Table 1.

Definition of Electrophysiological Diagnostic Outcomes

Outcome*Median NerveUlnar NerveCombined MUD
DMLDSLDMLDSL
NormalNormalNormalNormalNormalNormal
CTSAbnormalAbnormalNormalNormalAbnormal
Ulnar§NormalNormalAbnormalAbnormalNormal
NonspecificAbnormalAbnormalAbnormalAbnormalNormal
  • * 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.