Neurosurgery notes/Median nerve of peripheral nerve injuries

Median nerve of peripheral nerve injuries

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Parent item
Peripheral nerve injuries
Sub-item
Median nerve entrapment in Carpal tunnel
Median nerve injury/compression in arm
Median nerve entrapment in forearm
RAG
RAG

Overview

  • Injury/compression sites
      • A. Proximal arm
      • Complete palsy.
      • Usually due to trauma.
      B. Distal arm
      • Supracondylar spur with ligament of Struthers.
      • Supracondylar fracture.
      C. Proximal forearm
      • Musculotendinous compression
        • Bicipital aponeurosis.
        • Pronator teres syndrome.
        • Sublimis arch.
      D. AIN neuropathy
      E. Carpal tunnel syndrome
      • Transverse carpal ligament (TCL).
Motor innervation Pronator teres (C6. C7) Flexor carpi radialis (FCR) (C6. C7) Palmaris longus (G7, C8) r digitorum superficialis (FDS) (C8, Tl) AIN Flexor digitorum profundus l, Il (FDP) (a, Tl Flexor pollicis longus (FPL) (C8. Tl) Pronator quadratus (Cl. C8) uctor pollicis brevis (APB) (C8. Tl) exor pollicis brevis (FPB) (C8, Tl) ens pollicis (C8, Tl) lumbricals 1 , 2 W/ Median nerve ([C51, C6, a, C8, Tl) Sensory innervation — Palmar cutaneous branch radial & ulnar n Injury / compression sites A. Prox. arm = complete palsy • Trauma (usually) B. Distal arm: • Supracondylar spur ± ligament of Struthers • Supracondylarfracture C. Proximal FA * musculotendinous compression 1. Bicipital aponeurosis 2. Pronator teres S. 3. Sublimis arch . AIN neuropathy . Carpal tunnel S.: TCL
Median nerve ([C5], C6, C7, C8, T1)

Definition

  • Flexor pollicis brevis has a dual innervation by the median and ulnar nerves

Struthers ligament

  • Fibrous band extends from a bone spike located on the anteromedial face of the lower third of the humerus known as the supracondylar process and is part of the medial epicondyle of the humerus.
Ulnar Nerve Anatomy, Course and Supply | Bone and Spine

Motor and sensory deficits

1.5.2 Median Nerve Entrapment Sites: Motor and Sensory Deficits (Table 1.5b) Elbo Wrist 1. Motor+ Sens . pronatorteres (C6. C7 ) radians (FCR) (G, a) • palmaris longus (Q , flexor digitorum superficialis Function pronates FA flexes wrist in radial direction corrugates palm skin flexes fingers 2— 5 @ prox- IP joints flexes fingers 2. part Of 3 @ dist. IP joint flexes thumb@dist. IP pronates FA radial 2/3 of palm abducts thumb away from palm flexes thimb @ MCP joint + opposesthumb fingers 2.3: flex MCP joint. extend prox- IP joint • volarfirvers 1-3. radial • of dist phalanxes.' ulnar 2 3 AIN flexor digitorum profundus l, 11 (FOP) flexor pollicis longus (FPL) (C, 11) pronator q uadratus (C7.C8) palmar cutaneouÖr. recurrent thenar motor abductor pollicis 11) flexor pollicis brevis (superf. head) (FRB) opponens pollicis (G, 11) • 2(C8.T1) common & properdigital nerves Legends: O Joint, — : mixed nerve, — , — : sensory nerve . In the table, boxes containing muscles are : motor nerve colored with blue shades and their deficits with gray shades. Boxes containing nerve br., which innervate skin as well as their deficit are colored areen. Red boxes show Dossible entraoment sites.

Q&A

  • What is the Gantzer muscle?
      • An aberrant accessory head to the flexor pollicis longus that may be a point of compression of the anterior interosseous nerve.

Images

chia' rulialis Palrngis k-'ngus (ulnar llaleral wp*d An in palm r oi miian ulnM 2nd mid&• and distal Only ting oi with digital posterior (dorsal)