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Neurorehabilitation and Neural Repair Feb 2022Speech entrainment (SE), the online mimicking of an audio-visual speech model, has been shown to increase speech fluency in individuals with non-fluent aphasia. One...
BACKGROUND
Speech entrainment (SE), the online mimicking of an audio-visual speech model, has been shown to increase speech fluency in individuals with non-fluent aphasia. One theory that may explain why SE improves speech output is that it synchronizes functional connectivity between anterior and posterior language regions to be more similar to that of neurotypical speakers.
OBJECTIVES
The present study tested this by measuring functional connectivity between 2 regions shown to be necessary for speech production, and their right hemisphere homologues, in 24 persons with aphasia compared to 20 controls during both free (spontaneous) speech and SE.
METHODS
Regional functional connectivity in participants with aphasia were normalized to the control data. Two analyses were then carried out: (1) normalized functional connectivity was compared between persons with aphasia and controls during free speech and SE and (2) stepwise linear models with leave-one-out cross-validation including normed functional connectivity during both tasks and proportion damage to the left hemisphere as independent variables were created for each language score.
RESULTS
Left anterior-posterior functional connectivity and left posterior to right anterior functional connectivity were significantly more similar to connectivity of the control group during SE compared to free speech. Additionally, connectivity during free speech was more associated with language measures than connectivity during SE.
CONCLUSIONS
Overall, these results suggest that SE promotes normalization of functional connectivity (i.e., return to patterns observed in neurotypical controls), which may explain why individuals with non-fluent aphasia produce more fluent speech during SE compared to spontaneous speech.
Topics: Adult; Aged; Aphasia, Broca; Chronic Disease; Connectome; Female; Humans; Imitative Behavior; Magnetic Resonance Imaging; Male; Middle Aged; Mouth; Outcome Assessment, Health Care; Speech Perception; Speech Therapy; Stroke Rehabilitation; Visual Perception
PubMed: 34968159
DOI: 10.1177/15459683211064264 -
Annals of Indian Academy of Neurology 2022Chronic encephalitis manifesting as an epilepsy syndrome most commonly presents as Rasmussen's syndrome, usually characterized by epilepsia partialis continua,...
Chronic encephalitis manifesting as an epilepsy syndrome most commonly presents as Rasmussen's syndrome, usually characterized by epilepsia partialis continua, hemiparesis, and progressive cortical deficits such as aphasia, hemianopia, and cognitive decline. It is characterized by progressive hemispheric cortical atrophy on imaging and is usually seen in childhood. Adult-onset of the syndrome is rare, and only a few cases have been reported with bilateral symptoms. We present a patient with pseudobulbar affect and frontal lobe dysfunction who developed multifocal myoclonic jerks, right hemibody focal motor seizures, and right hemiparesis with bilateral cerebellar signs. Magnetic resonance imaging showed progressive hemispheric atrophy and bilateral features in Positron emission tomography-computed tomography (PET CT). Brain biopsy revealed chronic T-cell infiltrate. We discuss this case as the patient had several features that were atypical for Rasmussen's encephalitis (or syndrome).
PubMed: 35936618
DOI: 10.4103/aian.aian_982_21 -
Brain Communications 2022Although impaired discourse production is one of the prominent features of aphasia, only a handful of investigations have addressed the cognitive, linguistic and neural...
Although impaired discourse production is one of the prominent features of aphasia, only a handful of investigations have addressed the cognitive, linguistic and neural processes that support the production of coherent discourse. In this study, we investigated the cognitive and neural correlates of discourse coherence in a large mixed cohort of patients with post-stroke aphasia, including the first voxel-based lesion-symptom mapping of coherence deficits. Discourse responses using different tasks were collected from 46 patients with post-stroke aphasia, including a wide range of classifications and severity levels, and 20 matched neuro-typical controls. Global coherence, defined as the degree to which utterances related to the expected topic of discourse, was estimated using a previously validated computational linguistic approach. Coherence was then related to fundamental language and cognitive components in aphasia identified using an extensive neuropsychological battery. Relative to neuro-typical controls, patients with aphasia exhibited impaired coherence, and their ability to maintain coherent discourse was related to their performance on other language components: phonological production, fluency and semantic processing, rather than executive functions or motor speech. These results suggest that impairments in core language components play a role in reducing discourse coherence in post-stroke aphasia. Whole-brain voxel-wise lesion-symptom mapping using univariate and multivariate approaches identified the contribution of the left prefrontal cortex, and particularly the inferior frontal gyrus (pars triangularis), to discourse coherence. These findings provide convergent evidence for the role of the inferior frontal gyrus in maintaining discourse coherence, which is consistent with the established role of this region in producing connected speech and semantic control (organizing and selecting appropriate context-relevant concepts). These results make an important contribution to understanding the root causes of disrupted discourse production in post-stroke aphasia.
PubMed: 35774183
DOI: 10.1093/braincomms/fcac147 -
Trials Jun 2022Motor aphasia after stroke is a common and intractable complication of stroke. Acupuncture and language training may be an alternative and effective approach. However,...
BACKGROUND
Motor aphasia after stroke is a common and intractable complication of stroke. Acupuncture and language training may be an alternative and effective approach. However, the efficacy of acupuncture and language training for motor aphasia after stroke has not been confirmed. The main objectives of this trial are to evaluate the effectiveness and safety of acupuncture and low-intensity, low-dose language training in treating ischemic motor aphasia after stroke from 15 to 90 days.
METHODS
This is a multicenter randomized sham-controlled clinical trial. We will allocate 252 subjects aged between 45 and 75 years diagnosed with motor aphasia after stroke with an onset time ranging from 15 to 90 days into two groups randomly in a 1:1 ratio. Patients in the experimental group will be treated with "Xing-Nao Kai-Qiao" acupuncture therapy plus language training, and those in the control group will be treated with sham-acupoint (1 cun next to the acupoints) acupuncture therapy plus language training. All the patients will be given acupuncture and language training for 6 weeks, with a follow-up evaluation 6 weeks after the end of the treatment and 6 months after the onset time. The patients will mainly be evaluated using the Western Aphasia Battery and Chinese Functional Communication Profile, and the incidence of treatment-related adverse events at the 2nd, 4th, and 6th weeks of treatment will be recorded. The baseline characteristics of the patients will be summarized by group, the chi-squared test will be used to compare categorical variables, and repeated measures of analysis of variance or a linear mixed model will be applied to analyze the changes measured at different time points.
DISCUSSION
The present study is designed to investigate the effectiveness and safety of traditional acupuncture therapy and language training in ischemic motor aphasia after stroke and explore the correlation between the treatment time and clinical effect of acupuncture. We hope our results will help doctors understand and utilize acupuncture combined with language training.
TRIAL REGISTRATION
ChiCTR ChiCTR1900026740 . Registered on 20 October 2019.
Topics: Acupuncture Points; Acupuncture Therapy; Aged; Aphasia, Broca; Combined Modality Therapy; Humans; Language Therapy; Middle Aged; Multicenter Studies as Topic; Randomized Controlled Trials as Topic; Stroke; Treatment Outcome
PubMed: 35773693
DOI: 10.1186/s13063-022-06280-2 -
Scientific Reports Jun 2021Electroencephalographic synchrony can help assess brain network status; however, its usefulness has not yet been fully proven. We developed a clinically feasible method... (Observational Study)
Observational Study
Electroencephalographic synchrony can help assess brain network status; however, its usefulness has not yet been fully proven. We developed a clinically feasible method that combines the phase synchrony index (PSI) with resting-state 19-channel electroencephalography (EEG) to evaluate post-stroke motor impairment. In this study, we investigated whether our method could be applied to aphasia, a common post-stroke cognitive impairment. This study included 31 patients with subacute aphasia and 24 healthy controls. We assessed the expressive function of patients and calculated the PSIs of three motor language-related regions: frontofrontal, left frontotemporal, and right frontotemporal. Then, we evaluated post-stroke network alterations by comparing PSIs of the patients and controls and by analyzing the correlations between PSIs and aphasia scores. The frontofrontal PSI (beta band) was lower in patients than in controls and positively correlated with aphasia scores, whereas the right frontotemporal PSI (delta band) was higher in patients than in controls and negatively correlated with aphasia scores. Evaluation of artifacts suggests that this association is attributed to true synchrony rather than spurious synchrony. These findings suggest that post-stroke aphasia is associated with alternations of two different networks and point to the usefulness of EEG PSI in understanding the pathophysiology of aphasia.
Topics: Aged; Aged, 80 and over; Aphasia; Cross-Sectional Studies; Electroencephalography Phase Synchronization; Feasibility Studies; Female; Frontal Lobe; Healthy Volunteers; Humans; Male; Middle Aged; Nerve Net; Rest; Severity of Illness Index; Stroke; Temporal Lobe
PubMed: 34127750
DOI: 10.1038/s41598-021-91978-7 -
Cortex; a Journal Devoted To the Study... Oct 2022Impairments in speech production can have devastating effects on the overall quality of life in left-hemisphere stroke survivors with aphasia; however, there is a...
Impairments in speech production can have devastating effects on the overall quality of life in left-hemisphere stroke survivors with aphasia; however, there is a paucity of research focusing on neural deficits in speech motor planning networks that are activated prior to the onset of speech production in this clinical population. In the present study, we examined directional brain connectivity correlates of speech preparation and planning in low-β (13-20 Hz) and high-β (21-30 Hz) band neural oscillations in participants aphasia compared with controls prior to the onset of speech. Electroencephalographic (EEG) data were concurrently recorded from 33 participants with post-stroke aphasia and 22 neurologically intact controls while they engaged in speech production tasks. Using Granger causality, brain connectivity was calculated between electrode pairs that fell within fronto-frontal, fronto-central, and fronto-parietal networks implicated in sensorimotor integration and speech planning. Clinical assessment was further conducted in post-stroke participants to measure the severity of language impairment associated with aphasia. Increased intra-hemispheric connectivity was found within low- and high-β bands in the left parieto-central and parieto-frontal as well as the right fronto-frontal and fronto-central electrodes in post-stroke participants compared with controls prior to the onset of speech production. In addition, we found that decreased inter-hemispheric centro-central connectivity within high-β band was negatively correlated with aphasia severity whereas increased parieto-frontal connectivity within high-β band was positively correlated with aphasia severity. These findings suggest that participants with left-hemisphere stroke express aberrant brain connectivity within low- and high-β bands in both left and right hemispheres during the planning phase of speech production, and that these deficits are associated with specific aspects of their language impairment, as indicated by their clinical symptoms due to aphasia.
Topics: Aphasia; Brain; Humans; Language Development Disorders; Magnetic Resonance Imaging; Quality of Life; Speech; Stroke
PubMed: 35973239
DOI: 10.1016/j.cortex.2022.07.001 -
Neurology Jul 2020To compare the sensitivity of structural MRI and F-fludeoxyglucose PET (FDG-PET) to detect longitudinal changes in frontotemporal dementia (FTD).
OBJECTIVE
To compare the sensitivity of structural MRI and F-fludeoxyglucose PET (FDG-PET) to detect longitudinal changes in frontotemporal dementia (FTD).
METHODS
Thirty patients with behavioral variant FTD (bvFTD), 7 with nonfluent/agrammatic variant primary progressive aphasia (nfvPPA), 16 with semantic variant primary progressive aphasia (svPPA), and 43 cognitively normal controls underwent 2-4 MRI and FDG-PET scans (total scans/visit = 270) as part of the Frontotemporal Lobar Degeneration Neuroimaging Initiative study. Linear mixed-effects models were carried out voxel-wise and in regions of interest to identify areas showing decreased volume or metabolism over time in patients as compared to controls.
RESULTS
At baseline, patients with bvFTD showed bilateral temporal, dorsolateral, and medial prefrontal atrophy/hypometabolism that extended with time into adjacent structures and parietal lobe. In nfvPPA, baseline atrophy/hypometabolism in supplementary motor cortex extended with time into left greater than right precentral, dorsolateral, and dorsomedial prefrontal cortex. In svPPA, baseline atrophy/hypometabolism encompassed the anterior temporal and medial prefrontal cortex and longitudinal changes were found in temporal, orbitofrontal, and lateral parietal cortex. Across syndromes, there was substantial overlap in the brain regions showing volume and metabolism loss. Even though the pattern of metabolic decline was more extensive, metabolic changes were also more variable and sample size estimates were similar or higher for FDG-PET compared to MRI.
CONCLUSION
Our findings demonstrated the sensitivity of FDG-PET and structural MRI for tracking disease progression in FTD. Both modalities showed highly overlapping patterns of longitudinal change and comparable sample size estimates to detect longitudinal changes in future clinical trials.
Topics: Aged; Atrophy; Cerebral Cortex; Disease Progression; Female; Fluorodeoxyglucose F18; Frontotemporal Dementia; Humans; Longitudinal Studies; Magnetic Resonance Imaging; Male; Middle Aged; Neuroimaging; Neuropsychological Tests; Positron-Emission Tomography; Radiopharmaceuticals
PubMed: 32591470
DOI: 10.1212/WNL.0000000000009760 -
Brain Sciences Mar 2022Obstructive sleep apnea is highly prevalent in the post-stroke population, and has been shown to affect cognitive, neurological, and functional status. Continuous... (Review)
Review
Obstructive sleep apnea is highly prevalent in the post-stroke population, and has been shown to affect cognitive, neurological, and functional status. Continuous positive airway pressure (CPAP) treatment is one of the most effective interventions for obstructive sleep apnea, but compliance is often low due to confounding effects of co-occurring conditions, side effects of treatment titration procedures, and individual patient personality characteristics, perceptions, and social factors. Current research suggests that CPAP treatment for obstructive sleep apnea is not associated with significant risk and can subsequently improve post-stroke motor and neurocognitive function. However, effects of CPAP treatment on post-stroke speech and language recovery remain unclear. Post-stroke communication disorders (e.g., aphasia, dysarthria, and apraxia) are also highly prevalent in this population. Knowledge of the potential positive impact of CPAP on language recovery could contribute to patients' motivation to comply with CPAP treatment and provide incentive for speech-language pathologists to refer patients to sleep medicine specialists. In this review of the literature, we examine the question of what effect CPAP treatment may have on post-stroke speech and language function and recovery, as well as summarize the current knowledge on cognitive, neurological, and functional effects. While this review of the literature found CPAP to have varying effects on different cognitive domains, there was not sufficient evidence to determine effects on language recovery. Further research is necessary to determine the potential effects of CPAP treatment on speech and language recovery among stroke patients.
PubMed: 35326335
DOI: 10.3390/brainsci12030379 -
Cerebral Cortex (New York, N.Y. : 1991) May 2022It is assumed that there are a static set of "language regions" in the brain. Yet, language comprehension engages regions well beyond these, and patients regularly...
It is assumed that there are a static set of "language regions" in the brain. Yet, language comprehension engages regions well beyond these, and patients regularly produce familiar "formulaic" expressions when language regions are severely damaged. These suggest that the neurobiology of language is not fixed but varies with experiences, like the extent of word sequence learning. We hypothesized that perceiving overlearned sentences is supported by speech production and not putative language regions. Participants underwent 2 sessions of behavioral testing and functional magnetic resonance imaging (fMRI). During the intervening 15 days, they repeated 2 sentences 30 times each, twice a day. In both fMRI sessions, they "passively" listened to those sentences, novel sentences, and produced sentences. Behaviorally, evidence for overlearning included a 2.1-s decrease in reaction times to predict the final word in overlearned sentences. This corresponded to the recruitment of sensorimotor regions involved in sentence production, inactivation of temporal and inferior frontal regions involved in novel sentence listening, and a 45% change in global network organization. Thus, there was a profound whole-brain reorganization following sentence overlearning, out of "language" and into sensorimotor regions. The latter are generally preserved in aphasia and Alzheimer's disease, perhaps explaining residual abilities with formulaic expressions in both.
Topics: Brain Mapping; Comprehension; Humans; Language; Magnetic Resonance Imaging; Overlearning; Speech; Speech Perception
PubMed: 34585723
DOI: 10.1093/cercor/bhab354 -
Epilepsia Open Mar 2023Insular epilepsy (IE) is an increasingly recognized cause of drug-resistant epilepsy amenable to surgery. However, concerns of suboptimal seizure control and permanent... (Meta-Analysis)
Meta-Analysis Review
Insular epilepsy (IE) is an increasingly recognized cause of drug-resistant epilepsy amenable to surgery. However, concerns of suboptimal seizure control and permanent neurological morbidity hamper widespread adoption of surgery for IE. We performed a systematic review and individual participant data meta-analysis to determine the efficacy and safety profile of surgery for IE and identify predictors of outcomes. Of 2483 unique citations, 24 retrospective studies reporting on 312 participants were eligible for inclusion. The median follow-up duration was 2.58 years (range, 0-17 years), and 206 (66.7%) patients were seizure-free at last follow-up. Younger age at surgery (≤18 years; HR = 1.70, 95% CI = 1.09-2.66, P = .022) and invasive EEG monitoring (HR = 1.97, 95% CI = 1.04-3.74, P = .039) were significantly associated with shorter time to seizure recurrence. Performing MR-guided laser ablation or radiofrequency ablation instead of open resection (OR = 2.05, 95% CI = 1.08-3.89, P = .028) was independently associated with suboptimal or poor seizure outcome (Engel II-IV) at last follow-up. Postoperative neurological complications occurred in 42.5% of patients, most commonly motor deficits (29.9%). Permanent neurological complications occurred in 7.8% of surgeries, including 5% and 1.4% rate of permanent motor deficits and dysphasia, respectively. Resection of the frontal operculum was independently associated with greater odds of motor deficits (OR = 2.75, 95% CI = 1.46-5.15, P = .002). Dominant-hemisphere resections were independently associated with dysphasia (OR = 13.09, 95% CI = 2.22-77.14, P = .005) albeit none of the observed language deficits were permanent. Surgery for IE is associated with a good efficacy/safety profile. Most patients experience seizure freedom, and neurological deficits are predominantly transient. Pediatric patients and those requiring invasive monitoring or undergoing stereotactic ablation procedures experience lower rates of seizure freedom. Transgression of the frontal operculum should be avoided if it is not deemed part of the epileptogenic zone. Well-selected candidates undergoing dominant-hemisphere resection are more likely to exhibit transient language deficits; however, the risk of permanent deficit is very low.
Topics: Humans; Child; Adolescent; Retrospective Studies; Treatment Outcome; Follow-Up Studies; Electroencephalography; Magnetic Resonance Imaging; Drug Resistant Epilepsy; Seizures; Epilepsy; Aphasia; Postoperative Complications
PubMed: 36263454
DOI: 10.1002/epi4.12663