Crossroads in aphasia rehabilitation

This thesis focusses on two types of aphasia rehabilitation, cognitive linguistic treatment (CLT) and AAC (Augmentative and Alternative Communication) training. In a study of the effect of nonlinguistic variables on the outcome of CLT, it was shown, that neuropsychological data contributed significantly to the prediction of verbal communicative ability after treatment. It is concluded that a neuropsychological assessment is needed in all aphasic patients before treatment is started. In a study of the efficacy of AAC in people with a severe aphasia, a computerised communication aid, TouchSpeak (TS), was developed and tested in 34 aphasic patients. 57 % of the participants used the device in everyday life scenarios and overall communicative abilities improved with TS training. The final chapter presents a new test for overall (verbal and nonverbal) communication in people with a severe aphasia. In a pilot group, patients with a severe aphasia showed large variation in overall scores. In addition, several communicative patterns could be described

Transcranial direct current stimulation in post-stroke sub-acute aphasia: Study protocol for a randomized controlled trial

Background: Transcranial direct current stimulation (tDCS) is a promising new technique to optimize the effect of regular Speech and Language Therapy (SLT) in the context of aphasia rehabilitation. The present study focuses on the effect of tDCS provided during SLT in the sub-acute stage after stroke. The primary aim is to evaluate the potential effect of tDCS on language functioning, specifically on word-finding, as well as generalization effects to verbal communication. The secondary aim is to evaluate its effect on social participation and quality of life, and its cost-effectiveness. Methods: We strive to include 58 stroke patients with aphasia, enrolled in an inpatient or outpatient stroke rehabilitation program, in a multicenter, double-blind, randomized controlled trial with two parallel groups and 6 months' follow-up. Patients will participate in two separate intervention weeks, with a pause of 2 weeks in between, in the context of their regular aphasia rehabilitation program. The two intervention weeks comprise daily 45-minute sessions of word-finding therapy, combined with either anodal tDCS over the left inferior frontal gyrus (1 mA, 20 minutes; experimental condition) or sham-tDCS over the same region (control condition). The primary outcome measure is word-finding. Secondary outcome measures are verbal communication, social participation, quality of life, and cost-effectiveness of the intervention. Discussion: Our results will contribute to the discussion on whether tDCS should be implemented in regular aphasia rehabilitation programs for the sub-acute post-stroke population in terms of (cost-)effectiveness. Trial registration: Nederlands Trail Register: NTR4364. Registered on 21 February 2014

Comparison of two configurations of transcranial direct current stimulation for treatment of aphasia

Objective: To compare 2 configurations of transcranial direct current stimulation (tDCS) for treatment of aphasia. Design: Randomized cross-over study. Subjects: Patients with chronic post-stroke aphasia (n = 13). Methods: TDCS was combined with word-finding therapy in 3 single sessions. In session 1, sham-tDCS/ pseudo-stimulation was applied. In sessions 2 and 3, 2 active configurations were provided in random order: Anodal tDCS over the left inferior frontal gyrus (l-IFG) and anodal tDCS over the left posterior superior temporal gyrus (l-STG). The optimal configuration was determined per individual based on a pre-set improvement in naming trained (> 20%) and untrained picture items (> 10%). Results: Overall, participants improved on trained items (median = 50%; interquartile range = 20-85) and post-treatment performance was highest in the active l-IFG condition (p = 0.040). Of the 13 participants, 6 (46%) showed relevant improvement during active tDCS; either in the l-IFG condition (n = 4; 31%) or in both the l-IFG and l-STG conditions (n = 2; 15%). On the untrained items there was no improvement (median = 0%; interquartile range = 0-0). Conclusion: This randomized cross-over single-session protocol to determine an optimal tDCS configuration for treatment of aphasia suggests that only performance on trained items can be used as guidance for configuration, and that it is relevant for half of the patients. For this subgroup, the l-IFG configuration is the optimal choice

Part of the message comes in gesture: how people with aphasia convey information in different gesture types as compared with information in their speech

Background: Studies have shown that the gestures produced by people with aphasia (PWA) can convey information useful for their communication. However, the exact significance of the contribution to message communication via gesture remains unclear. Furthermore, it remains unclear how different gesture types and representation techniques impact message conveyance. Aims: The present study aimed to investigate the contribution of gesture to PWA’s communication. We specifically focussed on the degree to which different gesture types and representation techniques convey information absent in the speech of PWA. Methods & Procedure: We studied the gestures produced by 46 PWA and nine non-brain-damaged participants (NBDP) during semi-structured conversation. For each of the different types of gestures and representation techniques we identified whether these conveyed essential information, that is information that was absent in speech. Rather than looking at information that was either similar to information in speech or additional to information in speech, we focused on the essential gestures only. Outcomes & Results: For PWA, a fifth of their gestures were Essential. Despite individual differences between PWA, the majority produced more Essential gestures than NBDP, who produced limited amounts of Essential gestures. Essential information was mostly conveyed by specific gesture types: Pointing, Emblems and Iconic gesture. Within the group of iconic gestures, not only Handling and Enact but also Object and Shape gestures, were often Essential. Conclusions: Our findings suggest that a great proportion of gestures produced by most PWA convey information essential for understanding their communication. In their communication advice, speech language therapists could draw attention to specific gesture types to make sure that interlocutors pay more attention to these gestures when communicating with PWA

Change in Right Inferior Longitudinal Fasciculus Integrity Is Associated With Naming Recovery in Subacute Poststroke Aphasia

Background. Despite progress made in understanding functional reorganization patterns underlying recovery in subacute aphasia, the relation between recovery and changes in white matter structure remains unclear. Objective. To investigate changes in dorsal and ventral language white matter tract integrity in relation to naming recovery in subacute poststroke aphasia. Methods. Ten participants with aphasia after left-hemisphere stroke underwent language testing and diffusion tensor imaging twice within 3 months post onset, with a 1-month interval between sessions. Deterministic tractography was used to bilaterally reconstruct the superior longitudinal fasciculus (SLF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), middle longitudinal fasciculus (MdLF), and uncinate fasciculus (UF). Per tract, the mean fractional anisotropy (FA) was extracted as a measure of microstructural integrity. Naming accuracy was assessed with the Boston Naming Test (BNT). Correlational analyses were performed to investigate the relationship between changes in FA values and change in BNT score. Results. A strong positive correlation was found between FA change in the right ILF within the ventral stream and change on the BNT (r = 0.91, P <.001). An increase in FA in the right ILF was associated with considerable improvement of naming accuracy (range BNT change score: 12-14), a reduction with limited improvement or slight deterioration. No significant correlations were found between change in naming accuracy and FA change in any of the other right or left ventral and dorsal language tracts. Conclusions. Naming recovery in subacute aphasia is associated with change in the integrity of the right ILF

Linguistic deficits in the acute phase of stroke

Background and Purpose: For the diagnosis of aphasia early after stroke, several screening tests are available to support clinical judgment. None of these tests enables the clinician to assess the underlying linguistic deficits, i. e. semantic, phonological and syntactic deficits, which provides indispensable information for early therapeutic decisions. The ScreeLing was designed as a screening test to detect semantic, phonological and syntactic deficits. The ScreeLing's sensitivity, specificity and accuracy in detecting aphasia and semantic, phonological and syntactic deficits were determined. Methods: The ScreeLing was validated in an acute stroke population against a combined reference diagnosis of aphasia (aphasia according to at least two of the following measures: neurologist's judgment, linguist's judgment, Tokentestscore). The three ScreeLing subtests were validated in the aphasic population against the presence or absence of a semantic, phonological and/or syntactic deficit according to an experienced clinical linguist. Results: From a consecutive series of 215 stroke patients, 63 patients were included. The ScreeLing was an accurate test for the detection of aphasia (0.92), with a sensitivity of 86% and specificity of 96%. Sensitivity of subtests was 62% for semantics, 54% for phonology and 42% for syntax. Specificity was 100% for semantics and phonology and 80% for syntax, and accuracy 0.84 for semantics, 0.87 for phonology and 0.64 for syntax. Conclusions: The ScreeLing is an accurate test that can be easily administered and scored to detect aphasia in the first weeks after stroke. Furthermore, the ScreeLing is suitable for revealing underlying linguistic deficits, especially semantic and phonological deficits

Insight into the neurophysiological processes of melodically intoned language with functional MRI

Background: Melodic Intonation Therapy (MIT) uses the melodic elements of speech to improve language production in severe nonfluent aphasia. A crucial element of MIT is the melodically intoned auditory input: the patient listens to the therapist singing a target utterance. Such input of melodically intoned language facilitates production, whereas auditory input of spoken language does not. Methods: Using a sparse sampling fMRI sequence, we examined the differential auditory processing of spoken and melodically intoned language. Nineteen right-handed healthy volunteers performed an auditory lexical decision task in an event related design consisting of spoken and melodically intoned meaningful and meaningless items. The control conditions consisted of neutral utterances, either melodically intoned or spoken. Results: Irrespective of whether the items were normally spoken or melodically intoned, meaningful items showed greater activation in the supramarginal gyrus and inferior parietal lobule, predominantly in the left hemisphere. Melodically intoned language activated both temporal lobes rather symmetrically, as well as the right frontal lobe cortices, indicating that these regions are engaged in the acoustic complexity of melodically intoned stimuli. Compared to spoken language, melodically intoned language activated sensory motor regions and articulatory language networks in the left hemisphere, but only when meaningful language was used. Discussion: Our results suggest that the facilitatory effect of MIT may - in part - depend on an auditory input which combines melody and meaning. Conclusion: Combined melody and meaning provide a sound basis for the further investigation of melodic language processing in aphasic patients, and eventually the neurophysiological processes underlying MIT. Compared to spoken language, melodically intoned language activated sensory motor regions and articulatory language networks in the left hemisphere, but only when meaningful language was used. Our results suggest that the facilitatory effect of MIT may - in part - depend on an auditory input which combines melody and meaning. As such, they provide a sound basis for further investigation of melodic language processing in aphasic patients, and eventually the neurophysiological processes underlying MIT

Cerebellar Cathodal Transcranial Direct Stimulation and Performance on a Verb Generation Task: A Replication Study

The role of the cerebellum in cognitive processing is increasingly recognized but still poorly understood. A recent study in this field applied cerebellar Transcranial Direct Current Stimulation (c-tDCS) to the right cerebellum to investigate the role of prefrontal-cerebellar loops in language aspects of cognition. Results showed that the improvement in participants' verbal response times on a verb generation task was facilitated immediately after cathodal c-tDCS, compared to anodal or sham c-tDCS. The primary aim of the present study is to replicate these findings and additionally to investigate possible longer term effects. A crossover within-subject design was used, comparing cathodal and sham c-tDCS. The experiment consisted of two visits with an interval of one week. Our results show no direct contribution of cathodal c-tDCS over the cerebellum to language task performance. However, one week later, the group receiving cathodal c-tDCS in the first visit show less improvement and increased variability in their verbal response times during the second visit, compared to the group receiving sham c-tDCS in the first visit. These findings suggest a potential negative effect of c-tDCS and warrant further investigation into long term effects of c-tDCS before undertaking clinical studies with poststroke patients with aphasia

Screening tests for aphasia in patients with stroke: a systematic review

Aphasia has a large impact on the quality of life and adds significantly to the costs of stroke care. Early recognition of aphasia in stroke patients is important for prognostication and well-timed treatment planning. We aimed to identify available screening tests for differentiating between aphasic and non-aphasic stroke patients, and to evaluate test accuracy, reliability, and feasibility. We searched PubMed, EMbase, Web of Science, and PsycINFO for published studies on screening tests aimed at assessing aphasia in stroke patients. The reference lists of the selected articles were scan

ImPACT: a multifaceted implementation for conversation partner training in aphasia in Dutch rehabilitation settings.

Purpose: Exploration of the clinical uptake of a novel conversation partner training (CPT) programme in aphasia in ten Dutch rehabilitation facilities and identification of its perceived facilitators and barriers in service providers, and the evaluation of the implementation methods used. Method: Ten rehabilitation centres took part in a multifaceted implementation of conversation partner training over thirteen months. Each centre selected two speech and language therapists to act as knowledge brokers whose role it was to raise awareness of CPT in the team and to facilitate getting partners of people with aphasia into the programme. The implementation was evaluated using analysis of recruitment data and questionnaires, supplemented by consensus data and scrutiny of implementation plans. Results: Successful implementation was described as 1) four dyads included during the intervention period, 2) two more dyads included after the intervention period, before the end of the study and 3) inclusion of Partners of Aphasic Clients Conversation Training (PACT) in a description of the logistics of local stroke care (stroke care pathway). Seven centres were successful in reaching the target inclusion of 6 dyads in total. Only one centre had care pathways in place. From a recruitment pool of 504 dyads, 41 dyads were recruited and 34 partners completed the implementation of PACT study (ImPACT). Observed facilitators included the motivation to engage partners in the rehabilitation process and the perceived added value of PACT. The perceived barriers focused on time limitations within current systems to discuss the consequences of PACT with relevant professionals and to establish allocated time for PACT within existing care routines. Conclusions: The motivation of professionals to involve partners in the rehabilitation process assisted with the introduction of PACT in practice. The main barrier was time, linked to the requirement to think through integration of this innovation within existing care. Longer term evaluation would ascertain how centres sustain uptake without support