Neuroimaging Correlates of Post-Stroke Aphasia Rehabilitation in a Pilot Randomized Trial of Constraint-Induced Aphasia Therapy

Progress in the clinical application of constraint-induced therapy following stroke since 2014

Stroke is a group of cerebrovascular diseases with high prevalence and mortality rate. Stroke can induce many impairments, including motor and cognitive dysfunction, aphasia/dysarthria, dysphagia, and mood disorders, which may reduce the quality of life among the patients. Constraint-induced therapy has been proven to be an effective treatment method for stroke rehabilitation. It has been widely used in the recovery of limb motor dysfunction, aphasia, and other impairment like unilateral neglect after stroke. In recent years, constraint-induced therapy can also combine with telehealth and home rehabilitation. In addition, constraint-induced therapy produces significant neuroplastic changes in the central nervous system. Functional magnetic resonance imaging, diffusion tensor imaging, and other imaging/electrophysiology methods have been used to clarify the mechanism and neuroplasticity. However, constraint-induced therapy has some limitations. It can only be used under certain conditions, and the treatment time and effectiveness are controversial. Further research is needed to clarify the mechanism and effectiveness of CI therapy.

The Role of Three-dimensional Model in Preoperative Communication Before Partial Nephrectomy and Postoperative Management

Objective

To investigate the role of the three-dimensional (3D) image reconstruction technique in preoperative communication before partial nephrectomy (PN) and postoperative follow-up.

Methods

A retrospective study was performed with 158 renal cancer patients treated with PN at our center from May 1, 2017 to April 30, 2019. 81 patients (group A) had preoperative communication using the 3D reconstruction technique, while 77 patients (group B) did not. The surgeon explained the anatomical structure, tumor characteristics, and surgical approach in detail to the two groups of patients. Each patient completed a questionnaire. The loss to follow-up rate over a 3-year period was counted for both groups, and non-cancer-related serious complications such as renal failure and cardio-cerebrovascular disease were observed. This research did not include patients who returned for follow-up care owing to associated complications such as postoperative chronic kidney disease. Comparisons between two groups were performed using the Mann-Whitney U test and chi-square test.

Results

All patients showed no statistically significant differences in basic clinical parameters, such as age, gender, body mass index, tumor size, and R.E.N.A.L. score (P ​> ​0.05). In group A, patients were significantly more likely to experience understanding of renal anatomy (P ​= ​0.001), characteristics of renal cell carcinoma (P ​= ​0.003), surgical approach (P ​= ​0.007), and relief of preoperative anxiety (P ​= ​0.013). The follow-up adherence at 3 years postoperatively in group A and group B was 21 cases and 10 cases, respectively (P ​= ​0.041). In addition, glomerular filtration rate < 60 ​mL/min/1.73 ​m² or serum creatinine > 186 ​μmol/L at 3 years after surgery occurred in 5 patients in group A and 13 in group B (P ​= ​0.034), and a systolic blood pressure rise greater than 20 ​mmHg occurred in 9 patients in group A and 18 in group B (P ​= ​0.041).

Conclusions

The use of 3D reconstruction techniques for preoperative communication can successfully improve patients' perception and comprehension of kidney tumors and PN, as well as help to prevent serious postoperative non-cancer-related complications.

Lesion correlates of auditory sentence comprehension deficits in post-stroke aphasia

Auditory sentence comprehension requires coordination of multiple levels of processing: auditory-phonological perception, lexical-semantic comprehension, syntactic parsing and discourse construction, as well as executive functions such as verbal working memory (WM) and cognitive control. This study examined the lesion correlates of sentence comprehension deficits in post-stroke aphasia, building on prior work on this topic by using a different and clinically-relevant measure of sentence comprehension (the Token Test) and multivariate (SCCAN) and connectome-based lesion-symptom mapping methods. The key findings were that lesions in the posterior superior temporal lobe and inferior frontal gyrus (pars triangularis) were associated with sentence comprehension deficits, which was observed in both mass univariate and multivariate lesion-symptom mapping. Graph theoretic measures of connectome disruption were not statistically significantly associated with sentence comprehension deficits after accounting for overall lesion size.

A Pilot Randomized Controlled Trial of Intermittent Theta Burst Stimulation as Stand-Alone Treatment for Post-Stroke Aphasia: Effects on Language and Verbal Functional Magnetic Resonance Imaging (fMRI)

BACKGROUND There is an ongoing need for facilitating language recovery in chronic post-stroke aphasia. The primary aim of this study (NCT01512264) was to examine if noninvasive intermittent theta burst stimulation (iTBS) applied to the injured left-hemispheric cortex promotes language improvements and fMRI changes in post-stroke aphasia. MATERIAL AND METHODS Participants were randomized to 3 weeks of sham (Tx0) or 1-3 weeks of iTBS (Tx123). We assessed participants who completed the first 2 functional MRI (fMRI) sessions (T1, T2) where they performed 2 overt language fMRI tasks, and examined longitudinal response after 3 months (T3). Language performance and fMRI activation changes, and relationships between these changes were assessed. RESULTS From T1 to T2, both groups showed improvements on the Boston Naming Test (BNT). From T1 to T3, Tx123 improved on the Aphasia Quotient, post-scan word recognition on the verbal paired associates task (VPAT), and perceived communicative ability. Each group exhibited significant activation changes between T1 and T2 for both tasks. Only the Tx123 group exhibited fMRI activation changes between T2 to T3 on the verb-generation task and between T1 and T3 on VPAT. Delayed aphasia symptom improvement for Tx123 was associated with increased left ventral visual stream activation from T1 to T3 (rho=0.74, P=0.0058), and with decreased bilateral supplementary motor area activation related to VPAT encoding from T2 to T3 (rho=-0.80, P=0.0016). CONCLUSIONS Observed iTBS-induced language improvements and associations between delayed fMRI changes and aphasia improvements support the therapeutic and neurorehabilitative potential of iTBS in post-stroke aphasia recovery.

Novel Advances to Post-Stroke Aphasia Pharmacology and Rehabilitation

Aphasia is one of the most common clinical features of functional impairment after a stroke. Approximately 21–40% of stroke patients sustain permanent aphasia, which progressively worsens one’s quality of life and rehabilitation outcomes. Post-stroke aphasia treatment strategies include speech language therapies, cognitive neurorehabilitation, telerehabilitation, computer-based management, experimental pharmacotherapy, and physical medicine. This review focuses on current evidence of the effectiveness of impairment-based aphasia therapies and communication-based therapies (as well as the timing and optimal treatment intensities for these interventions). Moreover, we present specific interventions, such as constraint-induced aphasia therapy (CIAT) and melodic intonation therapy (MIT). Accumulated data suggest that using transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) is safe and can be used to modulate cortical excitability. Therefore, we review clinical studies that present TMS and tDCS as (possible) promising therapies in speech and language recovery, stimulating neuroplasticity. Several drugs have been used in aphasia pharmacotherapy, but evidence from clinical studies suggest that only nootropic agents, donepezil and memantine, may improve the prognosis of aphasia. This article is an overview on the current state of knowledge related to post-stroke aphasia pharmacology, rehabilitation, and future trends.

Intermittent Theta Burst Stimulation (iTBS) for Treatment of Chronic Post-Stroke Aphasia: Results of a Pilot Randomized, Double-Blind, Sham-Controlled Trial

Background

Research indicates intermittent theta burst stimulation (iTBS) is a potential treatment of post-stroke aphasia.

Material/Methods

In this double-blind, sham-controlled trial (NCT 01512264) participants were randomized to receive 3 weeks of sham (G₀), 1 week of iTBS/2 weeks of sham (G₁), 2 weeks of iTBS/1 week of sham (G₂), or 3 weeks of iTBS (G₃). FMRI localized residual language function in the left hemisphere; iTBS was applied to the maximum fMRI activation in the residual language cortex in the left frontal lobe. FMRI and aphasia testing were conducted pre-treatment, at ≤1 week after completing treatment, and at 3 months follow-up.

Results

27/36 participants completed the trial. We compared G₀ to each of the individual treatment group and to all iTBS treatment groups combined (G_1–3). In individual groups, participants gained (of moderate or large effect sizes; some significant at P<0.05) on the Boston Naming Test (BNT), the Semantic Fluency Test (SFT), and the Aphasia Quotient of the Western Aphasia Battery-Revised (WAB-R AQ). In G_1–3, BNT, and SFT improved immediately after treatment, while the WAB-R AQ improved at 3 months. Compared to G₀, the other groups showed greater fMRI activation in both hemispheres and non-significant increases in language lateralization to the left hemisphere. Changes in IFG connectivity were noted with iTBS, showing differences between time-points, with some of them correlating with the behavioral measures.

Conclusions

The results of this pilot trial support the hypothesis that iTBS applied to the ipsilesional hemisphere can improve aphasia and result in cortical plasticity.

Functional Magnetic Resonance Imaging of Language Following Constraint-Induced Aphasia Therapy Primed with Intermittent Theta Burst Stimulation in 13 Patients with Post-Stroke Aphasia

Background

Aphasia is a debilitating consequence of stroke. This study aimed to investigate the role of functional magnetic resonance imaging (fMRI) activation changes during overt language tasks in promoting language improvements following constraint-induced aphasia therapy (CIAT) primed with intermittent theta burst stimulation (iTBS) in 13 patients with aphasia following ischemic stroke.

Material/Methods

Participants with post-stroke aphasia participated in CIAT primed with iTBS on 10 consecutive weekdays. They also underwent language testing and fMRI while performing overt language tasks at baseline (N=13), immediately post-treatment (N=13), and after 3 months (N=12). Outcome measures were compared between time points, and relationships between changes in language ability and fMRI activation were examined.

Results

We observed improvements in naming (p<0.001), aphasia symptoms (p=0.038), apraxia of speech symptoms (p=0.040), perception of everyday communicative ability (p=0.001), and the number of spoken words produced during fMRI (p=0.028). Pre- to post-treatment change in naming was negatively correlated with change in right postcentral gyrus activation related to noun-verb associations (rho=−0.554, p=0.0497). Change in aphasia symptoms from immediately after to 3 months post-treatment was negatively correlated with change in bilateral supplementary motor area activation related to verbal encoding (rho=−0.790, p=0.0022).

Conclusions

Aphasia improvements coupled with fMRI activation changes over time provide support for treatment-induced neuroplasticity with CIAT primed with iTBS. However, a larger randomized sham-controlled study is warranted to confirm our findings and further our understanding of how iTBS can potentiate beneficial effects of language therapy in post-stroke aphasia.

Neuroplasticity in post-stroke aphasia: A systematic review and meta-analysis of functional imaging studies of reorganization of language processing

Recovery from aphasia is thought to depend on neural plasticity, that is, functional reorganization of surviving brain regions such that they take on new or expanded roles in language processing. We carried out a systematic review and meta-analysis of all articles published between 1995 and early 2020 that have described functional imaging studies of six or more individuals with post-stroke aphasia, and have reported analyses bearing on neuroplasticity of language processing. Each study was characterized and appraised in detail, with particular attention to three critically important methodological issues: task performance confounds, contrast validity, and correction for multiple comparisons. We identified 86 studies describing a total of 561 relevant analyses. We found that methodological limitations related to task performance confounds, contrast validity, and correction for multiple comparisons have been pervasive. Only a few claims about language processing in individuals with aphasia are strongly supported by the extant literature: first, left hemisphere language regions are less activated in individuals with aphasia than neurologically normal controls, and second, in cohorts with aphasia, activity in left hemisphere language regions, and possibly a temporal lobe region in the right hemisphere, is positively correlated with language function. There is modest, equivocal evidence for the claim that individuals with aphasia differentially recruit right hemisphere homotopic regions, but no compelling evidence for differential recruitment of additional left hemisphere regions or domain-general networks. There is modest evidence that left hemisphere language regions return to function over time, but no compelling longitudinal evidence for dynamic reorganization of the language network.

Is Aphasia Treatment Beneficial for the Elderly? A Review of Recent Evidence

Purpose

We review recent literature regarding aphasia therapy in the elderly. Relevant articles from the last 5 years were identified to determine whether or not there is evidence to support that various therapeutic approaches can have a positive effect on post-stroke aphasia in the elderly.

Recent findings

There were no studies examining the effects of aphasia therapy specifically in the elderly within the timeframe searched. Therefore, we briefly summarize findings from 50 relevant studies that included large proportions of participants with post-stroke aphasia above the age of 65. A variety of behavioral and neuromodulation therapies are reported.

Summary

We found ample evidence suggesting that a variety of behavioral and neuromodulatory therapeutic approaches can benefit elderly individuals with post-stroke aphasia.

Constraint-induced aphasia therapy for patients with aphasia: A systematic review

Objectives

This study aimed to systematically evaluate the effects of constraint-induced aphasia therapy (CIAT) for aphasic patients reported by randomized controlled trials.

Methods

Relevant randomized controlled trials were retrieved from 11 electronic databases. A methodological quality assessment was conducted in accordance with the Cochrane Handbook, and meta-analyses were performed by using RevMan 5.2. A descriptive analysis was conducted when the included trials were not suitable for a meta-analysis.

Results

A total of 12 trials were included. A statistically significant group difference was shown from the meta-analysis in the results measured by the Western Aphasia Battery (random-effects model, MD = 1.23, 95% CI = 0.31 to 2.14, P < 0.01). However, there were no statistically significant differences shown in the results of the Boston Naming Test (fixed-effects model, MD = −1.79, 95% CI = −11.19 to 7.62, P > 0.05) and Aachen Aphasia Test (fixed-effects model, MD = −1.11, 95% CI = −4.49 to 2.27, P > 0.05). The descriptive analysis showed positive results in language performances of naming, repetition, and comprehension.

Conclusion

This systematic review indicated that CIAT was efficient for improving language performance with regard to naming, comprehension, repetition, written language, and oral language based on the current evidence. And this review provides some meaningful guides for clinical practice: expand the therapy duration to 2 or 3 h per day, focus on naming, and choose the best assessment tool. It also indicates a need for more rigorous, large-scale, and high-quality trials in the future.

Constrained-Induced Dysarthria Therapy: Case Report

We describe a 33-year-old woman with chronic bulbar dysarthria after ischemic brainstem stroke who underwent a new form of constraint-induced therapy, namely constraint-induced dysarthria therapy, based on three principles: avoidance of supportive devices, intensive therapy, and gradually augmenting difficulty. After a 2-month intervention, improvement was noted for speech intelligibility, fluency, and intensity. This led to increased communicative participation, including during conversation situations, which has been maintained over a 12-month follow-up.

BDNF genotype and tDCS interaction in aphasia treatment

Background:

Several studies, including a randomized controlled trial by our group, support applying anodal tDCS (A-tDCS) to the left hemisphere during behavioral aphasia treatment to improve outcomes. A clear mechanism explaining A-tDCS’s efficacy has not been established, but modulation of neuroplasticity may be involved.

Objective/hypothesis:

The brain-derived neurotrophic factor (BDNF) gene influences neuroplasticity and may modulate the effects of tDCS. Utilizing data from our recently completed trial, we conducted a planned test of whether aphasia treatment outcome is influenced by interaction between A-tDCS and a single-nucleotide polymorphism of the BDNF gene, rs6265.

Methods:

Seventy-four individuals with chronic stroke-induced aphasia completed 15 language therapy sessions and were randomized to receive 1 mA A-tDCS or sham tDCS (S-tDCS) to the intact left temporoparietal region for the first 20 min of each session. BDNF genotype was available for 67 participants: 37 participants had the typical val/val genotype. The remaining 30 participants had atypical BDNF genotype (Met allele carriers). The primary outcome factor was improvement in object naming at 1 week after treatment completion. Maintenance of treatment effects was evaluated at 4 and 24 weeks.

Results:

An interaction was revealed between tDCS condition and genotype for treatment-related naming improvement (F = 4.97, p = 0.03). Participants with val/val genotype who received A-tDCS showed greater response to aphasia treatment than val/val participants who received S-tDCS, as well as the Met allele carriers, regardless of tDCS condition.

Conclusion:

Individuals with the val/val BDNF genotype are more likely to benefit from A-tDCS during aphasia treatment.