| Abstract: | Electromyographic recordings of intrinsic laryngeal muscles were made during respiration, phonation, speech, and swallow in three subjects in two conditions: with and without intravenous administration of 5 mg of diazepam. The mean activity in microvolts of the thyroarytenoid and cricothyroid muscles was measured during respiration and the percentage increase over resting levels during inspiration, expiration, swallow, phonation, and speech. All subjects demonstrated significant (p ≤ 0.001) reductions in mean activity during respiration with diazepam. Significant (p ≤ 0.001) diazepam, subject, and subject by diazepam interactions were found in the percentage increase in muscle activation on each task. In one subject muscle activity consistently decreased, while in the other two subjects it consistently increased with diazepam. Although all had significant muscle relaxant effects, individuals differed in their diazepam responses during muscle activation. These differences may relate to a subject's age. |
