Medida do tempo de reação à apresentação de estímulos elétricos senoidais de 5, 250 e 2000 Hz

• Ano de defesa: 2009
• Autor(a) principal: Felix, Evandro Penteado Villar [UNIFESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Fibras nervosas; Limiar sensorial; Tempo de reação; Estimulação elétrica; Sensations; Electrical stimulation; Current Perceptions Threshold (CPT)
• Link de acesso: https://repositorio.unifesp.br/handle/11600/9809

Objective: to measure reaction times (RT) to different frequencies of electrical sinusoidal current stimulation. Methods: RTs were measured from 20 healthy volunteers (7 men). Electrical sinusoidal currents of 5, 250 and 2000 Hz at 1.1 sensory thresholds (ST) and also at 2ST for 5 Hz, were applied to the left index finger; responses were measure through the EMG responses of the right indicis proprius muscle. Results: The mean RT (range) obtained from fastest responses were significantly different, 0.57 (0.16 to 1.60) s, 0.34 (0.12 to 0.71) s and 0.22 (0.08 to 0.35) s, for responses to 5, 250 and 2000 Hz respectively and for 5 Hz at 2ST 0.22 (0.11 to 0.34) s. Conclusion: At. 1.1ST the RT elicited by sinusoidal electrical currents at different frequencies are mediated by different spectrum of fibers suggesting that 2000 Hz stimulates Aβ fibers, 250 Hz Aβ or Aδ fibers, 5 Hz Aβ, Aδ or C fibers and 5 Hz at 2ST stimulates Aβ fibers. Significance: Different frequencies of stimulation may activate different fibers: 2000 Hz (1.1ST) and 5 Hz (2ST) Aβ fibers, 250 Hz (1.1ST) Aβ or Aδ fibers and 5 Hz (1.1ST) Aβ, Aδ or C fibers. What fiber is initially stimulated by the lower frequencies depended on the subject studied.