Annals of the New York Academy of Sciences
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The assessment of residual brain function in the vegetative state, is extremely difficult and depends frequently on subjective interpretations of observed spontaneous and volitional behaviors. For those patients who retain peripheral motor function, rigorous behavioral assessment supported by structural imaging and electrophysiology is usually sufficient to establish a patient's level of wakefulness and awareness. However, it is becoming increasingly apparent that, in some patients, damage to the peripheral motor system may prevent overt responses to command, even though the cognitive ability to perceive and understand such commands may remain intact. Advances in functional neuroimaging suggest a novel solution to this problem; in several recent cases, so-called "activation" studies have been used to identify residual cognitive function and even conscious awareness in patients who are assumed to be vegetative, yet retain cognitive abilities that have evaded detection using standard clinical methods.
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Ann. N. Y. Acad. Sci. · Jan 2008
Clinical TrialThoracoscopic thymectomy with the da Vinci robotic system for myasthenia gravis.
Complete thymectomy (Thx) is a crucial part of treatment for myasthenia gravis (MG) and thymoma. The discussion about the necessity of radical, complete Thx and reduced invasiveness has led to no less than 14 different surgical approaches for Thx. The latest development is robotic-assisted surgery. ⋯ From the technical point of view, rThx has advantages for mediastinal dissection. rThx had a shorter learning curve. There might be better outcome results for rThx in MG patients, as compared with nonrobotic tThx. Therefore, rThx is a promising technique for minimally invasive Thx.
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Ann. N. Y. Acad. Sci. · Jan 2008
Structural factors influencing the efficacy of neuromuscular transmission.
Neuromuscular junctions (NMJs) in different species share many features of structure and function. At the same time, important differences distinguish, for example, human NMJs from those in other species. An understanding of the biological context of the human NMJ helps in the interpretation of the effects of disease on the biophysical properties of neuromuscular transmission. ⋯ A genetic influence on NMJ size has recently been discovered in some patients with limb-girdle myasthenia (LGM). Mutations of the gene encoding Dok-7, an essential component of the agrin-muscle-specific kinase pathway that controls postsynaptic differentiation at the mammalian NMJ, results in impaired transmission because the NMJs are abnormally small and have reduced folding but have a normal local density of normal acetylcholine receptors. This condition emphasizes the importance of structural features in achieving reliability of neuromuscular transmission.