title: Axonal loss in patients with inflammatory demyelinating polyneuropathy as determined by motor unit number estimation and MUNIX.
abstract: OBJECTIVE
  This study quantifies functioning axons and reinnervation by applying two methods multiple point stimulation (MPS) MUNE, and motor unit number index (MUNIX), in patients with acute- and chronic inflammatory demyelinating polyneuropathy (AIDP, CIDP).
  
  
  METHODS
  Nineteen patients with inflammatory demyelinating polyneuropathy (eleven AIDP and eight CIDP) were prospectively included. MPS MUNE and MUNIX examinations on the thenar muscle group by stimulating the median nerve were applied on all patients. Motor unit size was calculated as single motor unit potential (sMUP) and motor unit size index (MUSIX). The results were compared with twenty healthy subjects.
  
  
  RESULTS
  In AIDP patients mean MPS MUNE (106) and MUNIX (80) were lower than control MPS MUNE (329) and MUNIX (215) (p<0.001). In CIDP patients both MPS MUNE (88) and MUNIX (67) were lower than controls (p<0.001). In CIDP patients sMUP (63) and MUSIX (90) were higher than control sMUP (35) and MUSIX (58) (p<0.05 and p<0.01). When AIDP and CIDP groups were combined the sensitivity for MPS MUNE and MUNIX were 89.5% and 68.4%, respectively.
  
  
  CONCLUSIONS
  Decreased MPS MUNE and MUNIX suggest presence of axonal loss or loss of functioning axons in AIDP and CIDP. Increased motor unit size in CIDP patients indicates compensatory reinnervation. Moreover, both MPS MUNE and MUNIX can discriminate between disease versus non-disease.
  
  
  CONCLUSIONS
  Estimation of the number and the average size of motor units may have clinical value for the assessment of axonal loss or loss of functioning axons in patients with AIDP and CIDP.
authors.affiliation: Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Sansuthan
authors.initials: S
authors.lastname: Paramanathan
authors.affiliation: Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark. Electronic address: hatitank@rm.dk.
authors.forename: Hatice
authors.initials: H
authors.lastname: Tankisi
authors.affiliation: Department of Neurology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Henning
authors.initials: H
authors.lastname: Andersen
authors.affiliation: Department of Clinical Neurophysiology, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Anders
authors.initials: A
authors.lastname: Fuglsang-Frederiksen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001369:Axons / Q000473:pathology*; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D020275:Guillain-Barre Syndrome / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000473:pathology*; D020277:Polyradiculoneuropathy, Chronic Inflammatory Demyelinating / Q000175:diagnosis* / Q000503:physiopathology; D011446:Prospective Studies; D011999:Recruitment, Neurophysiological / Q000502:physiology; D055815:Young Adult
keywords: AIDP; CIDP; Inflammatory demyelinating polyneuropathies; MUNIX; Motor unit number estimation; Multiple point stimulation