title: Myelinated and unmyelinated endoneurial axon quantitation and clinical correlation.
abstract: BACKGROUND
  Different disease patterns result from loss of myelinated and unmyelinated axons, but quantitation to define their loss has been difficult.
  
  
  METHODS
  We measured large and small endoneurial axons in axonal neuropathies by staining them with peripherin and comparing their area to that of nonmyelinating Schwann cells stained with neural cell adhesion molecule (NCAM).
  
  
  RESULTS
  Loss of myelinated and unmyelinated axons was typically proportional, with predominant myelinated or unmyelinated axon loss in a few patients. Myelinated axon loss was associated with loss of distal vibration sense and sensory potentials (P < 0.0001) and was selective in patients with bariatric and bowel resection surgery (P < 0.001). Unmyelinated axon measurements correlated with skin (ankle P = 0.01; thigh P = 0.02) and vascular (nerve P < 0.0001; muscle P = 0.01) innervation.
  
  
  CONCLUSIONS
  Myelinated and unmyelinated axons can be quantitated by comparing areas of axons and nonmyelinating Schwann cells. Clinical features correlate with myelinated axon loss, and unmyelinated axon loss correlates with skin and vascular denervation.
authors.affiliation: Department of Neurology, Talpiot medical leadership program, Chaim Sheba Medical Center, Tel HaShomer, Israel, 52621 and Joseph Sagol neuroscience center, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.|Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Amir
authors.initials: A
authors.lastname: Dori
authors.affiliation: Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Glenn
authors.initials: G
authors.lastname: Lopate
authors.affiliation: Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Rati
authors.initials: R
authors.lastname: Choksi
authors.affiliation: Department of Neurology, Washington University School of Medicine, St. Louis, MO, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Pestronk
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology; D009413:Nerve Fibers, Myelinated / Q000378:metabolism / Q000473:pathology*; D036421:Nerve Fibers, Unmyelinated / Q000378:metabolism / Q000473:pathology*; D019006:Neural Cell Adhesion Molecules / Q000378:metabolism; D010525:Peripheral Nerves / Q000473:pathology*; D010523:Peripheral Nervous System Diseases / Q000175:diagnosis*; D012189:Retrospective Studies; D012720:Severity of Illness Index; D012867:Skin / Q000294:innervation / Q000473:pathology; D013223:Statistics as Topic; D055815:Young Adult
chemical_list: C488618:NCAM protein (681-695), human; D019006:Neural Cell Adhesion Molecules
keywords: myelinated axons; neuropathy; sural nerve biopsy; unmyelinated axons; vascular innervation