Quantitative histometric studies and relation of number and diameter of myelinated fibres to electrophysiological parameters in normal sensory nerves of man.

Quantitative histometric investigations were made in 6 radial and in 12 sural nerves of subjects without signs of a neuromuscular disorder. Nerve conduction velocities and amplitudes were studied on the same nerves. A linear relationship between the nerve fibre diameter and the conduction velocity of the fastest fibres was found. The conversion factor had a mean of 4.67, S.D. 0.16 in the radial nerves and an average value of 4.55, S.D. 0.19 in the sural nerves. Correlating the amplitudes of the compound nerve action potentials and the fibre number there was a linear proportionality between the log10 of number of fibres with a diameter of 11 mum and more, and the amplitude.