A J Espay1, S H Fox, C Marras, A E Lang, R Chen. 1. Toronto Western Research Institute and Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
Abstract
BACKGROUND: Respiratory myoclonus or diaphragmatic flutter is an unusual movement disorder with abnormal diaphragmatic activity, which may be associated with respiratory symptoms. The effects of distracting maneuvers on diaphragmatic activity have not been investigated. METHODS: Two patients with nondisabling abdominal movements of suspected diaphragmatic origin were studied with surface and needle electromyography (EMG). RESULTS: The abdominal movements resulted from isolated, rhythmic diaphragmatic contractions with variable EMG burst duration, suppressibility with breath-holding and distracting maneuvers, and other attributes of volitional control. CONCLUSION: "Respiratory myoclonus" may be a heterogeneous disorder ranging from synchronous movements of the diaphragm and other respiratory muscles associated with respiratory compromise, to diaphragmatic movements under at least some volitional control with no respiratory or functional disability. The latter group could be designated phenomenologically as "isolated diaphragmatic tremor."
BACKGROUND:Respiratory myoclonus or diaphragmatic flutter is an unusual movement disorder with abnormal diaphragmatic activity, which may be associated with respiratory symptoms. The effects of distracting maneuvers on diaphragmatic activity have not been investigated. METHODS: Two patients with nondisabling abdominal movements of suspected diaphragmatic origin were studied with surface and needle electromyography (EMG). RESULTS: The abdominal movements resulted from isolated, rhythmic diaphragmatic contractions with variable EMG burst duration, suppressibility with breath-holding and distracting maneuvers, and other attributes of volitional control. CONCLUSION: "Respiratory myoclonus" may be a heterogeneous disorder ranging from synchronous movements of the diaphragm and other respiratory muscles associated with respiratory compromise, to diaphragmatic movements under at least some volitional control with no respiratory or functional disability. The latter group could be designated phenomenologically as "isolated diaphragmatic tremor."
Authors: Vesper Fe Marie Llaneza Ramos; Elaine Considine; Barbara I Karp; Codrin Lungu; Katharine Alter; Mark Hallett Journal: Mov Disord Clin Pract Date: 2016-01-09