The electrodiagnostic examination of psychogenic swallowing disorders.

The article discusses the usefulness and technique of investigation of suspected psychogenic dysphagia by surface electromyography (sEMG) of deglutition. Thirty-two patients with suspected psychogenic dysphagia (Group 1) and 40 healthy individuals (Group 2) were involved in the study. The timing, amplitude and graphic patterns of activity of the masseter, submental, infrahyoid and trapezius muscles were examined during voluntary single water swallows ("normal"), and continuous drinking of 100 cc of water. The muscle activity in oral, pharyngeal and initial oesophageal stages of swallowing was measured, and graphic records were evaluated in relation to timing and voltage. Globus hystericus was found in only 14 patients of the Group 1 (43.75%). The main sEMG pattern of psychogenic dysphagia is a lack of any pathologic changes of timing, voltage and graphic patterns of deglutition. In 28% of cases tension of skeletal muscles not involved in deglutition was observed during single swallowing (vs. 0% in controls). Psychogenic/hysteria-conversion dysphagia 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. Surface EMG, being non-invasive and non-radiographic, can be used for screening purposes for patients with dysphagia thus avoiding expensive and time-consuming investigation.