Blog Archives

Lesions to the posterior insular cortex cause dysarthria

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.

from the European Journal of Neurology

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A one year prospective study of neurogenic stuttering following stroke: incidence and co-occurring disorders

In this prospective study, data on incidence, stuttering characteristics, co-occurring speech disorders, and recovery of neurogenic stuttering in a large sample of stroke participants were assessed. Following stroke onset, 17 of 319 participants (5.3%; 95% CI, 3.2 to 8.3) met the criteria for neurogenic stuttering. Stuttering persisted in at least 2.5% (95% CI, 1.1 to 4.7) for more than six months following the stroke. Participants with comorbid aphasia presented with a significantly higher frequency of stuttering compared to the group without aphasia (U = 13.00, p(1-tailed) = .02) but no difference was found for participants with co-occurring dysarthria and/or cognitive problems. Participants with neurogenic stuttering did not differ from those without stuttering in terms of stroke risk factors or stroke etiologic subtypes. Although the incidence of stuttering following stroke is lower than that for aphasia or dysarthria, these results show that clinicians should take neurogenic stuttering into account when assessing stroke participants’ speech and language.

from the Journal of Communication Disorders

Language and syntactic impairment following stroke in late bilingual aphasics

Conclusion
This pilot study suggests that, in late bilingual aphasics, syntactic judgment abilities may be more severely impaired in L2, and that this syntactic deficit is most likely to occur following anterior lesions.

from Brain and Language

Cathodal transcranial direct current stimulation of the right Wernicke’s area improves comprehension in subacute stroke patients

Previous studies have shown the appearance of right-sided language-related brain activity in right-handed patients after a stroke. Non-invasive brain stimulation such as transcranial direct current stimulation (tDCS) and repetitive transcranial magnetic stimulation (rTMS) have been shown to modulate excitability in the brain. Moreover, rTMS and tDCS have been found to improve naming in non-fluent post-stroke aphasic patients. Here, we investigated the effect of tDCS on the comprehension of aphasic patients with subacute stroke. We hypothesized that tDCS applied to the left superior temporal gyrus (Wernicke’s area) or the right Wernicke’s area might be associated with recovery of comprehension ability in aphasic patients with subacute stroke. Participants included right-handed subacute stroke patients with global aphasia due to ischemic infarct of the left M1 or M2 middle cerebral artery. Patients were randomly divided into three groups: patients who received anodal tDCS applied to the left superior temporal gyrus, patients who received cathodal tDCS applied to the right superior temporal gyrus, and patients who received sham tDCS. All patients received conventional speech and language therapy during each period of tDCS application. The Korean-Western Aphasia Battery (K-WAB) was used to assess all patients before and after tDCS sessions. After intervention, all patients had significant improvements in aphasia quotients, spontaneous speech, and auditory verbal comprehension. However, auditory verbal comprehension improved significantly more in patients treated with a cathode, as compared to patients in the other groups. These results are consistent with the role of Wernicke’s area in language comprehension and the therapeutic effect that cathodal tDCS has on aphasia patients with subacute stroke, suggesting that tDCS may be an adjuvant treatment approach for aphasia rehabilitation therapy in patients in an early stage of stroke.

from Brain and Language

Technologies and strategies for people with communication problems following brain injury or stroke

Communication problems experienced following a brain injury or stroke not only impact a person’s ability to participate in their desired social and vocational roles but may also impact their ability to participate in decision-making about their care, participate in therapy and receive counseling and education. Many technologies exist, including Augmentative and Alternative Communication (AAC), which can help increase communication and life participation following a brain injury or stroke. This article will define and describe a variety of AAC technologies and interventions for people with communication problems following acquired brain injury as well as discuss assessment, training and funding issues.

from Neurorehabilitation

Mortality and Nursing Care Dependency One Year After First Ischemic Stroke: An Analysis of German Statutory Health Insurance Data

Conclusion: Aphasia has a high impact on mortality and nursing care dependency after ischemic stroke, while dementia and depression are strongly associated with increasing nursing care dependency.

from Topics in Stroke Rehabilitation

Transcranial Magnetic Stimulation (TMS): Potential Progress for Language Improvement in Aphasia

Aphasia researchers and clinicians share some basic beliefs about language recovery post stroke. Most agree there is a spontaneous recovery period and language recovery may be enhanced by participation in a behavioral therapy program. The application of biological interventions in the form of pharmaceutical treatments or brain stimulation is less well understood in the community of people who work with individuals having aphasia. The purpose of this article is to review the literature on electrical brain stimulation as an intervention to improve aphasia recovery. The article will emphasize emerging research on the use of transcranial magnetic stimulation (TMS) to accelerate stroke recovery. We will profile the current US Food and Drug Administration (FDA)–approved application to depression to introduce its potential for future application to other syndromes such as aphasia.

from Topics in Stroke Rehabilitation

Clinical Challenges in the Evaluation and Treatment of Individuals with Poststroke Dysphagia

Although reported frequencies vary due to study design, patient characteristics, and method of ascertainment, dysphagia is a commonly encountered morbidity after stroke. Consequently, speech-language pathologists’ clinical caseloads are heavily populated with individuals with poststroke dysphagia. The body of knowledge about swallowing and swallowing disorders has expanded exponentially over the last 3 decades, and speech-language pathologists are increasingly sophisticated in their evaluation and treatment of this patient population. Nevertheless, clinical quandaries persist regarding the management of these individuals. In this article, clinical challenges are discussed, including early detection of dysphagia and aspiration risk, treatment efficacy, refractory dysphagia, and noncompliance with treatment. Research relevant to these issues is reviewed to aid in formulating sound clinical decisions.

from Topics in Stroke Rehabilitation

Mechanisms of aphasia recovery after stroke and the role of noninvasive brain stimulation

One of the most frequent symptoms of unilateral stroke is aphasia, the impairment or loss of language functions. Over the past few years, behavioral and neuroimaging studies have shown that rehabilitation interventions can promote neuroplastic changes in aphasic patients that may be associated with the improvement of language functions. Following left hemisphere strokes, the functional reorganization of language in aphasic patients has been proposed to involve both intrahemispheric interactions between damaged left hemisphere and perilesional sites and transcallosal interhemispheric interactions between the lesioned left hemisphere language areas and homotopic regions in the right hemisphere. A growing body of evidence for such reorganization comes from studies using transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS), two safe and noninvasive procedures that can be applied clinically to modulate cortical excitability during post-stroke language recovery. We discuss a hierarchical model for the plastic changes in language representation that occur in the setting of dominant hemisphere stroke and aphasia. We further argue that TMS and tDCS are potentially promising tools for enhancing functional recovery of language and for further elucidating mechanisms of plasticity in patients with aphasia.

from Brain and Language

Racial Disparities in the Development of Dysphagia After Stroke: Further Evidence From the Medicare Database

Our findings confirm previous research suggesting an association between Asian race and dysphagia after stroke while adding evidence for increased odds in other racial/ethnic minority groups.

from Archives of Physical Medicine and Rehabilitation

Improved picture naming in aphasia patients treated with cathodal tDCS to inhibit the right Broca’s homologue area

Purpose: Previous reports have suggested that noninvasive cortical stimulation could influence speech production in patients with chronic stroke. Here, we evaluated the hypothesis that cathodal transcranial DC stimulation (ctDCS), a technique that decreases excitability of stimulated cortical sites, applied over a healthy right Broca’s homologue area could improve picture naming in patients with post-stroke aphasia. Methods: Ten right-handed patients with post-stroke aphasia were enrolled in this double blind, counterbalanced sham-controlled, crossover study. Each patient received an intervention of ctDCS (2 mA for 20 min) and of sham tDCS (2 mA for 1 min) daily for 5 consecutive days in a randomized crossover manner with a minimum interval of one week between interventions, over a healthy right Broca’s homologue area using a left supraorbital anode and simultaneous daily sessions of conventional word-retrieval training. The primary endpoint measure of this study was a standardized, validated Korean version of the Boston Naming Test, which is a measure of picture naming skills. Results: ctDCS was not found to have any adverse effects. Furthermore, significantly improved picture naming (p = 0.02) was observed at 1 hour following the last (5th) ctDCS treatment session, but no changes were observed after sham tDCS. Conclusion: These results demonstrate that cathodal tDCS over the right healthy Broca’s homologue area with a left supraorbital anodal location can improve picture naming task performance in post-stroke aphasia.

from Restorative Neurology and Neuroscience

Semantic dementia and persisting Wernicke’s aphasia: Linguistic and anatomical profiles

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke’s aphasia (WA) due to stroke. We compared 10 patients with SD to 10 age- and education-matched patients with WA in three language domains: language comprehension (single words and sentences), spontaneous speech and visual semantics. Neuroanatomical involvement was analyzed using disease-specific image analysis techniques: voxel-based morphometry (VBM) for patients with SD and overlays of lesion digitized lesion reconstructions in patients with WA. Patients with SD and WA were both impaired on tasks that involved visual semantics, but patients with SD were less impaired in spontaneous speech and sentence comprehension. The anatomical findings showed that different regions were most affected in the two disorders: the left anterior temporal lobe in SD and the left posterior middle temporal gyrus in chronic WA. This study highlights that the two syndromes classically associated with language comprehension deficits in aphasia due to stroke and neurodegenerative disease are clinically distinct, most likely due to distinct distributions of damage in the temporal lobe.

from Brain and Language

“W” is for bath: Can associative errors be cued?

Semantic aphasia (SA) refers to a condition in which the control processes associated with the use of semantic information become compromised. This condition compromises patients’ abilities to accurately name pictures, and they produce semantic errors in the form of co-ordinate items, such as “shower” for BATH. Previous research has demonstrated that these patients are sensitive to phonemic cues during picture naming, whether they promote the correct response (e.g., /b/) or the incorrect semantically related response (e.g., /sh/). A similar pattern is observed in normal participants when asked to perform tempo picture naming, in which the timing constraints undermine semantic control processes. SA patients are also known to produce associative errors in picture naming, such as “water” for BATH. In this study, we extended previous work on phonemic cueing in SA patients and in normal participants in two ways: firstly, by using associative miscues to promote associative errors (e.g., /w/), and secondly, to confirm miscueing effects still hold when assessed relative to a neutral condition of an unrelated phoneme rather a simple beep. The results revealed that associative miscues are effective in reducing accuracy and promoting semantic errors in SA patients. Correlations between associative cueing effects and executive tests showed that the impact of associative miscues was more pronounced in those with greater semantic control impairment. Associative miscueing was also seen for normal participants during tempo picture naming, including a latency cost. Both the associative and also the co-ordinate miscueing effects were still apparent when the neutral condition consisted of an unrelated phoneme. The implications of these results for models of speech production and semantic representation are outlined.

from the Journal of Neurolinguistics

Semantic dementia and persisting Wernicke’s aphasia: Linguistic and anatomical profiles

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke’s aphasia (WA) due to stroke. We compared 10 patients with SD to 10 age- and education-matched patients with WA in three language domains: language comprehension (single words and sentences), spontaneous speech and visual semantics. Neuroanatomical involvement was analyzed using disease-specific image analysis techniques: voxel-based morphometry (VBM) for patients with SD and overlays of lesion digitized lesion reconstructions in patients with WA. Patients with SD and WA were both impaired on tasks that involved visual semantics, but patients with SD were less impaired in spontaneous speech and sentence comprehension. The anatomical findings showed that different regions were most affected in the two disorders: the left anterior temporal lobe in SD and the left posterior middle temporal gyrus in chronic WA. This study highlights that the two syndromes classically associated with language comprehension deficits in aphasia due to stroke and neurodegenerative disease are clinically distinct, most likely due to distinct distributions of damage in the temporal lobe.

from Brain and Language

Semantic dementia and persisting Wernicke’s aphasia: Linguistic and anatomical profiles

Few studies have directly compared the clinical and anatomical characteristics of patients with progressive aphasia to those of patients with aphasia caused by stroke. In the current study we examined fluent forms of aphasia in these two groups, specifically semantic dementia (SD) and persisting Wernicke’s aphasia (WA) due to stroke. We compared 10 patients with SD to 10 age- and education-matched patients with WA in three language domains: language comprehension (single words and sentences), spontaneous speech and visual semantics. Neuroanatomical involvement was analyzed using disease-specific image analysis techniques: voxel-based morphometry (VBM) for patients with SD and overlays of lesion digitized lesion reconstructions in patients with WA. Patients with SD and WA were both impaired on tasks that involved visual semantics, but patients with SD were less impaired in spontaneous speech and sentence comprehension. The anatomical findings showed that different regions were most affected in the two disorders: the left anterior temporal lobe in SD and the left posterior middle temporal gyrus in chronic WA. This study highlights that the two syndromes classically associated with language comprehension deficits in aphasia due to stroke and neurodegenerative disease are clinically distinct, most likely due to distinct distributions of damage in the temporal lobe.<p><p>from <a href=”Brain” _mce_href=”http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WC0-526MY1W-1&_user=108452&_coverDate=02%2F18%2F2011&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000059732&_version=1&_urlVersion=0&_userid=108452&md5=002ddc5a09de2364a6fdd719d92c8128&searchtype=a”>null”>http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WC0-526MY1W-1&_user=108452&_coverDate=02%2F18%2F2011&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_acct=C000059732&_version=1&_urlVersion=0&_userid=108452&md5=002ddc5a09de2364a6fdd719d92c8128&searchtype=a”><em>Brain and Language</em></a></p>