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Experimental Brain Research Jan 2024The present study examined opposing and following vocal responses to altered auditory feedback (AAF) to determine how damage to left-hemisphere brain networks impairs...
Impairment of the internal forward model and feedback mechanisms for vocal sensorimotor control in post-stroke aphasia: evidence from directional responses to altered auditory feedback.
The present study examined opposing and following vocal responses to altered auditory feedback (AAF) to determine how damage to left-hemisphere brain networks impairs the internal forward model and feedback mechanisms in post-stroke aphasia. Forty-nine subjects with aphasia and sixty age-matched controls performed speech vowel production tasks while their auditory feedback was altered using randomized ± 100 cents upward and downward pitch-shift stimuli. Data analysis revealed that when vocal responses were averaged across all trials (i.e., opposing and following), the overall magnitude of vocal compensation was significantly reduced in the aphasia group compared with controls. In addition, when vocal responses were analyzed separately for opposing and following trials, subjects in the aphasia group showed a significantly lower percentage of opposing and higher percentage of following vocal response trials compared with controls, particularly for the upward pitch-shift stimuli. However, there was no significant difference in the magnitude of opposing and following vocal responses between the two groups. These findings further support previous evidence on the impairment of vocal sensorimotor control in aphasia and provide new insights into the distinctive impact of left-hemisphere stroke on the internal forward model and feedback mechanisms. In this context, we propose that the lower percentage of opposing responses in aphasia may be accounted for by deficits in feedback-dependent mechanisms of audio-vocal integration and motor control. In addition, the higher percentage of following responses may reflect aberrantly increased reliance of the speech system on the internal forward model for generating sensory predictions during vocal error detection and motor control.
Topics: Humans; Feedback; Pitch Perception; Voice; Speech; Feedback, Sensory; Aphasia
PubMed: 37999725
DOI: 10.1007/s00221-023-06743-1 -
Brain : a Journal of Neurology Apr 2024It is debated whether primary progressive apraxia of speech (PPAOS) and progressive agrammatic aphasia (PAA) belong to the same clinical spectrum, traditionally termed...
It is debated whether primary progressive apraxia of speech (PPAOS) and progressive agrammatic aphasia (PAA) belong to the same clinical spectrum, traditionally termed non-fluent/agrammatic variant primary progressive aphasia (nfvPPA), or exist as two completely distinct syndromic entities with specific pathologic/prognostic correlates. We analysed speech, language and disease severity features in a comprehensive cohort of patients with progressive motor speech impairment and/or agrammatism to ascertain evidence of naturally occurring, clinically meaningful non-overlapping syndromic entities (e.g. PPAOS and PAA) in our data. We also assessed if data-driven latent clinical dimensions with aetiologic/prognostic value could be identified. We included 98 participants, 43 of whom had an autopsy-confirmed neuropathological diagnosis. Speech pathologists assessed motor speech features indicative of dysarthria and apraxia of speech (AOS). Quantitative expressive/receptive agrammatism measures were obtained and compared with healthy controls. Baseline and longitudinal disease severity was evaluated using the Clinical Dementia Rating Sum of Boxes (CDR-SB). We investigated the data's clustering tendency and cluster stability to form robust symptom clusters and employed principal component analysis to extract data-driven latent clinical dimensions (LCD). The longitudinal CDR-SB change was estimated using linear mixed-effects models. Of the participants included in this study, 93 conformed to previously reported clinical profiles (75 with AOS and agrammatism, 12 PPAOS and six PAA). The remaining five participants were characterized by non-fluent speech, executive dysfunction and dysarthria without apraxia of speech or frank agrammatism. No baseline clinical features differentiated between frontotemporal lobar degeneration neuropathological subgroups. The Hopkins statistic demonstrated a low cluster tendency in the entire sample (0.45 with values near 0.5 indicating random data). Cluster stability analyses showed that only two robust subgroups (differing in agrammatism, executive dysfunction and overall disease severity) could be identified. Three data-driven components accounted for 71% of the variance [(i) severity-agrammatism; (ii) prominent AOS; and (iii) prominent dysarthria]. None of these data-driven LCDs allowed an accurate prediction of neuropathology. The severity-agrammatism component was an independent predictor of a faster CDR-SB increase in all the participants. Higher dysarthria severity, reduced words per minute and expressive and receptive agrammatism severity at baseline independently predicted accelerated disease progression. Our findings indicate that PPAOS and PAA, rather than exist as completely distinct syndromic entities, constitute a clinical continuum. In our cohort, splitting the nfvPPA spectrum into separate clinical phenotypes did not improve clinical-pathological correlations, stressing the need for new biological markers and consensus regarding updated terminology and clinical classification.
Topics: Humans; Aphasia, Broca; Dysarthria; Apraxias; Language; Speech; Aphasia, Primary Progressive; Primary Progressive Nonfluent Aphasia
PubMed: 37988272
DOI: 10.1093/brain/awad396 -
Brain Communications 2023Apraxia of eyelid opening (or eye-opening apraxia) is characterized by the inability to voluntarily open the eyes because of impaired supranuclear control. Here, we...
Apraxia of eyelid opening (or eye-opening apraxia) is characterized by the inability to voluntarily open the eyes because of impaired supranuclear control. Here, we examined the neural substrates implicated in eye-opening apraxia through lesion network mapping. We analysed brain lesions from 27 eye-opening apraxia stroke patients and compared them with lesions from 20 aphasia and 45 hemiballismus patients serving as controls. Lesions were mapped onto a standard brain atlas using resting-state functional MRI data derived from 966 healthy adults in the Harvard Dataverse. Our analyses revealed that most eye-opening apraxia-associated lesions occurred in the right hemisphere, with subcortical or mixed cortical/subcortical involvement. Despite their anatomical heterogeneity, these lesions functionally converged on the bilateral dorsal anterior and posterior insula. The functional connectivity map for eye-opening apraxia was distinct from those for aphasia and hemiballismus. Hemiballismus lesions predominantly mapped onto the putamen, particularly the posterolateral region, while aphasia lesions were localized to language-processing regions, primarily within the frontal operculum. In summary, in patients with eye-opening apraxia, disruptions in the dorsal anterior and posterior insula may compromise their capacity to initiate the appropriate eyelid-opening response to relevant interoceptive and exteroceptive stimuli, implicating a complex interplay between salience detection and motor execution.
PubMed: 37953849
DOI: 10.1093/braincomms/fcad288 -
Clinical Neurology and Neurosurgery Dec 2023A resting-state functional magnetic resonance imaging (rs-fMRI) approach was used to explore functional connectivity (FC) in language and non-language brain networks in...
OBJECTIVE
A resting-state functional magnetic resonance imaging (rs-fMRI) approach was used to explore functional connectivity (FC) in language and non-language brain networks in acute post-stroke aphasia (PSA) patients, with a specific focus on the relationship between these fMRI results and patient clinical presentation.
METHODS
In total, 20 acute PSA patients and 30 age-, sex-, and education level-matched healthy control (HC) participants were recruited and subjected to rs-fMRI imaging. In addition, western aphasia battery analyses(WAB) were used to compute aphasia quotient (AQ) values for PSA patients. Granger causality was employed to examine connections among cognition-associated resting-state brain networks, and the right middle frontal gyrus (RMFG),the mirror brain regions of Broca's area and the Wernicke's area, the right superior temporal gyrus were selected as regions of interest (ROIs). The REST plus software was then used to perform FC analyses of these regions to analyze changes in FC related to PSA pathogenesis.
RESULTS
Relative to HC individuals, PSA patients exhibited significantly higher levels of intra-network FC between the right middle frontal gyrus (RMFG) and the left middle occipital gyrus (LMOG), with such FC being positively correlated with the AQ scores (P = 0.018). Moreover, reduced FC was detected between the Broca's area homolog and the left middle frontal gyrus (LMFG), while FC was enhanced between the Wernicke's area homolog and cerebellar vermis, and this FC was similarly positively correlated with patient AQ scores (P = 0.0297).
CONCLUSION
These results suggest that FC between the bilateral hemispheres of the brain is significantly disrupted in acute PSA patients, interfering with the normal non-specific language network. Aphasia severity was further found to correlate with FC among many of the analyzed regions of the brain.
Topics: Humans; Brain Mapping; Brain; Aphasia; Language; Magnetic Resonance Imaging; Broca Area
PubMed: 37951030
DOI: 10.1016/j.clineuro.2023.108044 -
Neurobiology of Language (Cambridge,... 2023After a stroke, individuals with aphasia often recover to a certain extent over time. This recovery process may be dependent on the health of surviving brain regions....
After a stroke, individuals with aphasia often recover to a certain extent over time. This recovery process may be dependent on the health of surviving brain regions. Leukoaraiosis (white matter hyperintensities on MRI reflecting cerebral small vessel disease) is one indication of compromised brain health and is associated with cognitive and motor impairment. Previous studies have suggested that leukoaraiosis may be a clinically relevant predictor of aphasia outcomes and recovery, although findings have been inconsistent. We investigated the relationship between leukoaraiosis and aphasia in the first year after stroke. We recruited 267 patients with acute left hemispheric stroke and coincident fluid attenuated inversion recovery MRI. Patients were evaluated for aphasia within 5 days of stroke, and 174 patients presented with aphasia acutely. Of these, 84 patients were evaluated at ∼3 months post-stroke or later to assess longer-term speech and language outcomes. Multivariable regression models were fit to the data to identify any relationships between leukoaraiosis and initial aphasia severity, extent of recovery, or longer-term aphasia severity. We found that leukoaraiosis was present to varying degrees in 90% of patients. However, leukoaraiosis did not predict initial aphasia severity, aphasia recovery, or longer-term aphasia severity. The lack of any relationship between leukoaraiosis severity and aphasia recovery may reflect the anatomical distribution of cerebral small vessel disease, which is largely medial to the white matter pathways that are critical for speech and language function.
PubMed: 37946731
DOI: 10.1162/nol_a_00115 -
Neurobiology of Language (Cambridge,... 2023Sentence structure, or syntax, is potentially a uniquely creative aspect of the human mind. Neuropsychological experiments in the 1970s suggested parallel syntactic...
Sentence structure, or syntax, is potentially a uniquely creative aspect of the human mind. Neuropsychological experiments in the 1970s suggested parallel syntactic production and comprehension deficits in agrammatic Broca's aphasia, thought to result from damage to syntactic mechanisms in Broca's area in the left frontal lobe. This hypothesis was sometimes termed , converging with developments in linguistic theory concerning central syntactic mechanisms supporting language production and comprehension. However, the evidence supporting an association among receptive syntactic deficits, expressive agrammatism, and damage to frontal cortex is equivocal. In addition, the relationship among a distinct grammatical production deficit in aphasia, paragrammatism, and receptive syntax has not been assessed. We used lesion-symptom mapping in three partially overlapping groups of left-hemisphere stroke patients to investigate these issues: grammatical production deficits in a primary group of 53 subjects and syntactic comprehension in larger sample sizes ( = 130, 218) that overlapped with the primary group. Paragrammatic production deficits were significantly associated with multiple analyses of syntactic comprehension, particularly when incorporating lesion volume as a covariate, but agrammatic production deficits were not. The lesion correlates of impaired performance of syntactic comprehension were significantly associated with damage to temporal lobe regions, which were also implicated in paragrammatism, but not with the inferior and middle frontal regions implicated in expressive agrammatism. Our results provide strong evidence against the overarching agrammatism hypothesis. By contrast, our results suggest the possibility of an alternative grammatical parallelism hypothesis rooted in paragrammatism and a central syntactic system in the posterior temporal lobe.
PubMed: 37946730
DOI: 10.1162/nol_a_00117 -
Frontiers in Neurology 2023Loss of time is a major obstacle to efficient stroke treatment. Our telestroke path intends to optimize prehospital triage using a video link connecting ambulance...
Real-time video analysis allows the identification of large vessel occlusion in patients with suspected stroke: feasibility trial of a "telestroke" pathway in Northwestern Switzerland.
BACKGROUND AND AIM
Loss of time is a major obstacle to efficient stroke treatment. Our telestroke path intends to optimize prehospital triage using a video link connecting ambulance personnel and a stroke physician. The objectives were as follows: (1) To identify patients suffering a stroke and (2) in particular large vessel occlusion (LVO) strokes as candidates for endovascular treatment. We have chosen the Rapid Arterial Occlusion Evaluation (RACE) scale for this purpose.
METHODS
This analysis aimed to verify the feasibility of prehospital stroke identification by video assessment. In this prospective telestroke cohort study, we included 97 subjects, in which the RACE score (items: facial palsy, arm and leg motor function, head and gaze deviation, and aphasia or agnosia) was applied, and the assessment videotaped by a trained member of the Emergency Medical Services (EMS) in the field using a mobile device. Each recorded patient video was independently assessed by three experienced stroke physicians from a certified stroke center and compared to the neuroimaging gold standard. Within this feasibility study, the stroke code was not altered by the outcome of the RACE assessment, and all patients underwent the standard procedures within the emergency unit.
RESULTS
We analyzed 97 patients (median age 78 years, 53% women), of whom 51 (52.6%) suffered an acute stroke, 12 (23.5%) of which were due to an LVO and 46 patients had symptoms mimicking a stroke. The sensitivity of stroke identification was 77.8%, and specificity was 53.6%. In regard to the identification of an LVO, sensitivity was 69.4% and specificity was 84.3%. The inter-rater agreement in the RACE-score assessment was ICC = 0.82 (intraclass-correlation coefficient).
CONCLUSION
These results confirm our hypothesis that the local telestroke concept is feasible. It allows correct (i) stroke and (ii) LVO identification in the majority of the cases and thus has the potential to assist in efficient prehospital triage.
PubMed: 37941577
DOI: 10.3389/fneur.2023.1232401 -
NeuroRehabilitation 2023Some research suggests that post-stroke aphasia can recover "on its own", however, there is evidence of a common neural substrate for motor and language systems. We...
Aphasia improvement without logotherapy during motor neurorehabilitation of post-stroke hemiparesis using virtual reality or modified constraint-induced movement therapy: A retrospective cohort.
BACKGROUND
Some research suggests that post-stroke aphasia can recover "on its own", however, there is evidence of a common neural substrate for motor and language systems. We hypothesize, that motor neurorehabilitation of hemiparesis could be related to simultaneous improvement in aphasia.
OBJECTIVE
To measure changes in post-stroke aphasia and its relation with hemiparesis treated with different therapies.
METHODS
Database information (n = 32) on post-stroke hemiparesis (Fugl-Meyer Scale evaluated) managed with virtual reality (VR) versus modified constraint-induced movement therapy (mCIMT) or regular therapy (rPT/OT) was analyzed. None received logotherapy (LT) by appointment at four months.
INCLUSION CRITERIA
< 3 months after the stroke, aphasia severe (Boston Aphasia Intensity Scale), and all three evaluations.
RESULTS
Twenty-one patient records met inclusion criteria (71,4% women and mean age 66,67±3,13 years) who received VR, mCIMT, or rPT/OT (n = 6, 8, and 7, respectively). There was continuous intra-groups improvement in aphasia (p < 0.05), but inter-groups the greater aphasia recovery (p = 0.05) and hemiparesis (p = 0.02) were in VR, with a high correlation in evolution between them (r = 0.73; p = 0.047).
CONCLUSION
High clinical correlation between aphasia, without LT, and hemiparesis evolution during motor neurorehabilitation would support common neural connections stimulation. We will conduct a clinical trial, with a larger sample size to contrast our hypothesis.
Topics: Female; Humans; Male; Aphasia; Logotherapy; Neurological Rehabilitation; Paresis; Recovery of Function; Retrospective Studies; Stroke; Stroke Rehabilitation; Virtual Reality; Middle Aged; Aged
PubMed: 37927287
DOI: 10.3233/NRE-230183 -
Journal of Speech, Language, and... Dec 2023The purpose of this project was to determine the feasibility of employing a functional magnetic resonance imaging (fMRI) task that captured activation associated with...
PURPOSE
The purpose of this project was to determine the feasibility of employing a functional magnetic resonance imaging (fMRI) task that captured activation associated with overt, unscripted (or free) discourse of people with aphasia (PWA), using a continuous scan paradigm.
METHOD
Seven participants (six females, ages 48-70 years) with chronic poststroke aphasia underwent two fMRI scanning sessions that included a discourse fMRI paradigm that consisted of five 1-min picture description tasks, using personally relevant photographs, interspersed with two 30-s control periods where participants looked at a fixation cross. Audio during the continuous fMRI scan was collected and marked with speaking times and coded for correct information units. Activation maps from the fMRI data were generated for the contrast between speaking and control conditions. In order to show the effects of the multi-echo data analysis, we compared it to a single-echo analysis by using only the middle echo (echo time of 30 ms).
RESULTS
Through the implementation of the free discourse fMRI task, we were able to elicit activation that included bilateral regions in the planum polare, central opercular cortex, precentral gyrus, superior temporal gyrus, middle temporal gyrus, superior temporal gyrus, Crus I of the cerebellum, as well as bilateral occipital regions.
CONCLUSIONS
We describe a new tool for assessing discourse recovery in PWA. By demonstrating the feasibility of a natural language paradigm in patients with chronic, poststroke aphasia, we open a new area for future research.
Topics: Female; Humans; Brain; Aphasia; Language; Motor Cortex; Magnetic Resonance Imaging
PubMed: 37917918
DOI: 10.1044/2023_JSLHR-23-00124 -
Cureus Sep 2023Progressive multifocal leukoencephalopathy (PML) is an infection caused by the John Cunningham virus (JCV), usually in an immunocompromised host. We present the case of...
Progressive multifocal leukoencephalopathy (PML) is an infection caused by the John Cunningham virus (JCV), usually in an immunocompromised host. We present the case of a 74-year-old male who presented with a six-week history of progressive memory loss, episodic confusion, and aphasia. Cranial nerve, motor, sensory, and coordination testing were unremarkable. Magnetic resonance imaging (MRI) of the brain and spectroscopy were concerning for primary CNS lymphoma vs. diffuse glioma. Microscopic examination after the patient underwent left frontal stereotactic brain biopsy was suggestive of a viral infection, and further testing with JCV DNA in-situ hybridization (ISH) confirmed the diagnosis of PML. The patient's condition started resolving without treatment. This case demonstrates, to our knowledge, the first known case of primary PML masquerading as CNS lymphoma in modern literature.
PubMed: 37876409
DOI: 10.7759/cureus.45815