1,721,005 research outputs found
Study of the connectivity of the fronto-parietal circuits in humans by means of TMS/EEG co-registration
No full textTranscranial magnetic stimulation in developmental stuttering: Relations with previous neurophysiological research and future perspectives
No full textDevelopmental stuttering (DS) is a disruption of the rhythm of speech, and affected people may be unable to execute fluent voluntary speech. There are still questions about the exact causes of DS. Evidence sug- gests there are differences in the structure and functioning of motor systems used for preparing, execut- ing, and controlling motor acts, especially when they are speech related. Much research has been obtained using neuroimaging methods, ranging from functional magnetic resonance to diffusion tensor imaging and electroencephalography/magnetoencephalography. Studies using transcranial magnetic stimulation (TMS) in DS have been uncommon until recently. This is surprising considering the relation- ship between the functionality of the motor system and DS, and the wide use of TMS in motor-related disturbances such as Parkinson’s Disease, Tourette’s Syndrome, and dystonia. Consequently, TMS could shed further light on motor aspects of DS. The present work aims to investigate the use of TMS for under- standing DS neural mechanisms by reviewing TMS papers in the DS field. Until now, TMS has contributed to the understanding of the excitatory/inhibitory ratio of DS motor functioning, also helping to better understand and critically review evidence about stuttering mechanisms obtained from different tech- niques, which allowed the investigation of cortico-basal-thalamo-cortical and white matter/connection dysfunctions
Long-range neural activity evoked by premotor cortex stimulation: a TMS/EEG co-registration study.
No full textThe premotor cortex is one of the fundamental structures composing the neural networks of the human brain. It is implicated in many behaviors and cognitive tasks, ranging from movement to attention and eye-related activity. Therefore, neural circuits that are related to premotor cortex have been studied to clarify their connectivity and/or role in different tasks. In the present work, we aimed to investigate the propagation of the neural activity evoked in the dorsal premotor cortex using transcranial magnetic stimulation/electroencephalography (TMS/EEG). Toward this end, interest was focused on the neural dynamics elicited in long-ranging temporal and spatial networks. Twelve healthy volunteers underwent a single-pulse TMS protocol in a resting condition with eyes closed, and the evoked activity, measured by EEG, was compared to a sham condition in a time window ranging from 45 ms to about 200 ms after TMS. Spatial and temporal investigations were carried out with sLORETA. TMS was found to induce propagation of neural activity mainly in the contralateral sensorimotor and frontal cortices, at about 130 ms after delivery of the stimulus. Different types of analyses showed propagated activity also in posterior, mainly visual, regions, in a time window between 70 and 130 ms. Finally, a likely "rebounding" activation of the sensorimotor and frontal regions, was observed in various time ranges. Taken together, the present findings further characterize the neural circuits that are driven by dorsal premotor cortex activation in healthy humans
Improvement of verbal behavior after pharmacological treatment of developmental stuttering: a case study
No full textDevelopmental stuttering is a disruption in normal speech fluency and rhythm. Developmental stuttering usually manifests between 6 and 9 years of age and may persist in adulthood. At present, the exact etiology of developmental stuttering is not fully clear. Besides, the dopaminergic neurological component is likely to have a causal role in the manifestation of stuttering behaviors. Actually, some studies seem to confirm the efficacy of antidopaminergic drugs (haloperidol, risperidone and olanzapine, among others) in controlling stuttering behaviors. We present a case of persistent developmental stuttering in a 24-year-old adult male who was able to control his symptoms to a significant extent after administration of risperidone, an antidopaminergic drug. Our findings show that the pharmacological intervention helped the patient improve on a set of fluency tasks but especially when the tasks involved the uttering of content words. Our results are discussed against the current theories on the cognitive and neurological basis of developmental stuttering
Risperidone reduces tic-like motor behaviors and linguistic dysfluences in severe persistent developmental stuttering
No full textThis case study shows the reduction of tic-like motor behaviors and linguistic dysfluencies in severe persistent developemental suttering after a risperidone treatment
Superior occipital lobe is involved in planning of reaching movements: evidence from transcranial magnetic stimulation
No full textImprovement of verbal behaviour after pharmacological treatment of developmental stuttering: a case study
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