Malingering dysphagia and odynophagia electromyographic assessment

Objective: The article discusses the usefulness and investigation technique of suspected malingering dysphagia/odynophagia by surface electromyography (sEMG) of deglutition. Methods: Forty patients with suspected malingering dysphagia (group 1), 40 patients with dysphagia/odynophagia due to tonsillectomy (group 2), and 40 healthy individuals (group 3) were involved in the study. The timing, amplitude, and graphic patterns of activity of the masseter, submental, and trapezius muscles were examined during voluntary single water swallows ("normal") and continuous drinking of 100 mL of water. The muscle activity in oral, pharyngeal, and initial esophageal stages of swallowing was measured, and graphic records were evaluated in relation to timing and voltage. Results: The main sEMG patterns of malingering dysphagia/odynophagia are prolonged time of the voluntary oral phase of a swallow (80% of cases, n = 32, P <.01 vs healthy volunteers) with normal timing of the reflex pharyngeal and initial esophageal phases and normal amplitude voltage. In 42.5% of cases (n = 17, P < .05 vs healthy volunteers), tension of skeletal muscles normally not involved in deglutition was observed during single swallowing being at the same time absent during continuous drinking. Conclusion: Dysphagia due to malingering has no pathologic sEMG patterns associated with deglutition. Skeletal muscle tension during deglutition, being observed in some cases, has no connection with the act of swallowing itself Prolonged oral phase of a swallow is factitious, nonpathologic. Surface EMG, being noninvasive, nonradiographic and inexpensive, can be used for patients with suspected malingering dysphagia, thus avoiding expensive and time-consuming investigation. (C) 2009 Elsevier Inc. All rights reserved.