Left-hemispheric dominance for articulation: a prospective study on acute ischaemic dysarthria at different localizations

Left hemisphere lateralization in unilateral upper motor neuron dysarthria via quantitative acoustic analysis

This paper aimed to identify specific acoustic parameters F1, F2, and Vowel Space Area (VSA), Vowel Articulation Index (VAI), Formant Centralization Ratio (FCR) for evaluating speech in Mandarin-speaking individuals with Unilateral Upper Motor Neuron (UUMN) dysarthria. Additionally, it explored the correlation between dysarthria severity and lesion side based on these parameters and scale results. This study conducted comparative study using acoustic spectral analysis to analyze phonetic features among UUMN dysarthria (UUMND) patients and neurologically normal adults, and the Left-sided and Right-sided upper motor neuron dysarthria (UMND) groups. The Mandibular-Oral Motor Function Assessment Scale (MOMFAS) was used in the study. The acoustic parameters F1, F2 and VSA, VAI, FCR showed significant differences between individuals with UUMN dysarthria and neurologically normal adults. Comparing left-sided upper motor neuron (UMN) dysarthria patients with right-sided UMN dysarthria patients, a considerable increase in FCR was observed in the left-sided group, while VSA and VAI showed significant decreases. The mean scale score of left-sided UMN dysarthria patients was also significantly lower than that of individuals with right-sided UMN dysarthria. The severity of UUMND was more pronounced in individuals with left-sided lesions, providing supportive evidence of lateralization on the left hemisphere. The acoustic indices F1, F2 and VSA, VAI, FCR can sensitively reflect the vowel changes of UUMND patients. They could be utilized not only to describe the acoustic properties of UUMND patients but also to assess the effectiveness of rehabilitation therapy on impaired vowel articulation in such patients.

New type of lacunar stroke presenting in brain perfusion images: A case report

BACKGROUND

A stroke is a significant brain event that impinges on individual motor or cognitive functions. In the lacunar stroke subtype of ischemic stroke, which results from blocked blood flow in certain brain areas, cases of dysarthria due to impaired blood flow are not uncommon. However, limited literature and research on the relevant pathophysiology and neural pathways exist.

CASE SUMMARY

We focus on a 60-year-old female with subacute stroke presenting symptoms including tongue deviation to the right, speech difficulty, choking on water, and biting the oral mucosa. She did not exhibit abnormalities in limb movement or sensation except for numbness in the tongue. We use single-photon emission computed tomography to reveal reduced blood flow in the left parietal lobe and bilateral temporal lobes. This report presents an atypical case of dysarthria, who exhibits abnormal articulation along with abnormal sensation and numbness in the tongue, prompting further investigation into the association between lacunar stroke subtypes, altered blood perfusion in affected brain regions, and neurological clinical status.

CONCLUSION

Dysarthria-plus syndrome in lacunar stroke isn’t solely related to motor function but also affects sensory function such as oral numbness.

Brain age prediction using interpretable multi-feature-based convolutional neural network in mild traumatic brain injury

BACKGROUND

Convolutional neural network (CNN) can capture the structural features changes of brain aging based on MRI, thus predict brain age in healthy individuals accurately. However, most studies use single feature to predict brain age in healthy individuals, ignoring adding information from multiple sources and the changes in brain aging patterns after mild traumatic brain injury (mTBI) were still unclear.

METHODS

Here, we leveraged the structural data from a large, heterogeneous dataset (N = 1464) to implement an interpretable 3D combined CNN model for brain-age prediction. In addition, we also built an atlas-based occlusion analysis scheme with a fine-grained human Brainnetome Atlas to reveal the age-sstratified contributed brain regions for brain-age prediction in healthy controls (HCs) and mTBI patients. The correlations between brain predicted age gaps (brain-PAG) following mTBI and individual's cognitive impairment, as well as the level of plasma neurofilament light were also examined.

RESULTS

Our model utilized multiple 3D features derived from T1w data as inputs, and reduced the mean absolute error (MAE) of age prediction to 3.08 years and improved Pearson's r to 0.97 on 154 HCs. The strong generalizability of our model was also validated across different centers. Regions contributing the most significantly to brain age prediction were the caudate and thalamus for HCs and patients with mTBI, and the contributive regions were mostly located in the subcortical areas throughout the adult lifespan. The left hemisphere was confirmed to contribute more in brain age prediction throughout the adult lifespan. Our research showed that brain-PAG in mTBI patients was significantly higher than that in HCs in both acute and chronic phases. The increased brain-PAG in mTBI patients was also highly correlated with cognitive impairment and a higher level of plasma neurofilament light, a marker of neurodegeneration. The higher brain-PAG and its correlation with severe cognitive impairment showed a longitudinal and persistent nature in patients with follow-up examinations.

CONCLUSION

We proposed an interpretable deep learning framework on a relatively large dataset to accurately predict brain age in both healthy individuals and mTBI patients. The interpretable analysis revealed that the caudate and thalamus became the most contributive role across the adult lifespan in both HCs and patients with mTBI. The left hemisphere contributed significantly to brain age prediction may enlighten us to be concerned about the lateralization of brain abnormality in neurological diseases in the future. The proposed interpretable deep learning framework might also provide hope for testing the performance of related drugs and treatments in the future.

The speech neuroprosthesis

Loss of speech after paralysis is devastating, but circumventing motor-pathway injury by directly decoding speech from intact cortical activity has the potential to restore natural communication and self-expression. Recent discoveries have defined how key features of speech production are facilitated by the coordinated activity of vocal-tract articulatory and motor-planning cortical representations. In this Review, we highlight such progress and how it has led to successful speech decoding, first in individuals implanted with intracranial electrodes for clinical epilepsy monitoring and subsequently in individuals with paralysis as part of early feasibility clinical trials to restore speech. We discuss high-spatiotemporal-resolution neural interfaces and the adaptation of state-of-the-art speech computational algorithms that have driven rapid and substantial progress in decoding neural activity into text, audible speech, and facial movements. Although restoring natural speech is a long-term goal, speech neuroprostheses already have performance levels that surpass communication rates offered by current assistive-communication technology. Given this accelerated rate of progress in the field, we propose key evaluation metrics for speed and accuracy, among others, to help standardize across studies. We finish by highlighting several directions to more fully explore the multidimensional feature space of speech and language, which will continue to accelerate progress towards a clinically viable speech neuroprosthesis.

Longitudinal flortaucipir, metabolism and volume differ between phonetic and prosodic speech apraxia

Progressive apraxia of speech (PAOS) is a neurodegenerative motor-speech disorder that most commonly arises from a four-repeat tauopathy. Recent studies have established that progressive apraxia of speech is not a homogenous disease but rather there are distinct subtypes: the phonetic subtype is characterized by distorted sound substitutions, the prosodic subtype by slow and segmented speech and the mixed subtype by a combination of both but lack of predominance of either. There is some evidence that cross-sectional patterns of neurodegeneration differ across subtypes, although it is unknown whether longitudinal patterns of neurodegeneration differ. We examined longitudinal patterns of atrophy on MRI, hypometabolism on 18F-fluorodeoxyglucose-PET and tau uptake on flortaucipir-PET in a large cohort of subjects with PAOS that had been followed for many years. Ninety-one subjects with PAOS (51 phonetic, 40 prosodic) were recruited by the Neurodegenerative Research Group. Of these, 54 (27 phonetic, 27 prosodic) returned for annual follow-up, with up to seven longitudinal visits (total visits analysed = 217). Volumes, metabolism and flortaucipir uptake were measured for subcortical and cortical regions, for all scans. Bayesian hierarchical models were used to model longitudinal change across imaging modalities with PAOS subtypes being compared at baseline, 4 years from baseline, and in terms of rates of change. The phonetic group showed smaller volumes and worse metabolism in Broca's area and the striatum at baseline and after 4 years, and faster rates of change in these regions, compared with the prosodic group. There was also evidence of faster spread of hypometabolism and flortaucipir uptake into the temporal and parietal lobes in the phonetic group. In contrast, the prosodic group showed smaller cerebellar dentate, midbrain, substantia nigra and thalamus volumes at baseline and after 4 years, as well as faster rates of atrophy, than the phonetic group. Greater hypometabolism and flortaucipir uptake were also observed in the cerebellar dentate and substantia nigra in the prosodic group. Mixed findings were observed in the supplementary motor area and precentral cortex, with no clear differences observed across phonetic and prosodic groups. These findings support different patterns of disease spread in PAOS subtypes, with corticostriatal patterns in the phonetic subtype and brainstem and thalamic patterns in the prosodic subtype, providing insight into the pathophysiology and heterogeneity of PAOS.

Neural basis of speech and grammar symptoms in non-fluent variant primary progressive aphasia spectrum

The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) is a neurodegenerative syndrome primarily defined by the presence of apraxia of speech (AoS) and/or expressive agrammatism. In addition, many patients exhibit dysarthria and/or receptive agrammatism. This leads to substantial phenotypic variation within the speech-language domain across individuals and time, in terms of both the specific combination of symptoms as well as their severity. How to resolve such phenotypic heterogeneity in nfvPPA is a matter of debate. 'Splitting' views propose separate clinical entities: 'primary progressive apraxia of speech' when AoS occurs in the absence of expressive agrammatism, 'progressive agrammatic aphasia' (PAA) in the opposite case, and 'AOS + PAA' when mixed motor speech and language symptoms are clearly present. While therapeutic interventions typically vary depending on the predominant symptom (e.g. AoS versus expressive agrammatism), the existence of behavioural, anatomical and pathological overlap across these phenotypes argues against drawing such clear-cut boundaries. In the current study, we contribute to this debate by mapping behaviour to brain in a large, prospective cohort of well characterized patients with nfvPPA (n = 104). We sought to advance scientific understanding of nfvPPA and the neural basis of speech-language by uncovering where in the brain the degree of MRI-based atrophy is associated with inter-patient variability in the presence and severity of AoS, dysarthria, expressive agrammatism or receptive agrammatism. Our cross-sectional examination of brain-behaviour relationships revealed three main observations. First, we found that the neural correlates of AoS and expressive agrammatism in nfvPPA lie side by side in the left posterior inferior frontal lobe, explaining their behavioural dissociation/association in previous reports. Second, we identified a 'left-right' and 'ventral-dorsal' neuroanatomical distinction between AoS versus dysarthria, highlighting (i) that dysarthria, but not AoS, is significantly influenced by tissue loss in right-hemisphere motor-speech regions; and (ii) that, within the left hemisphere, dysarthria and AoS map onto dorsally versus ventrally located motor-speech regions, respectively. Third, we confirmed that, within the large-scale grammar network, left frontal tissue loss is preferentially involved in expressive agrammatism and left temporal tissue loss in receptive agrammatism. Our findings thus contribute to define the function and location of the epicentres within the large-scale neural networks vulnerable to neurodegenerative changes in nfvPPA. We propose that nfvPPA be redefined as an umbrella term subsuming a spectrum of speech and/or language phenotypes that are closely linked by the underlying neuroanatomy and neuropathology.

Laterality in Parkinson's disease: A neuropsychological review

Laterality of motor symptom onset in Parkinson's disease is both well-known and under-appreciated. Treatment of disorders that have asymmetric pathological features, such as stroke and epilepsy, demonstrate the importance of incorporating hemispheric lateralization and specialization into therapy and care planning. These practices could theoretically extend to Parkinson's disease, providing increased diagnostic accuracy and improved treatment outcomes. Additionally, while motor symptoms have generally received the majority of attention, non-motor features (e.g., autonomic dysfunction) also decrease quality of life and are influenced by asymmetrical neurodegeneration. Due to the laterality of cognitive and behavioral processes in the two brain hemispheres, analysis of hemibody side of onset can potentially give insight into expected symptom profile of the patient and allow for increased predictive accuracy of disease progression and outcome, thus opening the door to personalized and improved therapy in treating Parkinson's disease patients. This review discusses motor and non-motor symptoms (namely autonomic, sensory, emotional, and cognitive dysfunction) of Parkinson's disease in respect to hemispheric lateralization from a theoretical perspective in hopes of providing a framework for future research and personalized treatment.

Neuroanatomical regions associated with non-progressive dysarthria post-stroke: a systematic review

Background

Dysarthria is a common and persisting sequela to stroke. It can have a negative influence on psychological wellbeing, and quality of life. This systematic review aimed to describe and identify the neuroanatomical regions associated with non-progressive dysarthria following stroke.

Methods

A systematic search of PubMed, Ovid Medline, CINAHL, Cochrane, Scopus, and ScienceDirect was conducted to identify all relevant articles published in peer-reviewed journals up to December 2021. Following data extraction, the National Institutes of Health (NIH) quality assessment tools were used to evaluate the methodological quality of the included studies.

Results

Out of 2186 papers found in the literature related to dysarthria post-stroke, 24 met the inclusion criteria. Eligible articles assessed 1150 post-stroke subjects. Out of them, 420 subjects had dysarthria from isolated lesions. Regarding dysarthric subjects with ischemic strokes, 153 sustained supratentorial infarctions, while 267 had infratentorial infarctions. The majority had pontine infarctions (n = 142), followed by infarctions in the corona radiata (n = 104), and the cerebellum (n = 64).

Conclusion

This systematic review is the first step toward establishing a neuroanatomical model of dysarthria throughout the whole brain. Our findings have many implications for clinical practice and provide a framework for implementing guidelines for early detection and management of dysarthria post-stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02877-x.

Cerebro-Cerebellar Networks in Migraine Symptoms and Headache

The cerebellum is associated with the biology of migraine in a variety of ways. Clinically, symptoms such as fatigue, motor weakness, vertigo, dizziness, difficulty concentrating and finding words, nausea, and visual disturbances are common in different types of migraine. The neural basis of these symptoms is complex, not completely known, and likely involve activation of both specific and shared circuits throughout the brain. Posterior circulation stroke, or neurosurgical removal of posterior fossa tumors, as well as anatomical tract tracing in animals, provided the first insights to theorize about cerebellar functions. Nowadays, with the addition of functional imaging, much progress has been done on cerebellar structure and function in health and disease, and, as a consequence, the theories refined. Accordingly, the cerebellum may be useful but not necessary for the execution of motor, sensory or cognitive tasks, but, rather, would participate as an efficiency facilitator of neurologic functions by improving speed and skill in performance of tasks produced by the cerebral area to which it is reciprocally connected. At the subcortical level, critical regions in these processes are the basal ganglia and thalamic nuclei. Altogether, a modulatory role of the cerebellum over multiple brain regions appears compelling, mainly by considering the complexity of its reciprocal connections to common neural networks involved in motor, vestibular, cognitive, affective, sensory, and autonomic processing—all functions affected at different phases and degrees across the migraine spectrum. Despite the many associations between cerebellum and migraine, it is not known whether this structure contributes to migraine initiation, symptoms generation or headache. Specific cerebellar dysfunction via genetically driven excitatory/inhibitory imbalances, oligemia and/or increased risk to white matter lesions has been proposed as a critical contributor to migraine pathogenesis. Therefore, given that neural projections and functions of many brainstem, midbrain and forebrain areas are shared between the cerebellum and migraine trigeminovascular pathways, this review will provide a synopsis on cerebellar structure and function, its role in trigeminal pain, and an updated overview of relevant clinical and preclinical literature on the potential role of cerebellar networks in migraine pathophysiology.

Types of motor speech impairments associated with neurologic diseases

Speech disturbances are common consequences of acquired brain injury or neurodegenerative impairment. Although sudden difficulties with speech may signal acute pathologic conditions such as cerebrovascular accidents, determining the etiology of insidious disruptions in communication can be less straightforward. The identification of motor speech impairment, independent of difficulties with language, can be useful for diagnosis since there are subtle, albeit distinct, patterns of speech production impairments associated with different neurologic conditions. Furthermore, the identification of impairments specific to speech production can help elucidate the suspected pathologic mechanisms or even the neuroanatomic structures compromised. During a routine clinical evaluation, early warning signs of motor speech impairment may go undetected if a clinician is unaccustomed to examining motor speech or is unaware of its manifestations. Accordingly, this chapter provides clinicians with a concise yet thorough guide for the practical assessment and differential diagnosis of motor speech disorders (MSDs)-apraxia of speech and dysarthrias. This chapter is divided into neurologic conditions associated with disorders of speech planning/programming, execution, and articulatory control. The underlying mechanisms associated with these impairments are presented both from a clinical perspective as well as through a scientific discussion of recent research in the field on MSDs.

The Screening Test for Aphasia and Dysarthria (STAD) for Patients with Neurological Communicative Disorders: A Large-Scale, Multicenter Validation Study in Japan

INTRODUCTION

Evaluation of multiple domains, such as language, articulation, and cognitive function, is frequently required in neurological communicative disorders. The purpose of this study was to investigate the performance of a 10-min screening scale for estimating aphasia, dysarthria, and cognitive dysfunction using a multicenter, large-sized consecutive series.

METHODS

We conducted a multicenter validation study that included 314 patients with brain injury between February 1 and June 31, 2018, from 20 medical centers across Japan. The Screening Test for Aphasia and Dysarthria (STAD) was developed in Japan in 2009, and a previous smaller-scale retrospective study established its high to moderate validity. All patients had undergone the STAD, and 212 of them underwent the Western Aphasia Battery or Assessment of Motor Speech for Dysarthria. The effect size on all 29 items and receiver operating curves of 3 sections of the STAD were analyzed based on external criteria, which were decided considering the clinical diagnosis of aphasia, dysarthria, and cognitive dysfunction. Correlations between the STAD and reference tests were calculated.

RESULTS

The phi coefficients of 23 out of 29 items exceeded the moderate effect size of 0.3 toward the targeted disorder. Overall, there was a good balance between sensitivity (82-92%) and specificity (77-78%), with moderate to large positive and negative likelihood ratios (3.7-4.19 and 0.1-0.23). The Pearson's r between the verbal section and Western Aphasia Battery Aphasia Quotient, the articulation section and Assessment of Motor Speech for Dysarthria, and the nonverbal section and Western Aphasia Battery Nonlinguistic Skills were 0.89, 0.70, and 0.79, respectively.

CONCLUSION

We demonstrated that the STAD has acceptable content and concurrent validity for the assessment of communicative function in patients with brain injury. This short screening tool can be useful in specific contexts, such as in early bedside investigations, to obtain a quick summary of communicative function prior to the administration of other tests, and in cases where more in-depth testing is not feasible.

Dysarthria following acute ischemic stroke: Prospective evaluation of characteristics, type and severity

BACKGROUND

Dysarthria is a common symptom following stroke and represents an important cause of functional impairment in stroke patients. A better characterization of dysarthria could facilitate differential diagnosis and optimize healthcare service distribution.

AIM

To determine the speech characteristics, dysarthria type and severity in the acute phase following ischemic stroke in a comprehensive stroke centre.

METHODS & PROCEDURES

First-ever ischemic stroke patients consecutively admitted to the Stroke Unit of Ghent University Hospital were included in this prospective clinical study between March 2018 and October 2019. All participants admitted to the Stroke Unit were screened for dysarthria by a speech-language pathologist within 72 h after admission. When dysarthria was identified, speech characteristics were evaluated via auditory-perceptual assessment and objective measurement of acoustic parameters. Dysarthria type was determined based on the Mayo Classification System. Severity of impairment was scored at function and activity level using the Radboud Dysarthria Assessment and the evaluation of speech intelligibility at sentence level using the Dutch Speech Intelligibility Assessment. In addition, dysarthria recovery was separately evaluated in all participants using the National Institutes of Health Stroke Scale (NIHSS) at hospital admission, day 3 ± 2 and day 7.

OUTCOMES & RESULTS

A total of 67 out of 151 participants (44%; mean age = 69 years; SD = 13; 28 females) were diagnosed with dysarthria in the acute phase following stroke. Standardized assessments were possible in 72% (48/67) of participants. Imprecise articulation of consonants, harsh voice quality and audible inspiration were the most frequent observed speech characteristics. The acoustic parameters maximum phonation time and maximum loudness deviated most from normative values. Unilateral upper motor neuron (UUMN) was the main dysarthria type present in 52% (25/48) of participants. A total of 58% (28/48) and 71% (34/48) of participants had no/minimal/mild difficulties at the functional and activity levels, respectively. Speech intelligibility was mildly impaired (median = 91%; IQR = 73-97). According to the NIHSS, sub-item speech score at hospital admission, 46% (70/151) of participants had dysarthria, of which half recovered completely from their dysarthria within 1 week after stroke symptom onset.

CONCLUSIONS & IMPLICATIONS

UUMN was the dominant dysarthria type, and the majority of participants had a mild dysarthria. Half the participants showed complete recovery within 1 week following symptom onset. The observed speech characteristics mainly reflect impairments in the subsystem's articulation, phonation and respiration. Objective measurements of acoustic parameters corroborate these findings. Future research should focus on longitudinal assessment to investigate recovery of symptoms and the long-term impact of dysarthria on social participation. What this paper adds What is already known on the subject There are few data concerning the presentation of dysarthria following acute ischemic stroke. Moreover, previous research did not include objective measurements of speech characteristics and dysarthria severity. There was a need to determine prospectively speech characteristics, dysarthria type and severity in a stroke population using standardized assessments. What this paper adds to existing knowledge The findings of this study show a high prevalence of dysarthria following acute ischemic stroke. This study confirms previous findings that the speech of dysarthric patients following acute ischemic stroke was mostly characterized by imprecise articulation of consonants, a harsh voice quality and audible inspiration. The results of the objective measures confirm these findings. We added evidence that UUMN is the most prevalent dysarthria type in a stroke population, and that the majority of participants had mild dysarthria. A high rate of dysarthria recovery was seen in the first week following symptom onset. What are the potential or actual clinical implications of this work? The findings of this study contribute to the limited research performed regarding post-stroke dysarthria. The results can help optimize the distribution of healthcare resources. The majority of participants have a mild dysarthria, making the identification of the specific needs of this group an important area of concern. The evaluation of impaired speech subsystems and characteristics, especially supplemented with objective measures of acoustic parameters, and the classification of the type and severity of dysarthria can be helpful to monitor early progress in the acute phase post-stroke.

A Case of Isolated Dysarthria in a COVID-19 Infected Stroke Patient: A Nondisabling Neurological Symptom With Grave Prognosis

Isolated dysarthria is a speech abnormality characterized by slurring without any language dysfunction, or other neurological deficits. In an acute setting, it is commonly associated with stroke. In the context of social distancing during the current corona virus disease 2019 (COVID-19) pandemic, nondisabling symptoms such as isolated dysarthria can delay a patient's perception to seek immediate medical care. We present a rare case of isolated dysarthria in a COVID-19 infected stroke patient with a grave prognosis. A 79-year-old African American male presented with isolated dysarthria that manifested two days prior to his hospital visit. The dysarthria assessment showed impaired articulation, phonation, and prosody. Other neurological examinations were normal. He tested positive for the COVID-19 infection. His pulmonary CT scan showed bilateral ground glass opacities. An electrocardiogram showed atrial fibrillation (AF). Brain MRI revealed a punctate acute infarction in the left frontal lobe. Initially, he was treated with IV anticoagulation, oral beta-blocker, azithromycin and hydroxychloroquine, but he dramatically deteriorated within a week exhibiting a highly elevated cytokine level eventually resulting in multi-system organ failure. Despite aggressive treatment with steroids, tocilizumab and other supportive measures, the patient died of cardiac arrest. Our case highlights that acute stroke could manifest as an isolated dysarthria, which is an indicator of increased severity and high mortality with COVID-19 infection. Public awareness about the stroke symptom awareness should be emphasized.

Articulation lost in space. The effects of local orobuccal anesthesia on articulation and intelligibility of phonemes

Motor speech requires numerous neural computations including feedforward and feedback control mechanisms. A reduction of auditory or somatosensory feedback may be implicated in disorders of speech, as predicted by various models of speech control. In this paper the effects of reduced somatosensory feedback on articulation and intelligibility of individual phonemes was evaluated by using topical anesthesia of orobuccal structures in 24 healthy subjects. The evaluation was done using a combination of perceptual intelligibility estimation of consonants and vowels and acoustic analysis of motor speech. A significantly reduced intelligibility was found, with a major impact on consonant formation. Acoustic analysis demonstrated disturbed diadochokinesis. These results underscore the clinical importance of somatosensory feedback in speech control. The interpretation of these findings in the context of speech control models, neuro-anatomy and clinical neurology may have implications for subtyping of dysarthria.

Dysarthria and stroke. The effectiveness of speech rehabilitation. A systematic review and meta-analysis of the studies

INTRODUCTION

Speech difficulties, such as dysarthria or aphasia, in addition to motor impairments are frequently seen in post-stroke patients.

EVIDENCE ACQUISITION

Literature searches with the keywords: "stroke" and "dysarthria" and "diagnosis" and "stroke" and "dysarthria" and "assessment" were conducted using PubMed, EMBASE, Cochrane Library, and Web of Science databases to perform the systematic review about the methods used to measure the severity of dysarthria in subjects post-stroke. The search was performed by two authors from 15 January to 22 February 2020. The research identified a total of 402 articles for the search using the keywords "stroke" and "dysarthria," and "diagnosis" and 84 references for the search using the keywords "stroke" and "dysarthria" and "assessment." Sixty-nine selected articles were analyzed by the reviewers. Thirty-seven publications met the inclusion criteria and were included in the systematic review. Thirty-two articles were excluded for several reasons: 1) 12 involved individuals with aphasia or other speech problems different from dysarthria; 2) 12 examined different topics from our aim; and 3) eight did not include post-stroke cases.

EVIDENCE SYNTHESIS

The systematic review identified methods for measuring the severity of post-stroke dysarthria. The meta-analysis showed the acoustic parameters affected in dysarthria secondary to stroke and the differences in these parameters after speech therapy.

CONCLUSIONS

The alternating and sequential motion rate (AMR- Pə, AMR-Tə, AMR-Kə, and SMR-PəTəKə) and maximum phonation time were significantly improved after speech rehabilitation.

Prevalence of aphasia after stroke in a hospital population in southern Brazil: a retrospective cohort study

Background: Aphasia negatively impacts quality of life. This is the first Brazilian study that investigates the prevalence of aphasia and its related factors, the results of which may underpin hospital and health service planning for this vulnerable population.Objective: To establish the prevalence of aphasia in patients after first-ever ischemic stroke (FEIS) and associated factors.Methods: This is a retrospective cohort study, based on a database held in Joinville, Brazil. All cases of FEIS admitted to one public hospital in Joinville in 2015 were selected. The diagnosis of aphasia was verified by neurologists through the language item of the National Institute of Health Stroke Scale (NIHSS).Results: Of the 350 patients with FEIS, 79 (22.6%) had aphasia. Patients with aphasia (PWA) were older, with a higher likelihood of dysarthria, more thrombolytic use, and greater stroke severity. PWA had higher mortality than patients without aphasia (24.1% versus 10.7%, p = .004) and longer hospitalization time (21.32 versus 17.46 days, p = .009). Higher NIHSS score was an independent predictor for the occurrence of aphasia on admission (OR 1.24, 95% CI 1.17-1.31, p < .001). Older age (OR 1.06, 95% CI 1.03-1.09, p < .001) and stroke severity by NIHSS (OR 1.19, 95% CI 1.12-1.25, p = <0.001) were independent predictors of death.Conclusions: PWA may need more health care during hospitalization, because of the severity of the stroke, and their frailty. Further studies are needed to assess the direct impact of aphasia on inpatients.

Avoiding Misdiagnosis in Patients With Posterior Circulation Ischemia: A Narrative Review

Posterior circulation strokes represent 20% of all acute ischemic strokes. Posterior circulation stroke patients are misdiagnosed twice as often compared to those with anterior events. Misdiagnosed patients likely have worse outcomes than correctly diagnosed patients because they are at risk for complications of the initial stroke as well as recurrent events due to lack of secondary stroke prevention and failure to treat the underlying vascular pathology. Understanding important anatomic variants, the clinical presentations, relevant physical examination findings, and the limitations of acute brain imaging may help reduce misdiagnosis. We present a symptom-based review of posterior circulation ischemia focusing on the subtler presentations with a brief discussion of basilar stroke, both of which can be missed by the emergency physician. Strategies to avoid misdiagnosis include establishing an abrupt onset of symptoms, awareness of the nonspecific presentations, consideration of basilar stroke in altered patients and using a modern approach to diagnosis of the acutely dizzy patient.

Assessment of Dysarthria Using One-Word Speech Recognition with Hidden Markov Models

BACKGROUND

The gold standard in dysarthria assessment involves subjective analysis by a speech-language pathologist (SLP). We aimed to investigate the feasibility of dysarthria assessment using automatic speech recognition.

METHODS

We developed an automatic speech recognition based software to assess dysarthria severity using hidden Markov models (HMMs). Word-specific HMMs were trained using the utterances from one hundred healthy individuals. Twenty-eight patients with dysarthria caused by neurological disorders, including stroke, traumatic brain injury, and Parkinson's disease were participated and their utterances were recorded. The utterances of 37 words from the Assessment of Phonology and Articulation for Children test were recorded in a quiet control booth in both groups. Patients were asked to repeat the recordings for evaluating the test-retest reliability. Patients' utterances were evaluated by two experienced SLPs, and the consonant production accuracy was calculated as a measure of dysarthria severity. The trained HMMs were also employed to evaluate the patients' utterances by calculating the averaged log likelihood (aLL) as the fitness of the spoken word to the word-specific HMM.

RESULTS

The consonant production accuracy reported by the SLPs strongly correlated (r = 0.808) with the aLL, and the aLL showed excellent test-retest reliability (intraclass correlation coefficient, 0.964).

CONCLUSION

This leads to the conclusion that dysarthria assessment using a one-word speech recognition system based on word-specific HMMs is feasible in neurological disorders.

Speech and Language Impairments After Childhood Arterial Ischemic Stroke: Does Hemisphere Matter?

BACKGROUND

The association between left hemisphere stroke and acute speech and language impairment is well documented in adults. However, little is known about this association in childhood arterial ischemic stroke. Here we examined potential predictors of acute speech (dysarthria and apraxia) and language impairments after childhood arterial ischemic stroke, including site of lesion.

METHODS

Children with radiologically confirmed acute arterial ischemic stroke, admitted to a tertiary pediatric hospital from 2004 to 2012, were identified from an institutional registry. We examined the prevalence of dysarthria, apraxia, and language impairment within two weeks of the stroke. Associations with age at stroke event, lesion side (left, right, or bilateral), and arterial territory affected (anterior, posterior, or both) were assessed using logistic regression.

RESULTS

Sixty-two children with mean age eight years (range three to 17 years) were identified. Strokes were located in the left (32%), right (44%), or both hemispheres (24%). Dysarthria (74%) and language impairment (50%) were frequent. Verbal dyspraxia was less common (11%). There was little evidence that variables of interest, including site of lesion, were significantly associated with increased odds of dysarthria or language impairment (all P > 0.49).

CONCLUSIONS

Regardless of age, children are at high risk of communication disorders after stroke. Unlike adults, left hemisphere stroke was not associated with either speech or language impairment in our cohort, suggesting there may be bihemispheric contribution to language function. Future studies are needed to examine whether the predictors examined here determine long-term outcomes.

Sound Distortion Errors in Aphasia With Apraxia of Speech

Purpose Loosely defined diagnostic criteria for acquired apraxia of speech (AOS) limit clinicians' ability to diagnose the disorder validly and reliably. The purpose of this study was to contribute to the development of more precise diagnostic guidelines by characterizing the frequency and quality of sound distortion errors in speakers with clinically diagnosed AOS. Method Audio-recorded motor speech evaluations from 24 speakers with AOS and aphasia were analyzed by trained listeners using a narrow phonetic transcription protocol that included 12 distortion categories. We calculated percentage of segments transcribed with phonemic error, distortion error, and a combination of phonemic and distortion error. Results Distortion frequency varied substantially across participants, distributing on a continuum from 5% to 22% of segments. The frequency of phonemic errors was significantly greater than the frequency of distortion errors, which, in turn, was greater than the frequency of distorted substitution errors. The most common distortion qualities were voicing ambiguity and segment lengthening, but over 40% of distortion errors were distributed across an assortment of tongue modifications. Conclusions The results replicated observations from previous studies of speakers with quantitatively defined AOS in a new sample of participants with clinically diagnosed AOS. Similar distortion qualities were observed across studies, offering focus for diagnosticians and guidance for operationalizing future measures. The broad performance continua we observed help explain why binary classification of the presence/absence of AOS can be challenging and indicate a need to develop quantitative norms.

Acoustic properties of vowel production in Mandarin-speaking patients with post-stroke dysarthria

This study investigated the acoustic features of vowel production in Mandarin-speaking patients with post-stroke dysarthria (PSD). The subjects included 31 native Mandarin-speaking patients with PSD (age: 25–83 years old) and 38 neurologically normal adults in a similar age range (age: 21–76 years old). Each subject was recorded producing a list of Mandarin monosyllables that included six monophthong vowels (i.e., /a, i, u, ɤ, y, o/) embedded in the /CV/ context. The patients’ speech samples were evaluated by two native Mandarin speakers. The evaluation scores were then used to classify all patients into two levels of severity: mild or moderate-to-severe. Formants (F1 and F2) were extracted from each vowel token. Results showed that all vowel categories in the patients with PSD were produced with more variability than in the healthy speakers. Great overlaps between vowel categories and reduced vowel space were observed in the patients. The magnitude of the vowel dispersion and overlap between vowel categories increased as a function of the severity of the disorder. The deviations of the vowel acoustic features in the patients in comparison to the healthy speakers may provide guidance for clinical rehabilitation to improve the speech intelligibility of patients with PSD.

A Brain Marker for Developmental Speech Disorders

OBJECTIVE

To characterize the organization of speech- and language-related white matter tracts in children with developmental speech and/or language disorders.

STUDY DESIGN

We collected magnetic resonance diffusion-weighted imaging data from 41 children, ages 9-11 years, with developmental speech and/or language disorders, and compared them with 45 typically developing controls with the same age range. We used probabilistic tractography of diffusion-weighted imaging to map language (3 segments of arcuate fasciculus, extreme capsule system) and speech motor (corticobulbar) tracts bilaterally. The corticospinal and callosal tracts were used as control regions. We compared the mean fractional anisotropy and diffusivity values between atypical and control groups, covarying for nonverbal IQ. We then examined differences between atypical subgroups: developmental speech disorder (DSD), developmental language disorder, and co-occurring developmental speech and language disorder.

RESULTS

Fractional anisotropy in the left corticobulbar tract was lower in the DSD than in the control group. Radial and mean diffusivity were higher in the DSD than the developmental language disorder, co-occurring developmental speech and language disorder, or control groups. There were no group differences for any metrics in the language or control tracts.

CONCLUSIONS

Atypical development of the left corticobulbar tract may be a neural marker for DSD. This finding is in line with reports of speech disorder after left corticobulbar damage in children and adults with brain injury. By contrast, we found no association between diffusion metrics in language-related tracts in developmental language disorder, and changes for language disorders are likely more complex.

Migraine with brainstem aura: Why not a cortical origin?

Background Migraine with brainstem aura is defined as a migraine with aura including at least two of the following symptoms: dysarthria, vertigo, tinnitus, hypacusis, diplopia, ataxia and/or decreased level of consciousness. Aim The aim of this study is to review data coming from clinical observations and functional mapping that support the role of the cerebral cortex in the initiation of brainstem aura symptoms. Results Vertigo can result from a vestibular cortex dysfunction, while tinnitus and hypacusis can originate within the auditory cortex. Diplopia can reflect a parieto-occipital involvement. Dysarthria can be caused by dysfunctions located in precentral gyri. Ataxia can reflect abnormal processing of vestibular, sensory, or visual inputs by the parietal lobe. Alteration of consciousness can be caused by abnormal neural activation within specific consciousness networks that include prefrontal and posterior parietal cortices. Conclusion Any symptom of so-called brainstem aura can originate within the cortex. Based on these data, we suggest that brainstem aura could have a cortical origin. This hypothesis would explain the co-occurrence of typical and brainstem aura during attacks and would fit with the theory of cortical spreading depression. We propose that migraine with brainstem aura should be classified as a typical migraine aura.

The pulvinar nucleus is associated with the presence of dysarthria in patients with basal ganglia hemorrhage

Dysarthria is a frequent symptom in patients with stroke. The anatomical structures responsible for dysarthria have been reported in patients with lacunar infarcts, but the related lesions in patients with basal ganglia hemorrhage (BGH) have not been investigated. The aim of this study was to identify associations between the lesion location and the presence/absence of dysarthria in patients with BGH using voxel-based lesion symptom mapping (VLSM) analyses. A retrospective analysis was conducted on 26 patients with acute BGH (mean age, 54.0 years; men:women, 14:12) who underwent conservative management. The patients were classified into groups based on the presence or absence of dysarthria at the time of admission, which was determined by reviewing the patients' medical records. Brain lesions were traced on magnetic resonance images that were acquired within the first 3 weeks after BGH onset, and then separate high-resolution region-of-interest images were generated. Associations between dysarthria and the lesion location were determined with the VLSM analyses. The average volume of the delimited lesions was 7.38±5.75cm³. The VLSM analyses identified several voxel clusters, mainly in the pulvinar nucleus of the left thalamus, that were significantly related to the presence of dysarthria at admission. These findings suggest that patients with BGH extending into the left pulvinar nucleus should be monitored for dysarthria.

Clinical Characteristics and Lesions Responsible for Swallowing Hesitation After Acute Cerebral Infarction

Some stroke patients with a unilateral lesion demonstrate acute dysphagia characterized by a markedly prolonged swallowing time, making us think they are reluctant to swallow. In order to clarify the clinical characteristics and causative lesions of delayed swallowing, we conducted a retrospective analysis of 20 right-handed patients without a history of swallowing dysfunction who underwent videofluorography on suspicion of dysphagia after a first ischemic stroke. The oral processing time plus the postfaucial aggregation time required to swallow jelly for patients classified as having delayed swallowing was over 10 s. The time required for swallowing jelly was significantly longer than that without the hesitation (median value, 24.1 vs. 8.9 s, P < 0.001). The oral processing time plus the postfaucial aggregation time required for patients with delayed swallowing to swallow thickened water was largely over 5 s and significantly longer than that of patients without swallowing hesitation (median value, 10.2 vs. 3.3 s, P < 0.001). Swallowing hesitation caused by acute unilateral infarction could be separated into two different patterns. Because four of the five patients with a rippling tongue movement in the swallowing hesitation pattern had a lesion in the left primary motor cortex, which induces some kinds of apraxia, swallowing hesitation with a rippling tongue movement seems to be a representative characteristic of apraxia. The patients with swallowing hesitation with a temporary stasis of the tongue in this study tended to have broad lesions in the frontal lobe, especially in the middle frontal gyrus, which is thought to be involved in higher cognition.

Pure dysarthria and dysarthria-facial paresis syndrome due to internal capsule and/or corona radiata infarction

Background

Pure dysarthria (PD) and dysarthria-facial paresis syndrome (DFP) mainly result from lenticulostriate artery territory infarction. PD and DFP are rare clinical entities, often grouped without distinction. The purpose of this study was to examine clinical and radiographic differences between PD and DFP due to unilateral internal capsule and/or corona radiata infarction.

Methods

Using a database that included consecutive patients with ischemic stroke admitted to the neurological stroke units of three hospitals within 7 days from onset between September 2011 and April 2014, we retrospectively extracted first-ever stroke patient data, who presented with PD or DFP with a single ischemic lesion localized in the internal capsule and/or corona radiata. Patients with weakness, ataxia, sensory deficit, or cortical symptoms were excluded. Ischemic lesion volume was calculated by the ABC/2 method on diffusion-weighted imaging (DWI). DWI images were normalized and superimposed to the template for PD and DFP. We compared patients' characteristics between PD and DFP.

Results

A total of 2126 patients, including 65 patients (3.1 %) with PD or DFP, were registered. Of these, 13 PD patients and 18 patients with DFP due to unilateral internal capsule and/or corona radiata infarction were included for analysis. Compared with DFP patients, PD patients had longer onset-to-door time (median 37.5 vs. 10.8 h, p = 0.031), shorter vertical length (C component) of ischemic lesions (median 12.0 vs. 18.8 mm, p = 0.007), and smaller ischemic lesion volume (median 285 vs. 828 mm³, p = 0.023). Ischemic lesions causing PD were located more frequently in the left hemisphere than DFP (92 % vs. 56 %, p = 0.045). The superimposed lesion pattern indicated that DFP had lesions more medial and involving posterior portions of the putamen and the caudate body, as well as more of the genu and posterior limb of the internal capsule, than PD. Ninety days after onset, symptoms disappeared in 21 (72 %) out of 29 patients.

Conclusions

In cerebral infarction limited to the internal capsule and/or corona radiata, PD is derived from smaller and left-sided lesions with delay in diagnosis compared with DFP. The clinical course of those with PD and DFP might be benign.

Effect of Repetitive Transcranial Magnetic Stimulation on Patients With Dysarthria After Subacute Stroke

OBJECTIVE

To evaluate whether repetitive transcranial magnetic stimulation (rTMS) could improve dysarthria in stroke patients at the subacute stage.

METHODS

This study was a prospective, randomized, double-blind controlled trial. Patients who had unilateral middle cerebral artery infarction were enrolled. In patients in the rTMS group, we found hot spots by searching for the evoked motor potential of the orbicularis oris on the non-affected side. We performed rTMS at a low frequency (1 Hz), 1,500 stimulations/day, 5 days a week for 2 weeks on the hotspots. We used the same protocol in the sham stimulation group patients as that in the rTMS group, except that the angle of the coil was perpendicular to the skull rather than tangential to it. The patients in both groups received speech therapy for 30 minutes, 5 days a week from a skilled speech therapist. The speech therapist measured the Urimal Test of Articulation and Phonology, alternative motion rates, sequential motion rates, and maximal phonation time before and after intervention sessions.

RESULTS

Forty-two patients were enrolled in this study and 20 completed the study. Statistical analysis revealed significant improvements on the dysarthria scales in both groups. The sequential motion rate (SMR)-PǝTǝKǝ showed significantly greater improvement in the rTMS group patients than in the sham stimulation group.

CONCLUSION

Patients in the rTMS group showed greater improvement in articulation than did patients in the sham rTMS group. Therefore, rTMS can have a synergistic effect with speech therapy in treating dysarthria after stroke.

Anatomy and lateralization of the human corticobulbar tracts: an fMRI-guided tractography study

The left hemisphere lateralization bias for language functions, such as syntactic processing and semantic retrieval, is well known. Although several theories and clinical data indicate a link between speech motor execution and language, the functional and structural brain lateralization for these functions has never been examined concomitantly in the same individuals. Here, we used functional MRI during rapid silent syllable repetition (/lalala/, /papapa/ and /pataka/, known as oral diadochokinesis or DDK) to map the cortical representation of the articulators in 17 healthy adults. In these same participants, functional lateralization for language production was assessed using the well-established verb generation task. We then used DDK-related fMRI activation clusters to guide tractography of the corticobulbar tract from diffusion-weighted MRI. Functional MRI revealed a wide inter-individual variability of hemispheric asymmetry patterns (left and right dominant, as well as bilateral) for DDK in the motor cortex, despite predominantly left hemisphere dominance for language-related activity in Broca's area. Tractography revealed no evidence for structural asymmetry (based on fractional anisotropy) within the corticobulbar tract. To our knowledge, this study is the first to reveal that motor brain activation for syllable repetition is unrelated to functional asymmetry for language production in adult humans. In addition, we found no evidence that the human corticobulbar tract is an asymmetric white matter pathway. We suggest that the predominance of dysarthria following left hemisphere infarct is probably a consequence of disrupted feedback or input from left hemisphere language and speech planning regions, rather than structural asymmetry of the corticobulbar tract itself.

Neuroradiology and voice findings in stroke

Neurological dysphonias are vocal disorders followed by injuries or changes in the nervous system. Stroke is the second leading cause of death worldwide and the brain damage caused by it can affect communication in several aspects. The changes in the vocal features caused by these lesions are poorly described regarding the location and extent of cerebral involvement. The aim of this study was to describe vocal parameters of ten elderly patients affected by stroke according to the topography of the lesion at neuroimaging. We recorded from them: perceptual and auditory evaluation of voice and laryngeal diadochokinesis. Neuroimaging studies were classified according to location, extent, laterality territory of brain injury. The results show a population of extensive middle cerebral artery strokes and strokes with varied location in the brain. The subjects' voices showed predominantly the presence of roughness, breathiness, richeness and instability, and change in laryngeal motor control, demonstrated by reduced speed and instability in laryngeal diadochokinesis. These features presented in patients with extensive middle cerebral artery stroke and in patients with short strokes with varied location in the brain. The results suggest that the vocal features in the assessed cases do not depend only on the topography of the brain damage. Thus, it is important to consider the patient as unique in clinical evaluation.

Speech motor deficits in cerebellar infarctions

Functional imaging studies demonstrated cerebellar activation during speech movements in the rostral cerebellar region. Ischemic lesions of this area, which is supplied by the superior cerebellar artery, induce dysarthria.

Aphasia and Dysarthria in Acute Stroke: Recovery and Functional Outcome

Background Aphasia and dysarthria have major implications for activities of daily living and social participation following stroke. Few studies describe recovery in the acute stroke setting. We described the evolution of aphasia and dysarthria by three-months poststroke. Methods We conducted a retrospective analysis of pooled clinical trial data from the Virtual International Stroke Trials Archive. We defined aphasia and dysarthria at baseline as a score of ≥1 on the Best Language (Item 9) and Dysarthria (Item 10) domains of the National Institutes of Health Stroke Scale, respectively. We described recovery from these impairments by three-months. Covariate adjusted analyses described the associations between aphasia, dysarthria, and functional outcome using the modified Rankin Scale at three-months following stroke. Results At baseline, 4039/8904 (45·4%) people presented with aphasia and 6192 (69·5%) with dysarthria; 2639 (29·6%) had both impairments. By three-months, aphasia and dysarthria had resolved in 1292/7219 (17·9%) and 2892/7219 (40·1%) survivors, respectively, but persisted in 1713/7219 (23·7%) and 1940/7219 (27%), respectively. Age and severity of initial stroke were associated with poor recovery, whereas thrombolysis was associated with improved recovery. Aphasia at baseline [ P = 0·049, odds ratio = 0·89, 95% confidence interval (0·79,1·00)] and persistent aphasia at three-months [ P < 0·0001, odds ratio = 0·31, 95% confidence interval (0·27, 0·35)] were each associated with poorer modified Rankin Scale scores at three-months. Conclusion Aphasia or dysarthria persisted in at least a quarter of people in our dataset at three-months following stroke. The association between persistent aphasia at three-months and poor modified Rankin Scale renders this impairment a major therapeutic target for recovery and restitution.

Apraxia of speech: concepts and controversies

PURPOSE

This article was written as an editorial to a collection of original articles on apraxia of speech (AOS) in which some of the more recent advancements in the understanding of this syndrome are discussed. It covers controversial issues concerning the theoretical foundations of AOS. Our approach was motivated by a change of perspective on motor speech that has taken place in neurobiology, neurolinguistics, phonology, and phonetics during the past few decades.

METHOD

The literature on AOS is reviewed from 3 different but overlapping perspectives-that is, a disconnection, a motor memory, and a fine motor skill perspective. Separate sections are devoted to the delimitations of AOS from oral facial apraxia, dysarthria, and phonological impairment.

CONCLUSIONS

We conclude that many of the still unresolved conceptual issues about AOS arise from an underspecification of existing models of spoken language production. We suggest that phonological and motor impairments of sound production should be studied by an integrated approach.

Analysis of voice impairment in aphasia after stroke-underlying neuroanatomical substrates

Phonation is a fundamental feature of human communication. Control of phonation in the context of speech-language disturbances has traditionally been considered a characteristic of lesions to subcortical structures and pathways. Evidence suggests however, that cortical lesions may also implicate phonation. We carried out acoustic and perceptual analyses of the phonation of /a/ in 60 males with aphasia (20 Wernicke's, 20 Broca's, 20 subcortical aphasia) and 20 males matched in age with no neurological or speech-language disturbances. All groups with aphasia were significantly more impaired on the majority of acoustic and perceptual measures as compared with the control speakers. Within the subjects with aphasia, subjects with subcortical aphasia were more impaired on most measures compared to subjects with Broca's aphasia, and they, in turn, more impaired than those with Wernicke's aphasia. Lesions in regions involved in sound production-perception result in dysfunction of the entire neurocognitive system of articulation-phonological language processing.

Speech and oromotor outcome in adolescents born preterm: relationship to motor tract integrity

OBJECTIVE

To assess speech abilities in adolescents born preterm and investigate whether there is an association between specific speech deficits and brain abnormalities.

STUDY DESIGN

Fifty adolescents born prematurely (<33 weeks' gestation) with a spectrum of brain injuries were recruited (mean age, 16 years). Speech examination included tests of speech-sound processing and production and speech and oromotor control. Conventional magnetic resonance imaging and diffusion-weighted imaging was acquired in all adolescents born preterm and 30 term-born control subjects. Radiological ratings of brain injury were recorded and the integrity of the primary motor projections was measured (corticospinal tract and speech-motor corticobulbar tract [CST/CBT]).

RESULTS

There were no clinical diagnoses of developmental dysarthria, dyspraxia, or a speech-sound disorder, but difficulties in speech and oromotor control were common. A regression analysis revealed that presence of a neurologic impairment, and diffusion-weighted imaging abnormalities in the left CST/CBT were significant independent predictors of poor speech and oromotor outcome. These left-lateralized abnormalities were most evident at the level of the posterior limb of the internal capsule.

CONCLUSION

Difficulties in speech and oromotor control are common in adolescents born preterm, and adolescents with injury to the CST/CBT pathways in the left-hemisphere may be most at risk.

Neural bases of childhood speech disorders: lateralization and plasticity for speech functions during development

Current models of speech production in adults emphasize the crucial role played by the left perisylvian cortex, primary and pre-motor cortices, the basal ganglia, and the cerebellum for normal speech production. Whether similar brain-behaviour relationships and leftward cortical dominance are found in childhood remains unclear. Here we reviewed recent evidence linking motor speech disorders (apraxia of speech and dysarthria) and brain abnormalities in children and adolescents with developmental, progressive, or childhood-acquired conditions. We found no evidence that unilateral damage can result in apraxia of speech, or that left hemisphere lesions are more likely to result in dysarthria than lesion to the right. The few studies reporting on childhood apraxia of speech converged towards morphological, structural, metabolic or epileptic anomalies affecting the basal ganglia, perisylvian and rolandic cortices bilaterally. Persistent dysarthria, similarly, was commonly reported in individuals with syndromes and conditions affecting these same structures bilaterally. In conclusion, for the first time we provide evidence that longterm and severe childhood speech disorders result predominantly from bilateral disruption of the neural networks involved in speech production.

Lesions to the posterior insular cortex cause dysarthria

BACKGROUND

Up to now, there are few systematic studies in a sufficient number of patients with lesions involving the insular cortex (IC) examining whether damage of the IC is directly related to dysarthria. Thus, this is the first study applying modern voxel-lesion behaviour mapping (VLBM) aimed to examine whether the IC is involved in dysarthria - and if so - which part of the IC is involved.

METHODS

Twenty-five patients with acute stroke lesions affecting the IC and peri-insular region were investigated employing VLBM analysis.

RESULTS

Present data indicated that dysarthria is associated with stroke lesions affecting the right- and left-sided posterior IC.

CONCLUSIONS

Owing to the known extensive spectrum of cortical and subcortical somatosensory and motor connections, it seems that the IC might be one region involved in the generation of speech motor execution.

Resultados preliminares do estudo da compreensão em sujeitos disatricos

OBJETIVO: apresentar estudo sobre a compreensão de linguagem em sujeitos disártricos. MÉTODO: estudo retrospectivo, descritivo, de caráter qualitativo e quantitativo com 60 sujeitos com idade entre 40 a 70 anos. Foi realizado o cruzamento das tarefas de compreensão do protocolo Montreal Toulouse (versão alfa): compreensão de palavras orais (CPO) e escritas (CPE); frases simples orais (CFSO) e escritas(CFSE); frases complexas orais (CFCO) e escritas (CFCE). RESULTADOS: com respeito à comparação entre a compreensão oral e a escrita, quanto maior a CPO maior a CPE; quanto maior a CFSO, maior CFSE e vice-versa; relativamente à compreensão oral e escrita, quanto maior a CP, maior CF; quanto maior a CFS, maior CFC e vice-versa; em relação à comparação de idade, gênero, e CFCO e CFCE, não se observa relações significativas. CONCLUSÃO: nos pacientes deste estudo, verificou-se que a compreensão das estruturas mais simples favorece a compreensão das mais complexas; a dificuldade de compreensão de estruturas simples apresenta relação direta com a dificuldade de compreensão de estruturas complexas.

Adaptação para a língua Portuguesa e aplicação de protocolo de avaliação das disartrias de origem central em pacientes com Doença de Parkinson

OBJETIVO: traduzir e adaptar protocolo desenvolvido por pesquisadores alemães, adequando-o às características fonéticas e linguísticas do português falado no Brasil. Caracterizar os componentes de fala mais alterados na população com doença de Parkinson, comparando-os com grupo de sujeitos normais na mesma faixa etária. MÉTODOS: realizou-se a tradução e adaptação do protocolo. Posteriormente foram avaliados 21 pacientes com diagnóstico neurológico de Doença de Parkinson nos estágios Hoehn &Yarh, entre 2 e 3, e 10 sujeitos normais. O protocolo incluía avaliação da respiração, fonação, ressonância, articulação, prosódia e a análise acústica dos parâmetros vocais. RESULTADOS: o protocolo mostrou-se de fácil aplicação clínica. Nos sujeitos com doença de Parkinson foram observadas alterações predominantes na fonação (85,9%) e articulação (42,9%). CONCLUSÃO: o estudo demonstrou ser o protocolo uma ferramenta eficiente para a avaliação da disartria em pacientes com doença de Parkinson.

Role of cerebellum in fine speech control in childhood: persistent dysarthria after surgical treatment for posterior fossa tumour

Dysarthria following surgical resection of childhood posterior fossa tumour (PFT) is most commonly documented in a select group of participants with mutism in the acute recovery phase, thus limiting knowledge of post-operative prognosis for this population of children as a whole. Here we report on the speech characteristics of 13 cases seen long-term after surgical treatment for childhood PFT, unselected for the presence of post-operative mutism (mean time post-surgery=6y10m, range 1;4-12;6 years, two had post-operative mutism), and examine factors affecting outcome. Twenty-six age- and sex- matched healthy controls were recruited for comparison. Participants in both groups had speech assessments using detailed perceptual and acoustic methods. Over two-thirds of the group (69%) with removal of PFT had a profile of typically mild dysarthria. Prominent speech deficits included consonant imprecision, reduced rate, monopitch and monoloudness. We conclude that speech deficits may persist even up to 10 years post-surgery in participants who have not shown mutism in the acute phase. Of cases with unilateral lesions, poorer outcomes were associated with right cerebellar tumours compared to left, consistent with the notion based on adult data that speech is controlled by reciprocal right cerebellar/left frontal interactions. These results confirm the important role of the cerebellum in the control of fine speech movements in children.

Dysarthria in stroke: a narrative review of its description and the outcome of intervention

Dysarthria is a frequent and persisting sequel to stroke and arises from varied lesion locations. Although the presence of dysarthria is well documented, for stroke there are scant data on presentation and intervention outcome. A literature search was undertaken to evaluate (a) the features of dysarthria in adult stroke populations relative to the conventional Mayo system for classification, which was developed from diverse pathological groups, and (b) the current status of evidence for the effectiveness of intervention in dysarthria caused by stroke. A narrative review of results is presented. The limited data available indicate that, regardless of stroke location, imprecise articulation and slow speaking rate are consistent features, and voice disturbances, especially harshness, and reduced prosodic variation are also common. Dysarthria is more prevalent in left than in right hemisphere lesions. There is a need for comprehensive, thorough analysis of dysarthria features, involving larger populations, with stroke and other variables controlled and with appropriate age-referenced control data. There is low level evidence for benefits arising from intervention in stroke-related dysarthria. Because studies involve few participants, without external control, and sometimes include stroke with other aetiologies, their results lack the required weight for confident evidence-based practice.