Nerve conduction normals and instructions

median motor distance 7 cm DML <4.5> 49

ulnar motor distance 6.5 cm ; DML <> 51

median antidromic ( rings index, stim at wrist) distance 13 cm; peak latency <>15 (if under 60) and >10 (if over 60).

median orthodromic (palmar) (bar on wrist, stim at mid-palm) d=8cm; peak lat 2.3

distal antidromic (rings on index; stim mid palm with same 8 cm distance, beyond carpal tunnel to differentiate CTS and PN) Note-- can do same for ulnar if desired difference > .3 ms is abnormal

radial median comparison-- rings on thumb, stim radial and median each at 10 cm; > 4 ms difference is abnormal

median-ulnar comparison-- rings on ring finger, d 14 cm to median and ulnar both; > 4 ms is abnormal difference

lumbrical motor-- put G1 next to tendon near 1st palmar crease stim palm; indicated if motor is absent.

lateral antebrachial-- measure 12 cm to radial stylus from biceps insertion; compare to opposite side; if abnormal suggests plexus rather than radiculopathy.

medial antebrachial-- measure 12 cm to ulnar stylus from biceps insertion; compare to opposite side; if abnormal suggests plexus rather than radiculopathy.

Radial sensory-- put G1 on radial tendonnear snuffbox towards thumb. measure 10 cm. Amp>20 is normal, latency less important, can compare to opposite side.

Radial motor-- G1 on EDC or EIC; d about 10 cm, measure also spiral groove (with calipers) and axilla or Erb's point.

dorsal ulnar cutaneous-- d 10 cm; G1 at base of 4th metacarpal with palm downl;stim ulnar nerve; if normal suggests problem in wrist.

f wave estimates-- measure estimate to xiphoid from leg, to sternum in arm; take velocity times 2 divided by the velocity. (controls for height).

Peroneal distance 8.5; amp >2; DML<>4; DML < distance =" 14">6; latency < 4.5

saphenous-- 2 methods 1) stimulate knee between gracilis and sartorius, go 10 cm distal just off tibia or 2) distal method; G! behind tibia 1 cm north of medial malleolus, go 14 cm.

phrenic-- stimulate at bottom of SCM; G1 at anterior axillary line in bottom intercostal space; G2 near midline.

Rep stim for periodic paralysis: rep stim; exercisse for 3-4 min with rest every 30 sec or so; repeat rep stim; check CMAP every five minutes for up to 45 minutes; if amplitude drops out in 80 % of cases.