Table 2.

Nerve conduction studies

Patient	Age at testing (years)	Sural SNAP (µV)	Median SNAP (µV)	Median DML (ms)	Median CMAP (mV)	Median MNCV (m/s)	Peroneal CMAP (mV)	Peroneal MNCV (m/s)
Normal valuesa	–	≥6	≥20	≤4.4	≥4	≥49	≥2	≥44
S1	14	3	7	7	5.1	41	0.8	29
	15	Undetect.	4	13	4.3	37	2.2	Undetect.
S2	7	–	–	14	–	12	–	–
	19	–	Undetect.	18	–	4	–	–
	35	–	–	20	1	4	–	–
	39	–	Undetect.	19	0.6	3	–	Undetect.
	41	Undetect.	Undetect.	25	0.5	3	Undetect.	Undetect.
	41	–	–	35	0.2	3	Undetect.	25
S3	4	Undetect.	–	14	0.5	11	Undetect.	Undetect.
	18	–	Undetect.	16	0.6	7	Undetect.	Undetect.
A2	54	Undetect.	–	–	–	–	Undetect.	Undetect.
A3	48	Undetect.	–	–	–	–	0.3	Undetect.
	56	Undetect.	6	17	1.7	23	Undetect.	Undetect.
A4	5	Undetect.	Undetect.	13u	1.9u	12u	0.1	16
A8	11	Undetect.	22	15	5	32	0.4	14

The median nerve sensory nerve action potential was measured in digit 2. The median distal motor latency and compound motor action potential were recorded from the abductor pollicis brevis muscle. The median motor nerve conduction velocity was measured from elbow to wrist. The ulnar nerve distal motor latency and compound motor action potential were measured below the elbow, and the ulnar motor nerve conduction velocity was measured across the elbow. The peroneal compound motor action potential was measured in the extensor digitorum brevis muscle, and the peroneal motor nerve conduction velocity was measured from the fibular head to ankle.

^aNormal values from Preston and Shapiro, 2005.

CMAP = compound motor action potential; DML = distal motor latency; MNCV = motor nerve conduction velocity; undetect. = no response detected; – = not done; SNAP = sensory nerve action potential; u = Ulnar nerve.