Electrophysiological evaluation of jitter and muscle fiber conduction velocity in situ post COVID-19

• Grant number: 22/02291-1
• Support Opportunities: Regular Research Grants
• Start date: July 01, 2022
• End date: June 30, 2024
• Field of knowledge: Health Sciences - Medicine - Medical Clinics
• Principal Investigator: João Aris Kouyoumdjian
• Grantee: João Aris Kouyoumdjian
• Host 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

A considerable proportion of patients presents residual symptoms for more than six months after acute COVID-19 infection, even in uncomplicated cases. This multi-systemic and non-uniform symptomatic set is called provisionally "post-COVID-19 syndrome", and according to meta-analysis studies, abnormalities in pulmonary function (21%), olfactory dysfunction and neurological abnormalities (24%) and generalized symptoms, especially chronic pain and fatigue (63%) are the most prevalent symptoms. Single fiber electromyography aims to measure jitter, defined as time variation, in microseconds, of the recording action potentials of isolated muscle fiber in consecutive discharges after axonal activation. The jitter increases in disturbances of the neuromuscular junction of any nature, provided that the safety factor of neuromuscular transmission is reduced. The propagation velocity of the muscle fiber action potentials can be measured in situ, reflecting the muscle membrane's excitability and the muscle fiber's diameter. The present study aims to measure the jitter and the propagation velocity of muscle fiber action potentials in patients who had COVID-19 without the need for ventilatory support in the acute phase. The minimum time interval after acute COVID-19 will be six months. The same values will also be evaluated in a control group of apparently healthy subjects who did not have COVID-19. The functional evaluation of the neuromuscular junction in vivo and the measurement of the velocity propagation of the action potentials of muscle fibers isolated in situ will help understand the role of the neuromuscular junction and muscle fibers in the pathophysiology of chronic residual fatigue after COVID-19. (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

JOÃO ARIS KOUYOUMDJIAN; EDUARDO DE PAULA ESTEPHAN. Avaliação eletrofisiológica da junção neuromuscular: breve revisão. Arquivos de Neuro-Psiquiatria, v. 81, n. 12, p. 1040-1052, 2024-01-15. (17/13262-4, 22/02291-1, 08/10082-6)

KOUYOUMDJIAN, JOAO ARIS; GRACA, CARLA RENATA. Muscle fiber conduction velocity in situ revisited: A new approach to an ancient technique. FRONTIERS IN NEUROLOGY, v. 14, p. 10-pg., 2023-02-23. (22/02291-1)

KOUYOUMDJIAN, JOAO ARIS; GRACA, CARLA RENATA. Concentric needle jitter: Reference values in stimulated Tibialis Anterior muscle. FRONTIERS IN NEUROLOGY, v. 13, p. 7-pg., 2022-07-22. (22/02291-1)