title: Noise-enhanced vibrotactile sensitivity in older adults, patients with stroke, and patients with diabetic neuropathy.
abstract: OBJECTIVE
  To test the hypothesis that vibrotactile detection thresholds in older adults, patients with stroke, and patients with diabetic neuropathy can be significantly reduced with the introduction of mechanical noise.
  
  
  METHODS
  A randomized controlled study.
  
  
  METHODS
  A university research laboratory.
  
  
  METHODS
  Twelve healthy elderly subjects (age range, 67-85y), 5 patients with stroke (age range, 24-64y), and 8 patients with diabetic neuropathy (age range, 53-77y).
  
  
  METHODS
  Each subject's detection thresholds (ie, minimum level of stimulus to be detected) for a vibrotactile stimulus without and with mechanical noise (ie, random vibration with a small intensity) were determined by using a 4-, 2-, and 1-stepping algorithm. The stimuli were applied to the fingertip and/or to the first metatarsal of the foot.
  
  
  METHODS
  Detection threshold for a vibrotactile stimulus.
  
  
  RESULTS
  The detection threshold at the fingertip for the vibration stimulus with mechanical noise was significantly lower than that without mechanical noise for all 12 elderly subjects, for 4 of the 5 patients with stroke, and all 8 patients with diabetic neuropathy. For the 8 patients with diabetes, mechanical noise also significantly reduced the vibrotactile detection threshold at the foot.
  
  
  CONCLUSIONS
  Reduced vibrotactile sensitivity in older adults, patients with stroke, and patients with diabetic neuropathy can be significantly improved with input mechanical noise. Noise-based techniques and devices may prove useful in overcoming age- and disease-related losses in sensorimotor function.
authors.affiliation: Center for BioDynamics and Department of Biomedical Engineering, Boston University, Boston, MA 02215, USA.
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.forename: Lewis A
authors.initials: LA
authors.lastname: Lipsitz
authors.forename: Manuel
authors.initials: M
authors.lastname: Montero-Odasso
authors.forename: Jonathan
authors.initials: J
authors.lastname: Bean
authors.forename: D Casey
authors.initials: DC
authors.lastname: Kerrigan
authors.forename: James J
authors.initials: JJ
authors.lastname: Collins
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003929:Diabetic Neuropathies / Q000150:complications / Q000534:rehabilitation*; D005260:Female; D005385:Fingers / Q000294:innervation; D005528:Foot / Q000294:innervation; D006801:Humans; D006987:Hypesthesia / Q000209:etiology / Q000534:rehabilitation*; D008297:Male; D008875:Middle Aged; D009622:Noise; D010470:Perceptual Masking; D012684:Sensory Thresholds; D018709:Statistics, Nonparametric; D020521:Stroke / Q000150:complications; D000071939:Stroke Rehabilitation