Continuous Sensory Electrical Stimulation for the Suppression of Parkinsonian Rest Tremor

Abstract

This paper aims to investigate the effect of continuous sensory electrical stimulation (SES) on the suppression of a Parkinsonian rest tremor. Fourteen patients with Parkinson’s disease participated in this study. Three wrist muscles were electrically stimulated on sensory level under motor threshold. Intensity of stimulation was determined for each muscle of each patient as the maximum tolerable current amplitude that does not induce muscle contraction. Tri-axial gyro sensors were attached to three upper limb segments. The angular velocity of each segment was measured for each of the three sessions, i.e., PRE-, ON- and POST- stimulations. Outcome measures were the tremor amplitude and main frequency of each axis in the power spectrum. Decrease in tremor amplitude was significant at ON and POST sessions in finger and at POST session in hand and forearm. Decrease in main frequency was significant mainly at ON session. About one-third of patients showed reduction in tremor power at ON-stimulation and at POST-stimulation. Subjects with suppression of tremor showed greater initial tremor amplitude than those without suppression. Continuous SES suppressed the Parkinsonian rest tremor. The results suggest that the properties of tremor-generating loop may be altered by continuous SES and the effect lasts temporarily.

Peripheral electrical stimulation to reduce pathological tremor: a review

“…Among the review articles, ten studies reported the effects of peripheral electrical stimulation results on patients with ET [18][19][20][21][22][23][24][25][26][27] while ten studies reported on patients with PD [28][29][30][31][32][33][34][35][36][37] and seven studies included both patients with ET and patients with PD [16,17,[38][39][40][41][42]. In order to compare electrical stimulation strategies, some studies also included healthy volunteers that either mimicked tremorgenic activity during experimentation or were subject to artificially induced tremors for experimentation [31,38,41].…”

“…However, the activation of afferent pathways with the real physiological tremorgenic phase is not achieved. Some studies applied electrical stimulation without following any time pattern or synchronization to mechanical or physiological events [21,22,28,[30][31][32][33][34][35]. This stimulation strategy has been labelled as continuous stimulation in this review (Fig.…”

“…Since the anatomy of the forearm comprises a great array of superimposed muscles controlling the wrist and fingers, some studies also placed electrodes over both wrist and finger flexors and extensors [16,20,29]. Other studies targeted both the wrist and elbow joint, placing electrodes over biceps brachii and triceps brachii [17,21,22,34,35,40,41]. Jitkritsadakul et al [30,33] designed an intervention protocol and glove device to stimulate the abductor pollicis brevis as well as the first and second dorsal interosseous muscles.…”

“…Hao et al [32] and Xu et al [31] explored the short-term tremor reduction effect immediately following 5 s after stimulation. Heo et al [21,22,34,35] assessed tremor before stimulation, during 15 s stimulation windows, and 5 min after stimulation ended. Lin et al [23] and Pahwa et al [24] proposed a 40 min stimulation session, assessing tremor before and after the stimulation, which was realized in the Isaacson et al clinical trials [26].…”

EFFECT OF SENSORY ELECTRICAL STIMULATION ON RESTING TREMORS IN PATIENTS WITH PARKINSON’S DISEASE AND SWEDDs

“…2,7 Sensory electrical stimulation (SES) was shown to be effective at suppressing essential tremors 8,9 and Parkinson's disease resting tremors. 10 As artificial sensory signals, such as imposed passive movement, could modulate tremors in PD, 11 applying proper electrical sensory stimulation may be able to suppress tremors in PD patients. In contrast, no evidence of tremor modulation via sensory signals in SWEDDs patients has been noted.…”