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Accessory nerve stimulation in the assessment of myasthenia gravis
Author(s) -
Schumm Fritz,
Stöhr Manfred
Publication year - 1984
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880070211
Subject(s) - stimulation , accessory nerve , medicine , anatomy , ulnar nerve , neuromuscular transmission , brachial plexus , median nerve , myasthenia gravis , motor nerve , anesthesia , elbow
Repetitive nerve stimulation (5/second) was done at the median nerve at the wrist and at the accessory nerve just behind the sternocleidomastoid muscle before and 20 seconds to 5 minutes after tetanic nerve stimulation (1 minute). Since the degree of the neuromuscular block depends on the body temperature these investigations were done successively at skin temperatures of 32°C and 36°C. A comparison of the results obtained revealed the highest rate of pathologic decrement with posttetanic accessory nerve stimulation (32°C = 77%, 36°C = 87%), whereas with posttetanic median nerve stimulation pathological results were obtained in a significantly lower proportion (32°C = 50%, 36°C = 60%). The advantages of the stimulation of the accessory nerve for the detection of partial neuromuscular block are: 1. The superficially located accessory nerve allows for supramaximal stimulation with rather low stimulus intensities (6–20 mA). 2. Since the accessory nerve is mainly a motor nerve, the stimulation is less painful than the stimulation of a mixed nerve. 3. Stimulation of a proximal nerve is more sensitive for detecting a defect in neuromuscular transmission than stimulation of a distal nerve. 4. There is no risk of a pneumothorax and of a traumatic nerve lesion as there is with stimulation of the brachial plexus by needle electrodes.