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Concept: Aphasia

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Objective:The aim was to evaluate behavioural therapy as a treatment for low mood in people with aphasia.Design:A randomized controlled trial comparing behavioural therapy plus usual care with a usual care control. Potential participants with aphasia after stroke were screened for the presence of low mood. Those who met the criteria and gave consent were randomly allocated.Setting:Participants were recruited from hospital wards, community rehabilitation, speech and language therapy services and stroke groups.Subjects:Of 511 people with aphasia identified, 105 had low mood and were recruited.Interventions:Behavioural therapy was offered for up to three months. Outcomes were assessed three and six months after random allocation.Main measures:Stroke Aphasic Depression Questionnaire, Visual Analog Mood Scales ‘sad’ item, and Visual Analogue Self-Esteem Scale.Results:Participants were aged 29 to 94 years (mean 67.0, SD 13.5) and 66 (63%) were men. Regression analysis showed that at three months, when baseline values and communication impairment were controlled for, group allocation was a significant predictor of the Stroke Aphasic Depression Questionnaire (P < 0.05), visual analogue 'sad' (P = 0.03), and Visual Analogue Self-Esteem Scale (P < 0.01). At six months, group alone was a significant predictor of the Stroke Aphasic Depression Questionnaire (P < 0.05), and remained significant when baseline values were controlled for (P = 0.02). Mean Stroke Aphasic Depression Questionnaire 10-item hospital version scores decreased from baseline to six months by six points in the intervention group as compared with an increase of 1.9 points in the control group.Conclusions:Behavioural therapy seemed to improve the mood of people with aphasia.

Concepts: Expressive aphasia, Regression analysis, Dyslexia, Aphasia, Traumatic brain injury, Randomness, Randomized controlled trial, Stroke

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Wernicke’s aphasia is characterized by severe word and sentence comprehension impairments. The location of the underlying lesion site, known as Wernicke’s area, remains controversial. Questions related to this controversy were addressed in 72 patients with primary progressive aphasia who collectively displayed a wide spectrum of cortical atrophy sites and language impairment patterns. Clinico-anatomical correlations were explored at the individual and group levels. These analyses showed that neuronal loss in temporoparietal areas, traditionally included within Wernicke’s area, leave single word comprehension intact and cause inconsistent impairments of sentence comprehension. The most severe sentence comprehension impairments were associated with a heterogeneous set of cortical atrophy sites variably encompassing temporoparietal components of Wernicke’s area, Broca’s area, and dorsal premotor cortex. Severe comprehension impairments for single words, on the other hand, were invariably associated with peak atrophy sites in the left temporal pole and adjacent anterior temporal cortex, a pattern of atrophy that left sentence comprehension intact. These results show that the neural substrates of word and sentence comprehension are dissociable and that a circumscribed cortical area equally critical for word and sentence comprehension is unlikely to exist anywhere in the cerebral cortex. Reports of combined word and sentence comprehension impairments in Wernicke’s aphasia come almost exclusively from patients with cerebrovascular accidents where brain damage extends into subcortical white matter. The syndrome of Wernicke’s aphasia is thus likely to reflect damage not only to the cerebral cortex but also to underlying axonal pathways, leading to strategic cortico-cortical disconnections within the language network. The results of this investigation further reinforce the conclusion that the left anterior temporal lobe, a region ignored by classic aphasiology, needs to be inserted into the language network with a critical role in the multisynaptic hierarchy underlying word comprehension and object naming.

Concepts: Neuron, Broca's area, Cerebrum, Aphasia, Brain, Temporal lobe, Wernicke's area, Cerebral cortex

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BACKGROUND: In the last decade transcranial direct current stimulation (tDCS) have been introduced in aphasia post-stroke recovery as a tool for modulating neuroplasticity. However, it is still unclear whether tDCS should be applied at rest (off-line) or combined with behavioural treatment strategies (on-line), therefore, this study investigates the effect of repeated sessions of off-line tDCS on language recovery in post-stroke chronic aphasic patients. METHODOLOGY: Eight post-stroke patients with different type and degree of chronic aphasia underwent two weeks of off-line anodal tDCS (2mA intensity for 20minutes a day) on Broca’s area and two weeks of sham stimulation as a control condition. Language recovery was measured assessing object and action naming abilities with a computerized picture naming task. RESULTS: No significant difference between anodal tDCS and sham stimulation, both for object and action naming tasks, was found. Descriptive analysis of single cases showed that after tDCS only one patient improved substantially on action naming task. CONCLUSION: With the exception of one patient, the overall results suggest that in chronic aphasic patients the off-line tDCS protocol applied in this study is not effective in improving noun and verb naming abilities.

Concepts: Language, Noun, Transcranial direct current stimulation, Nominal aphasia, Wernicke's area, Conduction aphasia, Broca's area, Aphasia

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There is a growing body of evidence to support the use of non-invasive brain stimulation techniques such as transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) for the treatment of acquired speech and language disorders. The aim of the present paper is to review evidence to support the use of these procedures in the treatment of aphasia and dysarthria. Both TMS and tDCS are described in terms of their underlying principles and biophysics and their relative advantages and disadvantages for rehabilitation of acquired neurogenic communication disorders. Several studies have documented positive effects of inhibitory repetitive TMS (rTMS) to right Broca’s area homologue on language recovery in non-fluent aphasia post-stroke. Improved language outcomes subsequent to high frequency rTMS applied to the lesioned hemisphere have also been documented. Similarly, therapeutic benefits have also been reported following tDCS, although the findings are less consistent than is the case with rTMS. Improved articulatory function and speech intelligibility has been noted in response to stimulation with excitatory rTMS in Parkinson’s disease. It is suggested that the use of brain stimulation techniques in combination with more traditional therapies may represent the most innovative future approach to the treatment of acquired communication disorders.

Concepts: Neurology, Brain, Language, Broca's area, Neurophysiology, Aphasia, Transcranial direct current stimulation, Transcranial magnetic stimulation

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In most cases, aphasia is caused by strokes involving the left hemisphere, with more extensive damage typically being associated with more severe aphasia. The classical model of aphasia commonly adhered to in the Western world is the Wernicke-Lichtheim model. The model has been in existence for over a century, and classification of aphasic symptomatology continues to rely on it. However, far more detailed models of speech and language localization in the brain have been formulated. In this regard, the dual stream model of cortical brain organization proposed by Hickok and Poeppel is particularly influential. Their model describes two processing routes, a dorsal stream and a ventral stream, that roughly support speech production and speech comprehension, respectively, in normal subjects. Despite the strong influence of the dual stream model in current neuropsychological research, there has been relatively limited focus on explaining aphasic symptoms in the context of this model. Given that the dual stream model represents a more nuanced picture of cortical speech and language organization, cortical damage that causes aphasic impairment should map clearly onto the dual processing streams. Here, we present a follow-up study to our previous work that used lesion data to reveal the anatomical boundaries of the dorsal and ventral streams supporting speech and language processing. Specifically, by emphasizing clinical measures, we examine the effect of cortical damage and disconnection involving the dorsal and ventral streams on aphasic impairment. The results reveal that measures of motor speech impairment mostly involve damage to the dorsal stream, whereas measures of impaired speech comprehension are more strongly associated with ventral stream involvement. Equally important, many clinical tests that target behaviours such as naming, speech repetition, or grammatical processing rely on interactions between the two streams. This latter finding explains why patients with seemingly disparate lesion locations often experience similar impairments on given subtests. Namely, these individuals' cortical damage, although dissimilar, affects a broad cortical network that plays a role in carrying out a given speech or language task. The current data suggest this is a more accurate characterization than ascribing specific lesion locations as responsible for specific language deficits.awx363media15705668782001.

Concepts: Dysprosody, Speech repetition, Conduction aphasia, Psychology, Brain, Aphasia, Traumatic brain injury, Language

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Semantic cognition requires a combination of semantic representations and executive control processes to direct activation in a task- and time-appropriate fashion [Jefferies, E., & Lambon Ralph, M. A. Semantic impairment in stroke aphasia versus semantic dementia: A case-series comparison. Brain, 129, 2132-2147, 2006]. We undertook a formal meta-analysis to investigate which regions within the large-scale semantic network are specifically associated with the executive component of semantic cognition. Previous studies have described in detail the role of left ventral pFC in semantic regulation. We examined 53 studies that contrasted semantic tasks with high > low executive requirements to determine whether cortical regions beyond the left pFC show the same response profile to executive semantic demands. Our findings revealed that right pFC, posterior middle temporal gyrus (pMTG) and dorsal angular gyrus (bordering intraparietal sulcus) were also consistently recruited by executively demanding semantic tasks, demonstrating patterns of activation that were highly similar to the left ventral pFC. These regions overlap with the lesions in aphasic patients who exhibit multimodal semantic impairment because of impaired regulatory control (semantic aphasia)-providing important convergence between functional neuroimaging and neuropsychological studies of semantic cognition. Activation in dorsal angular gyrus and left ventral pFC was consistent across all types of executive semantic manipulation, regardless of whether the task was receptive or expressive, whereas pMTG activation was only observed for manipulation of control demands within receptive tasks. Second, we contrasted executively demanding tasks tapping semantics and phonology. Our findings revealed substantial overlap between the two sets of contrasts within left ventral pFC, suggesting this region underpins domain-general control mechanisms. In contrast, we observed relative specialization for semantic control within pMTG as well as the most ventral aspects of left pFC (BA 47), consistent with our proposal of a distributed network underpinning semantic control.

Concepts: Temporal lobe, Wernicke's area, Process control, Executive functions, Aphasia, Superior temporal gyrus, Cerebrum, Cerebral cortex

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Posterior reversible encephalopathy syndrome (PRES) is an increasingly well recognised clinical and radiological condition. Here we report on the first known published case of PRES in a weightlifter. We present a 34-year-old man with acute onset visual disturbance and expressive dysphasia which occurred after an intensive gym session.

Concepts: Posterior reversible encephalopathy syndrome, Aphasia, Report, Expressive aphasia

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PURPOSE: This study was conducted to evaluate the clinical utility of error variability for differentiating between apraxia of speech (AOS) and aphasia with phonemic paraphasia. METHOD: Participants were 32 individuals with aphasia after left cerebral injury. Diagnostic groups were formed based on operationalized measures of recognized articulatory and prosodic characteristics of AOS and phonemic paraphasia. Sequential repetitions of multisyllabic words were elicited as part of a motor speech evaluation and transcribed phonetically. Four metrics of variability at the syllable and word levels were derived from these transcripts. RESULTS: The measures yielded different magnitudes of variability. There were no group differences between participants who displayed speech profiles consistent with AOS and participants who displayed speech profiles indicative of aphasia with phonemic paraphasia. Rather, correlation coefficients and analyses of covariance showed that the variability metrics were significantly mediated by overall error rate. Additionally, variability scores for individuals with salient diagnoses of AOS and conduction aphasia were inconsistent with current diagnostic guidelines. CONCLUSIONS: The results do not support diagnostic validity of error variability for differentiating between AOS and aphasia with phonemic paraphasia. Future research using error variability metrics should account for overall error rate in the analysis and matching of participant groups.

Concepts: Participation, Mathematical analysis, Neurological disorders, Phonetics, Apraxia, Paraphasia, Phonology, Aphasia

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We report the clinical assessment of J.P., an 86 year-old man with Broca’s aphasia complaining of memory problems. Our aim was to objectively investigate his level of cognitive functioning using standardized neuropsychological tests in order to determine the nature of his memory impairment. J.P.’s medical history included left-middle cerebral artery (left-MCA) stroke, high frequency hearing loss, macular degeneration, and a recent hospitalization related to a fall. Results from his neuropsychological testing and from information gathered during the clinical interview with his wife suggested that a deficit in executive functioning might have been the source for some of his perceived memory problems. We were unable to detect any progressive cognitive decline that might have been suggestive of something more sinister. Despite his age J.P. was a fully functioning and highly contributing member of his society who was completing quite complex activities of daily living (ADLs). We provided J.P. with a compensatory set of strategies in order for him to circumvent his executive difficulties and impairment in expressive language. In the elderly population survivors of stroke are continuing to rise with improvements in drug treatment and primary care. This case study is important as it provides information on neuropsychological assessment in aphasia; and draws attention to valuable information in a client’s clinical history that might help clarify the prognosis.

Concepts: Aphasia, Neuropsychological test, Clinical neuropsychology, Psychology, Cognition, Clinical psychology, Neuropsychology, Neuropsychological assessment

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Recent evidence has fuelled the debate on the role of massed practice in the rehabilitation of chronic post-stroke aphasia. Here, we further determined the optimal daily dosage and total duration of intensive speech-language therapy.

Concepts: Hypertension, Efficacy, Medical terms, Expressive aphasia, Aphasia, Stroke, Traumatic brain injury, Randomized controlled trial