Translational research in aphasia: from neuroscience to neurorehabilitation.

PURPOSE: In this article, the authors encapsulate discussions of the Language Work Group that took place as part of the Workshop in Plasticity/NeuroRehabilitation Research at the University of Florida in April 2005. METHOD: In this narrative review, they define neuroplasticity and review studies that demonstrate neural changes associated with aphasia recovery and treatment. The authors then summarize basic science evidence from animals, human cognition, and computational neuroscience that is relevant to aphasia treatment research. They then turn to the aphasia treatment literature in which evidence exists to support several of the neuroscience principles. CONCLUSION: Despite the extant aphasia treatment literature, many questions remain regarding how neuroscience principles can be manipulated to maximize aphasia recovery and treatment. They propose a framework, incorporating some of these principles, that may serve as a potential roadmap for future investigations of aphasia treatment and recovery. In addition to translational investigations from basic to clinical science, the authors propose several areas in which translation can occur from clinical to basic science to contribute to the fundamental knowledge base of neurorehabilitation. This article is intended to reinvigorate interest in delineating the factors influencing successful recovery from aphasia through basic, translational, and clinical research.     

A systematic review of the effectiveness and cost‐effectiveness of bilateral multichannel cochlear implants in adults with severe‐to‐profound hearing loss

Clin. Otolaryngol. 2012, 37 , 342–354 Background: In the UK, approximately 10 000 people have cochlear implants, more than 99% with a unilateral implant. Evidence shows that adults implanted bilaterally may benefit from binaural advantages; however, systematic review evidence is limited. Objectives of the review: To conduct a systematic review to discover the evidence for effectiveness and cost‐effectiveness of using bilateral cochlear implants in adults with severe‐to‐profound hearing loss by comparing their effectiveness with unilateral cochlear implantation or unilateral cochlear implantation and acoustic hearing aid in the contralateral ear. Type of review: Systematic review. Search strategy: This examined 16 electronic databases, plus bibliographies and references for published and unpublished studies. Evaluation method: Abstracts were independently assessed against inclusion criteria by two researchers, and disagreements were resolved. Selected papers were then retrieved and further independently assessed in a similar way. Included studies had their data extracted by one reviewer and checked by another. Results: Searches yielded 2892 abstracts producing 19 includable studies. Heterogeneity between studies precluded meta‐analysis. However, all studies reported that bilateral cochlear implants improved hearing and speech perception: one randomised controlled trial found a significant binaural benefit over the first ear alone for speech and noise from the front (12.6 ± 5.4%, P < 0.001) and when noise was ipsilateral to the first ear (21 ± 6%, P < 0.001); and another found a significant benefit for spatial hearing at 3 and 9 months post‐implantation compared with pre‐implantation [mean difference (sd ) scores: 3 months = 1.46 (0.83–2.09), P < 0.01].Quality of life results varied, showing bilateral implantation may improve quality of life in the absence of worsening tinnitus. Limited cost‐effectiveness evidence showed that bilateral implantation is probably only cost‐effective at a willingness‐to‐pay threshold above £62 000 per quality adjusted life year. Conclusions: Despite inconsistency in the quality of available evidence, the robustness of systematic review methods gives weight to the positive findings of included studies demonstrating that bilateral implantation is clinically effective in adults but unlikely to be cost‐effective.     

Effectiveness of multi‐channel unilateral cochlear implants for profoundly deaf children: a systematic review

Background: Annually an estimated 223 children in the UK are born with or acquire permanent profound bilateral deafness (PBHL ≥ 95 dB). These children may gain little or no benefit from acoustic hearing aids. However, cochlear implants might enable them to hear. Objectives of the review: To bring together the diverse research in this area under the rigor of a systematic review to discover the strength of evidence when comparing the effectiveness of unilateral cochlear implants with non‐technological support or acoustic hearing aids in children with PBHL. Type of review: Systematic review. Search strategy: This examined 16 electronic data bases, plus bibliographies and references for published and unpublished studies. Evaluation method: Abstracts were independently assessed against inclusion criteria by two researchers, results were compared and disagreements resolved. Included papers were then retrieved and further independently assessed in a similar way. Remaining studies had their data independently extracted by one of five reviewers and checked by another reviewer. Results: From 1,580 abstracts and titles 15 studies were included. These were of moderate to poor quality. The large amount of heterogeneity in design and outcomes precluded meta‐analysis. However, all studies reported that unilateral cochlear implants improved scores on all outcome measures. Additionally five economic evaluations found unilateral cochlear implants to be cost‐effective for profoundly deaf children at UK implant centres. Conclusions: The robustness of systematic review methods gives weight to the positive findings of 15 papers reporting on this subject that they individually lack; while an RCT to show this would be unethical.     

Laser vs microdebrider eustachian tuboplasty for the treatment of chronic adult eustachian tube dysfunction: A systematic review

ObjectivesMultiple treatments are described in the literature for the treatment of chronic Eustachian tube dysfunction but high-level quality evidence seems missing to support these treatments. This systematic review aimed to determine and compare the safety and efficacy of Laser Eustachian tuboplasty and Microdebrider Eustachian tuboplasty as a treatment for long-term Eustachian tube dysfunction.Data sourcesA total of 12 electronic databases were searched up to April 2018 for published and unpublished literature in the English language. References of included studies were checked.MethodsA systematic review was undertaken. Outcomes assessed were: primary outcomes-subjective improvement in symptoms (ETDQ-7), audiometric improvement of hearing, improvement of negative middle ear pressure noticed in tympanometry, objective improvement of tympanic membrane retraction. Secondary outcomes were-the ability to auto-insufflate Eustachian tube i.e. Valsalva manoeuvre, improved quality of life, passive tubal opening, tubomanometry, swallowing test, reduction in mucosal inflammation of Eustachian tube orifice in the nose, complications from the procedure, the need for further procedures. Results are reported in a narrative synthesis as a meta-analysis was not possible due to heterogeneous data.ResultsThree studies were included. All included studies were small-scale case series (13–38 participants). Studies were conducted outside the UK. Subjective and objective improvement of Eustachian tube function was reported in all studies. But all included studies were at high risk of bias and subject to multiple limitations. No major complications were reported in either study.ConclusionsBased on current evidence, it is not possible to recommend the clinical use of either of these two interventions i.e. Laser or Microdebrider Eustachian tuboplasty. Lack of controlled studies was identified as a gap in the evidence. Future research should be directed toward designing randomised controlled trials. These trials should use strict standard methodology and reporting criteria. Future trials should make use of consensus statement document about Eustachian tube dysfunction definition, diagnostic methods, and outcome assessment criteria to design clinical trials.     

Systematic reviews of the effectiveness and cost-effectiveness of multi-channel unilateral cochlear implants for adults

Clin. Otolaryngol. 2010, 35 , 87–96 Objective: In the UK approximately 3% of over 50 years olds and 8% of over 70 year olds have severe (794–94 dBHL) to deafness. As deafness increased, hearing aids become increasingly ineffective. Cochelear implants can provide an alternative treatment. Objective of review: To bring together the research evidence through the robustness of a systematic review of the effectiveness of unilateral cochlear implants for adults. We also sought to systematically review the published literature on cost-effectiveness. Types of review: Systematic review. Search strategy: This examined 16 electronic databases, plus bibliographies and references for published and unpublished studies from inception to june 2009. Evaluation method: Abstracts were independently assessed against inclusion criteria by two researchers were compared and disagreements resolved. Included papers were then retrieved and further independently assessed in a similar way. Remaining studies had their data independently extracted by one of five reviewers and checked by another reviewer. Results: From 1,580 titles and abstracts nine studies were included. These were of variable quality; some study's results should be viewed with caution. The studies were too hetrogeneous to pool the data. However, overall the results firmly supported the use of unilateral cochler implants for severe to profoundly deaf adults. Additionally, four UK based economic evaluations found unilateral cochlear implants to be cost-effectivene in adults at UK implants centres. Conclusion: The methodologically weak but universally positive body of effectiveness evidence supports the use of unilateral cochlear implants in adults. Previous economic evaluations indicate that such implants are likely to be cost-effective.     

Effectiveness of Intratympanic Dexamethasone Injection for Tinnitus Treatment: A Systematic Review and Meta-Analysis

ObjectivesIntratympanic dexamethasone injection (ITDI) has been introduced as a treatment option for subjective tinnitus. However, the effects of ITDI on patients with tinnitus remain unclear. In the present systematic review and meta-analysis, we evaluated the effectiveness of ITDI for tinnitus treatment.MethodsWe searched Medline, the Cochrane Central Register of Controlled Trials, and Embase. Four double-blind randomized controlled trials that tested the efficacy of ITDI compared with a placebo were deemed eligible for a quantitative meta-analysis, while four prospective studies and seven retrospective studies reporting the effectiveness of ITDI on tinnitus treatment were included in a qualitative synthesis.ResultsIn the four studies included in the quantitative meta-analysis, ITDI did not show evidence of tinnitus improvement compared with placebo (odds ratio [OR], 1.38; 95% confidence interval, 0.53–3.61). In the 11 studies included in the qualitative synthesis, seven retrospective studies without controls reported rates of tinnitus improvement after ITDI ranging from 35.9% to 91.3%. In the four prospective studies with controls, ITDI seemed to be effective when combined with other drugs for tinnitus treatment.ConclusionITDI alone did not show a significant effect for treating tinnitus compared with placebo. However, the potential of combination treatment of ITDI with other drugs for tinnitus therapy should be further studied in more systematic research.     

Quality of life and functional outcomes in the management of early glottic carcinoma: a systematic review of studies comparing radiotherapy and transoral laser microsurgery

Clin. Otolaryngol. 2010, 35 , 373–382 Background: Early glottic carcinoma can be managed by radiotherapy and transoral laser microsurgery with similar control and survival rates. The functional and quality of life outcomes of these interventions are therefore important to guide management. Objective of review: To compare the different treatment modalities for early glottic carcinoma with respect to quality of life, post-treatment voice character and swallowing outcomes. Type of review: A systematic review of the literature with defined search strategy. Search strategy: Searches of EBM databases, and literature databases using key words: glotti*, laryn*, neoplasm, radiotherapy and laser surgery from 1970 to November 2009. Articles were screened for relevance using pre-determined inclusion and exclusion criteria. Evaluation method: Articles reviewed by authors and data compiled in tables for analysis. Results: No randomised controlled trials were identified. There were 15 studies reporting vocal outcomes, and perception of voice disability was measured in eight studies; numbers were low in all the papers. Cumulatively, results for 880 patients were included, 448 had trans-oral laser microsurgery and 442 had radiotherapy. For vocal outcomes, 12 studies found no significant difference between radiotherapy and laser surgery, three reported superior outcomes for radiotherapy, whereas for the perception of voice disability, five reported no difference between treatment groups, while the remaining three reported conflicting results. Nine studies reported quality of life outcomes; seven of these reported no difference between the treatment groups in overall scores although some report differences in subsets of questions. Conclusions: The evidence base to date demonstrates comparable vocal and quality of life outcomes for radiotherapy and transoral laser surgery for early glottic carcinoma. There is a need for consensus on which measures of vocal quality and life satisfaction to be used in research trials to allow comparison between studies.     

Measuring and inducing brain plasticity in chronic aphasia

Brain plasticity associated with anomia recovery in aphasia is poorly understood. Here, I review four recent studies from my lab that focused on brain modulation associated with long-term anomia outcome, its behavioral treatment, and the use of transcranial brain stimulation to enhance anomia treatment success in individuals with chronic aphasia caused by left hemisphere stroke. In a study that included 15 participants with aphasia who were compared to a group of 10 normal control subjects, we found that improved naming ability was associated with increased left hemisphere activity. A separate study (N = 26) revealed similar results in that improved anomia treatment outcome was associated with increased left hemisphere recruitment. Taken together, these two studies suggest that improved naming in chronic aphasia relies on the damaged left hemisphere. Based on these findings, we conducted two studies to appreciate the effect of using low current transcranial electrical stimulation as an adjuvant to behavioral anomia treatment. Both studies yielded positive findings in that anomia treatment outcome was improved when it was coupled with real brain stimulation as compared with a placebo (sham) condition. Overall, these four studies support the notion that the intact cortex in the lesioned left hemisphere supports anomia recovery in aphasia. LEARNING OUTCOMES: Readers will (a) be able to appreciate the possible influence of animal research upon the understanding of brain plasticity induced by aphasia treatment, (b) understand where functional changes associated with anomia treatment occur in the brain, (c) understand the basic principles of transcranial direct current stimulation, and (d) understand how brain stimulation coupled with aphasia treatment may potentially improve treatment outcome.     

Acute computerized tomographic scans: their value in the localization of lesions and as prognostic indicators in aphasia

Twenty three patients with past or present evidence of aphasia following either stroke (n = 19) or head trauma (n = 4) were given the Boston Diagnostic Aphasia Examination in order to classify their aphasia type and determine their language deficit at least three months postonset of their neurological disorder. The location and extent of brain lesions identified from computerized tomographic (C.T.) scans taken in the acute stage and, wherever possible, in the chronic stage (n = 7) were correlated with the type of aphasia. Lesions associated with global, Wernicke's, Broca's, conduction, and anomic aphasia are described and discussed in relation to the findings of previously reported clinico-C.T. scan correlation studies. The value of the acute stage C.T. scan as a predictor of long-term language deficits is discussed.     

Speech intelligibility benefits of frequency-lowering algorithms in adult hearing aid users: a systematic review and meta-analysis

Objective: This systematic review evaluated the effectiveness of two frequency-lowering schemes, non-linear frequency compression and frequency transposition, at improving speech intelligibility for adult hearing-impaired populations. Design: A systematic search of 10 electronic databases was carried out using pre-defined inclusion criteria. Accepted articles were then critically appraised using the Effective Public Health Practice Project (EPHPP) Critical Appraisal Tool. Outcome results were further synthesised where possible using random effects meta-analysis to provide overall combined estimates of the treatment differences along with 95% confidence intervals. Study sample: A total of 20 articles were accepted for final review. Results: Overall, study quality was of moderate strength. Meta-analysis found a statistically significant benefit in favour of frequency-lowering for consonant recognition testing in quiet across 145 participants with both algorithms providing comparable gains. Equivalent results were found between frequency-lowering and conventional processing on all other speech measures. Conclusions: Based on the available data, frequency-lowering does seem to provide some improvement in an individual’s speech intelligibility dependant on the stimulus type, although the benefits were modest. This improvement was not seen across all measures, however those who do not benefit from the technology will also not be harmed by trialling it.     

Local anaesthetic for post‐tonsillectomy pain: a systematic review and meta‐analysis

Background: Tonsillectomy is one of the most commonly performed procedures in otolaryngology. Pain is a significant aspect of post‐operative patient morbidity. The use of local anaesthetic, by infiltration or topical application, has been advocated as a way of reducing post‐operative pain. Objectives: To review the current evidence for the use of local anaesthetic as a means of reducing post‐tonsillectomy pain and reducing supplemental analgesic requirements. Type of review: A systematic review of the literature pertaining to the use of local anaesthetic agents for post‐tonsillectomy pain and meta‐analysis of randomised control trials assessing pain scores. Search strategy: Systematic literature searches of MEDLINE (1952–2008), EMBASE (1974–2008) and the Cochrane Central Register of Controlled Trials. Evaluation method: Review of all randomised controlled trials by two authors and grading of articles for quality. Results: Thirteen studies were included. Overall, local anaesthetic, applied topically or infiltrated, significantly reduces pain scores compared with controls at 4–6 h, ?0.66 (95% CI: ?0.82, ?0.50); 20–24 h, ?0.34 (95% CI: ?0.51, ?0.18) and on day 5, ?0.97 (95% CI: ?1.30, ?0.63) (standardised mean differences). These changes approximate to a reduction in pain of between 7 and 19 mm on a 0–100 mm visual analogue scale. Most studies did not report a difference in supplemental analgesia or in adverse events. Conclusion: Local anaesthetic does seem to provide a modest reduction in post‐tonsillectomy pain. Topical local anaesthetic on swabs appears to provide a similar level of analgesia to that of infiltration without the potential adverse effects and should be the method of choice for providing additional post‐operative analgesia.     

Outcome of intensive language treatment in aphasia

Sixty-eight aphasic inpatients received intensive language treatment (9 hr per week over a period of 6-8 weeks). Outcome was assessed by means of the Aachen Aphasia Test (AAT), a standardized test battery for the German language. For patients with duration of aphasia up to 12 months, amount of improvement was corrected by the expected rate of spontaneous recovery as determined by a previous multicenter follow-up study. About two thirds of the patients showed significant improvement in AAT performance according to psychometric single case analysis procedures. A similar rate of improvement was found for individuals with chronic aphasia beyond the stage of spontaneous recovery.     

Vocational and social outcomes of adults with chronic aphasia

Vocational and social outcomes of rehabilitation, such as employment, Social Integration, and life satisfaction, are critical determinants of the usefulness of rehabilitation. The purpose of this study was to describe the employment status, Social Integration, and perceived life satisfaction of adults with chronic aphasia 2 years after discharge from an intensive treatment program. Among the 20 survey respondents, 62% of those who had been working prior to aphasia onset were also working at the time of follow-up. Those who were working before but not after onset had higher Home Integration scores. There was a relatively large perceived change in communication from clinic discharge to the 2-year follow-up. Eighty-five percent of the respondents indicated a positive life satisfaction rating. There was a significant positive relationship between Home Integration and life satisfaction ratings. The results are discussed in relation to other reports of employment and social outcomes for stroke and aphasia.

Learning outcomes

As a result of this activity, the participant will be able to: (1) identify factors that may contribute to the successful return to work for adults with chronic aphasia; (2) describe the vocational and social outcomes of a select group of adults with chronic aphasia after participation in an intensive treatment program; and (3) discuss future need areas in understanding vocational and social participation for adults with chronic aphasia after intervention.     

The effect of a therapy dog on the communication skills of an adult with aphasia

Little evidence-based research has been published within the field of communication disorders on the role of dogs as catalysts for human communication. This single participant study, a point of entry into this realm of research, explores the effects of a therapy dog on the communication skills of a patient with aphasia receiving intensive speech and language therapy within a rehabilitation setting. The researchers conclude that the presence of the dog does have the potential to stimulate both overt social-verbal and social-nonverbal communication. LEARNING OUTCOMES: As a result of this activity the reader will be able to (1) describe the beneficial role of dogs to serve as catalysts for human communication (2) describe ways in which a person with aphasia may be assisted by a therapy dog and (3) become familiar with an animal-assisted therapy (AAT) program set-up for patients with communication disorders within a rehabilitation setting.     

Systematic review of the literature on the clinical effectiveness of the cochlear implant procedure in adult patients

The aim of this systematic review was to summarize the results of scientific publications on the clinical effectiveness of the cochlear implant (CI) procedure in adults. The members of the Working Group first examined existing research evidence from the national and international literature and main international guidelines. They considered as universally accepted the usefulness/effectiveness of unilateral cochlear implantation in severely-profoundly adult patients. Accordingly, they focused their attention on the systematic reviews addressing clinical effectiveness and cost/efficacy of CI procedures, with particular regard to the most controversial issues for which international consensus is still lacking. The following aspects were evaluated: monolateral CI in advanced-age adult patients; bilateral (simultaneous/sequential) CI vs. unilateral CI and vs. bimodal stimulation; benefits derived from the monolateral CI procedure in adult patients with prelingual deafness. With regard to CI in elderly patients, the selected studies document an improvement of the quality of life and perceptive abilities after CI, even if the benefits were found to be inferior in patients over 70 years at the time of surgery. Thus, from the results of the studies included in the review, advanced age is not a contraindication for the CI procedure. With respect to unilateral CI, bilateral CI offers advantages in hearing in noise, in sound localization and less during hearing in a silent environment. However, high interindividual variability is reported in terms of benefits from the second implant. With regard to CI in prelingually deaf adults, the selected studies document benefits deriving from the CI procedure in terms of improvement of perceptive abilities and in the quality of life after CI, as well as subjectively perceived benefits. However, there is high interindividual variability and the study sample is limited.     

Cognition and aphasia: a discussion and a study

The relation between other aspects of cognition and language status of individuals with aphasia is not well-established, although there is some evidence that integrity of non-linguistic skills of attention, memory, executive function and visuospatial skills can not be predicted on the basis of aphasia severity. At the same time, there is a growing realization among rehabilitation specialists, based on clinical experience and preliminary studies, that all domains of cognition are important to aphasia therapy outcomes. This paper describes a new study of the relation between linguistic and nonlinguistic skill in a group of individuals with aphasia. No significant relationship was found between linguistic and nonlinguistic skills, and between nonlinguistic skills and age, education or time post onset. Instead, individual profiles of strengths and weaknesses were found. The implications of these findings for management of aphasia patients is discussed. Learning outcomes: Readers of this papers will be able to: list five primary domains of cognition and relate each to an aspect of aphasia therapy; describe at least three studies that examined the relation between cognition and aphasia; describe four nonlinguistic tasks of cognition that can be used with a wide range of aphasia patients.     

A systematic review and meta-analysis assessing the effectiveness of alternative listening devices to conventional hearing aids in adults with hearing loss

Abstract

Recent technological advances have led to a rapid increase in alternative listening devices to conventional hearing aids. The aim was to systematically review the existing evidence to assess the effectiveness of alternative listening devices in adults with mild and moderate hearing loss. A systematic search strategy of the scientific literature was employed, reported in accordance with the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) checklist. Eleven studies met eligibility for inclusion: two studies evaluated personal sound amplification products, and nine studies assessed remote microphone systems (frequency modulation, Bluetooth, wireless). The evidence in this review suggests that alternative listening devices improve behavioural measures of speech intelligibility relative to unaided and/or aided conditions. Evidence for whether alternative listening devices improve self-reported outcomes is inconsistent. The evidence was judged to be of poor to good quality and subject to bias due to limitations in study design. Our overall recommendation is that high-quality evidence (i.e. randomised controlled trials) is required to demonstrate the effectiveness of alternative listening devices. Such evidence is not currently available and is necessary to guide healthcare commissioners and policymakers when considering new service delivery models for adults with hearing loss.

Review registration: Prospective Register of Systematic Reviews (PROSPERO), CRD42015029582     

Repetitive transkranielle Magnetstimulation

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive, painless method used to stimulate areas of the brain through the intact skull by means of magnetic fields. Depending on the stimulation frequency, the effect on concurrent brain areas is either inhibiting or exciting. As a result, it should be possible to inhibit compensatory hyperactivation in certain brain areas or to temporarily enhance cortical excitability. Therefore, rTMS potentially represents an adjuvant treatment for aphasia. In this article, the literature regarding rTMS as a treatment for aphasia is reviewed and followed by a case report of a 79-year-old man who 3 years after stroke received rTMS (3?×?10 sessions) in combination with articulation therapy. Even though linguistic assessments did not show enhancements in language skills, the patient’s family reported changes in communication patterns and behavior and explicitly asked to continue the rTMS treatment sessions. Reasons why no enhancements could be reported might be found in the type of language disorder (a comorbid speech disorder) or the stimulation protocol. Further studies are needed to evaluate the true potential of rTMS in the treatment of aphasia.     

Possible demographic influences on differentiating normal from aphasic performance

To determine the psychometric validity of current language impairment, communication activity limitation, and quality of life measures for differentiating normal from chronically aphasic adults, we examined possible threats to test accuracy by the demographic variables age, educational level, and gender. A total of 18 chronically aphasic and 18 nonaphasic adults were evaluated with six measures. The results of correlational analyses indicated that, within the normal adult and aphasic adult groups, there exist significant relationships between some, but not all, demographic variables and performance on language impairment, communication activity limitation, and quality of life measures. Moreover, for certain variables, the strengths of these relationships differ significantly between normal and aphasic groups. Thus, adjustments in test scores or norms may be necessary to diagnose the presence or absence of aphasia. Otherwise, the tests' ability to differentiate between normal and aphasic adults may be compromised. Educational objectives: Readers will be able to: (1) explain the relationship between test accuracy and psychometric validity; (2) state the direction of significant relationships (i.e., positive or negative) among demographic variables and test performance, within normal and aphasic adult groups; (3) explain necessary considerations in the adjustment of general test norms or scores based on a particular subject's age, education, or gender.