Aphasia

Note: When reviewing the findings, it is important to note that they are always made according to randomized clinical trial (RCT) criteria – specifically as compared to a control group. To clarify, if a treatment is “effective” it implies that it is more effective than the control treatment to which it was compared. Non-randomized studies are no longer included when there is sufficient research to indicate strong evidence (level 1a) for an outcome.

Currently, many approaches are used to restore language function. These include: speech therapy, constraint-induced therapy, intention/attention treatment, group communication, animal-assisted therapy, and computerized therapy. The present review examines the scientific evidence on the effectiveness of each of the above mentioned approaches in patients with post-stroke aphasia.

Fourty-seven studies (23 high quality RCTs –and 1 follow-up study of one of these RCTs–, 10 fair quality RCTs, 4 pre-post studies, 4 quasi-experimental studies and 5 single case studies) have examined the effectiveness of several therapies for aphasia in patients with aphasia post-stroke. Specifically, speech and language therapy (SLT), constraint-induced aphasia therapy (CIAT), intention/attention treatment, group communication, animal-assisted therapy, and computerized therapy have been examined. A Cochrane review of SLT interventions for post-stroke aphasia by Kelly et al. (2010) concluded that SLT is beneficial in the treatment of aphasia post-stroke, although there is no conclusive evidence of the most effective intervention. Comparison of results among studies is complicated by variation in the type, frequency and duration of SLT, severity and type of aphasia, and outcome measures of speech, language and communication. Further, the reliability of results is impacted by small sample sizes within many studies. Teasell et al. (2011) note that the failure to identify a consistent benefit associated with SLT might have been due to the low intensity of SLT applied in negative studies, while positive studies appear to apply higher intensities of therapy. The Cochrane review by Kelly et al. (2010) reported a trend in favour of intensive SLT compared to conventional SLT, and an earlier meta-analysis by Bhogal et al. (2003) reported that intense therapy given over a short amount of time can result in greater improvements in language abilities.

Please click here to see the Authors’ Results Table.

Acute phase - Cognitive-linguistic therapy

Functional communicationNot effective1b

One high quality RCT  (de Jong-Hagelstein et al., 2010) has investigated the effect of cognitive-linguistic treatment initiated during  the acute phase of stroke recovery on functional communication skills of patients with aphasia. This high quality RCT randomised patients to receive either cognitive-linguistic treatment (CLT – semantic and/or phonological training) or communicative treatment (compensatory strategies and use of residual language skills). Functional verbal communication was measured by the Amsterdam-Nijmegan Everyday Language Test scale A: Understandability (ANELT-A). No significant between-group differences in functional communication were found at mid-treatment (3 months) or post-treatment (6 months).

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that cognitive-linguistic treatment initiated in  the acute phase of stroke recovery is not more effective than communicative treatment in improving functional communication skills of patients with aphasia.

Phonological skillsNot effective1b

One high quality RCT  (de Jong-Hagelstein et al., 2010) has investigated the effect of cognitive-linguistic treatment initiated during the acute phase of stroke recovery on phonological skills of patients with aphasia. and. This high quality RCT randomised to receive either cognitive-linguistic treatment (CLT – semantic and/or phonological training) or communicative treatment (compensatory strategies and use of residual language skills). Phonological ability was measured by the Psycholinguistic Assessment of Language Processing in Aphasia (PALPA) nonword repetition subtest, the PALPA auditory lexical decision subtest, and a letter fluency task. A significant between-group difference in letter fluency was seen in favour of the CLT group compared to the communicative treatment group at 6 months post-stroke. There were no differences in other phonological measures at 3 months (mid-treatment) or 6 months (post-treatment).

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that cognitive-linguistic treatment initiated in  the acute phase of stroke recovery is not more effective than communicative treatment in improving phonological skills of patients with aphasia.
Note: However, a significant between-group difference in letter fluency was seen at post-treatment in favour of the cognitive-linguistic treatment group.

Semantic skillsNot effective1b

One high quality RCT  (de Jong-Hagelstein et al., 2010) has investigated the effect of cognitive-linguistic treatment initiated during the acute phase of stroke recovery on semantic skills of patients with aphasia. This high quality RCT randomised patients to receive either cognitive-linguistic treatment (CLT – semantic and/or phonological training) or communicative treatment (compensatory strategies and use of residual language skills). Semantic ability was measured by the Semantic Association Test – verbal version (SAT), the Psycholinguistic Assessment of Language Processing in Aphasia (PALPA) semantic association with low imageability words subtest, and the Semantic Word Fluency test. A significant between-group difference was seen in favour of the CLT group compared to the communicative treatment group in Semantic Word Fluency at 3 months post-stroke (mid-treatment), but did not remain significant at 6 months (post-treatment). There were no differences in other measures of semantic ability at either time point.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that cognitive-linguistic treatment initiated in  the acute phase of stroke recovery is not more effective than communicative treatment in improving semantic ability of patients with aphasia.
Note: While the high quality RCT found a significant between-group difference in semantic word fluency at mid-treatment in favour of the cognitive-linguistic treatment group, this was not maintained at post-treatment.

Acute phase - Communication partners

AphasiaNot effective1a

Two high quality RCTs (Wertz et al., 1986; Hartman & Landau, 1987) and 1 fair quality RCT (Meikle et al., 1979) have investigated the effectiveness of communication partners in the treatment of aphasia during the acute phase of stroke recovery.

The first high quality RCT (Wertz et al., 1986) randomized patients to (1) a clinic-treatment group who received 8 to 10 hours of individualized speech therapy with a speech pathologist for 12 weeks then no treatment for the following 12 weeks, (2) a home-treatment group who received 8 to 10 hours of a speech pathology treatment program administered by a trained family member or friend for 12 weeks then no treatment for the following 12 weeks, or (3) a deferred-treatment group who received no treatment for 12 weeks then clinic-based speech therapy with a speech pathologist for the following 12 weeks. Language ability was measured at baseline and weeks 6, 12, 18 and 24 using the Porch Index of Communicative Ability (PICA), Communicative Abilities in Daily Living (CADL), Reading Comprehension Battery for Aphasia (RCBA), Token Test, and Colored Progressive Matrices (CPM). There was a significant between-group difference in PICA overall percentile score in favour of the clinic group compared to the deferred group at 12 weeks. However, there was no significant difference between the clinic group and the home group, or the home group and the deferred group at this time point. Comparison of PICA scores from week 12 to week 24 indicated no significant differences between any groups.

The second high quality RCT (Hartman & Landau, 1987) randomized patients to receive either conventional speech therapy (task-oriented aphasia therapy) or counseling (non-directive counseling and conversation). Language ability was measured monthly for the 7 months of therapy and a further 3 months post-treatment using the PICA. No significant between-group differences were seen at any time point.

The fair quality RCT (Meikle et al., 1979) randomized patients to receive either conventional speech language therapy (SLT) or therapy from a non-professional volunteer. Language ability was measured using the PICA. At post-treatment there were no significant differences between the two groups.

Conclusion: There is strong evidence (level 1a) from 2 high quality RCTs and 1 fair quality RCT that communication partners are not more effective than conventional SLT in the treatment of aphasia during the acute phase of stroke recovery.
Note: A Cochrane review (Kelly et al., 2010) concluded that SLT administered by a trained and supervised volunteer is as effective as conventional SLT. See the section: Time since stroke not specified to one period > Communication partners for more information.

Acute phase - Speech and language therapy (SLT)

AphasiaConflicting4

Two high quality RCTs (Laska et al., 2011; Wertz et al., 1986) have investigated the effectiveness of speech language therapy (SLT) in the treatment of aphasia during the acute phase of stroke recovery.

The first high quality RCT (Laska et al., 2011) randomized patients to receive either speech language therapy (SLT) for weekly 45-minute sessions for 21 days, or no therapy. Language ability was measured using the Amsterdam-Nijmegan Everyday Language Test (ANELT) and the aphasia coefficient (Coeff) of a short adjusted version of the Norsk grunntest for afasi (NGA). No between-group differences were seen at either post-treatment (3 weeks) or follow-up (6 weeks).

The second high quality RCT (Wertz et al., 1986) randomized patients to (1) a clinic-treatment group who received 8 to 10 hours of individualized speech therapy with a speech pathologist for 12 weeks then no treatment for the following 12 weeks, (2) a home-treatment group who received 8 to 10 hours of a speech pathology treatment program administered by a trained family member or friend for 12 weeks then no treatment for the following 12 weeks, or (3) a deferred-treatment group who received no treatment for 12 weeks then clinic-based speech therapy with a speech pathologist for the following 12 weeks. Language and communication skills were measured by the PICA, Communicative Abilities in Daily Living (CADL), Reading Comprehension Battery for Aphasia (RCBA), Token Test, and Colored Progressive Matrices (CPM) at baseline and 6, 12, 18, and 24 weeks. There was a significant between-group difference in PICA overall percentile score in favour of the clinic group compared to the deferred group at 12 weeks. However, there was no significant difference between the clinic group and the home group, or the home group and the deferred group at this time point. Comparison of PICA scores from week 12 to week 24 indicated no significant differences between any groups.

Conclusion: There is conflicting evidence (level 4) between 2 high quality RCTs comparing SLT and no therapy in the treatment of aphasia in the acute stage of stroke recovery. The study that found positive results provided SLT more frequently and for a longer period of time than the study that found no significant difference between SLT and no therapy.
Note: A Cochrane review (Kelly et al., 2010) similarly concluded that results from RCTs tend to favour SLT intervention post-stroke, although there is no conclusive evidence regarding the effectiveness of SLT, or a specific form of SLT, in the treatment of aphasia post-stroke. Factors such as variety in the type and intensity of treatment, severity and type of aphasia, small sample sizes, and use of non-standardised outcome measures may obscure results. See the section: Time since stroke not specified to one period > Communication partners for more information.

Subacute phase

Communication groupsNot effective1b

One high quality RCT (Wertz et al., 1981) investigated the effectiveness of communication groups in the treatment of aphasia in patients with subacute stroke. This high quality RCT  randomized patients to receive group therapy or individual therapy. Language abilities were measured post-treatment using the Porch Index of Communication Abilities (PICA). There was a significant between-group difference in graphic (writing) element of aphasia, in favour of patients who received individual therapy compared to patients who received group therapy. No other significant between-group differences were found.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that group therapy is not more effective than individual therapy in improving language abilities in patients with subacute stroke and aphasia.
Note: Furthermore the high quality RCT found that individual therapy was more effective than communication group in improving patients’ graphic skills.

Intensive speech therapyNot effective1b

One high quality RCT (Bakheit et al., 2007) has investigated the effectiveness of intensive speech pathology in the treatment of aphasia during the subacute phase of stroke recovery. This high quality RCT randomized patients to receive either intensive treatment (5 hours/week for 12 weeks) or standard treatment (2 hours/week for 12 weeks). Language function was measured using the Western Aphasia Battery at 4, 8, 12 and 24 weeks. There were no significant between-group differences at any time point. However, as none of the patients assigned to the intensive therapy group received the full course of therapy, a subgroup analysis was performed comparing outcomes among patients who received 80% or more of intended therapy intensity with patients who received standard therapy. Again, there were no significant between-group differences in language function at any time point.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that intensive speech therapy is not more effective than standard therapy in improving language function in patients with stroke and aphasia.
Note: However, a Cochrane review (Kelly et al., 2010) and a  meta-analysis  (Bhogal et al., 2003) reported improved outcomes following intensive SLT compared to conventional SLT. See the section: Time since stroke not specified to one period > Intensive speech and language therapy for more information.

Repetitive transcranial magnetic stimulation (rTMS)Effective1b

One high quality RCT (Weiduschat et al., 2011) has investigated the effect of repetitive transcranial magnetic stimulation (rTMS) in the treatment of aphasia during the subacute phase of stroke recovery. This high quality RCT  randomized patients to receive inhibitory rTMS to the inferior frontal gyrus (rTMS group) or sham rTMS. Patients received 1Hz rTMS at 90% of motor threshold for 20 minutes, followed by 45 minutes of speech and language therapy, 5 days/week for 2 weeks. Language skills were measured using the Aachen Aphasia Test (AAT). There was a significant between-group difference on overall AAT scores in favour of the rTMS group compared to the sham group at post-treatment.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that rTMS is more effective than sham stimulation in improving language skills in patients with subacute stroke and aphasia.

Speech and language therapy (SLT)Not effective1b

One high quality RCT (Lincoln et al., 1984) has investigated the effectiveness of speech language therapy (SLT) in the treatment of aphasia during the subacute phase of stroke recovery. This high quality RCT randomized patients to receive speech therapy (1 hour twice-weekly for 34 weeks) or no treatment. Language was assessed at baseline, mid-treatment and post-treatment using the Porch Index of Communicative Abilities (PICA) and the Functional Communication Profile (FCP). No significant between-group differences were found at either post-intervention time point.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that SLT is not more effective than no therapy in the treatment of aphasia in the subacute stage of stroke recovery.
Note
: A Cochrane review (Kelly et al., 2010) concluded that results from RCTs tend to favour SLT intervention post-stroke, although there is no conclusive evidence regarding the effectiveness of SLT, or a specific form of SLT, in the treatment of aphasia post-stroke. Factors such as variety in the type and intensity of SLT, severity and type of aphasia, small sample sizes, and use of non-standardised outcome measures may obscure results. See the section: Time since stroke not specified to one period on Communication partners for more information.

Transcranial Direct Current Stimulation (tDCS)Effective1b

One high quality RCT (You et al., 2011) has investigated the effectiveness of transcranial direct current stimulation (tDCS) in the treatment of aphasia during the subacute phase of stroke recovery. This high quality RCT randomized patients to receive cathodal transcranial direct current stimulation (tDCS) to the right superior temporal gyrus, anodal tDCS to the left superior temporal gyrus, or sham tDCS. tDCS was applied at 2-mA during ten 30-minute sessions (5 days a week for 2 weeks). All participants also received conventional speech-language pathology. Language ability was measured at baseline and post-treatment (2 weeks) using the Korean – Western Aphasia Battery (K-WAB) auditory verbal comprehension, spontaneous speech, repetition and naming subtests and aphasia quotient. A significant between-group difference in auditory verbal comprehension was seen at post-treatment in favour of the cathodal tDCS group compared to the anodal tDCS group and the sham tDCS group. No other significant between-group differences were found.

Conclusion: There is moderate evidence (level 1b) from one high quality RCT that cathodal tDCS is more effective than anodal tDCS and sham stimulation in improving auditory verbal comprehension, but not other language skills, in patients with subacute stroke and aphasia.

Chronic phase

Animal assisted therapyInsufficient evidence5

Two case studies (LaFrance et al., 2007; Macauley et al., 2006) examined the effectiveness of animal assisted therapy in the treatment of aphasia in the chronic stage of stroke recovery.

In the first single-subject case study (LaFrance et al., 2007), a patient demonstrated more social-verbal and social non-verbal communicative behaviors when accompanied to the ward by a therapy dog and its handler compared to when the patient was accompanied by a porter alone after 11 weeks of treatment.

In the second case study (Macauley et al., 2006) of three patients, there was no significant difference between patients when they received conventional speech therapy compared to when they received animal-assisted speech therapy, as measured by the Western Aphasia Battery (WAB) after 12 weeks of treatment.

Conclusion: There is insufficient evidence (level 5) regarding the effectiveness of animal-assisted therapy for the treatment of aphasia in patients with  chronic stroke, however 1 of 2 case studies found some improvements following animal-assisted therapy.

Communication groupsEffective1b

One high quality RCT (Elman & Burnstein-Ellis, 1999) investigated the effectiveness of communication groups in the treatment of aphasia in the chronic phase of stroke recovery. This high quality RCT  found a significant improvement in language abilities for patients with chronic stroke who received group communication treatment compared to those that received no treatment, as measured by the Western Aphasia Battery, Aphasia Quotient (WAB AQ) and the Communicative Abilities in Daily Living Test (CADL), 4 months post treatment.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that communication groups are more effective than no therapy in improving language abilities in patients with chronic stroke and aphasia.

Communication partners vs non-trained in strokeConflicting4

Two high quality RCTs (Kagan et al., 2001; Worrall et al., 2000) and one pre-post design study (Lyon et al., 1997) have investigated the effect of communication partners on communication skills among volunteers or caregivers of patients with aphasia and chronic stroke.

The first high quality RCT (Kagan et al., 2001) randomized volunteers at an aphasia centre to a training group that received the Supported Conversation for Adults with Aphasia (SCA) workshop or a control group that received no training. Patients randomized to volunteers. Patient’s communication skills were measured using the Measure of Participation in Conversation for Adults with Aphasia – interaction and transaction skills. At post-treatment significant between-group differences in patients’ interaction and transaction skills were found in favour of the SCA group compared to the control group.

The second high quality RCT (Worrall et al., 2000) found no significant difference between patients with chronic stroke who participated in the “Speaking Out” Program with volunteers and those patients who participated in recreational activities, as measured with the Western Aphasia Battery (WAB), the American Speech-Language Hearing Association Functional Assessment of Communication Skills (AHSA FACS), the Communicative Effectiveness Index (CETI), and the Functional Communication Therapy Planner (FCTP) after 40 weeks of participation in the study.

The pre-post design study (Lyon et al., 1997) assigned triads (patients with chronic stroke, carer, communication partner) to participate in a communication partner training program to enhance communication and wellbeing among patients and carers. One third of participants were randomly assigned to a deferred treatment group, although comparisons between groups were not made. Patients’ language and communication was measured using the Boston Diagnostic Aphasia Examination (BDAE), the Communication Abilities in Daily Living (CADL). Patients, caregivers and communication partners evaluated change in the patient’s communication using the non-standardized Communication Readiness and Use Index (CRUI). There were no significant differences from pre- to post-treatment on standardized measures of patient communication (BDAE, CADL) in either intervention or deferred treatment groups. A significant improvement from pre- to post-treatment on the non-standardized measure of communication (CRUI), was reported by patients, carers and communication partners. The authors of the study note that the deferred treatment group also demonstrated mild to moderate gains on these measures before commencing treatment.

Conclusion: There is conflicting evidence (level 4) between 2 high quality RCTs regarding the effectiveness of communication partners compared to non-trained communication partners in the treatment of aphasia among patients with chronic stroke. One high quality RCT found that trained communication partners were more effective than non-trained communication partners, whereas the second high quality RCT found that trained communication partners were not more effective than recreational activities with a volunteer. Further, a pre-post design study found a significant improvement on a non-standardized measure of communication, but not on standardized measures of language or communication.

Communication partners training (impact on partners)Effective1b

The high quality RCT (Kagan et al., 2001) have investigated the effect of communication partners training on communication skills among partners of patients with aphasia and chronic stroke. This high quality RCT randomized volunteers at an aphasia centre to a training group that received the Supported Conversation for Adults with Aphasia (SCA) workshop or a control group that received no training. Patients were randomized to volunteers. Volunteers’ skills were measured using Measure of Supported Conversation for Adults with Aphasia – ability to acknowledge and ability to reveal communication competence. At post-treatment a significant between-group difference in volunteers’ ability to acknowledge and reveal communication competence of patients with aphasia was found in favour of the SCA group compared to the control group.

Conclusion: There is moderate evidence  (level 1b) from 1 high quality RCT that communication partner training is more effective than no communication training in improving communication skills among people working with patients with chronic stroke and aphasia.

Computer-based interventionNot effective1b

One high quality RCT (Doesborgh et al., 2004b), 1 fair quality RCT (Katz & Wertz, 1997) and 2 case studies (Mortley et al., 2004Aftonomos et al., 1997) investigated the effect of computer-based therapy in the treatment of aphasia during the chronic phase of stroke recovery.

The high quality RCT (Doesborgh et al., 2004b) found no significant difference between patients who received therapy with Multicue (a computer program) compared to those who received no therapy on naming and verbal communication measured with the Boston Naming Test (BNT) or the Amsterdam Nijmegen Everyday Language Test-scale (ANELT) after 10-11 hours of treatment.

The fair quality RCT (Katz & Wertz, 1997) found a significant difference between patients who received computer reading treatment compared to those who received computer stimulation and no treatment on the Porch Index of Communicative Abilities (PICA) and the Western Aphasia Battery (WAB) tests after 26 weeks of treatment.

The first case study (Mortley et al., 2004) found significant improvement on the 162 objects naming test among patients after 6 months of at-home computerized treatment. These results were maintained 6 weeks after therapy had ended.

The second case study (Aftonomos et al., 1997) found significant improvement on the Porch Index of Communicative Abilities (PICA), the Boston Naming Test (BNT), the Western Aphasia Battery (WAB), and the Boston Diagnostic Aphasia Examination (BDAE) among patients who received 40 hours of therapy with the computerized Lingraphica system.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that computer-based interventions are not more effective than no therapy for improving language abilities in patients with chronic stroke and aphasia.
Note:
However, one fair quality RCT and two case studies found that computer-based interventions are effective for improving language abilities in patients with chronic stroke and aphasia.

Constraint-induced aphasia therapy (CIAT)Effective1b

Two high quality RCTs (Pulvermüller et al., 2001; Meinzer et al., 2007), and 2 fair quality RCTs (Maher et al., 2005; Meinzer et al., 2005) investigated the effect of constraint-induced therapy in the treatment of aphasia during the chronic phase of stroke recovery.

The first high quality RCT (Pulvermüller et al., 2001) found significant improvement in patients who received constraint-induced aphasia therapy (CIAT) compared to those who received conventional therapy as measured by the Aachen Aphasia Battery (AAT) and the Community Activity Log (CAL) after 10 days of treatment.

The second high quality RCT (Meinzer et al., 2007) randomized patients to a constraint-induced aphasia therapy (CIAT) group facilitated by an experienced therapist or a CIAT group facilitated by a trained relative. Patients’ aphasia was measured at baseline and post-treatment using the Aachen Aphasia Test. Within-group improvements were observed and there were no significant between-group differences at post-treatment.
Note: As both interventions include CIAT, this study is not considered to determine the level of evidence.

The first fair quality RCT (Maher et al., 2005) found no significant difference between patients treated with CIAT compared to those that had the Promoting Aphasic Communicative Effectiveness (PACE) intervention, as assessed on the Western Aphasia Battery (WAB), the Boston Naming Test, and the Action naming test, 2 weeks post-treatment.

The second fair quality RCT (Meinzer et al., 2005) found no significant difference between patients who received CIAT compared to CIAT PLUS (CIT with additional training in everyday language with the assistance of family members), measured by the AAT, CAL and the Communicative Effectiveness Index (CETI), after 2 weeks of treatment.
Note: As both interventions include CIAT, this study is not considered to determine the level of evidence.

Conclusion: There is moderate (level 1b) evidence from 1 high quality RCT that constraint-induced aphasia therapy (CIAT) is more effective than conventional SLT for promoting recovery from aphasia among patients with chronic stroke. However, 1 fair quality RCT found no difference between CIAT and an SLT program.
Note:
One high quality RCT found no difference between CIAT offered by a clinician as compared to CIAT offered by a trained family member and a fair quality RCT  also found no difference between CIAT and CIAT with additional training of a family member.

Intensive speech therapyEffective2b

One quasi-experimental design study (Brindley et al., 1989) has investigated the impact of intensive speech pathology in the treatment of aphasia during the chronic phase of stroke recovery. This quasi-experimental design study assigned patients to receive 3 months of intensive speech-language pathology (SLP) preceded and followed by 3 months of non-intensive SLP. Intensive SLP was provided for 5 hours a day, 5 days a week; non-intensive (conventional) SLP was provided for 1-2 hours a week. Language skills were measured using the Functional Communication Profile (FCP) movement, speech, understanding, reading, other and overall scores, and a 200-word sample of conversation that was analyzed using the Language Assessment, Remediation and Screening Procedure (LARSP). Relatives completed a questionnaire regarding patients’ functional language skills before and after the intensive language phase. Significant differences in FCP speech and overall improvement scores were seen when comparing the first phase of non-intensive treatment and intensive treatment. Significant differences in FCP movement, speech and overall scores were seen when comparing intensive treatment and the second phase of non-intensive treatment. There were no significant differences between non-intensive and intensive treatments in LARSP word sample analyses or relatives’ evaluation of patients’ functional language skills.

Conclusion: There is limited evidence ( level 2b) from one quasi-experimental design study that intensive therapy is more effective than conventional therapy in improving language skills in patients with chronic stroke and aphasia. However, no significant differences in language word sample or relatives’ evaluation of functional language skills were seen between intensive and non-intensive interventions.
Note: A Cochrane review (Kelly et al., 2010) and a  meta-analysis  (Bhogal et al., 2003) reported improved outcomes following intensive SLT compared to conventional SLT. See the section: Time since stroke not specified to one period > Intensive speech and language therapy for more information.

Repetitive transcranial magnetic stimulation (rTMS)Effective1b

One high quality RCT (Barwood et al., 2011a and Barwood et al., 2011b – follow up study) and three non-experimental studies (Szaflarski et al., 2011Naeser et al., 2005Martin et al., 2004) have investigated the effect of repetitive transcranial magnetic stimulation (rTMS) to Broca’s Area in the treatment of aphasia during the chronic phase of stroke recovery.

The first high quality RCT (Barwood et al., 2011a) randomized patients to receive either rTMS (1Hz for 20 mins) or sham rTMS. Behavioural language function was measured using the Boston Naming Test (BNT) and Boston Diagnostic Aphasia Examination (BDAE), and lexical semantic function was measured using the Snodgrass and Vanderwart picture-naming inventory. At 3 weeks a significant between-group difference was seen in favour of the rTMS group compared to the sham treatment group on the BNT, BDAE subtests (naming actions, naming tools and instruments, repetition of sentences, picture description complexity index, picture description longest words per phrase, commands and overall score), and the Snodgrass and Vanderwart picture-naming inventory subtests (latency, accuracy).

In a follow-up study (Barwood et al., 2011b), significant between-group differences were seen on BDAE subtests (naming actions, naming tools and instruments, picture description complexity index and overall score), and the Snodgrass and Vanderwart picture-naming inventory – accuracy subtest. Interestingly, the treatment group scored significantly lower than the sham group on the Snodgrass and Vanderwart picture-naming inventory – latency subtest at 2 months. No significant differences were reported for other outcomes.

The first pre-post design study (Szaflarski et al., 2011) applied rTMS to patients with moderate to severe aphasia. Patients received rTMS to the left-hemisphere Broca’s area for 200 seconds over 10 days. Measures were taken at baseline and post-treatment and outcomes were measured using the Boston Naming Test (BNT), Controlled Oral Word Association Test (COWAT), Semantic Fluency Test (SFT), Boston Diagnostic Aphasia Examination (BDAE) Complex Ideation Subtest, Peabody Vocabulary Test IV (PPVT-IV), and a mini Communicative Abilities Log (CAL). A significant improvement on the SFT was found post-treatment.

The second pre-post study (Naeser et al., 2005) studied the effect of low frequency rTMS treatment on patients with chronic stroke and chronic aphasia. The study found some short-term improvements in naming (as measured by the Snodgrass and Vanderwart) as well as some longer lasting improvement in naming (as measured by the Boston Naming test and the Boston Diagnostic Aphasia Exam) following rTMS at 1Hz and 90% of resting motor threshold to the anterior portion of the right Broca’s area for 5 x 20 minutes per week for 2 weeks.

The third pre-post design study (Martin et al., 2004) applied rTMS to patients with chronic stroke and aphasia (5 to 11 years post left hemisphere stroke). Patients received rTMS to the right-hemisphere Broca’s Area 45 at 1Hz for 20 minutes, 5 days/week for 2 weeks. Measures were taken at baseline, 2 weeks (post-treatment) and 2 months (follow-up) and outcomes were measured using the first 20 items of the Boston Naming Test (BNT) and naming subtests of the Boston Diagnostic Aphasia Exam (BDAE). Patients demonstrated significant improvement on the BNT and naming subtests of the BDAE at 2 months (follow-up).

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCTs that repetitive transcranial magnetic stimulation (rTMS) is more effective than sham stimulation in improving language skills in patients with chronic stroke and aphasia. Further, three non-experimental studies found improved language skills following rTMS.

Speech and language therapy (SLT)Insufficient evidence5

One case study (Raymer & Kohen, 2006) has investigated the effectiveness of speech and language therapy (SLT) in the treatment of aphasia during the chronic phase of stroke recovery. In the case study, two patients received twice-weekly speech therapy for sentence-based word retrieval training. Treatment ceased when patients achieved 90% accuracy in three sessions or a maximum of 10 sessions. One patient demonstrated improved performance of noun retrieval, naming untrained words and production of spontaneous sentences. Both patients demonstrated improved performance on the Action Naming Test (ANT) and the Reading Comprehension Battery for Aphasia (RCBA).

Conclusion: There is insufficient evidence (level 5) regarding the effectiveness of speech and language therapy (SLT) for improving language skills of patients with chronic stroke and aphasia. However, 1 case study reported improved language skills following speech and language therapy.
Note: A Cochrane review (Kelly et al., 2010) similarly concluded that results from RCTs tend to favour SLT intervention post-stroke, although there is no conclusive evidence regarding the effectiveness of SLT, or a specific form of SLT, in the treatment of aphasia post-stroke. Factors such as variety in the type and intensity of treatment, severity and type of aphasia, small sample sizes, and use of non-standardised outcome measures may obscure results. See the section: Time since stroke not specified to one period > Communication partners for more information.

Transcranial Direct Current Stimulation (tDCS)Effective1a

Three high quality RCTs (Flöel et al., 2011; Fridriksson et al., 2011; Baker et al., 2010) and one quasi-experimental study (Monti et al., 2008) have investigated the effectiveness of transcranial direct current stimulation (tDCS) in the treatment of aphasia during the chronic phase of stroke recovery.

The first high quality RCT (Flöel et al., 2011) conducted a crossover comparison of anomia training with anodal tDCS (1mA for 20 mins), cathodal tDCS (1mA for 20 mins) and sham tDCS (1mA for 30 secs) in patients with chronic stroke and aphasia. Language ability was measured using the Aachen Aphasia Test – naming subtest at baseline, immediately following completion of each phase of tDCS (post-treatment) and 2 weeks following completion of each phase of tDCS (follow-up). A significant difference in naming accuracy was seen in favour of anodal tDCS compared to sham tDCS at post-treatment and follow-up, and in favour of C-tDCS compared to S-tDCS at post-treatment only. A significant difference was also seen in favour of A-tDCS compared to C-tDCS at follow-up.

The second high quality RCT (Fridriksson et al., 2011) conducted a crossover comparison of anodal transcranial direct current stimulation (A-tDCS) and sham transcranial direct current stimulation (S-tDCS) with computerized anomia training in patients with chronic stroke and aphasia. Language ability was measured by reduced reaction time during correct naming of trained nouns. A greater reduction in reaction time was seen following A-tDCS compared to S-tDCS at post-treatment (5 days) and at follow-up (4 weeks).

The third high quality RCT (Baker et al., 2010) conducted a crossover comparison of anodal transcranial direct current stimulation (A-tDCS) and sham transcranial direct current stimulation (S-tDCS) with computerized anomia training in patients with chronic stroke and aphasia. Language ability was measured by naming accuracy of trained and untrained nouns. A significant improvement in naming accuracy of trained nouns from baseline was seen in favour of A-tDCS compared to S-tDCS at post-treatment (5 days) and at follow-up (12 days). There was no significant difference between groups in naming accuracy of untrained nouns.

The quasi-experimental study (Monti et al., 2008) conducted a crossover comparison of anodal tDCS (A-tDCS), cathodal tDCS (C-tDCS) and sham tDCS (S-tDCS) applied to Broca’s Area and occipital areas in patients with chronic non-fluent aphasia. Language ability was measured by picture naming accuracy and reaction time. A significant difference in picture naming reaction time was seen in favour of C-tDCS compared to S-tDCS immediately following tDCS to Broca’s Area. No significant changes in naming reaction time or accuracy were noted following AtDCS and StDCS to Broca’s Area, nor following tDCS to or occipital areas.

Conclusion: There is strong evidence (level 1a) from 3 high quality RCTs that anodal tDCS is more effective than sham tDCS in improving naming reaction time or/and naming accuracy of trained nouns (but not untrained nouns) in patients with chronic stroke and aphasia. Furthermore, one quasi-experimental study found that cathodal tDCS to Broca’s Area is more effective than sham tDCS in improving naming skills (reaction time, accuracy) of patients. However, this  quasi-experimental study  found no difference between A-tDCS and sham tDCS to Broca’s Area.
Note: One study (Baker et al., 2010) suggests that increasing and decreasing cortical excitability may not have mutually exclusive effects and, therefore, both anodal and cathodal tDCS may be of benefit.

Time since stroke not specified to one period

Cathodal Transcranial Direct Current Stimulation (tDCS)Not effective2b

One quasi-experimental study (Kang et al., 2011) has investigated the effectiveness of transcranial direct current stimulation in the treatment of aphasia following stroke. This quasi-experimental study conducted a crossover comparison of cathodal tDCS (2mA for 20 mins) and sham stimulation (2mA for 1 min) to the healthy right Broca’s homologue area of patients. Patients also received daily word retrieval training. Language ability was measured using a Korean version of the Boston Naming Test (BNT) – naming accuracy and response time, as well as non-standardized measures of % of cued responses and speed of response. No between-group differences were seen on any outcome at post-treatment, although as a significant trend towards increased naming accuracy (BNT) was seen in favour of the cathodal tDCS group compared to the sham group.

Conclusion: There is limited evidence (level 2b) from 1 quasi-experimental study that cathodal tDCS to Broca’s Area is not more effective than sham tDCS in improving language skills in patients with aphasia following stroke.
Note: However, a high quality RCT that examined the use of tDCS with patients with chronic stroke alone found that cathodal tDCS to Broca’s Area was more effective than sham tDCS in improving patients’ naming skills – see the section In Chronic > Transcranial Direct Current Stimulation for study results.

Cognitive-linguistic therapy-functional communicationNot effective1b

One high quality RCT (Doesborgh et al., 2004a) has investigated the effect of cognitive-linguistic treatment in the recovery of functional communication skills among patients with aphasia following stroke. This high quality RCT  randomised patients with subacute/chronic stroke to receive either semantic treatment or phonological treatment. Functional verbal communication was measured by the Amsterdam-Nijmegan Everyday Language Test scale A: Understandability (ANELT-A). Both groups demonstrated significant improvement in functional verbal communication (ANELT-A scores), although there was no significant difference between groups for ANELT-A final score or mean improvement.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT indicating no significant difference between semantic treatment and phonological treatment in improving functional communication skills in patients with post-stroke aphasia.

Cognitive-linguistic therapy-phonological skillsEffective1b

One high quality RCT (Doesborgh et al., 2004a) has investigated the effect of cognitive-linguistic treatment in the recovery of phonological skills among patients with aphasia following stroke. This high quality RCT  randomised patients with subacute/chronic stroke to receive either semantic treatment or phonological treatment. Phonological ability was measured by the Psycholinguistic Assessment of Language Processing in Aphasia (PALPA) nonword repetition and auditory lexical decision subtests. At post-treatment there was a significant between-group difference in auditory lexical decision skills, in favour of the phonological group compared to the semantic group.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that phonological treatment is more effective than semantic treatment in improving lexical decision skills but not other phonological skills of patients with post-stroke aphasia.

Cognitive-linguistic therapy-semantic skillsNot effective1b

One high quality RCT (Doesborgh et al., 2004a) has investigated the effect of cognitive-linguistic treatment in the recovery of semantic skills among patients with aphasia following stroke. This high quality RCT  randomised patients with subacute/chronic stroke to receive either semantic treatment or phonological treatment. Semantic ability was measured by the Semantic Association Test (SAT) and the Psycholinguistic Assessment of Language Processing in Aphasia (PALPA) – synonym judgment subtest. No between-group differences in semantic skills were found at post-treatment.

Conclusion: There is moderate evidence (level 1b) from 1 high quality RCT that indicating no significant difference between semantic treatment and phonological treatment in improving semantic skills in patients with post-stroke aphasia.

Communication partners (impact on partners)Effective1b

One high quality RCT (Legg et al., 2005) and one systematic review (Simmons-Mackie et al., 2010) have investigated the effect of communication partners on communication skills among volunteers or caregivers of patients with aphasia following stroke.

The high quality RCT (Legg et al., 2005) randomized medical students to an experimental group that received training in supported communication techniques for patients with aphasia, or a control group that received education on aphasia alone. Students’ interviewing skills were assessed using a modified version of the Calgary Cambridge Observation Guide (mCCOG), a modified version of the Supported Conversation Analysis (mSCA), and visual analogue scales of students’ perception of the interview, ability to obtain relevant information and quality of the interaction. Patients’ perception of the students’ performance were measured using visual analogue scales of their overall perception of the interview, the ability to provide relevant information, and satisfaction with the encounter. At post-treatment, significant between-group differences were seen in favour of the treatment group compared to the control group on mCCOG subtests (establishing rapport, exploration of problems, providing structure to the consultation, developing rapport), mSCA subtests (acknowledging competence, revealing competence, ensures patient understanding, verifies information), students’ overall perception of the interview, and students’ perception of the quality of their interaction with the patient. However, there were no significant differences between groups on patients’ ratings of students’ performance.

The systematic review (Simmons-Mackie et al., 2010) reviewed 31 studies (the 2 high quality RCTs have been reviewed on StrokEngine) from 1975 to April 2008 regarding communication partner training with adults with aphasia following stroke. Communication partners included caregivers, relatives, acquaintances, volunteers, students and others. Approaches included communication skills training, education or counseling programs through group training, dyad training or training with the conversation partner alone. There was substantial variation in the duration and intensity of interventions. Outcome measures included activity/participation, psychosocial well-being, quality of life and knowledge of aphasia among communication partners. Review of the literature revealed that communication partner training is effective in improving communication activities/participation of the communication partner. There was insufficient evidence regarding the effect of training on psychosocial adjustment and quality of life among communication partners.

Conclusion: There is moderate evidence  (level 1b) from 1 high quality RCT that communication training is more effective than no communication training in improving communication skills among people working with patients with aphasia after a stroke. Further, a systematic review concluded that communication partner training is effective in improving communication among communication partners.

Communication partners (impact on patients)Not effective2b

One Cochrane review (Kelly et al., 2010), 1 systematic review (Simmons-Mackie et al., 2010) and 2 fair quality RCTs (Shewan & Kertesz, 1984David et al., 1982) have examined the effectiveness of communication partners in the treatment of aphasia following stroke.

The Cochrane review (Kelly et al., 2010) provided an update to a previous review of speech and language therapy (SLT) interventions for the treatment of aphasia in adults with stroke, which included a comparison of SLT vs. social support and communication stimulation. The review concluded that SLT administered by a trained, supervised volunteer was as effective as SLT administered by a professional Speech-Language Pathologist.

The systematic review (Simmons-Mackie et al., 2010) reviewed 31 studies (the 2 high quality RCTs have been reviewed on StrokEngine) from 1975 to April 2008 regarding communication partner training with adults with aphasia following stroke. Communication partners included caregivers, relatives, acquaintances, volunteers, students and others. Approaches included communication skills training, education or counseling programs through group training, dyad training or training with the conversation partner alone. There was substantial variation in the duration and intensity of interventions. Outcome measures included the patients’ language function/impairment, activity/participation, psychosocial well-being, and knowledge of aphasia. The conclusion indicated that communication partner training may be effective in improving communication activities/participation in patients with chronic aphasia. There was insufficient evidence regarding the effect of communication partner training on language impairment and psychosocial well-being among patients with chronic stroke, or outcomes for patients with acute/subacute stroke.

The first fair quality RCT (Shewan & Kertesz, 1984) randomized patients with acute or chronic stroke and aphasia to receive (1) language-oriented therapy, (2) stimulation-facilitation therapy, (3) stimulation therapy provided by nurses (UNST) or (4) a no-treatment control group. Language ability was measured using the Western Aphasia Battery Language Quotient (WAB-LQ) and Cortical Quotient (WAB-CQ), and the Auditory Comprehension Test for Sentences (ACTS) at baseline and 3, 6 and 12 months. At 12 months a significant between-group difference was seen on WAB-LQ and WAB-CQ scores, in favour of the stimulation-facilitation therapy group compared to the control group. A significant between-group difference was seen on the WAB-LQ in favour of the language-oriented therapy group compared to the control group. No other significant between-group differences were reported.

The second fair quality RCT (David et al., 1982) randomized patients with acute or chronic stroke and aphasia to receive conventional speech therapy for 30 hours over 15-20 weeks, or communication support from untrained volunteers for 2 hours. Language ability was measured using the Functional Communication Profile (FCP) at baseline, weeks 2, 4, 8 and 12, and post-treatment. No significant between-group differences were found at any time point.

Conclusion: There is limited evidence (level 2a) from 2 fair quality RCTs that communication support with trained or untrained communication partners is not more effective than conventional speech therapy or no therapy in the treatment of aphasia following stroke. Similarly, a Cochrane review concluded that SLT administered by a trained and supervised volunteer is as effective as conventional SLT, and a systematic review concluded that there is insufficient evidence regarding the effectiveness of communication partner training in the treatment of aphasia following stroke.

Intensive speech and language therapyNot effective1b

One Cochrane review (Kelly et al., 2010), 1 meta-analysis (Bhogal et al., 2003), and 1 high quality RCT (Denes et al., 1996) have investigated the effectiveness of intensive speech pathology in the treatment of aphasia following stroke.

The Cochrane review (Kelly et al., 2010) provided an updated review of speech and language therapy (SLT) interventions for the treatment of aphasia in adults with stroke. The review included comparison of intensive SLT vs. conventional SLT and reported that results trended towards intensive SLT compared to conventional SLT. A significant between-group difference was seen in expressive language only, in one study (see Denes et al., 1996 below). The Cochrane review noted that more participants withdrew from intensive SLT interventions.

The meta-analysis (Bhogal et al., 2003) examined the relationship between intensity of speech therapy for aphasia and aphasia recovery. The meta-analysis reviewed 10 controlled trials (9 studies are included and reviewed on StrokEngine). Studies that found a significant benefit from therapy provided 8.8 hours/week for 11.2 weeks (average 98.4 hours), in contrast to studies that found no benefit, which provided 2 hours for 22.9 weeks (average 43.6 hours). The total length of therapy was inversely related with hours of therapy/week and total hours of therapy provided. A significant inverse correlation was found between length of therapy and patients’ change scores on the Porch Index of Communicative Ability (PICA). A significant correlation was seen between number of hours of therapy and patients’ improvement on the PICA and Token Test. That is, intense therapy given over a short amount of time can result in greater improvements in language abilities.

The high quality RCT (Denes et al., 1996) randomised patients with chronic stroke and global aphasia to receive either intensive treatment (average of 130 therapy sessions over 6 months) or standard treatment (average of 60 therapy sessions over 6 months). Language impairment was measured using the Aachen Aphasia Test (AAT) subtests (token test, repetition, written language, comprehension, naming) and overall profile level. At 6 months (post-treatment) there was a significant difference in the AAT written language subtest only, in favour of the intensive treatment group compared to the standard treatment group.

Conclusion: There is strong evidence (level 1a) from one Cochrane review and one meta-analysis that intensive speech language therapy is more effective than standard therapy in improving language function in patients with aphasia following stroke. One high quality RCT found a significant improvement in written language skills, but not other speech or language skills following intensive speech therapy compared to standard therapy.

Speech and language therapy (SLT)Not effective2a

A Cochrane review (Kelly et al., 2010), 5 fair quality RCTs (Smania et al., 2006Smania et al., 2000Prins et al., 1989Shewan & Kertesz, 1984Lincoln et al., 1982) and 1 quasi-experimental designed study (Poeck et al., 1989) investigated the effectiveness of speech therapy in the treatment of aphasia following stroke.

The Cochrane review (Kelly et al., 2010) provided an update to a previous review of speech and language therapy (SLT) interventions for the treatment of aphasia in adults with stroke. This review investigated SLT vs. no SLT, and one SLT intervention vs. another SLT intervention. While results indicated that SLT is effective in the treatment of aphasia post-stroke, the review was not able to provide conclusive evidence of the most effective intervention.

The first fair quality RCT (Smania et al., 2006) randomized patients with stroke (time since strokenot specified), limb apraxia and aphasia to receive speech-language therapy (SLT) for aphasia or no SLT. The ‘no SLT’ group received limb apraxia therapy for the same frequency and duration as the SLT group. Measures were taken at baseline and post-treatment and included tests of verbal comprehension (Token Test), general intelligence (Raven’s Progressive Matrices), oral apraxia, constructional apraxia, ideational apraxia, ideomotor apraxia, gesture comprehension and a questionnaire of activities of daily living completed by the patient’s caregiver. At post-treatment there were significant between-group differences in non-language outcomes of ideomotor apraxia, gesture comprehension and ADLs, in favour of the ‘no SLT’ group compared to the SLT group. No other significant differences between groups were seen at post-treatment or follow-up, although the SLT group demonstrated a significant improvement in intelligence and verbal comprehension tests post-treatment.

The second fair quality RCT (Smania et al., 2000) randomized patients with subacute or chronic stroke, limb apraxia and aphasia to receive SLT for aphasia or no SLT. The ‘no SLT’ group received a behavioural training program for limb apraxia for the same frequency and duration as the SLT group. Measures were taken at baseline and post-treatment using neuropsychological tests for assessment of aphasia, verbal comprehension (Token Test), general intelligence (Raven’s Progressive Matrices), oral apraxia, construction apraxia and limb praxic function (ideational apraxia, ideomotor apraxia, gesture recognition). The SLT group demonstrated no significant improvement on any measure, whereas the ‘no SLT’ group demonstrated a significant improvement in limb praxic function.
Note: Post-treatment between-group differences were not reported, so this study is not included in determining level of evidence, below.

The third fair quality RCT (Prins et al., 1989) randomized patients with subacute or chronic stroke and aphasia to receive (1) Systematic Therapy for Auditory Comprehension Disorders in Aphasic Patients (STACDAP) that comprised a subset of nonverbal, phonology, lexical-semantics and morphosyntax activities, (2) conventional stimulation therapy or (3) no-therapy. Language was measured using the Token Test and the STACDAP tests of phonology, lexicon, morphosyntax, word discrimination, body-part identification, miscellaneous commands, reading comprehension, naming, sentence construction and spontaneous speech. A significant between-group difference was seen on the sentence construction task, in favour of the STACDAP group and the no-therapy group compared to the conventional therapy group. No other significant differences were seen between groups.

The fourth fair quality RCT (Shewan & Kertesz, 1984) randomized patients with acute or chronic stroke and aphasia to receive (1) language-oriented therapy, (2) stimulation-facilitation therapy, (3) stimulation therapy provided by nurses (UNST) or (4) a no-treatment control group. Language ability was measured using the Western Aphasia Battery Language Quotient (WAB-LQ) and Cortical Quotient (WAB-CQ), and the Auditory Comprehension Test for Sentences (ACTS) at baseline and 3, 6 and 12 months. At 12 months a significant between-group difference was seen on WAB-LQ and WAB-CQ scores, in favour of the stimulation-facilitation therapy group compared to the control group. A significant between-group difference was seen on the WAB-LQ in favour of the language-oriented therapy group compared to the control group. No other significant between-group differences were reported.

The fifth fair quality study (Lincoln et al., 1982) randomized patients with moderate aphasia (time since stroke not specified) to 1 of 4 groups that received (i) speech therapy + non-specific treatment; (ii) non-specific treatment followed by 4 weeks of speech therapy; (iii) 4 weeks of speech therapy + operant training; or (iv) operant training + speech therapy. Speech therapy was conventional speech therapy; operant training followed a specific verbal conditioning procedure; and non-specific treatment comprised a conversation session about a series of predetermined topics with a therapist (attention placebo condition). All interventions were conducted for 4 weeks, so that each patient received 2 interventions over 8 weeks. Measures were taken at baseline and at weeks 4 and 8 using the Porch Index of Communicative Ability (PICA). There were no significant differences between groups at any time point.

The quasi-experimental design study (Poeck et al., 1989) compared results between patients with acute to chronic stroke and aphasia who received intensive language-oriented treatment or a control group who received no treatment. Patients’ language ability was measured using the Aachen Aphasia Test (AAT) token test, repetition, written language, naming and comprehension subtests. At post-treatment, there was a significant between-group difference in AAT token test and repetition scores among patients with ‘early’ stroke (1-4 months post-stroke) in favour of the treatment group compared to the control group. No other significant between-group differences were found.

Conclusion: There is limited evidence (level 2a) from 3 fair quality RCTs and 1 quasi-experimental design study that speech therapy is not more effective than control interventions (e.g. no SLT, operant training, attention placebo) in the treatment of aphasia following stroke. However, one fair quality RCT found that SLT (language-oriented therapy and stimulation-facilitation therapy) was more effective than no therapy in improving language ability among patients with post-stroke aphasia. Further, the quasi-experimental design study found better outcomes on two language subtests following speech therapy compared to no therapy among patients with acute to chronic stroke and aphasia. These 2 studies that found results in favour of SLT provided SLT for a longer duration (12–18 months) than studies that found negative results.
Note: A Cochrane review (Kelly et al., 2010) concluded that results from RCTs tend to favour SLT intervention post-stroke, although there is no conclusive evidence regarding the effectiveness of SLT, or a specific form of SLT, in the treatment of aphasia post-stroke. Factors such as variety in the type and intensity of treatment, severity and type of aphasia, small sample sizes, and use of non-standardised outcome measures may obscure results.
Note: One fair quality RCT did not report between-group differences and so is not included in determining level of evidence.


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