Median nerve F wave conduction in healthy subjects over age sixty-five.

Parameters of the median nerve F wave and peripheral motor nerve conduction in 51 healthy male and female human subjects 67 to 89 years of age are described. F wave responses were elicited by stimulation of the nerve at the wrist. Motor nerve conduction velocity (MNCV) was determined for the forearm segment. Major results of this study of an older group of subjects demonstrate that: 1) the shortest F wave latency (SFWL) and the MNCV were slower in our older subjects than values in younger subjects; 2) there was no significant correlation between SFWL and age within the age group examined; 3) distal motor conduction latency was significantly slower in subjects age 75-89 years than in those age 67-74 years; 4) SFWL and MNCV of females were significantly faster than that of males; 5) a positive correlation was found between SFWL and arm length and a predictive formula is derived. An upper limit of normal F wave wrist latency of 31 msec for females and 34.4 msec for males over 65 years of age is proposed as a guideline.