title: Autonomic evaluation is independent of somatic evaluation for small fiber neuropathy.
abstract: BACKGROUND
  The relationship between the autonomic reflex screening test (ARS) and measures of sensory function and structure (quantitative sensory testing (QST) and intraepidermal nerve fiber density (IENFD)) remains uncertain in patients with distal small fiber neuropathy (SFN). The aim of this study was to evaluate the correlations among a range of autonomic (quantitative sudomotor axon reflex test (QSART), cardiovagal and cardio adrenergic tests and the composite autonomic severity score (CASS)) and somatic sensory measures (QST of vibration, cooling and heat-pain thresholds and IENFD).
  
  
  METHODS
  122 patients with clinically suspected sensory neuropathy without motor weakness and with normal nerve conduction studies underwent blinded autonomic reflex screening test (ARS), quantitative sensory testing (QST) and skin biopsy (IENFD) for diagnosis of SFN. The relationship between autonomic and somatic sensory measures was assessed.
  
  
  RESULTS
  There was no association between autonomic function measures (QSART volume, CASS_QSART, CASS_vagal, CASS_adrenergic or total CASS) and small fiber sensory measures (IENFD, cooling or heat-pain thresholds). Weak correlations were noted among some modalities of QST (vibration and cooling thresholds) and IENFD.
  
  
  CONCLUSIONS
  Autonomic and sensory outcomes are independent (complementary) measures of distal SFN, and should where feasible be used concurrently in the evaluation of SFN.
authors: Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA. Electronic address: pthaiset@unmc.edu.
authors: Pariwat
authors: P
authors: Thaisetthawatkul
authors: Department of Neurological Sciences, University of Nebraska Medical Center, Omaha, NE, USA; Neurology Section, VA Nebraska-Western Iowa Health Care System, Omaha, NE, USA.
authors: J Americo
authors: JA
authors: Fernandes Filho
authors: Department of Neurology, University of Rochester Medical Center, Rochester, NY, USA.
authors: David N
authors: DN
authors: Herrmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017776:Autonomic Pathways / Q000473:pathology / Q000503:physiopathology*; D001794:Blood Pressure / Q000502:physiology; D004916:Erythromelalgia / Q000175:diagnosis*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D009460:Neurologic Examination; D012018:Reflex / Q000502:physiology*; D012189:Retrospective Studies; D012684:Sensory Thresholds / Q000502:physiology; D012867:Skin / Q000294:innervation; D014636:Valsalva Maneuver / Q000502:physiology; D055815:Young Adult
keywords: Autonomic; Intraepidermal nerve fiber density; Quantitative sensory testing; Quantitative sudomotor axon reflex test; Skin biopsy; Small fiber neuropathy