Neurophysiologie clinique = Clinical neurophysiology
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During the past decade, a large amount of work on transcranial magnetic stimulation (TMS) has been performed, including the development of new paradigms of stimulation, the integration of imaging data, and the coupling of TMS techniques with electroencephalography or neuroimaging. These accumulating data being difficult to synthesize, several French scientific societies commissioned a group of experts to conduct a comprehensive review of the literature on TMS. This text contains all the consensual findings of the expert group on the mechanisms of action, safety rules and indications of TMS, including repetitive TMS (rTMS). ⋯ The use of TMS/rTMS is discussed in the context of chronic pain, movement disorders, stroke, epilepsy, tinnitus and psychiatric disorders. There is already a sufficient level of evidence of published data to retain a therapeutic indication of rTMS in clinical practice (grade A) in chronic neuropathic pain, major depressive episodes, and auditory hallucinations. The number of therapeutic indications of rTMS is expected to increase in coming years, in parallel with the optimisation of stimulation parameters.
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Obstructive sleep apnoea syndrome (OSAS) constitutes a new major public health problem because of its several pathophysiologic consequences such as cognitive disorders, excessive daytime sleepiness with risks of traffic accidents, cardiovascular implications, and decrease of quality of life. The necessity of a gold-standard polysomnography to ensure an accurate diagnosis implies an expensive, technical and time-consuming examination. Thus, it seems logical to develop new systems so as to diagnose SAS and to make it possible to detect apnoeas/hypopnoeas easily during sleep even at home. ⋯ The dedicated automatic analysis based on mandibular movements presents a good potential for the diagnosis of OSAS. The AHI computed by the automatic method is correlated with the AHI-PSG and the Somnolter could easily be used both in hospital, and in ambulatory settings.
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The primary purpose of this study was to provide insight into the central changes that occur in amyotrophic lateral sclerosis (ALS) with a view to understanding how these could contribute to symptoms. ⋯ Measurements of cortical motor excitatory changes in ALS confirm the presence of corticospinal hypoexcitability. Additionally we found increased excitability of presumed intracortical GABAb circuits that correlated with the severity of ALS. We postulate that the disease results in an imbalance between excitation and inhibition in the cortex that can contribute to clinical symptoms.
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There is a growing and unprecedented interest in the objective evaluation of the subcortical processes that are involved in speech perception, with potential clinical applications in speech and language impairments. Here, we review the studies illustrating the development of electrophysiological methods for assessing speech encoding in the human brainstem: from the pioneer recordings of click-evoked auditory brainstem responses (ABR), via studies of frequency-following responses (FFR) to the most recent measurements of speech ABR (SABR) or ABR in response to speech sounds. ⋯ The SABR test is an objective and non-invasive tool for assessing individual capacity of speech encoding in the brainstem. SABR characteristics are potentially useful both as a diagnosis tool of speech encoding deficits and as an assessment tool of the efficacy of rehabilitation programs in patients with learning and/or auditory processing disorders.
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Comparative Study Clinical Trial
Comparison of "standard" and "navigated" procedures of TMS coil positioning over motor, premotor and prefrontal targets in patients with chronic pain and depression.
Since about 15 years, transcranial magnetic stimulation (TMS) is used as a technique to investigate the function of specific cortical regions. Single pulse TMS studies have targeted the dorsolateral premotor cortex (dlPMC) to characterize premotor-motor interactions in movement disorders. Repetitive TMS (rTMS) trials have targeted the dorsolateral prefrontal cortex (dlPFC) to treat depression. ⋯ The present results incline to be cautious on the pathophysiological interpretations of previous results reported in TMS studies based on "standard" targeting, e.g. regarding premotor-motor interactions. Similarly, the inaccuracy of the "standard" procedure of coil positioning could partly explain the between-study variability of the therapeutic effects produced by rTMS in patients with depression. Our results strongly support a more anterior and lateral placement of the TMS coil for dlPFC stimulation in the treatment of depression.