Improvement of sensorimotor functions in old age by passive sensory stimulation

Abstract

Sensorimotor functions decrease in old age. The well-documented loss of tactile acuity in elderly is accompanied by deterioration of haptic performance and fi ne manipulative movements. Physical training and exercise can maintain sensorimotor fi tness into high age. However, regular schedules of training require discipline and physical fi tness. We here present an alternative interventional paradigm to enhance tactile, haptic, and fi ne motor performance based on passive, sensory stimulation by means of tactile coactivation. This approach is based on patterned, synchronous tactile stimulation applied to the fi ngertips for 3 hours. The stimulation drives plastic reorganizational changes in somatosensory cortex that affect perception and behavior: We demonstrate that following 3 hours of coactivation tactile acuity as well as haptic object exploration and fi ne motor performance are improved for at least 96 hours. Because this kind of intervention does not require active participation or attention of the subjects, we anticipate that coactivation is a prime candidate for future therapeutic interventions in patients with impaired sensorimotor abilities. It can be assumed that the maintenance and restoration of sensorimotor functions can ensure and preserve independence of daily living. Further optimizing of the stimulation protocol can be assumed to strengthen both the range and durability of its effi cacy.

Sex-Specific Links in Motor and Sensory Adaptations to Repetitive Motion–Induced Fatigue

“…In addition, fatigue-terminal AD thresholds were significantly greater in the condition with sensory stimulation than when stimulation was absent (Time × Condition interaction). Despite previous research demonstrating that sensory supplementation has a beneficial effect on sensory function (Freyer, Reinacher, Nolte, Dinse, & Ritter, 2012;Kalisch, Tegenthoff, & Dinse, 2008), our data suggest that stimulation may add the effects of fatigue on the sensory system and lead to a larger decrease in sensory detection capability. Results from other experimental fatigue protocols have found significant increases in sensory thresholds of both fatigued and nonfatigued muscles (Han et al, 2015;Kosek & Lundberg, 2003;Moufflet & Côté, 2015).…”

Age-related changes in cutaneous sensation in the healthy human hand

“…Age-related changes in sensation are usually investigated at a single site, typically the index fingertip (e.g., Thornbury and Mistretta 1981;Desrosiers et al 1996;Tremblay et al 2005;Murata et al 2010), although the tip of the little finger (Bruce 1980), two to three fingertips (Cole et al 1998;BearLehman et al 2003), or all five fingertips (Kalisch et al 2008;Aoki and Fukuoka 2010), have been compared. Changes in cutaneous sensation are more frequently reported using two-point discrimination, again most often at the fingertips (e.g., Bovenzi and Zadini 1989;Woodward 1993;Desrosiers et al 1996;Stevens and Choo 1996;Kalisch et al 2008;van Nes et al 2008) although the palm and dorsal surface have been studied (Axelrod and Cohen 1961;Gellis and Pool 1977;Stevens and Choo 1996). Despite the natural variability of cutaneous thresholds across the hand (Weber 1834;Stevens and Choo 1996), only a single study has compared two-point discrimination on the dominant hand at multiple sites that include both palmar and dorsal aspects (Gellis and Pool 1977).…”

“…Despite the natural variability of cutaneous thresholds across the hand (Weber 1834;Stevens and Choo 1996), only a single study has compared two-point discrimination on the dominant hand at multiple sites that include both palmar and dorsal aspects (Gellis and Pool 1977). Similarly, age-related threshold changes for both two-point discrimination and von Frey filaments have only been compared at the fingertips of one hand (Desrosiers et al 1996;Tremblay et al 2005;Kalisch et al 2008), and at two sites on the palm (Axelrod and Cohen 1961). Despite methodological differences, these studies suggest that thresholds for von Frey and two-point discrimination may increase in the fingertips by as much as 10-fold between 20 and 90 years.…”

Tactile stimulation interventions: Influence of stimulation parameters on sensorimotor behavior and neurophysiological correlates in healthy and clinical samples

“…It thus allows for a systematic investigation on perceptual learning processes (Fraser et al, 2002), and also for practical applications. For example, rTS might help to increase tactile abilities in individuals with a high need for these, such as artists and fine mechanics (Ragert et al, 2004;Reuter, Voelcker-Rehage, Solveig, & Godde, unpublished), or with sensory impairments due to age (Dinse et al, 2006;Kalisch, Tegenthoff, & Dinse, 2008;Kalisch, Tegenthoff, & Dinse, 2010;Voelcker-Rehage & Godde, 2010) or stroke (K. Johansson, Lindgren, Widner, Wiklund, & Johansson, 1993;Sullivan & Hedman, 2008).…”

“…At last, rTS was shown to also affect the motor cortex, which enables applications such as treating paralysis and motor impairment (Conforto, Cohen, dos Santos, Scaff, & Marie, 2007;Conforto et al, 2010; e.g. Kalisch et al, 2008). In addition to its non-invasive nature, rTS has the advantage of being relatively easy and convenient to apply.…”