Prolonged Mechanical Noise Restores Tactile Sense in Diabetic Neuropathic Patients

Abstract

Acute application of stochastic resonance (SR), defined as a subsensory level of mechanical noise presented directly to sensory neurons, improves the vibration and tactile perception in diabetic patients with mild to moderate neuropathy. This study examined the effect of 1 hour of continuous SR stimulation on sensory nerve function. Twenty diabetic patients were studied. The effect of stimulation was measured at 2 time points, at the beginning and after 60 minutes of continual SR stimulation. This effect was measured using the vibration perception threshold (VPT) at the big toe under 2 conditions: a null (no SR) condition and active SR, defined as mechanical noise below the subject's own threshold of perception. The measurements under null and active conditions were done randomly and the examiner was blinded regarding the type of condition. Immediately after SR application, the VPT with SR in null condition was similar to baseline (32.2 +/- 13.1, P = nonsignificant) but was significantly lower during active SR (27.4 +/- 11.9) compared with both baseline (P = .018) and off position (P = .045). The 60 minutes VPT with active SR (28.7 +/- 11.1) reached significance comparing the baseline when one outlier was removed from the analysis (P = .031). It may be concluded that SR for a continuous 60-minute period can sustain the VPT improvement in diabetic patients with moderate to severe neuropathy. These results permit the conclusion that there is no short-term adaptation to the stimulation signal. Long-term application of this technique, perhaps in the form of a continually vibrating shoe insert, or insole, may result in sustained improvement of nerve function.

Development and Validation of Wearable Inertial Sensor System for Postural Sway Analysis

“…However, our results revealed that stochastic resonance during these somatosensory-compromised conditions improved postural sway compared to control groups without vibratory input (Figure 8). These results are in agreement with previous research examining the effects of stochastic resonance on postural sway (Bagherzadeh Cham et al, 2016;Cloutier et al, 2009;Galica et al, 2009;Hijmans, Geertzen, Zijlstra, Hof, & Postema, 2008;Khaodhiar et al, 2003;Priplata, Niemi, Harry, Lipsitz, & Collins, 2003;Priplata et al, 2006;Stephen et al, 2012;Wang & Yang, 2012;Wei et al, 2012). We found significant improvements in sway fluctuation measurements at the vibration frequency of 220Hz.…”

Development and Validation of Wearable Systems for Human Postural Sway Analysis

“…However, our results revealed that stochastic resonance during these somatosensory-compromised conditions improved postural sway compared to control groups without vibratory input. These results are in agreement with previous research examining the effects of stochastic resonance on postural sway (Bagherzadeh Cham et al, 2016, Cloutier et al, 2009, Bagherzadeh Cham et al, 2016, Postema et al, 2009, Costa et al, 2007, Wei et al, 2012. We found significant improvements in COP measurements at vibration frequency of 220Hz.…”

Necessity of noise in physiology and medicine

“…Noise-based devices, such as randomly vibrating shoe insoles [10] that apply noise during specific activities or throughout the day, may enable people to overcome functional difficulties due to age-related sensory loss [11], [64], [76], [77], [78], [79]. Furthermore, noise-based mechanical ventilators can improve gas exchange and could have a significant effect on morbidity by breaking the chain of injury propagation in acute lung injury [80].…”