristics (age, time since stroke, and severity profiles), interventions, and outcomes.

Authors' conclusions
Our review provides evidence of the effectiveness of SLT for people with aphasia following stroke in terms of improved functional communication, reading, writing, and expressive language compared with no therapy. There is some indication that therapy at high intensity, high dose or over a longer period may be beneficial. HIgh-intensity and high dose interventions may not be acceptable to all.

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Speech and language therapy for aphasia following stroke

—Patients with chronic aphasia were assigned randomly to a group to receive either conventional aphasia therapy or constraint-induced (CI) aphasia therapy, a new therapeutic technique requiring intense practice over a relatively short period of consecutive days. CI aphasia therapy is realized in a communicative therapeutic environment constraining patients to practice systematically speech acts with which they have difficulty. Patients in both groups received the same amount of treatment (30 to 35 hours) as 10 days of massed-practice language exercises for the CI aphasia therapy group (3 hours per day minimum; 10 patients) or over a longer period of ≈4 weeks for the conventional therapy group (7 patients). CI aphasia therapy led to significant and pronounced improvements on several standard clinical tests, on self-ratings, and on blinded-observer ratings of the patients’ communicative effectiveness in everyday life. Patients who received the control intervention failed to achieve comparable improv...

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Constraint-Induced Therapy of Chronic Aphasia After Stroke

An extensive search of aphasia-treatment literature yielded 55 reports of clinical outcomes satisfying the essential criteria for inclusion in a meta-analysis. The results confirmed those of an ear...

A Meta-Analysis of Clinical Outcomes in the Treatment of Aphasia

Aphasia

Five Veterans Administration Medical Centers participated in an investigation designed to compare individual with group treatment for aphasic patients who had suffered a left hemisphere cerebral vascular accident. Patients who met selection criteria were assigned randomly to either traditional, individual, stimulus-response type treatment of specific language deficits or group therapy designed to improve communication through group interaction and discussion with no direct treatment of specific language deficits. All patients received eight hours of therapy each week beginning at four weeks postonset and continuing until 48 weeks postonset or until they dropped out of the study. A battery of language measures and a clinical neurologic evaluation were administered at intake and every 11 weeks a patient was in the study. Results show both individually and group-treated patients made significant improvement in language abilities. Individual treatment resulted in significantly better overall performance on th...

Veterans Administration Cooperative Study on Aphasia

"Statistical Prediction of Change in Aphasia," JSHR, 23, 312–321, 1980, by Bruce E. Porch, et al., contains an error. On page 314, the example predictive equation should read, "Statistical Predicti...

Statistical Prediction of Change in Aphasia

Latencies of same-different judgments to pairs of two-digit numerals were recorded for stimuli presented in familiar or unfamiliar (inverted) orientation. Familiar stimuli were responded to more quickly than unfamiliar. For both stimulus types, latencies were correlated with the syllable length of the verbal representation of the numerals, allowing the interpretation that the effect of stimulus orientation is on encoding processes. In two other experiments, it was found that familiarity had no effect on different judgments when the stimuli were relatively simple (e.g., a single digit), but did affect different judgments with more complex stimuli. These results were related to the hypothesis that the complexity of verbal material determines whether different judgments are instigated by visual or by verbal representations of the stimuli.

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The effects of familiarity in a perceptual matching task

Two general viewpoints were advanced as explanations of whiteness constancy: (a) an inferential process, in which noise illuminance variation) is suppressed, and (b) an insensitivity hypothesis, in which Os show an insensitivity to illuminance variation in well-articulated fields. Category judgments of illuminance and albedo variation were given by three Os to either unpatterned (isolated surface) or patterned (two surfaces, one of which was constant in albedo) stimuli. Judgments of the patterned stimuli differed from judgments of the unpatterned stimuli in that Os showed increased sensitivity to real albedo variation (whiteness constancy) and a corresponding decreased sensitivity to real illuminance variation, allowing the interpretation that stimulus conditions producing whiteness constancy are also those producing insensitivity to illuminance variation.

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Whiteness constancy: Inference or insensitivity?

Summary.-2 experiments were conducted to determine whether words and pictures are coded and processed in different fashions. In Exp. I, reaction times (RTs) of same-different judgments were recorded for pairs of words which differed in syllable length (1 vs 3). RTs were longer for the threesyllable than the one-syllable words, indicating a sequentially organized verbal code. Exp. I1 employed a pictorial representation of the words used in Exp. I. There was no correlation between RTs and the syllable length of the picture names in Exp. 11, suggesting that S employed an imaginal code for the pictures which involved parallel, rather than sequential, processing. The results of both studies were taken as support for Paivio's (1971) dual-coding hypothesis. Paivio (1971, Ch. 2) has argued for a dual-coding system in human information processing in which there are two distinct symbolic systems capable of coding and representing various kinds of stimulus information. These two coding systems, imaginal and verbal, are distinguished in terms of both their processing characteristics and the kinds of stimulus information they are best suited to handle. The imaginal coding sys.em is viewed as a parallel processing system, in both the spatial and operational sense (see Neisser, 1967, p. 72 ) and is primarily suited for the processing of relatively concrete information. Paivio defines the concreteness dimension in terms of the directness of sensory reference, which ranges from fairly abstract items (such as words which are fairly remote from the objecrs and events they represent) to relatively concrete materials (such as pictures or actual objects). When dealing with relatively concrete materials, e.g., pictures, the human organism is believed to use an imaginal coding system which represents the spatial properties of the information. This characteristic of representing the spatial properties of stimuli is what makes the imaginal coding system primarily a parallel-processing system, i.e., each stage occurs simultaneously and independently. Obviously this coding system is functionally linked to the process of visual perception. The verbal coding system, on the other hand, is primarily a sequential processing system capable of dealing most effectively with relatively abstract materials, e.g., words. The verbal coding system is sequential in the sense that the processing of information tends to unfold over time, with each stage being

Thomas P. Friden

Papers

Veterans Administration Cooperative Study on Aphasia

Statistical Prediction of Change in Aphasia

The effects of familiarity in a perceptual matching task

Whiteness constancy: Inference or insensitivity?

Verbal and imaginal coding of words and pictures