Language Performance In Patients Research Articles

Exploring language performance in people with mild cognitive impairment and Alzheimer's disease: a prospective longitudinal study

Background/Aims Language changes are the earliest signs and symptoms of mild cognitive impairment and Alzheimer's disease. The aim of this study was to explore the language difference performance between people with mild cognitive impairment, people with Alzheimer's disease and healthy individuals as a control group. To accomplish this aim, the language profile of both mild cognitive impairment and Alzheimer's disease needs to be characterised to determine which feature is more affected by both mild cognitive impairment and Alzheimer's disease among expressive language, receptive language, executive function and memory performance. Methods This case-control prospective study involved 90 participants. The Mini-Mental Status Examination and the Functional Assessment Staging Tool were used to classify the participants into three groups: people with mild cognitive impairment, people with Alzheimer's disease and healthy individuals as a control group. Then, the language performance of patients in the mild cognitive impairment and Alzheimer's disease groups was investigated and compared with those of the control group by using the Barnes Language Assessment. The groups were reassessed 6 months later to see if there was any change in language ability. Results The results showed that the mild cognitive impairment group and Alzheimer's disease group had significant decreases in expressive language (P>0.01), executive function (P>0.01), receptive language (P>0.01) and memory skills (P>0.01) from baseline to the reassessment at 6 months. Conclusions Language deficits, especially expressive language deficits, could appear before impairment in executive function, receptive language and verbal episodic memory in participants with mild cognitive impairment or Alzheimer's disease. Speech and language therapists can use the findings of this study to design and implement treatment programmes.

Long-term effects of transcranial direct current stimulation (tDCS) combined with speech language therapy (SLT) on post-stroke aphasia patients: A systematic review and network meta-analysis of randomized controlled trials.

Transcranial direct current stimulation (tDCS) is a noninvasive neuromodulation tool for improving language performance in patients with aphasia after stroke. However, it remains unclear whether it has long-term effects. After consulting a large number of relevant studies, it was found that there are no definitive conclusions about the long-term effects of tDCS on post-stroke aphasia patients. To determine whether tDCS has long-term effects on post-stroke aphasia patients (PAPs) and which type of tDCS has the most beneficial treatment effects on language performance (especially naming ability). A network meta-analysis was conducted by searching for randomized controlled trials (RCTs) published until April 2023 in the following databases: Web of Science, Embase, Medline (from OVID and PubMed), PsycInfo and PsycARTICLES (from OVID). We only included RCTs published in English. PAPs treated by tDCS combined with speech-language therapy were selected. Sham tDCS was the control group. Naming ability or other language performance must be assessed at follow-up states. Two reviewers independently used checklists to assess the primary outcome (the long-term effects on naming ability) and the secondary outcome (other language performance, such as communication). Cochrane Collaboration guidelines were used to assess the risk of bias. Seven studies with 249 patients were included for data synthesis. For primary outcomes (naming nous), there was no obvious evidence to show a difference between interventions (C-tDCS vs. S-tDCS SMD = 0.06, 95% CI = -1.01, 1.12; A-tDCS vs. S-tDCS SMD = 0.00, 95% CI = -0.66, 0.65; D-tDCS vs. S-tDCS SMD = 0.77, 95% CI = -0.71, 2.24; A-tDCS vs. C-tDCS SMD = -0.06, 95% CI = -1.31,1.19; D-tDCS vs. C-tDCS SMD = 0.71, 95% CI = -1.11,2.53; D-tDCS vs. A-tDCS SMD = 0.77, 95% CI = -0.84, 2.39). In addition, no evidence showed differences in communication ability (C-tDCS vs. S-tDCS SMD = 0.08 95% CI = -1.77, 1.92; A-tDCS vs. S-tDCS SMD = 1.23 95% CI = -1.89, 4.34; D-tDCS vs. S-tDCS SMD = 0.70; 95% CI = -1.93, 3.34; A-tDCS vs. C-tDCS SMD = 1.15 95% CI = -2.48, 4.77; D-tDCS vs. C-tDCS SMD = 0.62 95% CI = -2.59, 3.84; D-tDCS vs. A-tDCS SMD = -0.52 95% CI = -4.60, 3.56). It seems that tDCS has no long-term effects on post-stroke aphasia patients in naming nouns and communication in terms of the results of our network meta-analysis. However, the results should be interpreted with caution. In the future, more RCTs with long follow-up times should be included in the research to conduct subgroup or meta-regression analyses to obtain a sufficient effect size.

Feasibility of Speech Testing Using Wireless Connection in Single-Sided Cochlear Implant Users.

The speech tests used to evaluate language performance in patients with bilateral deafness (BiD) and cochlear implant (CI) are problematic if applied to patients with single-sided deafness (SSD) because normal ear hearing should be excluded. Thus, we investigated the feasibility of using wireless connection to evaluate speech intelligibility of the CI ear in patients with SSD. Subjects and. Patients with BiD and SSD were administered the word recognition scores (WRS) and speech intelligibility tests using an iPadbased wireless connection and conventional methods. To exclude normal side hearing in patients with SSD, masking noise and "plugged and muffed" method were used in the WRS and speech intelligibility tests, respectively. In patients with BiD, the WRS and speech intelligibility tests results using wireless connection and conventional methods were similar. In patients with SSD, the WRS using masking noise in the normal hearing ear was similar to that of using wireless connection. However, 3 of 11 patients with SSD showed under-masked results if using the "plugged and muffed" method. Speech intelligibility testing using wireless connection is a convenient and reliable method for evaluating CI performance in patients with SSD. The "plugged and muffed" method is not recommended for evaluating CI performance in patients with SSD.

The impact of patient factors and tumor characteristics on language neuroplasticity in left hemispheric diffuse gliomas prior to surgical resection

Language networks are reorganized during glioma growth, leading to varying language performance in patients with gliomas located inor around language-eloquent areas. Therefore, pre-treated language performance reflects the neuroplasticity potential. Different domains of language processing, such as speech expression, repetition, and comprehension, involving different neural networks. We analyzed the effects of patient factors and tumor characteristics on the pre-treated performance to investigate neuroplastic potential of different language domains. Patient age, sex, education level, tumor grade, language pathway involvement, T1 contrast enhanced (C+), and FLAIR (T2) volume were selected as variables. The correlation with abnormal language performance was verified using univariate and multivariate logistic regression. In total, 104 left hemispheric gliomapatients were enrolled in this study. 44% of patients had repetitive abnormalities, 34.9% had comprehensive abnormalities, and 32.1% had expressive abnormalities. The proportion of normal language performance was 60% in grade 2 and 3 gliomas and 16% in grade 4 gliomas. Tumor grade (p = 0.006) and T2 volume (p = 0.008) were associated with abnormal performance in the expressive domain, education level (p = 0.004) and T1 C+ volume (p = 0.049) in the repetitive domain, and education level (p = 0.013), T2 volume (p = 0.011), and tumor grade (p = 0.089) in the comprehensive domain. Different clinical and radiological factors affected the abnormal performance of the three language domains, indicating their functional connectivity and neuroplastic potential are inherently varied. The dynamic interactions between patient factors, tumor characteristics, and language processing should be considered when resecting left hemispheric gliomas.

Cognitive Reserve Moderates the Association Between Cerebral Blood Flow and Language Performance in Older Adults with Mild Cognitive Impairment

AbstractBackgroundIt has consistently been demonstrated that individuals with higher cognitive reserve (CR) exhibit decreased risk for dementia, and differences in cerebral blood flow (CBF) among those with higher CR may offer a protective mechanism against the cognitive changes associated with dementia. We sought to investigate CR as a moderator of the effect of CBF on memory and language performance in patients with mild cognitive impairment (MCI) and those who are cognitively unimpaired (CU).MethodOlder adults from the Alzheimer’s Disease Neuroimaging Initiative (ADNI; N = 46 MCI, 101 CU) underwent neuropsychological evaluation and arterial spin labeling MRI, which was used to quantify CBF in a priori regions. Estimated VIQ from the American National Adult Reading Test was used as a CR proxy. Multiple linear regressions assessed for (1) effect of CR on cognition, (2) effect of CR on CBF, and (3) interaction between CR and CBF on cognition. Cognitive outcomes included memory (word list) and language (category fluency, naming). All models adjusted for age, gender, APOE e4 allele frequency, and education, and interactions additionally adjusted for baseline FDG and pulse pressure.ResultVIQ was not associated with memory but was positively associated with fluency and naming in both groups (ps<0.005). VIQ was not associated with CBF in either group. Individuals with MCI showed a significant interaction between VIQ and CBF on fluency across several regions, including the bilateral hippocampus (p = 0.003), bilateral inferior temporal gyrus (p = 0.008), superior frontal gyrus (p = 0.005), and inferior frontal gyrus (p<0.001). For all models, as CR increased, the magnitude of the association between CBF and performance increased. These interactions were not significant in the CU group. Models with naming or memory as the outcome variable were not significant in either group. Results remained similar when education was not adjusted for.ConclusionThese results suggest that among individuals with MCI, the association between CBF and category fluency is dependent on CR, even after adjusting for several factors. Specifically, higher CR may serve as a protective factor against the negative effect of CBF reductions on fluency. Further research is needed to clarify the role that CR plays as a moderator of CBF and cognition.

Combined anodal transcranial direct current stimulation and behavioural naming treatment improves language performance in patients with post-stroke aphasia

ABSTRACT Primary objective During the last decade, studies using anodal transcranial Direct Current Stimulation (atDCS) have yielded promising results in patients with aphasia. The main aim of the present pilot study was to assess the effects of combined atDCS over the left posterior perisylvian region and behavioral naming training on the behavioral outcomes of language comprehension and production of patients with post-stroke aphasia. Research design A 2 × 2 quasi-experimental design was conducted, optimal to compare changes after treatment in experimental versus control group. Methods and Procedures Ten patients with post-stroke aphasia were enrolled in this study: half received atDCS on the left posterior perisylvian region while they underwent a 2-week behavioral naming training. The other half received sham stimulation. The outcomes were measured using the abbreviated form of the Boston Diagnostic Aphasia Examination and analyzed using ANOVAs. Main outcomes and Results Both groups improved their performance in Oral comprehension, Narrative writing and Language Competence Index, but only those that received anodal tDCS presented better results in the Naming category after the treatment. Conclusions AtDCS on the left posterior perisylvian area seems to be a promising tool for boosting the outcomes of behavioral naming therapy in patients with post-stroke aphasia.

The Relationship Between Visuoconstructive Abilities and Language Performance in Patients With Aphasia After Stroke.

This study aimed to investigate the visuoconstructive abilities and the relationship between visuoconstructive function and language performance in aphasic patients. Right-handed 24 aphasic patients (males 14, females 10) with at least 3 months post-stroke and 32 age-matched healthy controls participated in this study. Visuoconstructive function was assessed by 3 levels of task difficulty: simple (drawing objects), intermediate (clock drawing), and complex (copy subtest of Rey complex figure test and block construction). Aphasic patients were divided into 3 sub-groups (mild, moderate to severe, and very severe group) according to severity of aphasia and compared with the control group, respectively. We analyzed the relation all levels of visuoconstructive tasks to aphasia quotient (AQ) and sub-domain scores of K-WAB. Moderate to severe aphasia group demonstrated no significant differences in scores of simple drawing objects compared to controls, but clock drawing, Rey complex figure copy and block design showed significantly decreased scores. Very severe group showed significantly lower scores in all levels of visuoconstructive tasks than the control. Correlation between all levels of visuoconstructive tasks except drawing objects and AQ were found to be statistically significant. Among the tasks, the clock drawing test revealed the highest correlation with language performance. Visuoconstructive abilities varied according to the severity of aphasia and the level of visuoconstructive tasks. Therefore, a thorough individual assessment of visuoconstructive function is needed to plan and predict the treatment and prognosis of aphasia and the clock drawing test may be a useful screening tool to evaluate this function.

Improvement in language function in patients with aphasia using computer-assisted executive function training: A controlled clinical trial.

Nonverbal cognitive training for aphasia has gained popularity. Prior research has found that cognitive status correlates with language function. To determine whether nonverbal computer-assisted executive control training (CAET) to improve cognitive status affects language performance in patients with aphasia (PWA) and executive dysfunction. A single blind randomized trial. Department of Rehabilitation, Affiliated Hospital of Xuzhou Medical University. A total of 68 individuals were randomized, underwent treatment and were included in the analysis (CAET group, n = 33; control group, n = 35). The experimental group was treated with 4 weeks of traditional speech and language therapy (SLT) combined with CAET. The control group underwent SLT only. Western Aphasia Battery [WAB]) with executive dysfunction (as assessed by the verbal fluency test [VFT], the Proverbs Test, the Tower of London Test [TLT], the Stroop Color and Word Test [SCWT], and the Trail Making Test [TMT]). Differences between pre- and posttreatment language outcomes except oral naming (group × time, p=.236) were significantly greater in the experimental group compared with the control group: spontaneous speech (group × time, p=.026), auditory comprehension (group × time, p < .001), speech repetition (group × time, p=.001), and aphasia quotient (AQ; group × time, p < .001). A similar effect was observed for cognitive function such as Trial Making Test (TMT)-A (group × time, p=.006), TMT-B (group × time, p=.005), and verbal fluency test (VFT-V; group × time, p=.018). The study demonstrates that CAET combined with SLT can yield favorable language outcomes for PWA, especially improvements in auditory comprehension and AQ. CAET combined with SLT generates benefits in both cognitive function and language performance.

Effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy versus healthy controls – A prospective study

We aimed to evaluate the effect of sleep quality on memory, executive function, and language performance in patients with refractory focal epilepsy and controlled epilepsy and compare these with healthy individuals. We prospectively enrolled 37 adolescent and adult patients with refractory focal epilepsy (Group 1) and controlled epilepsy (Group 2) in each group. History pertaining to epilepsy and sleep were recorded, and all patients underwent overnight polysomnography. Language, memory, and executive function assessments were done using Western Aphasia Battery, Post Graduate Institute (PGI) memory scale, and battery of four executive function tests (Trail Making Test A & B, Digit symbol test, Stroop Task, and Verbal Fluency Test), respectively. Forty age- and sex-matched controls were also included in the study. Significant differences were noted in both objective and subjective sleep parameters among all the groups. On polysomnography, parameters like total sleep time, sleep efficiency, sleep latency, and rapid eye movement (REM) latency were found to be significantly worse in Group 1 as compared with Group 2. Cognitive and executive parameters were significantly impaired in Group 1. Shorter total sleep time, poorer sleep efficiency, and prolonged sleep latencies were observed to be associated with poor memory and executive function in patients with refractory epilepsy. Our study strongly suggests that sleep disturbances, mainly shorter total sleep time, poor sleep efficiency, and prolonged sleep latencies, are associated with impaired memory and executive function in patients with refractory focal epilepsy and to a lesser extent, among those with medically controlled epilepsy.

Transcranial direct current stimulation (tDCS) facilitates verb learning by altering effective connectivity in the healthy brain

Recent studies have shown that the left inferior frontal gyrus (IFG) plays a key role in language learning. Facilitatory stimulation over this region by means of anodal transcranial direct current stimulation (tDCS) can modulate linguistic abilities in healthy individuals and improve language performance in patients with post-stroke aphasia. Neuroimaging studies in healthy participants have suggested that anodal tDCS decreases task-related activity at the stimulated site when applied during different language tasks, and changes resting-state connectivity in a larger network of areas associated with language processing. However, to date, the neural correlates of the potential beneficial effects of tDCS on verb learning remain unclear. The current study investigated how anodal tDCS during verb learning modulates task-related activity and effective connectivity in the healthy language network. To this end, we combined a verb learning paradigm during functional neuroimaging with simultaneous tDCS over the left IFG in healthy human volunteers. We found that, relative to sham stimulation, anodal tDCS significantly decreased task-related activity at the stimulated left IFG and in the right homologue. Effective connectivity analysis showed that anodal tDCS significantly decreased task-related functional coupling between the left IFG and the right insula. Importantly, the individual decrease in connectivity was significantly correlated with the individual behavioural improvement during anodal tDCS. These results demonstrate, for the first time, that the behavioural improvements induced by anodal tDCS might be related to an overall decrease in processing effort both with respect to task-related activity and effective connectivity within a large language network.

Symmetry of the arcuate fasciculus and its impact on language performance of patients with brain tumors in the language-dominant hemisphere.

OBJECTIVE Cerebral damage in frontal, parietal, and temporal brain areas and, probably more importantly, their interconnections can lead to deficits in language. However, neural plasticity and repair allow the brain to partly compensate for neural injury, mediated by both functional and structural changes. In this study, the authors sought to systematically investigate the relationship between language performance in brain tumor patients and structural perisylvian pathways (i.e., the arcuate fasciculus [AF]) using probabilistic fiber tracking on diffusion tensor imaging. The authors used a previously proposed model in which the AF is divided into anterior, long, and posterior segments. The authors hypothesized that right-handed patients with gliomas in the language-dominant (left) hemisphere would benefit from a more symmetrical or right-lateralized language pathway in terms of better preservation of language abilities. Furthermore, they investigated to what extent specific tumor characteristics, including proximity to the AF, affect language outcome in such patients. METHODS Twenty-seven right-handed patients (12 males and 15 females; mean age 52 ± 16 years) with 11 low-grade and 16 high-grade gliomas of the left hemisphere underwent 3-T diffusion-weighted MRI (30 directions) and language assessment as part of presurgical planning. For a systematic quantitative evaluation of the AF, probabilistic fiber tracking with a 2 regions of interest approach was carried out. Volumes of the 3 segments of both hemispheric AFs were evaluated by quantifying normalized and thresholded pathways. Resulting values served to generate the laterality index of the AFs. RESULTS Patients without language deficits tended to have an AF that was symmetric or lateralized to the right, whereas patients with deficits in language significantly more often demonstrated a left-lateralized posterior segment of the AF. Patients with high-grade gliomas had more severe language deficits than those with low-grade gliomas. Backward logistic regression revealed the laterality index of the posterior AF segment and tumor grade as the only independent statistically significant predictors for language deficits in this cohort. CONCLUSIONS In addition to the well-known fact that tumor entity influences behavioral outcome, the authors' findings suggest that the right homologs of structural language-associated pathways could be supportive for language function and facilitate compensation mechanisms after brain damage in functionally eloquent areas. This further indicates that knowledge about preoperative functional redistribution (identified by neurofunctional imaging) increases the chance for total or near-total resections of tumors in eloquent areas. In the future, longitudinal studies with larger groups are mandatory to overcome the methodological limitations of this cross-sectional study and to map neuroplastic changes associated with language performance and rehabilitation in brain tumor patients.

Altered cerebral activity associated with topiramate and its withdrawal in patients with epilepsy with language impairment: An fMRI study using the verb generation task.

Topiramate (TPM) is well recognized for its negative effects on language in healthy volunteers and patients with epilepsy. The aim of this study was to investigate the brain activation and deactivation patterns in TPM-treated patients with epilepsy with language impairment and their dynamic alteration during TPM withdrawal using functional magnetic resonance imaging (fMRI) with the verb generation task (VGT). Twelve patients with epilepsy experiencing subjective language disfluency after TPM add-on treatment (TPM-on) and thirty sex- and age-matched healthy controls (HCs) were recruited. All subjects received a battery of neuropsychological tests and an fMRI scan with the VGT. Withdrawal of TPM was attempted in all patients. Only six patients reached complete withdrawal without seizure relapses (TPM-off), and these patients underwent a reassessment of neuropsychological and neuroimaging tests. The neuropsychological tests demonstrated objective language impairments in TPM-on patients. Compared with the HCs, the bilateral medial prefrontal cortex and the posterior midline and lateral parts of the default mode network (DMN) (including the bilateral posterior cingulate cortex (PCC), the right medial prefrontal cortex, the right angular gyrus, the right inferior temporal gyrus, and the bilateral supramarginal gyrus) in TPM-on patients failed to deactivate during the VGT. Their task-induced activation patterns were largely similar to those of the HCs. After TPM withdrawal, partial improvement of both task-induced deactivation of the DMN (the left parahippocampal gyrus and the bilateral PCC) and task-related activation of the language network (the right middle frontal gyrus and the left superior occipital gyrus) was identified along with partial improvement of neuropsychological tests. Task-induced deactivation is a more sensitive neuroimaging biomarker for the impaired language performance in patients administered TPM than task-induced activation. Disruption and reorganization of the balance between the DMN and the cortical language networks are found along with reversible TPM-related language impairment. These results may suggest an underlying brain mechanism by which TPM affects cognitive function.

Language impairment in cerebellar ataxia

Several studies have suggested that language impairment can be observed in patients with cerebellar pathology. The aim of this study was to investigate language performance in patients with spinocerebellar ataxia type 6 (SCA6). We assessed speech and language in 29 SCA6 patients with standardized linquistic tests and correlated this with the severity of ataxia, as quantified by the Scale of Assessment and Rating of Ataxia. Individual patients show mild-to-moderate linguistic impairment. Linguistic abnormalities were most distinct on the writing and comprehension subtests. A strong correlation between severity of ataxia and linguistic performance was consistently found. This study confirms the occurrence of linguistic impairments in patients with cerebellar degenerative diseases, such as SCA6. The relation between linguistic abnormalities and severity of ataxia provides further evidence for a role of the cerebellum in linguistic processing.

P 114. Anodal transcranial direct current stimulation in early treatment of post-stroke non-fluent aphasia

Introduction Neuroimaging studies suggests that increased level of cortical excitability in the stroke-affected left hemisphere is associated with better language improvement in aphasic patients. Recent neurostimulating studies showed that combination of behavioural therapy with excitatory anodal transcranial direct current stimulation (A-tDCS) of perilesional cortex in the language-dominant left hemisphere improve language performance in patients with chronic post-stroke aphasia. Objective The aim of this study was to investigate the impact of A-tDCS on language in aphasics in the early post-stroke rehabilitation period when most adaptive changes in cortical excitability are possible and most conventional therapies are conducted. We hypothesized that early reactivation of preserved language-related structures and their neighboring regions may facilitate the restoration of the neuronal language network manifested by better naming. Methods 24 patients with moderate or severe non-fluent aphasia were randomized to receive 15 consecutive daily sessions of A-tDCS (1 mA, 10 min; A-tDCS group = 14) or sham tDCS (1 mA, 25 s; sham tDCS group = 10) over Broca’s area followed by 45-min routine speech and language training. Naming ability was assessed before and after the rehabilitation, and three months later using Boston Naming Test. Naming accuracy and speed were chosen as outcome measures. Results Although both groups significantly improved after the therapy, there were no statistically significant differences between groups in either short-term or long-term tDCS effects when naming accuracy and naming time were analyzed. However, for response time A-tDCS group obtained higher effect sizes both post-treatment and at the 3-month follow-up. Conclusions The findings provide only a weak evidence of A-tDCS behavioural gains during early neurorehabilitation of post-stroke aphasia. Further research is needed to investigate the effectiveness of this kind of neuromodulation. Different modes and parameters of tDCS should be explored considering such important factors determining recovery from aphasia as type and severity of language impairment, lesion site and size, time since stroke, and degree of hemispheric language laterality.

Statistical Mapping Analysis of Brain Metabolism in Patients with Subcortical Aphasia after Intracerebral Hemorrhage: A Pilot Study of F-18 FDG PET Images

PurposeThis study was aimed to evaluate the brain metabolism in patients with subcortical aphasia after intracerebral hemorrhage (ICH) and the relationship between the severity of aphasia and regional brain metabolism, by using statistical mapping analysis of F-18 fluorodeoxyglucose positron emission tomography (F-18 FDG PET) images.Materials and MethodsSixteen right-handed Korean speaking patients with subcortical aphasia following ICH were enrolled. All patients underwent Korean version of the Western Aphasia Battery and the brain F-18 FDG PET study. Using statistical parametric mapping analysis, we compared the brain metabolisms shown on F-18 FDG PET from 16 patients with subcortical aphasia and 16 normal controls. In addition, we investigated the relationship between regional brain metabolism and the severity of aphasia using covariance model.ResultsCompared to the normal controls, subcortical aphasia after ICH showed diffuse hypometabolism in the ipsilateral cerebrum (frontal, parietal, temporal, occipital, putamen, thalamus) and in the contralateral cerebellum (P corrected<0.001), and showed diffuse hypermetabolism in the contralateral cerebrum (frontal, parietal, temporal) and in the ipsilateral cerebellum (P FDR corrected<0.001). In the covariance analysis, increase of aphasia quotient was significantly correlated with increased brain metabolism in the both orbitofrontal cortices, the right hippocampal and the right parahippocampal cortices (P uncorrected<0.01).ConclusionOur findings suggest that frontal, parietal, and temporal cortices, which are parts of neural network for cognition, may have a supportive role for language performance in patients with subcortical aphasia after ICH.

Neuroscience insights improve neurorehabilitation of poststroke aphasia

The treatment of aphasias-acquired language disorders-caused by stroke and other neurological conditions has benefitted from insights from neuroscience and neuropsychology. Hebbian mechanisms suggest that massed practice and exploitation of residual neurological capacities can aid neurorehabilitation of patients with poststroke aphasia, and progress in basic neuroscience research indicates that the language system of the human brain is functionally interwoven with perceptual and motor systems. Intensive speech and language therapies, including constraint-induced aphasia therapy, that activate both the linguistic and concordant motor circuits utilize the knowledge gained from these advances in neuroscience research and can lead to surprisingly rapid improvements in language performance, even in patients with chronic aphasia. Drug-based therapies alone and in conjunction with behavioral language therapies also increase language performance in patients with aphasia. Furthermore, noninvasive transcranial magnetic stimulation and electrical stimulation techniques that target neuronal activity within perilesional areas might help patients with aphasia to regain lost language functions. Intensive language-action therapies that lead to rapid improvements in language skills might provide a new opportunity for investigating fast plastic neuronal changes in the areas of the brain associated with language processing. Here, we review progress in basic neuroscience research and its translational impact on the neurorehabilitation of language disorders after stroke.

Severe Impairment Battery Language scale: A language-assessment tool for Alzheimer's disease patients

Background Communication problems are common in Alzheimer's disease (AD) patients, but instruments to assess these symptoms are limited. Our objective was to create a new scale, based on the language subscale of the Severe Impairment Battery (SIB), as a sensitive and reliable measurement of treatment effects on language performance. Methods All 24 items of the SIB language subscale were chosen for analysis. Baseline scores of 1320 moderate-to-severe patients (Mini-Mental State Examination [MMSE] score, <15), from a combined AD database of four Memantine clinical trials (Study Codes: IE-2101, MEM-MD-01, MEM-MD-02, and MRZ-9605), were used for item reduction according to a standard principal components factor analysis. All items with loadings >0.5 on the identified factors were selected for inclusion in the new language scale. Correlations with existing AD scales were examined. Results The analysis indicated six factors, with 21 of 24 items showing loadings >0.5. The resulting 21-item SIB Language (SIB-L) scale exhibited high internal consistency (Cronbach's α = 0.809). The maximal SIB-L score was 41 points, with a measurement error of 3.7 points. The stratification of baseline SIB-L scores (mean, 31.7; SD, 8.4) by MMSE scores (mean, 9.7; SD, 3.3) showed a high variance in SIB-L scores. This confirms that patients with a low MMSE score can possess preserved language abilities. The SIB-L scale did not exhibit substantial floor-and-ceiling effects. Conclusions The new SIB-L is a fast (<15 minutes) and easily administered scale with favorable psychometric characteristics for assessing language impairment and treatment effects on the language performance of patients with moderate to severe AD.

Aphasia therapy on a neuroscience basis

Background: Brain research has documented that the cortical mechanisms for language and action are tightly interwoven and, concurrently, new approaches to language therapy in neurological patients are being developed that implement language training in the context of relevant linguistic and non‐linguistic actions, therefore taking advantage of the mutual connections of language and action systems in the brain. A further well‐known neuroscience principle is that learning at the neuronal level is driven by correlation; consequently, new approaches to language therapy emphasise massed practice in a short time, thus maximising therapy quantity and frequency and, therefore, correlation at the behavioural and neuronal levels. Learned non‐use of unsuccessful actions plays a major role in the chronification of neurological deficits, and behavioural approaches to therapy have therefore employed shaping and other learning techniques to counteract such non‐use. We wish to thank Chris Code, Barbro Johansson, Bettina Mohr, and two anonymous referees for their comments on an earlier version of this article and for their helpful suggestions. This work was supported by the Medical Research Council (UK) and by the European Community under the “New and Emerging Science and Technologies Programme” (NESTCOM project) and by the Ministerio de Educacion y Ciencia, Spain (SEJ2007‐67793). Aims: Advances in theoretical and experimental neuroscience have important implications for clinical practice. We exemplify this in the domain of aphasia rehabilitation. Main Contribution: Whereas classical wisdom had been that aphasia cannot be significantly improved at a chronic stage, we here review evidence that one type of intensive language‐action therapy (ILAT)—constraint‐induced aphasia therapy—led to significant improvement of language performance in patients with chronic aphasia. We discuss perspectives for further improving speech‐language therapy, including drug treatment that may be particularly fruitful when applied in conjunction with behavioural treatment. In a final section we highlight intensive and rapid therapy studies in chronic aphasia as a unique tool for exploring the cortical reorganisation of language. Conclusions: We conclude that intensive language action therapy is an efficient tool for improving language functions even at chronic stages of aphasia. Therapy studies using this technique can open new perspectives for research into the plasticity of human language circuits.

Subcortical Aphasia

Very few neuroimaging studies have focused on follow-up of subcortical aphasia. Here, overt language production tasks were used to correlate regional cerebral blood flow (rCBF) changes and language performance in patients with vascular subcortical lesions. Seven aphasic patients were scanned twice with positron emission tomography (PET) at 1-year interval during a word-generation task. Using SPM2, Language-Rest contrast at PET1 was correlated to language performance and to time-lag from stroke. The same contrast was performed at PET2 and session effect (PET2-PET1) was correlated with performance improvement. At PET1, correlation between rCBF and delay from stroke involved mainly ventral regions of the left temporal cortex and mesial frontal cortex. Correlations between rCBF and performance showed predominantly left dorsal regions in the frontal, temporal, and parietal lobes, but also the left ventral temporal cortex. One year apart, language performance improved and rCBF increased in perisylvian regions bilaterally. Best performers at PET2 showed an increase of activity in left ventral temporal cortex as well as in right middle temporal gyrus. On follow-up, expected language improvement and increase of activation in the classical language areas and their counterparts were observed. Moreover, all correlational analyses both at PET1 and on follow-up implicated the anterior part of the left inferior temporal gyrus, suggesting a disconnection between the superior and inferior parts of the left temporal cortex and a specific role for this region in lexical semantic processing.

Alterations of 5-HT 3 receptor and plasma membrane dopamine transporter in nucleus accumbens of rats with voluntary chronic alcohol consumption

Recent studies have shown that the left inferior frontal gyrus (IFG) plays a key role in language learning. Facilitatory stimulation over this region by means of anodal transcranial direct current stimulation (tDCS) can modulate linguistic abilities in healthy individuals and improve language performance in patients with post-stroke aphasia. Neuroimaging studies in healthy participants have suggested that anodal tDCS decreases task-related activity at the stimulated site when applied during different language tasks, and changes resting-state connectivity in a larger network of areas associated with language processing. However, to date, the neural correlates of the potential beneficial effects of tDCS on verb learning remain unclear. The current study investigated how anodal tDCS during verb learning modulates task-related activity and effective connectivity in the healthy language network. To this end, we combined a verb learning paradigm during functional neuroimaging with simultaneous tDCS over the left IFG in healthy human volunteers. We found that, relative to sham stimulation, anodal tDCS significantly decreased task-related activity at the stimulated left IFG and in the right homologue. Effective connectivity analysis showed that anodal tDCS significantly decreased task-related functional coupling between the left IFG and the right insula. Importantly, the individual decrease in connectivity was significantly correlated with the individual behavioural improvement during anodal tDCS. These results demonstrate, for the first time, that the behavioural improvements induced by anodal tDCS might be related to an overall decrease in processing effort both with respect to task-related activity and effective connectivity within a large language network.