The Spectrum of Aphasia Subtypes and Etiology in Subacute Stroke

A Novel Approach for Aphasia Evaluation Based on ROI-Based Features From Structural Magnetic Resonance Image

Aphasia, affecting one-third of stroke survivors, impairs language comprehension and speech production, leading to challenges in daily interactions, social isolation, and economic losses. Assessing aphasia is crucial for effective rehabilitation and recovery in patients. However, the conventional behavioral-based evaluation, reliant on speech pathologists, is susceptible to individual variability, resulting in high labor costs, time-consuming processes, and low robustness. To address these limitations, this study introduces a novel evaluation method based on medical image processing and artificial intelligence. Magnetic resonance imaging (MRI) provides exceptional spatial resolution while mitigating the impact of individual variability. The image processing techniques were employed to extract pathological features, specifically region-of-interest (ROI)-based features. Subsequently, the evaluation models were trained using ROI-based features which initially identify the occurrence of aphasia and then categorize the type of aphasia, aiding clinicians in tailoring treatment to various therapeutic approaches and intensities. The evaluation models also predict the severity and generate scores for four types of language function: spontaneous speech, auditory comprehension, naming, and repetition. Both aphasia occurrence detection and aphasia type classification attain impressive accuracy rates of 100.00 $\pm$ 0.00% and 85.00 $\pm$ 13.23%, respectively. The severity prediction yields the lowest root mean square error (RMSE) of 17.03 $\pm$ 2.75, while the assessment of four language functions achieves the best RMSE of 1.27 $\pm$ 0.82. Utilising the advantages of a medical imaging-based automation approach, the proposed aphasia evaluation method provides a comprehensive procedure and generates rather accurate results. Hence it could assist the aphasia rehabilitation and substantially reduce clinicians' workload.

A Loss for Words: A Case of Aphemia

Aphemia, also known as pure motor mutism, is a rare disorder characterized by the loss of motor function to produce speech while retaining the ability to understand, read, and write language. Differentiating between aphemia and aphasia can be challenging in many cases, as they both present with similar physical exam findings. The key distinctions lie in the location of the insult in the cerebral parenchyma, the ability to understand language, and the associated dysphagia. We present the case of a 78-year-old male who presented with new-onset aphasia and was found to have aphemia based on physical examination and imaging findings.

Recognizing Aphemia and How to Differentiate From Aphasia in the Era of Telemedicine

Background

Aphemia, or pure motor mutism, is a phenomenon that has been reported previously in the literature and typically is associated with small infarcts in the inferior dominant precentral gyrus, pars opercularis, or inferior perirolandic gyrus. Clinically, it is important to distinguish aphemia from aphasia syndromes. Telemedicine is becoming more prevalent and involving neurologists across the country. This is an important consideration when addressing aphemic patients as many mistakes can be made during a virtual exam clouding a patient's clinical picture.

Case Presentation

Our patient is a 61-year-old female with a past medical history of hypertension, diabetes, and an old right frontoparietal stroke without any residual deficits. She presented after her family stated that she "quit speaking" for about seven hours. Initial neurological evaluation was done via telemedicine due to the COVID-19 pandemic and was pertinent for decreased consciousness, inability to answer either orientation question, a right facial droop, and aphasia. Later it was found that the patient exhibited a pure motor mutism rather than aphasia and had an MRI lesion in the left inferior precentral gyrus.

Conclusion

Differentiating aphemia from aphasia is an important clinical skill for a neurologist to foster especially in the era of telemedicine. An intimate knowledge of the parts of a speech exam are vital in directing emergency staff during stroke evaluation. Additionally, distinguishing these clinical syndromes has implications with respect to prognosis and long-term rehabilitation.

Factor Analysis of Spontaneous Speech in Aphasia

Purpose Spontaneous speech tasks are critically important for characterizing spoken language production deficits in aphasia and for assessing the impact of therapy. The utility of such tasks arises from the complex interaction of linguistic demands (word retrieval, sentence formulation, articulation). However, this complexity also makes spontaneous speech hugely variable and difficult to assess. The current study aimed to simplify the problem by identifying latent factors underlying performance in spontaneous speech in aphasia. The ecological validity of the factors was examined by examining how well the factor structures corresponded to traditionally defined aphasia subtypes. Method A factor analysis was conducted on 17 microlinguistic measures of narratives from 274 individuals with aphasia in AphasiaBank. The resulting factor scores were compared across aphasia subtypes. Supervised (linear discriminant analysis) and unsupervised (latent profile analysis) classification techniques were then conducted on the factor scores and the solutions compared to traditional aphasia subtypes. Results Six factors were identified. Two reflected aspects of fluency, one at the phrase level (Phrase Building) and one at the narrative level (Narrative Productivity). Two other factors reflected the accuracy of productions, one at the word level (Semantic Anomaly) and one at the utterance level (Grammatical Error). The other two factors reflected the complexity of sentence structures (Grammatical Complexity) and the use of repair behaviors (Repair), respectively. Linear discriminant analyses showed that only about two thirds of speakers were classified correctly and that misclassifications were similar to disagreements between clinical diagnoses. The most accurately diagnosed syndromes were the largest groups-Broca's and anomic aphasia. The latent profile analysis also generated profiles similar to Broca's and anomic aphasia but separated some subtypes according to severity. Conclusions The factor solution and the classification analyses reflected broad patterns of spontaneous speech performance in a large and representative sample of individuals with aphasia. However, such data-driven approaches present a simplified picture of aphasia patterns, much as traditional syndrome categories do. To ensure ecological validity, a hybrid approach is recommended, balancing population-level analyses with examination of performance at the level of theoretically specified subgroups or individuals. Supplemental Material https://doi.org/10.23641/asha.13232354.

Response to Speech and Language Therapy According to Artery Involvement and Lesion Location in Post-stroke Aphasia

PURPOSE

Aphasia is one of the most common complications after stroke and occurs in 21-38% of the patients during acute period. The present study aimed to investigate the response to speech and language therapy according to artery involvement and lesion location in patients with post-stroke aphasia.

METHOD

The medical records of 107 patients with post-stroke aphasia (mean age, 58.8 ± 14.8 years) who were admitted to a single rehabilitation center for usual care after stroke were reviewed. Location of the ischemic lesion and involved artery was determined assessing the brain MRI of the patients. All the patients received 24 sessions speech and language therapy (3 days a week) as a part of 8-week rehabilitation program. Evaluation of the aphasia was performed with Gülhane Aphasia Test-2 (GAT-2) at baseline and at the end of the rehabilitation program.

RESULTS

Baseline GAT-2 scores was significantly worse in patients with middle cerebral artery (MCA) involvement compared to patients with other artery involvements (p = 0.007). While the GAT-2 scores of patients with MCA involvement were improved significantly after speech and language therapy (p < 0.001), the changes in those with anterior cerebral artery (ACA) and posterior cerebral artery (PCA) involvements were not significant (p > 0.05).

CONCLUSIONS

The present findings suggested that speech functions might be more affected in ischemic lesion of MCA and response to SLT might be better in patients with MCA involvement.

Preliminary Assessment of a Hand and Arm Exoskeleton for Enabling Bimanual Tasks for Individuals With Hemiparesis

The design and preliminary assessment of a semi-powered hand and arm exoskeleton is described. The exoskeleton is designed to enable bimanual activities of daily living for individuals with chronic, upper-limb hemiparesis resulting from stroke. Specifically, the device augments the user's grasp strength and ability to extend the affected hand for bimanual tasks and supplements wrist and elbow stability while conducting these tasks. The exoskeleton is battery-powered and self-contained with all electronics and power units placed within the device structure. A preliminary assessment of the exoskeleton was performed with three subjects having right-sided upper-limb motor deficit resulting from stroke. For subjects with limited hand and arm functionality, the exoskeleton increased grasp strength and improved the ability to perform representative bimanual tasks.

Changes in Language Function and Recovery-Related Prognostic Factors in First-Ever Left Hemispheric Ischemic Stroke

Objective

To investigate longitudinal changes in language function in left-hemispheric ischemic stroke patients as well as factors that influence language recovery until 1 year after stroke onset.

Methods

We analyzed data from 235 patients with first-ever left-hemispheric ischemic stroke. All patients completed the Korean version of the Frenchay Aphasia Screening Test (K-FAST) at 7 days (T1), 3 months (T2), 6 months (T3), and 1 year (T4) after stroke onset. Repeated measures analysis of variance (ANOVA) was used to investigate changes in language function between time points. Subgroup analysis was performed according to the K-FAST scores at T1. Stroke lesion volume was assessed using diffusion tensor images, and involvement of language-related brain regions was examined. Multiple regression analysis was used to analyze factors influencing improvement of K-FAST score.

Results

The K-FAST scores at T1, T2, T3, and T4 differed significantly (p<0.05). In the subgroup analysis, only the severe group showed continuous significant improvement by 1 year. Factors that negatively influenced improvement of language function were the age at onset, initial National Institutes of Health Stroke Scale (NIHSS) score, and initial K-FAST score, whereas education level and stroke lesion volume positively affected recovery. Involvement of language-related brain regions did not significantly influence long-term language recovery after ischemic stroke.

Conclusion

Recovery of language function varied according to the severity of the initial language deficit. The age at stroke onset, education level, initial severity of aphasia, initial NIHSS score, and total stroke lesion volume were found to be important factors for recovery of language function.

Cerebral small vessel disease: from a focal to a global perspective

Cerebral small vessel disease (SVD) is commonly observed on neuroimaging among elderly individuals and is recognized as a major vascular contributor to dementia, cognitive decline, gait impairment, mood disturbance and stroke. However, clinical symptoms are often highly inconsistent in nature and severity among patients with similar degrees of SVD on brain imaging. Here, we provide a new framework based on new advances in structural and functional neuroimaging that aims to explain the remarkable clinical variation in SVD. First, we discuss the heterogeneous pathology present in SVD lesions despite an identical appearance on imaging and the perilesional and remote effects of these lesions. We review effects of SVD on structural and functional connectivity in the brain, and we discuss how network disruption by SVD can lead to clinical deficits. We address reserve and compensatory mechanisms in SVD and discuss the part played by other age-related pathologies. Finally, we conclude that SVD should be considered a global rather than a focal disease, as the classically recognized focal lesions affect remote brain structures and structural and functional network connections. The large variability in clinical symptoms among patients with SVD can probably be understood by taking into account the heterogeneity of SVD lesions, the effects of SVD beyond the focal lesions, the contribution of neurodegenerative pathologies other than SVD, and the interaction with reserve mechanisms and compensatory mechanisms.

Thrombolysis' benefits on early post-stroke language recovery in aphasia patients

INTRODUCTION

Thrombolysis may affect ischemic stroke-related size, pattern and nature of infarcts, and has the potential to change aphasia presentation and recovery. Data on evolution of post-stroke aphasia following thrombolysis are still scarce. The aim of this study was to determine the course of language recovery through a well-validated language assessment battery after acute ischemic stroke and investigate whether traditional categorical classifications of aphasia can describe the clinical picture in post-thrombolysis phase.

MATERIALS AND METHODS

Demographic, clinical, and language assessment data of 116 patients presenting sub-acute ischemic stroke aphasia (41 treated with r-tPA; 75 non-treated) were retrospectively analyzed. The participants were assessed by a clinical neuropsychologist with a variety of subtests taken from a well-validated Italian language battery (Neuro-Psychological Aphasia Evaluation).

RESULTS

The percentage of resolved aphasia was significantly higher in treated patients compared to non-treated patients (p = 0.005) and global aphasia was more common in the non-treated group (non-treated 30.7% vs treated 17.1%). Aphasia subtypes and stroke etiologies showed no significant association, except for small vessel etiology and resolved aphasia (p = 0.041). Reperfusion treatment, baseline NIHSS, and lacunar stroke were the predictors of aphasia recovery.

CONCLUSION

The percentage of resolved aphasia was significantly higher in the treated patients compared to the non-treated, with the latter showing a higher percentage of global aphasia. Identifying classic aphasia subtypes after thrombolysis is still possible since reperfused areas do not necessary change the classification or lead to completely different aphasic syndromes. Reperfusion treatment, baseline NIHSS, and lacunar stroke were the main predictors of aphasia recovery.

Sex differences in post-stroke aphasia rates are caused by age. A meta-analysis and database query

BACKGROUND

Studies have suggested that aphasia rates are different in men and women following stroke. One hypothesis says that men have more lateralized language function than women. Given unilateral stroke, this would lead to a prediction of men having higher aphasia rates than women. Another line of observations suggest that women are more severely affected by stroke, which could lead to a higher aphasia rate among women. An additional potential confounding variable could be age, given that women are typically older at the time of stroke.

METHODS & PROCEDURES

This study consists of two parts. First, a meta-analysis of the available reports of aphasia rates in the two sexes was conducted. A comprehensive literature search yielded 25 studies with sufficient information about both aphasia and gender. These studies included a total of 48,362 stroke patients for which aphasia rates were calculated. Second, data were extracted from an American health database (with 1,967,038 stroke patients), in order to include age and stroke severity into a regression analysis of sex differences in aphasia rates.

OUTCOMES & RESULTS

Both analyses revealed significantly larger aphasia rates in women than in men (1.1-1.14 ratio). This speaks against the idea that men should be more lateralized in their language function. When age and stroke severity were included as covariates, sex failed to explain any aphasia rate sex difference above and beyond that which is explained by age differences at time of stroke.

Validation of a prediction model for long-term outcome of aphasia after stroke

Background

About 30% of stroke patients suffer from aphasia. As aphasia strongly affects daily life, most patients request a prediction of outcome of their language function. Prognostic models provide predictions of outcome, but external validation is essential before models can be used in clinical practice. We aim to externally validate the prognostic model from the Sequential Prognostic Evaluation of Aphasia after stroKe (SPEAK-model) for predicting the long-term outcome of aphasia caused by stroke.

Methods

We used data from the Rotterdam Aphasia Therapy Study – 3 (RATS-3), a multicenter RCT with inclusion criteria similar to SPEAK, an observational prospective study. Baseline assessment in SPEAK was four days after stroke and in RATS-3 eight days. Outcome of the SPEAK-model was the Aphasia Severity Rating Scale (ASRS) at 1 year, dichotomized into good (ASRS-score of 4 or 5) and poor outcome (ASRS-score < 4). In RATS-3, ASRS-scores at one year were not available, but we could use six month ASRS-scores as outcome. Model performance was assessed with calibration and discrimination.

Results

We included 131 stroke patients with first-ever aphasia. At six months, 86 of 124 (68%) had a good outcome, whereas the model predicted 88%. Discrimination of the model was good with an area under the receiver operation characteristic curve of 0.87 (95%CI: 0.81–0.94), but calibration was unsatisfactory. The model overestimated the probability of good outcome (calibration-in-the-large α = − 1.98) and the effect of the predictors was weaker in the validation data than in the derivation data (calibration slope β = 0.88). We therefore recalibrated the model to predict good outcome at six months.

Conclusion

The original model, renamed SPEAK-12, has good discriminative properties, but needs further external validation. After additional external validation, the updated SPEAK-model, SPEAK-6, may be used in daily practice to discriminate between patients with good and patients with poor outcome of aphasia at six months after stroke.

Trial registration

RATS-3 was registered on January 13th 2012 in the Netherlands Trial Register: NTR3271. SPEAK was not listed in a trial registry.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1174-5) contains supplementary material, which is available to authorized users.

Considerations for the Use of Neuroimaging Technologies for Predicting Recovery of Speech and Language in Aphasia

PURPOSE

The number of research articles aimed at identifying neuroimaging biomarkers for predicting recovery from aphasia continues to grow. Although the clinical use of these biomarkers to determine prognosis has been proposed, there has been little discussion of how this would be accomplished. This is an important issue because the best translational science occurs when translation is considered early in the research process. The purpose of this clinical focus article is to present a framework to guide the discussion of how neuroimaging biomarkers for recovery from aphasia could be implemented clinically.

METHOD

The genomics literature reveals that implementing genetic testing in the real-world poses both opportunities and challenges. There is much similarity between these opportunities and challenges and those related to implementing neuroimaging testing to predict recovery in aphasia. Therefore, the Center for Disease Control's model list of questions aimed at guiding the review of genetic testing has been adapted to guide the discussion of using neuroimaging biomarkers as predictors of recovery in aphasia.

CONCLUSION

The adapted model list presented here is a first and useful step toward initiating a discussion of how neuroimaging biomarkers of recovery could be employed clinically to provide improved quality of care for individuals with aphasia.

The Prognosis and Recovery of Aphasia Related to Stroke Lesion

Objective

To investigate the effects of specific brain lesions on prognosis and recovery of post-stroke aphasia, and to assess the characteristic pattern of recovery.

Methods

Total of 15 subjects with first-ever, left hemisphere stroke, who were right handed, and who completed language assessment using the Korean version of the Western Aphasia Battery (K-WAB) at least twice during the subacute and chronic stages of stroke, were included. The brain lesions of the participants were evaluated using MRI-cron, SPM8, and Talairach Daemon software.

Results

Subtraction of the lesion overlap map of the participants who showed more than 30% improvement in the aphasia quotient (AQ) by the time of their chronic stage (n=9) from the lesion overlap map of those who did not show more than 30% improvement in the AQ (n=6) revealed a strong relationship with Broca's area, inferior prefrontal gyrus, premotor cortex, and a less strong relationship with Wernicke's area and superior and middle temporal gyri. The culprit lesion related to poor prognosis, after grouping the subjects according to their AQ score in the chronic stage (a cut score of 50), revealed a strong relationship with Broca's area, superior temporal gyrus, and a less strong relationship with Wernicke's area, prefrontal cortex, and inferior frontal gyrus.

Conclusion

Brain lesions in the Broca's area, inferior prefrontal gyrus, and premotor cortex may be related to slow recovery of aphasia in patients with left hemisphere stroke. Furthermore, involvement of Broca's area and superior temporal gyrus may be associated with poor prognosis of post-stroke aphasia.

Recovery and Rehabilitation after Intracerebral Hemorrhage

About half of patients survive intracerebral hemorrhage (ICH), but most are left with significant disability. Rehabilitation after ICH is the mainstay of treatment to reduce impairment, improve independence in activities, and return patients to meaningful participation in the community. The authors discuss the neuroplastic mechanisms underlying recovery in ICH, preclinical and clinical interventional studies to augment recovery, and the rehabilitative and medical management of post-ICH patients.

EXTENDING THE ASSESSMENT OF TECHNOLOGY-AIDED PROGRAMS TO SUPPORT LEISURE AND COMMUNICATION IN PEOPLE WITH ACQUIRED BRAIN INJURY AND EXTENSIVE MULTIPLE DISABILITIES

Intervention programs for people with acquired brain injury and extensive motor and communication impairment need to be diversified according to their characteristics and environment. These two studies assessed two technology-aided programs for supporting leisure (i.e., access to songs and videos) and communication (i.e., expressing needs and feelings and making requests) in six of those people. The three people participating in Study 1 did not possess speech but were able to understand spoken and written sentences. Their program presented leisure and communication options through written phrases appearing on the computer screen. The three people participating in Study 2 did not possess any speech and were unable to understand spoken or written language. Their program presented leisure and communication options through pictorial images. All participants relied on a simple microswitch response to enter the options and activate songs, videos, and communication messages. The data showed that the participants of both studies learned to use the program available to them and to engage in leisure and communication independently. The importance of using programs adapted to the participants and their environment was discussed.