title: Is the Frequency in Somatosensory Electrical Stimulation the Key Parameter in Modulating the Corticospinal Excitability of Healthy Volunteers and Stroke Patients with Spasticity?
abstract: Somatosensory electrical stimulation (SES) has been proposed as an approach to treat patients with sensory-motor impairment such as spasticity. However, there is still no consensus regarding which would be the adequate SES parameters to treat those deficits. Therefore, the aim of this study was to evaluate the effects of applying SES over the forearm muscles at four different frequencies of stimulation (3, 30, 150, and 300 Hz) and in two intervals of time (5' and 30') by means of transcranial magnetic stimulation and Hoffmann's reflex (H-reflex) in healthy volunteers (Experiments  I and II). A group of stroke patients (Experiment  III) was also preliminary evaluated to ascertain SES effects at a low frequency (3 Hz) applied for 30' over the forearm spastic flexors muscles by measuring the wrist joint passive torque. Motor evoked potentials and the H-reflex were collected from different forearm and hand muscles immediately before and after SES and up to 5' (Experiment  I) and 10' (Experiments  I and II) later. None of the investigated frequencies of SES was able to operate as a key in switching modulatory effects in the central nervous system of healthy volunteers and stroke patients with spasticity.
authors.affiliation: Laboratório de Instrumentação Biomédica, Programa de Engenharia Biomédica, COPPE, Universidade Federal do Rio de Janeiro, Avenida Horácio Macedo 2030, CT, Bloco H, Sala 327, Cidade Universitária, 21941-914 Ilha do Fundão, RJ, Brazil; Laboratório de Neurobiologia II, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, CCS, Bloco G, Sala G1-019, Cidade Universitária, 21941-902 Ilha do Fundão, RJ, Brazil; Departamento de Biociências da Atividade Física, Escola de Educação Física e Desportos, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 540, Cidade Universitária, 21941-599 Ilha do Fundão, RJ, Brazil.
authors.forename: Marco Antonio Cavalcanti
authors.initials: MA
authors.lastname: Garcia
authors.affiliation: Laboratório de Instrumentação Biomédica, Programa de Engenharia Biomédica, COPPE, Universidade Federal do Rio de Janeiro, Avenida Horácio Macedo 2030, CT, Bloco H, Sala 327, Cidade Universitária, 21941-914 Ilha do Fundão, RJ, Brazil.
authors.forename: João Marcos Yamasaki
authors.initials: JM
authors.lastname: Catunda
authors.affiliation: Laboratório de Instrumentação Biomédica, Programa de Engenharia Biomédica, COPPE, Universidade Federal do Rio de Janeiro, Avenida Horácio Macedo 2030, CT, Bloco H, Sala 327, Cidade Universitária, 21941-914 Ilha do Fundão, RJ, Brazil.
authors.forename: Marcio Nogueira
authors.initials: MN
authors.lastname: de Souza
authors.affiliation: Departamento de Fisioterapia, Faculdade de Medicina, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, CCS, Bloco K, Sala K2-49, Cidade Universitária, 21941-902 Ilha do Fundão, RJ, Brazil.
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Fontana
authors.affiliation: Instituto de Comunicação e Informação Científica e Tecnológica em Saúde (ICICT), Fundação Oswaldo Cruz (FIOCRUZ), Avenida Brasil 4365, 21040-900 Manguinhos, RJ, Brazil.
authors.forename: Sandro
authors.identifier: 0000-0001-5367-3397
authors.initials: S
authors.lastname: Sperandei
authors.affiliation: Laboratório de Neurobiologia II, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Avenida Carlos Chagas Filho 373, CCS, Bloco G, Sala G1-019, Cidade Universitária, 21941-902 Ilha do Fundão, RJ, Brazil.
authors.forename: Claudia D
authors.initials: CD
authors.lastname: Vargas
mesh_terms: D000328:Adult; D004558:Electric Stimulation / Q000379:methods; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006181:H-Reflex / Q000502:physiology; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D009128:Muscle Spasticity / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D010865:Pilot Projects; D011712:Pyramidal Tracts / Q000502:physiology*; D013003:Somatosensory Cortex / Q000502:physiology; D020521:Stroke / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult