title: Ultrasound as Diagnostic Tool for Diaphragmatic Myoclonus.
abstract: BACKGROUND
  Diaphragmatic myoclonus is a rare disorder of repetitive diaphragmatic contractions, acknowledged to be a spectrum that includes psychogenic features. Electromyography has been the diagnostic tool most commonly used in the literature.
  
  
  METHODS
  To test if we could perform a noninvasive technique to delineate the diaphragm as the source of abnormal movements and demonstrate distractibility and entrainability, we used B-mode ultrasound in a patient with diaphragmatic myoclonus.
  
  
  RESULTS
  Ultrasound imaging clearly delineated the diaphragm as the source of her abdominal movements. We were able to demonstrate entrainability of the diaphragm to hand tapping to a prescribed rhythm set by examiner.
  
  
  CONCLUSIONS
  We recommend the use of ultrasound as a noninvasive, convenient diagnostic tool for further studies of diaphragmatic myoclonus. We agree with previous findings that diaphragmatic myoclonus may be a functional movement disorder, as evidenced by distractibility and entrainability demonstrated on real-time video with ultrasonography.
authors.affiliation: Human Motor Control Section, National Institutes of Health, Bethesda, MD.
authors.forename: Vesper Fe Marie
authors.initials: VF
authors.lastname: Llaneza Ramos
authors.affiliation: Human Motor Control Section, National Institutes of Health, Bethesda, MD.
authors.forename: Elaine
authors.initials: E
authors.lastname: Considine
authors.affiliation: CNS, IRB, National Institutes of Health, Bethesda, MD.
authors.forename: Barbara I
authors.initials: BI
authors.lastname: Karp
authors.affiliation: Office of the Clinical Director, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD.
authors.forename: Codrin
authors.initials: C
authors.lastname: Lungu
authors.affiliation: Functional and Applied Biomechanics Section, Rehabilitation Medicine Department, National Institutes of Health, Bethesda, MD and Mount Washington Pediatric Hospital, Washington, DC.
authors.forename: Katharine
authors.initials: K
authors.lastname: Alter
authors.affiliation: Human Motor Control Section, National Institutes of Health, Bethesda, MD.
authors.forename: Mark
authors.initials: M
authors.lastname: Hallett
keywords: conversion; motor control; myoclonus; ultrasound