latency
Pronunciation: LAY-ten-see
The time delay between stimulus application and the recorded neurophysiological response.
Full Definition
Latency in neurophysiology represents the time interval, measured in milliseconds, between the application of a stimulus and the appearance of the resulting electrical response in the nervous system. This measurement is fundamental in nerve conduction studies and evoked potential testing, where prolonged latencies often indicate slowing of nerve conduction due to demyelination, compression, or other pathological processes. Different components of neurophysiological responses have characteristic normal latency values that serve as reference standards for clinical interpretation. Latency measurements must be precise and standardized, taking into account factors such as temperature, age, and limb length that can affect conduction times. Comparison of latencies between sides or with normative data helps identify focal or generalized nervous system dysfunction.
Usage
Usage note: Always report latency measurements in milliseconds and specify the anatomical pathway tested.
In Context
- "The median nerve showed prolonged distal latency consistent with carpal tunnel syndrome." — Nerve conduction study report
- "Visual evoked potential P100 latency was delayed bilaterally, suggesting optic pathway involvement." — Evoked potential study report