[A case report of diaphragmatic flutter].

A 18-year-old female complained of a dyspneic sensation and involuntary movements in the epigastrium. On physical examination, fine rhythmic movements in the epigastrium were observed on each inspiration with a rate of 5-10 per breath. Arterial blood gas analysis was normal. Recording of the respiratory parameters and the EMG of respiratory muscles were performed. Analysis of the respiratory flow revealed that her spontaneous inspirations consisted of short inspirations (i.e., flutter wave) (150-170 beats per minute). EMG of respiratory muscles demonstrated that these flutter waves were driven by intercostal muscles and diaphragm. The flutter waves were not suppressed by breath holding at the maximal inspiration. With intravenous injection of 200 mg of diphenylhydantoin, flutter waves disappeared within 10 minutes. There were no abnormal findings on chest roentgenogram, electrocardiogram, head CT scan and MRI of the cervical spine. During one year's follow up no attack developed again. We have encountered 3 cases of the syndrome since 1981. In two of them, the spontaneous respiration was superimposed on a high-frequency wave throughout the whole respiratory cycle while in one case the high-frequency wave developed only in the inspiratory phase of spontaneous respiration. In the present case the respiratory flow pattern was similar to the last mentioned and the EMG-analysis of respiratory muscles confirmed that the flutter waves were driven by intercostal muscles and diaphragm. Furthermore, synchronization of activities of the two respiratory muscles suggests that the syndrome is of central origin.