Utility of Nerve Conduction Studies for Carpal Tunnel Syndrome by Family Medicine, Primary Care, and Internal Medicine Physicians

Article Figures & Data

Table 1.

Definition of Electrophysiological Diagnostic Outcomes

Outcome^*	Median Nerve^†		Ulnar Nerve^†		Combined MUD
Outcome^*	DML	DSL	DML	DSL	Combined MUD
Normal	Normal	Normal	Normal	Normal	Normal
CTS^‡	Abnormal	Abnormal	Normal	Normal	Abnormal
Ulnar^§	Normal	Normal	Abnormal	Abnormal	Normal
Nonspecific^¶	Abnormal	Abnormal	Abnormal	Abnormal	Normal

* Normal, no neuropathy; CTS, carpal tunnel syndrome; ulnar, ulnar neuropathy; nonspecific, nonspecific upper extremity neuropathy affecting both median and ulnar nerves.
† DML, distal motor latency; DSL, distal sensory latency; MUD, median-ulnar distal sensory latency difference; normal DML or DSL, <97.5% of reference population; normal MUD, <90% of reference population; MUD threshold percentile lower than DML and DSL to match clinical practice.
‡ One of median nerve DML, median nerve DSL, or MUD must be abnormal.
§ One of ulnar nerve DML or DSL must be abnormal.
¶ One of median nerve DML or DSL must be abnormal and one of ulnar nerve DML or DSL must be abnormal.

Table 2.

Study Group Demographic Characteristics

Age Range (% Total)	Gender (% Female)	Height (cm)^*	Weight (kg)^*	BMI (kg/m²)^*
<30 (5.9)	73.2	168 (10)	84 (25)	29.5 (7.0)
30–39 (13.4)	71.1	167 (10)	86 (23)	30.5 (7.2)
40–49 (21.3)	71.7	167 (10)	87 (23)	31.0 (7.5)
50–59 (22.8)	71.6	166 (10)	86 (22)	31.0 (7.4)
60–69 (15.7)	71.1	165 (11)	85 (19)	31.2 (6.2)
≥70 (20.8)	71.8	163 (10)	76 (17)	28.4 (5.9)