title: Quantitative pilomotor axon reflex test: a novel test of pilomotor function.
abstract: BACKGROUND
  Cutaneous autonomic function can be quantified by the assessment of sudomotor and vasomotor responses. Although piloerector muscles are innervated by the sympathetic nervous system, there are at present no methods to quantify pilomotor function.
  
  
  OBJECTIVE
  To quantify piloerection using phenylephrine hydrochloride in humans.
  
  
  METHODS
  Pilot study.
  
  
  METHODS
  Hospital-based study.
  
  
  METHODS
  Twenty-two healthy volunteers (18 males,4 females) aged 24 to 48 years participated in 6 studies.
  
  
  METHODS
  Piloerection was stimulated by iontophoresis of 1% phenylephrine. Silicone impressions of piloerection were quantified by number and area. The direct and indirect responses to phenylephrine iontophoresis were compared on both forearms after pre treatment to topical and subcutaneous lidocaine and iontophoresis of normal saline.
  
  
  RESULTS
  Iontophoresis of phenylephrine induced piloerection in both the direct and axon reflex–mediated regions, with similar responses in both arms. Topical lidocaine blocked axon reflex–mediated piloerection post-iontophoresis (mean [SD], 66.6 [19.2] for control impressions vs 7.2 [4.3] for lidocaine impressions;P.001). Subcutaneous lidocaine completely blocked piloerection.The area of axon reflex–mediated piloerection was also attenuated in the lidocaine-treated region postiontophoresis (mean [SD], 46.2 [16.1]cm2 vs 7.2 [3.9]cm2; P.001). Piloerection was delayed in the axon reflex region compared with the direct region. Normal saline did not cause piloerection.
  
  
  CONCLUSIONS
  Phenylephrine provoked piloerection directly and indirectly through an axon reflex–mediated response that is attenuated by lidocaine. Piloerection is not stimulated by iontophoresis of normal saline alone.The quantitative pilomotor axon reflex test (QPART) may complement other measures of cutaneous autonomic nerve fiber function.
authors.affiliation: Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Timo
authors.initials: T
authors.lastname: Siepmann
authors.forename: Christopher H
authors.initials: CH
authors.lastname: Gibbons
authors.forename: Ben M
authors.initials: BM
authors.lastname: Illigens
authors.forename: Jacob A
authors.initials: JA
authors.lastname: Lafo
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Brown
authors.forename: Roy
authors.initials: R
authors.lastname: Freeman
mesh_terms: D000328:Adult; D000779:Anesthetics, Local / Q000494:pharmacology; D001369:Axons / Q000187:drug effects / Q000502:physiology*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D007478:Iontophoresis; D008012:Lidocaine / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000187:drug effects / Q000294:innervation; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D010863:Piloerection / Q000187:drug effects / Q000502:physiology*; D010865:Pilot Projects; D011930:Reaction Time / Q000187:drug effects; D012018:Reflex / Q000187:drug effects / Q000502:physiology*; D012828:Silicones; D012879:Skin Physiological Phenomena / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology; D055815:Young Adult
chemical_list: D000779:Anesthetics, Local; D012828:Silicones; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D008012:Lidocaine