Normative jitter studies with disposable concentric needle electrode in Orbicularis Oculi muscle

• Grant number: 08/10082-6
• Support type: Regular Research Grants
• Duration: February 01, 2009 - February 28, 2011
• Field of knowledge: Health Sciences - Medicine
• Principal Investigator: João Aris Kouyoumdjian
• Grantee: João Aris Kouyoumdjian
• Home Institution: Faculdade de Medicina de São José do Rio Preto (FAMERP). Secretaria de Desenvolvimento Econômico (São Paulo - Estado). São José do Rio Preto , SP, Brazil

Abstract

Single fiber electromyography (SFEMG) is a neurophysiologic method that can be very useful for diagnosing neuromuscular diseases, particularly those affecting neuromuscular junction as Myasthenia Gravis. The purpose of this study is the Orbicularis Oculi muscle jitter measurement in healthy adult's subjects using disposable concentric needle electrode (CNE). This method is not currently done in Brazil, in spite of have been doing in all developed countries since 1966. Also, CNE jitter is being introducing in the world in the past few years and very few normative studies is published till now. The techniques used for jitter measurement are: (1) minimal voluntarily muscle contraction activating pairs of single fiber action potentials (SFAPs); (2) axonal stimulation of facial nerve activating SFAPs. The recording will be made by disposable CNE instead of SFEMG reusable specific electrode that was forbidden in some countries. The jitter parameters obtained from both techniques will be compared, and are shorter in the stimulated one. The Orbicularis Oculi togheter with the Extensor Digitorum Communis muscles are the most useful in clinical practice. Jitter from Orbicularis Oculi reaches the high sensibility for diagnosing ocular forms from Myasthenia Gravis. The results from this project will be very useful for those we use this method in any part of the world, beyond introduce it in Brazil. (AU)