title: C8 and T1 innervation of forearm muscles.
abstract: OBJECTIVE
  C8-dominant innervation of ulnar-innervated and T1-dominant innervation of median-innervated intrinsic hand muscles have been suggested, although less is known regarding forearm muscles. We aimed to determine myotomal innervation of the forearm muscles based on the clinical and electromyographial findings of patients with C8 or T1 lesions.
  
  
  METHODS
  Medical Research Council scale and EMG findings were retrospectively reviewed in 16 patients with C8 lesions (2 postmedian sternotomy C8 plexopathy and 14 C8 radiculopathy) and 9 patients with T1-dominant lesions (8 true neurogenic thoracic outlet syndrome and 1 T1 radiculopathy).
  
  
  RESULTS
  Clinical and EMG findings revealed T1-dominant innervation of the flexor digitorum superficialis, flexor digitorum profundus of the index finger, abductor pollicis brevis, and flexor pollicis longus muscles, and C8-dominant innervation of the flexor carpi ulnaris, flexor digitorum profundus of the little finger, and digit extensors innervated by the posterior interosseous nerve. The first dorsal interosseous, and abductor digiti minimi muscles seem to be innervated by both C8 and T1 roots.
  
  
  CONCLUSIONS
  C8-dominant innervation of ulnar-innervated muscles and T1-dominant innervation of median-innervated muscles are also evident for forearm flexor muscles.
  
  
  CONCLUSIONS
  Such an additional evidence for myotomal innervation will improve localization in clinical as well as electrophysiological diagnoses.
authors.affiliation: Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Chiba
authors.affiliation: Department of Neurology, Tokyo Saiseikai Central Hospital, Tokyo, Japan.
authors.forename: Fumie
authors.initials: F
authors.lastname: Konoeda
authors.affiliation: Department of Neurology, Tokyo Metropolitan Geriatric Hospital, Tokyo, Japan.
authors.forename: Mana
authors.initials: M
authors.lastname: Higashihara
authors.affiliation: Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Kamiya
authors.affiliation: Department of Neurology, Faculty of Medicine, Kyorin University, Tokyo, Japan.
authors.forename: Chizuko
authors.initials: C
authors.lastname: Oishi
authors.affiliation: Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Hatanaka
authors.affiliation: Department of Neurology, Teikyo University School of Medicine, Kaga 2-11-1, Itabashi-ku, Tokyo, Japan. Electronic address: sonoom@med.teikyo-u.ac.jp.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Sonoo
mesh_terms: D000328:Adult; D002574:Cervical Vertebrae; D004576:Electromyography / Q000379:methods; D005260:Female; D005542:Forearm / Q000294:innervation* / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation* / Q000502:physiology; D012189:Retrospective Studies; D013126:Spinal Nerve Roots / Q000502:physiology; D013904:Thoracic Vertebrae
keywords: Forearm flexor muscles; Median nerve; Myotome; Radiculopathy; True neurogenic thoracic outlet syndrome; Ulnar nerve