title: Contribution of QSART to the diagnosis of small fiber neuropathy.
abstract: BACKGROUND
  We evaluated incorporation of the quantitative sudomotor axon reflex test (QSART) into the diagnostic criteria for small fiber neuropathy (SFN) as an addition to quantitative sensory testing (QST) and intraepidermal nerve fiber density (IENFD) testing.
  
  
  METHODS
  One hundred one patients with clinically suspected SFN underwent QSART, QST, and skin biopsy. The diagnostic yield of existing SFN criteria in these patients was compared with criteria incorporating QSART. The new combined diagnostic criteria were evaluated.
  
  
  RESULTS
  SFN was diagnosed in 38 of the 101 patients (38%) using current criteria. Addition of QSART existing SFN criteria resulted in an increased diagnostic yield to 67 patients (66%). Applying new SFN criteria requiring abnormality in at least 2 assessments among QSART, QST, and IENFD resulted in a diagnosis of SFN in 57 patients (56%).
  
  
  CONCLUSIONS
  Assessment of both somatic and peripheral autonomic small nerve fibers enhances diagnostic criteria for SFN.
authors: Department of Neurological Sciences, 982045 University of Nebraska Medical Center, Omaha, Nebraska, 68164, USA.
authors: Pariwat
authors: P
authors: Thaisetthawatkul
authors: J Americo M
authors: JA
authors: Fernandes Filho
authors: David N
authors: DN
authors: Herrmann
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001369:Axons / Q000502:physiology; D001706:Biopsy; D004558:Electric Stimulation; D004916:Erythromelalgia / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D009460:Neurologic Examination; D017288:Pain Threshold / Q000502:physiology*; D010525:Peripheral Nerves / Q000503:physiopathology*; D012018:Reflex / Q000502:physiology*; D012867:Skin / Q000294:innervation / Q000473:pathology; D055815:Young Adult
keywords: intraepidermal nerve fiber density; quantitative sensory testing; quantitative sudomotor axon reflex test; skin biopsy; small fiber neuropathy