Setup – Median Motor NCS

Electrode placement (use the bar electrode)

• E1 (black):  Abductor pollicis brevis (APB) muscle (laterally on the thenar eminence)
• E2 (red):  Distally along the thumb
• Ground:  Dorsum of hand

Stimulation site

• Two sites
  • Distal
    • (-) Cathode (black):  8-cm proximal to E1.  Note: Make the 8-cm line go to the middle of the wrist crease, then proximal along the median nerve.
    • (+) Anode (red):  proximal (in line with the median nerve)
  • Proximal
    • (-) Cathode (black):  Antecubital crease, medial to the biceps tendon.
    • (+) Anode (red):  proximal (in line with the median nerve)

      

Additional Information

• Type of stimulation = Orthodromic
• If the amplitude is low, move E1 around until you get it over the motor point before calling it truly low.
• CPT codes for nerve conduction studies
  • 95900 Nerve conduction, amplitude and latency/velocity study, each nerve; motor, without F-wave study
  • 95903 Nerve conduction, amplitude and latency/velocity study, each nerve; motor with F-wave study
  • 95904 Nerve conduction, amplitude and latency/velocity study, each nerve; motor with F-wave study, each nerve; sensory
  • 95934 H-reflex, amplitude and latency study; record gastrocnemius/soleus muscle
  • 95936 Record muscle other than gastrocnemius/soleus muscle