Aphasia – Treatment effectiveness and evidence

based practice

Treatment Efficacy

• Efficacy: improvements in an individuals communication as a result of clinical interventions provided by an SLT

• Difficult to combine results of studies due to differing:– Aetiologies– Methodologies– Types and severity of aphasia– Nature of treatment

Enderby and Emerson 1995

Systematic Reviews

• A scientific tool that can be used to appraise, summarise, and communicate the results and implications of otherwise unmanageable quantities of research

• Brings together separately conducted studies and synthesise their results

• E.g. Cochrane Database

Meta-analysis• A specific statistical strategy for assembling

the results of several studies into a single estimate

• Systematic reviews may or may not include meta-analysis, depending on whether the studies are similar enough so that combining their results is meaningful

• Strictly speaking a meta-analysis is an optional component of a systematic review. Not inter-changable words!

Cochrane Systematic Reviews

• Kelly, Brady and Enderby (2010)• 30 RCT’s (involving 1840 participants) comparing:

– SLT v’s no SLT – SLT versus social support or stimulation– One SLT intervention v’s another intervention

• In general, trials randomised small numbers across a range of characteristics (age, time since stroke, and severity), interventions and outcomes

Kelly, Brady and Enderby (2010)

• Concluded some indication for the effectiveness of SLT for those with aphasia following stroke (as compared with Enderby 2006b).

• Intense SLT was favoured over conventional SLT

• Therapist-trained and supervised volunteers as effective as provision by a professional

• Insufficient evidence for effectiveness of specific treatment approaches

Systematic Reviews

• Greener, Enderby and Whurr (2006b)– RCT’s for behavioural treatments for Aphasia

by SLT’s– 12 studies met criteria– All had limitations in methodology, and

incompleteness in which operational definitions and outcomes were communicated.

– Concluded RCT’s had neither demonstrated efficacy nor lack of efficacy

Cochrane Review• Greener, Enderby and Whurr (2010)

– Assessed the effects of drugs on language abilities for people with aphasia

– Particularly examined Piracetam – drug which improves memory, cognition, attention, concentration, motivation

– Has reportedly shown improvements in post stroke aphasia in some studies

– 10 trials included

– Weak evidence that patients were more likely to have improved on language measures at the end of the trial with piracetam

Meta-analysis

• Greenhouse et al (1990)– Analysed 13 pre-post tests of aphasia treatment – Average weighted effect size of 0.8 (medium to large

effect of change) from pre-treatment to post treatment

• Whurr Lorch and Nye (1992)– 45 aphasia treatment studies– Average effect size 0.59 between treated and

untreated populations.– Concluded treatments were generally effective

Meta-Analysis

• Robey (1998)– Analysis of 55 articles – aphasia therapy brought

about positive clinical outcomes– Positive outcomes were 1.83 times more likely for

those treated in acute period than for untreated individuals. Advocating early intervention

– Treatment length in excess of 2 hours per week brought about gains exceeding those of shorter treatment duration

– Those with severe aphasia also made large gains• These findings confirmed findings from earlier

study: Robey (1994)

Meta-Analysis

• Holland et al (1996)– Examined improvements in individual’s

communication behaviour resulting from clinical interventions from SLT and exceeding what could be expected from spontaneous recovery alone.

– 9 group studies, all enrolling >60 patients– Single, left hemi stroke, receiving >3hrs/week therapy

for >5m regardless of time post onset, made significantly more improvement than people with aphasia who were not treated

– 13 small group/single subject studies past period of spontaneous recovery. Gains made in most studies contributing to efficacy of chronic aphasia

Treatment of Word Retrieval Deficits in Aphasia

• Summary:• Task specific semantic therapy improves

semantic activities• Task specific phonological therapy improves

phonological activities• Limited evidence that semantic and phonological

cueing improve naming accuracy and word retrieval abilities

Salter,Teasell, Bhogal, Zettler, Foley (2009)Evidenced Based Review of Stroke Rehabilitation

Doesborg et al 2004

• RCT of 55 stroke patients 3-5m post onset• Combined semantic and phonological deficits • Randomly assigned to:

– Semantic treatment focused on interpretation of written words, sentences and text (e.g. semantic categories, anomalous sentences, semantic definitions)

– Control group focused on word sound structure (e.g. rhyming, word length, stress patterns, syllabification)

Doesborg et al 2004

• Treatment lasted until 10-12m post onset, receiving 40-60 hours individual treatment

• After semantic treatment patients significantly improved on Semantic Association Test.

• After sound structure treatment patients significantly improved on phonological measures

• All patients improved on Everyday Language Test

• Improved verbal communication was achieved for both groups

Treatment for Word Finding in Aphasia – Nickels (2010)

1. Therapy has item specific effects only2. Semantic and phonologically focused

treatments are mostly successful in improving word retrieval.

3. Semantic tasks don’t have to be hard to be effective

4. Semantic tasks are more effective with those with less semantic impairment

5. Semantic tasks usually require the word form to be effective

Treatment of Global Aphasia

• Summary:• Patients with global aphasia experience less

complete or slower rates of recovery• Can still benefit from an SLT rehab programme• Moderate evidence based on small RCT that

intensive “ecological” language therapy is associated with improvement across modalities

Salter,Teasell, Bhogal, Zettler, Foley (2009)

Evidence Based Review of Stroke Rehab

Denes et al 1996

• RCT of 17 patients with global aphasia• Random allocation to standard (60 sessions

over 6m) or intensive therapy (130 over 6m)• Approach in both groups “ecological” –

restoration of language in conversation • Comprehension targeted > production• Sessions 45-60min• Assessed at baseline and 6m Aachen Aphasia

Test

Denes et al 1996

• Results: – Both groups demonstrated improvement

across all subtests.– Between group differences significant for

written language subtest only

Aphasia Treatment in Polyglots

• Miertsch, Meisel and Isel (2009)– Does treatment of 1 language lead to improvement in

all languages?– 56yr old male, speaking German (L1), English (L2)

and French (L3)– Left CVA with a medium Wernicke’s aphasia: severe

WFD, semantic paraphasias, paragrammatism. Auditory language processing and phonological working memory worse than visual language processing

– Therapy for the study 8yrs post onset. 2x 45min/day for 3.5weeks in French.

Therapy

• Bilingual Aphasia Test administered• 5 exercise types in same order every day.• Therapy focussed on:

– Oral and auditory word finding of verbs and nouns

– Exercises with prepositions– Semantic-conceptual relationships between

words– Word finding in discourse

Results

• Before training best performance German.• Post treatment, performance improved

significantly in French as well as English. German did not improve.

• Further evidence that chronic aphasia can improve

• 2 Languages share a common semantic-conceptual memory system, though would expect improvement in German too. ?Length of training too short ?due to capabilities in that language prior to training.

Conclusions

Generally accepted that SLT works!

Basso (2005), Albert (2003), Bhogal, Teasell and Speechley (2003)