Electromyography (EMG) measures muscle response or electrical activity in response to a nerveâs stimulation of the muscle.The test is used to help detect neuromuscular abnormalities. During the test, one or more small needles (also called electrodes) are inserted through the skin into the muscle.n audio-amplifier is used so the activity can be heard.EMG measures the electrical activity of muscle during rest, slight contraction and forceful contraction. Muscle tissue does not normally produce electrical signals during rest.
Respiratory muscle weakness should be considered in patients whose dyspnea cannot be explained by pulmonary disease, cardiac disease, anemia, or deconditioning.First symptoms may occur when respiratory muscles are under increased load, such as when standing in deep water, swimming, or in the supine position.yspnea is common in advanced stages of neuromuscular disorders, but it is infrequently the presenting symptom. However, dyspnea is a frequent complaint in a primary care setting but is rarely caused by a respiratory muscle weakness.
The weakness may progress over hours to days to involve the arms, truncal muscles, cranial nerves, and muscles of respiration. Variants of GBS may present as pure motor dysfunction or acute dysautonomia. The mean time to the clinical function nadir is 12 days, with 98% of patients reaching a nadir by 4 weeks.runk, bulbar, and respiratory muscles can be affected as well. Patients may be unable to stand or walk despite reasonable strength, especially when ophthalmoparesis or impaired proprioception is present. Respiratory muscle weakness with shortness of breath may be present.