In the absence of trauma the diagnosis of tetanus is easily overlooked, and even in the presence of an infected wound and obvious lockjaw the bacteriologic studies may be negative. Tetanus toxin is known to act on the skeletal muscle, causing contracture as a characteristic manifestation.1 In local tetanus produced experimentally the action potentials of affected muscles have been shown to present constant activity with diphasic spikes.2 This abnormal electrical activity is a specific effect induced by tetanus toxin and when demonstrated should be of diagnostic value. Consequently, in a case of suspected tetanus of obscure origin, electromyograms were taken from the affected muscles and a test devised to quantitate the abnormality present for the purpose of prognosis and to aid in following the course of progress.
REPORT OF CASE
A man aged 21 entered the Massachusetts Eye and Ear Infirmary Jan. 28, 1941 because of
Watkins AL. ELECTROMYOGRAMS IN DIAGNOSIS AND PROGNOSIS OF TETANUS. JAMA. 1942;119(3):261-262. doi:10.1001/jama.1942.72830200003007b