Acoustic impedance study of peritubal myoclonus.

An audible clicking sound coexistent with the contractions of the peritubal muscles is thought to be an isolated form of palatal myoclonus that presents with myoclonal contractions of the soft palate, larynx, pharynx and, sometimes, cervicofacial area. Acoustic impedance measurements, by demonstrating the relation between the muscle contractions and the clicking noise, represent one of the ways in which the diagnosis can be confirmed. This paper reports the impedance changes following various maneuvers and simultaneous electromyography recordings in four patients with peritubal myoclonus and confirms the accuracy and simplicity of these tests. The pathology of peritubal myoclonus and its treatment options are discussed.