title: Upper leg conduction time distinguishes demyelinating neuropathies.
abstract: BACKGROUND
  The objective of this study was to determine whether differentiation between demyelinating and axonal neuropathies could be enhanced by comparing conduction time changes in defined segments of the total peripheral nerve pathway.
  
  
  METHODS
  Compound muscle action potentials (CMAPs) were elicited by cathodal stimulation of the tibial nerve at the ankle and popliteal fossa, and by paravertebral neuromagnetic stimulation at proximal and distal cauda equina while recording from muscles of the foot, shin, and thigh. Segmental conduction times were calculated in normal subjects; in patients with lumbosacral radiculopathy, distal symmetric diabetic neuropathy, amyotrophic lateral sclerosis, acute and chronic inflammatory demyelinating polyneuropathy; and in patients with anti-myelin-associated glycoprotein, myelomatous, and Charcot-Marie-Tooth type 1a polyneuropathies.
  
  
  RESULTS
  Distal cauda equina latency and CMAP duration and segmental conduction times in upper leg and cauda equina facilitated differentiation of demyelinating from axonal neuropathies, even in the presence of a range of reduced amplitude CMAPs.
  
  
  CONCLUSIONS
  Within the demyelinating neuropathy spectrum, it was further possible to distinguish subtypes.
authors.affiliation: Department of Neurology, Robert F. Furchgott Center for Neural and Behavioral Science, SUNY Downstate Medical Center, 450 Clarkson Avenue, Brooklyn, New York 11203, USA. paul.maccabee@downstate.edu
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Maccabee
authors.forename: Larry P
authors.initials: LP
authors.lastname: Eberle
authors.forename: Ian A G
authors.initials: IA
authors.lastname: Stein
authors.forename: Justin A
authors.initials: JA
authors.lastname: Willer
authors.forename: Mark E
authors.initials: ME
authors.lastname: Lipitz
authors.forename: Roger W
authors.initials: RW
authors.lastname: Kula
authors.forename: Tatiana
authors.initials: T
authors.lastname: Marx
authors.forename: Eugeniu V
authors.initials: EV
authors.lastname: Muntean
authors.forename: Vahe E
authors.initials: VE
authors.lastname: Amassian
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D003711:Demyelinating Diseases / Q000175:diagnosis* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011115:Polyneuropathies / Q000175:diagnosis* / Q000503:physiopathology*; D013848:Thigh / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult