title: Sensory electrical stimulation for suppression of postural tremor in patients with essential tremor.
abstract: Essential tremor is an involuntary trembling of body limbs in people without tremor-related disease. In previous study, suppression of tremor by sensory electrical stimulation was confirmed on the index finger. This study investigates the effect of sensory stimulation on multiple segments and joints of the upper limb. It denotes the observation regarding the effect's continuity after halting the stimulation. 18 patients with essential tremor (8 men and 10 women) participated in this study. The task, "arms stretched forward", was performed and sensory electrical stimulation was applied on four muscles of the upper limb (Flexor Carpi Radialis, Extensor Carpi Radialis, Biceps Brachii, and Triceps Brachii) for 15 seconds. Three 3-D gyro sensors were used to measure the angular velocities of segments (finger, hand, and forearm) and joints (metacarpophalangeal and wrist joints) for three phases of pre-stimulation (Pre), during-stimulation (On), and 5 minute post-stimulation (P5). Three characteristic variables of root-mean-squared angular velocity, peak power, and peak power frequency were derived from the vector sum of the sensor signals. At On phase, RMS velocity was reduced from Pre in all segments and joints while peak power was reduced from Pre in all segments and joints except for forearm segment. Sensory stimulation showed no effect on peak power frequency. All variables at P5 were similar to those at On at all segments and joints. The decrease of peak power of the index finger was noted by 90% during stimulation from that of On phase, which was maintained even after 5 min. The results indicate that sensory stimulation may be an effective clinical method to treat the essential tremor.
authors.affiliation: School of Biomedical Engineering, Konkuk University, Choongju, 380-701, Korea.
authors.forename: Jae-Hoon
authors.initials: JH
authors.lastname: Heo
authors.affiliation: School of Biomedical Engineering, Konkuk University, Choongju, 380-701, Korea.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Kim
authors.affiliation: School of Biomedical Engineering, Konkuk University, Choongju, 380-701, Korea.
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kwon
authors.affiliation: School of Biomedical Engineering, Konkuk University, Choongju, 380-701, Korea.
authors.forename: Sang-Ki
authors.initials: SK
authors.lastname: Lee
authors.affiliation: School of Biomedical Engineering, Konkuk University, Choongju, 380-701, Korea.|Research Institute of Biomedical Engineering, Konkuk University, Choongju, 380-701, Korea.
authors.forename: Gwang-Moon
authors.initials: GM
authors.lastname: Eom
authors.affiliation: Department of Neurology, College of Medicine, Korea University, Ansan, Korea.
authors.forename: Do-Young
authors.initials: DY
authors.lastname: Kwon
authors.affiliation: Department of Neurology, College of Medicine, Korea University, Anam, Korea.
authors.forename: Chan-Nyeong
authors.initials: CN
authors.lastname: Lee
authors.affiliation: Department of Neurology, College of Medicine, Korea University, Anam, Korea.
authors.forename: Kun-Woo
authors.initials: KW
authors.lastname: Park
authors.affiliation: Université libre de Bruxelles, Belgium.
authors.forename: Mario
authors.initials: M
authors.lastname: Manto
mesh_terms: D000344:Afferent Pathways / Q000503:physiopathology*; D000368:Aged; D004599:Electric Stimulation Therapy / Q000379:methods*; D020329:Essential Tremor / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy*; D005260:Female; D005385:Fingers / Q000294:innervation / Q000503:physiopathology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D012684:Sensory Thresholds; D016896:Treatment Outcome; D014202:Tremor / Q000209:etiology / Q000503:physiopathology / Q000628:therapy
keywords: Essential tremor; arms stretched forward; gyro sensor; postural tremor; sensory stimulation