Electromyography and clinical neurophysiology
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Electromyogr Clin Neurophysiol · Dec 1994
Comparative StudyPercutaneous sciatic somatosensory evoked potential. A comparison to the transcutaneous response.
Cerebral and spinal evoked potentials were recorded in response to percutaneous stimulation of the sciatic nerve at the inferior gluteal crease. To justify the invasiveness of the procedure, a comparison was made to transcutaneous stimulation of the inferior gluteal nerve at the same level.
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Electromyogr Clin Neurophysiol · Jul 1994
Participation of the sternocleidomastoid muscle on deep inspiration in man. An electromyographic study.
The sternocleidomastoid muscle (SCM), which is responsible for the mechanical action in the majority of the head movements, is also considered an accessory muscle for respiration. Its action in the inspiratory movements was studied electromyographically in 30 healthy young adults by considering the types of respiration, the different forms of deep inspiration, the breathing effort and the body position of these subjects. A prominent activity was found in those subjects whose respiration was of the costal type when they breathed rapidly and roughly and during the breathing effort. An outstanding difference of the action potentials of the SCM muscle was not observed during variation of the body positions.
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Electromyogr Clin Neurophysiol · Oct 1993
Autonomic system dysfunction in moderate diabetic polyneuropathy assessed by sympathetic skin response and Valsalva index.
30 patients with moderate diabetic polyneuropathy (Stage 2 according to Dyck) were evaluated for autonomic symptoms, sympathetic skin response (SSR) and Valsalva index. Their SSR were compared to a control group of 30 healthy normal subjects. Neuropathy was confirmed by history, clinical examination and nerve conduction measurements. ⋯ SSR amplitudes were significantly lower in diabetics (changed in 53%, absent in 20%) than in the controls. SSR abnormality correlated to some clinical and electroneurographic signs of neuropathy, suggesting similar affection of sympathetic and somatic fibres. Valsalva index was abnormal in 37% of patients showing no correlation to clinical, electroneurographic or SSR changes.
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Electromyogr Clin Neurophysiol · Sep 1993
Combined ultrasonographic and neurographic examination: a new technique to evaluate phrenic nerve function.
In this report a new technique for simultaneous assessment of the electrical and mechanical properties of the diaphragm is presented. The phrenic nerve of 9 healthy persons was stimulated at the neck using magnetic stimulation. ⋯ The data show that this method helps to distinguish the diaphragm muscle compound action potential from electrical activity derived from neighboring muscles activated by the brachial plexus. Furthermore, it provides a non-invasive tool which can easily be used in clinical practice to study the mechanical properties of the diaphragm.
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Electromyogr Clin Neurophysiol · Apr 1993
Electromyographic analysis of effort in grip strength assessment.
The purpose of the present research was to investigate the use of surface EMG in assessing effort while measuring grip strength with the Jamar dynamometer. We hypothesized that sincere, maximal grip contractions could be distinguished from feigned, submaximal contractions by differences in the amplitude and frequency content of the EMG, as well as by differences in force. Healthy subjects (seven men and ten women) were instructed on different trials to give a sincere (maximal, 100%) effort or a feigned (50% of maximal) effort with the right hand. ⋯ The 50% efforts showed a higher frequency EMG than did the 100%. The results supported the hypothesis that surface EMG may provide a measure of effort in a grip strength task. Analysis of the EMG, in conjunction with force analysis, has the potential of being a valuable tool for the clinician needing to determine whether a patient is giving a sincere, maximal effort or is feigning.