Influence of vibrotactile random noise on the smoothness of the grasp movement in patients with chemotherapy-induced peripheral neuropathy

[Purpose] Patients with chemotherapy-induced peripheral neuropathy (CIPN) often suffer from sensorimotor dysfunction of the distal portion of the extremities (e.g., loss of somatosensory sensation, numbness/tingling, difficulty typing on a keyboard, or difficulty undoing or doing up a button). The present study aimed to reveal the effects of subthreshold vibrotactile random noise stimulation on sensorimotor dysfunction in CIPN patients without exacerbating symptoms. [Methods] Twenty-five patients with CIPN and 28 age-matched healthy adults participated in this study. To reveal the effects of subthreshold vibrotactile random noise stimulation on sensorimotor function, participants were asked to perform grasp movement tasks during random noise stimulation delivered to the volar and dorsal wrist. We set three intensity conditions of the vibrotactile random noise: 0%, 60%, and 120% of the sensory threshold (Noise 0%, Noise 60%, and Noise 120% conditions). In the grasp movement task, the distance between the thumb and index finger was recorded while the participant attempted to grasp a target object, and the smoothness of the grasp movement was quantified by calculating normalized jerk in each experimental condition. The experimental data were compared using two-way repeated-measures analyses of variance with two binary factors: experimental condition (Noise 0%, 60%, 120%) × group (Healthy controls, CIPN patients).[Results] The smoothness of the grasp movement was only improved in the Noise 60% condition without exacerbating numbness/tingling in CIPN patients and healthy controls. [Conclusion] The current study suggested that the development of treatment devices using stochastic resonance can improve sensorimotor function for CIPN patients.[Trial registration] UMIN Clinical Trials Registry（UMIN-CTR）No. UMIN000024776https://rctportal.niph.go.jp/s/detail/um?trial_id=UMIN000024776#