Diagnosing and managing post-stroke aphasia

ABSTRACT

Introduction: Aphasia is a debilitating language disorder and even mild forms of aphasia can negatively affect functional outcomes, mood, quality of life, social participation, and the ability to return to work. Language deficits after post-stroke aphasia are heterogeneous.

Areas covered: The first part of this manuscript reviews the traditional syndrome-based classification approach as well as recent advances in aphasia classification that incorporate automatic speech recognition for aphasia classification. The second part of this manuscript reviews the behavioral approaches to aphasia treatment and recent advances such as noninvasive brain stimulation techniques and pharmacotherapy options to augment the effectiveness of behavioral therapy.

Expert opinion: Aphasia diagnosis has largely evolved beyond the traditional approach of classifying patients into specific syndromes and instead focuses on individualized patient profiles. In the future, there is a great need for more large scale randomized, double-blind, placebo-controlled clinical trials of behavioral treatments, noninvasive brain stimulation, and medications to boost aphasia recovery.

KEYWORDS:

• Aphasia
• stroke
• speech therapy
• noninvasive brain stimulation
• rehabilitation
• medication

Article highlights

• Aphasia diagnostics should expand beyond simply classifying patients by aphasia syndrome. Instead, an effort should be made to determine which linguistic and cognitive mechanisms are impaired.

• Comprehensive aphasia evaluation must include a thorough case history, assessments of linguistic/cognitive skills, and an appraisal of how functional communication has been affected by aphasia.

• Aphasia treatment must be individualized for patients in consideration of their goals, specific strengths, and deficits.

• Aphasia studies need to incorporate both impairment and functional-based outcome measures. Aphasia treatment studies have largely focused on impairment-based outcomes (e.g., naming); however, improvement of impairment level outcomes is not always followed by an improvement of functional communication. Therefore, it is necessary that primary outcome measures incorporate changes in functional communication, behavior, and quality of life measures.

• Pharmacological agents already approved for the treatment of other neurological and psychiatric disorders have been studied in patients with post-stroke aphasia. Several small case studies, open-label trials, and small randomized clinical trials show that pharmacotherapy provides benefits in stroke patients with aphasia; however, benefits are not evident for all drugs and for all aphasia severity levels.

• Non-invasive brain stimulation (NIBS) technologies such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) have shown promising results in case studies and clinical trials; however, these methods remain investigational for post-stroke aphasia and are not approved for clinical use.

• There is wide variation in protocols including stimulation location, stimulation intensity, number of treatment sessions, outcome measures, type of aphasia treatment, and time post-stroke. Determining optimal NIBS parameters as well as the mechanisms underlying treatment improvement is critical to facilitate transition to clinical practice.

Declaration of interest

The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or conflict with the subject matter or materials discussed in this manuscript apart from those disclosed.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

The research reported in this paper was supported by the National Institutes of Health (National Institute on Deafness and Other Communication Disorders) through award R00 DC015554. The content is solely the responsibility of the authors and does not necessarily represent the views of the National Institutes of Health.