Introduction: Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality.
View Article and Find Full Text PDFAttention is a complex construct that comprises at least three major subcomponents: alerting, spatial (re-)orienting, and executive functions, all of which have specific neural correlates along frontoparietal networks. Attention deficits are a common consequence of brain damage. Transcranial direct current stimulation (tDCS) has been shown to modulate spatial attention.
View Article and Find Full Text PDFGesture processing deficits constitute a key symptom of apraxia, a disorder of motor cognition frequently observed after left-hemispheric stroke. The clinical relevance of apraxia stands in stark contrast to the paucity of therapeutic options available. Transcranial direct current stimulation (tDCS) is a promising tool for modulating disturbed network function after stroke.
View Article and Find Full Text PDFFortschr Neurol Psychiatr
March 2013
Fabry's disease is an X-chromosomal linked recessive lysosomal storage disease caused by a deficiency of α-galactosidase A. Accumulation of toxic levels of sphingolipids leads to metabolic dysfunction in various cell types (endothelial cells, myocytes, fibroblasts) and organs thus causing a variety of symptoms. Neurological manifestations include recurrent strokes and polyneuropathy, many patients complain of pain or vertigo.
View Article and Find Full Text PDFThe right intraparietal sulcus (rIPS) is a key region for the endogenous control of selective visual attention in the human brain. Previous studies suggest that the rIPS is especially involved in top-down control and spatial distribution of attention across both visual hemifields. We further explored these attentional functions using transcranial direct current stimulation (tDCS) of the rIPS to modulate behavioral performance in a partial report task.
View Article and Find Full Text PDFTranscranial direct current stimulation (tDCS) is increasingly being used in human studies as an adjuvant tool to promote recovery of function after stroke. However, its neurobiological effects are still largely unknown. Electric fields are known to influence the migration of various cell types in vitro, but effects in vivo remain to be shown.
View Article and Find Full Text PDFNeglect is a multifaceted, complex syndrome, in which patients fail to detect or respond to stimuli or parts thereof located contralesionally. Non-invasive brain stimulation by means of transcranial magnetic stimulation (TMS) or transcranial direct current stimulation (tDCS) may not only be useful as diagnostic research tools to explore the pathophysiology of neglect, but also for ameliorating its symptoms. Current approaches for modulating neglect non-invasively are mainly based on the neurophysiological concept of interhemispheric inhibition, which suggests a pathological overactivation of the contralesional hemisphere due to reduced inhibitory influences from the lesioned one.
View Article and Find Full Text PDFBackground And Purpose: Neuroplastic alterations of cortical excitability and activity represent the likely neurophysiological foundation of learning and memory formation. Beyond their induction, alterations of these processes by subsequent modification of cortical activity, termed metaplasticity, came into the focus of interest recently. Animal slice experiments demonstrated that neuroplastic excitability enhancements, or diminutions, can be abolished by consecutive subthreshold stimulation.
View Article and Find Full Text PDFThe neural substrates of auditory motion processing are, at present, still a matter of debate. It has been hypothesized that motion information is, as in the visual system, processed separately from other aspects of auditory information, such as stationary location. Here we aimed to differentiate the location of auditory motion processing in human cortex using low-frequency repetitive transcranial magnetic stimulation (rTMS) in combination with a psychophysical task of motion discrimination.
View Article and Find Full Text PDFA spatial mismatch of up to 14 mm between optimal transcranial magnetic stimulation (TMS) site and functional magnetic resonance imaging (fMRI) signal has consistently been reported for the primary motor cortex. The underlying cause might be the effect of magnetic susceptibility around large draining veins in Gradient-Echo blood oxygenation level-dependent (GRE-BOLD) fMRI. We tested whether alternative fMRI sequences such as Spin-Echo (SE-BOLD) or Arterial Spin-Labeling (ASL) assessing cerebral blood flow (ASL-CBF) may localize neural activity closer to optimal TMS positions and primary motor cortex than GRE-BOLD.
View Article and Find Full Text PDFObjective: The contribution of the human anterior intraparietal area and the dorsal premotor cortex to arbitrary visuo-motor mapping during grasping were tested.
Methods: Trained right-handed subjects reached for and pincer-grasped a cube with the right hand in the absence of visual feedback after the cube location had been displayed for 200ms. During the reaching movements, the colour of the cube changed and visual feedback about the change of colour was provided for 100ms at 500ms after movement onset (at the time of peak grasp aperture).
Fortschr Neurol Psychiatr
December 2009
Dural arteriovenous fistulas (DAVFs) are abnormal arteriovenous shunts located within the dura mater representing approximately 10 - 15 % of all arteriovenous shunts in the central nervous system. The aetiology of spontaneous DAVFs remains to be elucidated. The symptoms associated with DAVFs can be highly variable and dependent upon the direction of the blood flow, the amount of arteriovenous shunting and the specific location of the fistula.
View Article and Find Full Text PDFTranscranial direct current stimulation is a painless, non-invasive brain stimulation technique that allows one to induce polarity-specific excitability changes in the human brain. Here, we investigated, for the first time in a 'proof of principle' study, the behavioural effect of transcranial direct current stimulation on visuospatial attention in both healthy controls and stroke patients suffering from left visuospatial neglect. We applied anodal, cathoP:dal or sham transcranial direct current stimulation (57 microA/cm(2), 10 min) to the left or right posterior parietal cortex.
View Article and Find Full Text PDFHuman speech and hand use both involve highly specialized complex movement patterns. Whereas previous studies in detail characterized the cortical motor systems mediating speech and finger movements, the network that provides coordination of concurrent speech and hand movements so far is unknown. Using functional magnetic resonance imaging (fMRI), the present study investigated differential cortical networks devoted to speech or fingertapping, and regions mediating integration of these complex movement patterns involving different effectors.
View Article and Find Full Text PDFRecent work has demonstrated that overt reading influences the excitability of the language-dominant hand motor cortex. However, this effect was related to speech output, whereas results on silent reading have been inconsistent, and have not allowed for systematic investigation of the different stages of word recognition. To investigate a possible modulation of the cortical excitability mediating hand movements through different stages of covert reading, motor evoked potentials (MEP) from hand muscles in right-handed subjects were recorded.
View Article and Find Full Text PDFAkinetic crisis (AC) is a much-feared complication of Parkinson's disease (PD) which may appear upon abrupt cessation or malabsorption of dopaminergic medication due to gastrointestinal tract disorders or acute surgery. Intravenous infusion of amantadine sulphate or subcutaneous administration of apomorphine are established treatment strategies for AC. We speculate whether the use of a non-invasive transdermal application form (patch) of a dopaminergic drug (rotigotine) may represent a useful alternative treatment option.
View Article and Find Full Text PDFWhen lifting objects of different mass but identical visual appearance, we apply grip forces that match the expected mass of the object. Here we study the role of the primary motor cortex (M1), the ventral premotor cortex (PMv) and the anterior intraparietal area (AIP) for predictive and reactive scaling of grip forces. Participants performed a precision grip between the index finger and thumb of the right hand to lift two different masses of identical visual appearance in random order.
View Article and Find Full Text PDFA 37-year-old woman was admitted to our department with general fatigue, fever, and asymmetric pain in her lower legs, 2 weeks after a common cold. Dynamic skeletal scintigraphy with 780 MBq (20 mCi) Tc-99m HDP revealed increased perfusion and tracer uptake in the soft tissue of the lower legs, suggesting an inflammatory etiology. A muscle biopsy revealed a vasculitic necrotizing myopathy predominantly affecting the small vessels of the lower legs.
View Article and Find Full Text PDFAction understanding and learning are suggested to be mediated, at least in part, by the human mirror neuron system (hMNS). Static images as well as videos of actions with the outcome occluded have been shown to activate the hMNS. However, whether the hMNS preferentially responds to end or means of an action remains to be investigated.
View Article and Find Full Text PDFInvestigations in macaques and humans have shown that the anterior intraparietal sulcus (IPS) has an important function in the integration of information from tactile and visual object manipulation. The goal of this study was to investigate the special functional role of the anterior IPS in visuo-tactile matching in humans. We used the "virtual-lesion" technique of repetitive transcranial magnetic stimulation (rTMS) to test the functional relevance of anterior IPS for visuo-tactile crossmodal matching.
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