NCS
Pronunciation: en-see-ESS
Also written as: NCS — Nerve Conduction Study
Abbreviation for nerve conduction study, the component of an electrodiagnostic evaluation that measures the speed and amplitude of electrical signals along peripheral nerves.
Full Definition
A nerve conduction study (NCS) applies surface electrodes to measure the conduction velocity, amplitude, and latency of sensory and motor nerve responses. It is performed in conjunction with EMG as part of a comprehensive electrodiagnostic evaluation in PM&R settings. NCS findings help differentiate axonal from demyelinating neuropathies, localise entrapment lesions, and assess the severity of peripheral nerve injuries. Editors should note that NCS results are reported with specific numerical values (e.g., 'conduction velocity of 42 m/s') and must not be rounded or paraphrased. The abbreviation 'NCS' must be defined on first use in formal reports; some documents use 'NCT' (nerve conduction test) or 'NCV' (nerve conduction velocity) interchangeably, which may require standardisation.
Usage
Usage note: Distinguish from EMG, which refers specifically to the needle electrode examination. 'NCV' (nerve conduction velocity) is a related but narrower term referring only to speed, not the full study.
In Context
- "NCS of the median nerve revealed prolonged distal motor latency and reduced amplitude, consistent with moderate carpal tunnel syndrome." — Electrodiagnostic Study Report
- "The editor standardized 'NCV' to 'NCS' throughout the report per the house style guide, then flagged for author approval." — Copy-Editing Revision Note