Mean values of excitability parameters derived from the multiple measures of nerve excitability performed on the median nerve in 38 normal subjects.

<p>First column shows mean ± standard deviation (SD). Second column shows Pearson product moment correlation coefficient between excitability measure and serum potassium. Third column shows p values (* = P<0.05, ** = <i>P</i><0.01, *** = <i>P</i><0.001). SDTC: strength-duration time constant. TEd20 and TEh20: threshold electrotonus changes due to depolarizing and hyperpolarizing currents respectively, set to 20% of control threshold; TEd40, TEh40 same, but for 40% polarizing currents; expressions in square brackets indicate times after start of 100 ms current, early [10–20 ms], late [90–100 ms] or around peak threshold change [ peak]. I/V: current-threshold. RRP: relative refractory period.