title: Median nerve fascicular anatomy as a basis for distal neural prostheses.
abstract: BACKGROUND
  Functional electrical stimulation (FES) serves as a possible therapy to restore missing motor functions of peripheral nerves by means of cuff electrodes. FES is established for improving lower limb function. Transferring this method to the upper extremity is complex, due to a lack of anatomical data on the physiological configuration of nerve fascicles. Our study's aim was to provide an anatomical basis for FES of the median nerve in the distal forearm and hand.
  
  
  METHODS
  We investigated 21 distal median nerves from 12 body donors. The peripheral fascicles were traced back by removing the external and interfascicular epineurium and then assigned to 4 quadrants.
  
  
  RESULTS
  A distinct motor and sensory distribution was observed. The fascicles innervating the thenar eminence and the first lumbrical muscle originated from the nerves' radial parts in 82%. The fascicle supplying the second lumbrical muscle originated from the ulnar side in 78%. No macroscopically visible plexus formation was observed for the distal median nerve in the forearm.
  
  
  CONCLUSIONS
  The findings on the distribution of the motor branches of the median nerve and the missing plexus formation may likely serve as an anatomical basis for FES of the distal forearm. However, due to the considerable variability of the motor branches, cuff electrodes will need to be adapted individually in FES. Taking into account the sensory distribution of the median nerve, FES may also possibly be applied in the treatment of regional pain syndromes.
authors.affiliation: Institute of Anatomy, University of Leipzig, Liebigstraße 13, D-04103 Leipzig, Germany; Department of Neurosurgery, University of Leipzig, Liebigstraße 20a, D-04103 Leipzig, Germany. Electronic address: uwe.planitzer@medizin.uni-leipzig.de.
authors.forename: Uwe
authors.initials: U
authors.lastname: Planitzer
authors.affiliation: Institute of Anatomy, University of Leipzig, Liebigstraße 13, D-04103 Leipzig, Germany.
authors.forename: Hanno
authors.initials: H
authors.lastname: Steinke
authors.affiliation: Department of Neurosurgery, University of Leipzig, Liebigstraße 20a, D-04103 Leipzig, Germany.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Meixensberger
authors.affiliation: Institute of Anatomy, University of Leipzig, Liebigstraße 13, D-04103 Leipzig, Germany.
authors.forename: Ingo
authors.initials: I
authors.lastname: Bechmann
authors.affiliation: Institute of Anatomy, University of Leipzig, Liebigstraße 13, D-04103 Leipzig, Germany.
authors.forename: Niels
authors.initials: N
authors.lastname: Hammer
authors.affiliation: Department of Neurosurgery, University of Leipzig, Liebigstraße 20a, D-04103 Leipzig, Germany.
authors.forename: Dirk
authors.initials: D
authors.lastname: Winkler
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019412:Anatomy, Cross-Sectional; D002102:Cadaver; D004210:Dissection; D004558:Electric Stimulation; D005260:Female; D005542:Forearm / Q000033:anatomy & histology / Q000294:innervation; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000033:anatomy & histology* / Q000166:cytology; D009046:Motor Neurons / Q000502:physiology; D058117:Neural Prostheses; D011474:Prosthesis Design; D011984:Sensory Receptor Cells / Q000502:physiology
keywords: Anatomy; Electrical stimulation; Median nerve fascicles; Prosthesis; Rehabilitation