Study of Nerve Conduction and Late Responses in Normal Chinese Infants, Children, and Adults

Abstract

Healthy Chinese individuals (n = 168), aged from 24 hours to 30 years, were studied to establish the following normal values: (1) motor conduction velocity, distal latency, amplitude, and F-wave velocity in the median, ulnar, tibial, and peroneal nerves; (2) H-reflex velocity and latency in the tibial nerve for all subjects as well as in the median and ulnar nerves in infants; (3) sensory conduction velocity, latency, and amplitude in the median, ulnar, and sural nerves; and (4) the difference in minimal latencies of both H-reflex and F-waves between corresponding nerves in opposite limbs and between two nerves in the same limb. The motor conduction velocities, sensory conduction velocities, F-wave velocities, and H-reflex velocities in newborns were approximately 50%, 40%, 40 to 45%, and 40 to 45% of adult values, respectively. At age 3 years, the normal values were in the adult range for all motor conduction velocities and for the sensory conduction velocities in the upper limbs. The sensory conduction velocities, H-reflex velocities, and F-wave velocities in the lower limbs did not reach adult values until age 6 years whereas the upper limb F-wave velocities reached adult levels between 6 and 14 years in different nerves. These results indicate that adult values for nerve conduction velocities, including the late responses, are reached earlier in the lower extremities; however, conduction velocities at any age are always faster in the upper limbs and in the proximal compared to the distal segments. The maturation process occurs most rapidly during the first 3 to 6 years of life, especially in the first year. This parallels the histologic development of peripheral nerves during childhood.

A study on median nerve conduction velocity in different age groups

“…Studies have proved that the motor and sensory conduction velocities in new born were 40% to 50% of adult values and at 3 years of age the normal values were in the adult range for all motor and sensory nerve conduction velocity. 2 Awang et al 3 observed that conduction velocity reduction with age was not very significant. Though it is agreed that aging alters nerve conduction studies, it does not clearly define the age group at which these changes occur.…”

Influence of age, height, gender on median and ulnar nerve conduction study

“…[16] There are many crosssectional studies that have estimated the reduction in NCV ranging between 0.13 m/sec and 0.22 m/sec [17] these also point to the fact that aging has a definite effect on the NC parameters. Cai and Zhang [18] reported in their study that the conduction velocity in a newborn is approximately 50% of adult values and progressively increase, reaching the adult value at the age of three. There is an accelerated rate of decline in total number of muscle fibers commencing at the age of 25 years thereby affecting the conduction velocity.…”

Characteristic MRI features of chronic inflammatory demyelinating polyradiculoneuropathy

“…There was no family history of neuromuscular disorders, including polyneuropathy. Electrophysiological examination at 11 years of age showed low amplitudes of compound muscle action potential (CMAP) and slow motor nerve conduction velocities (MCV) ( Table 1) [2]. Although mild exacerbation and remission of symptoms reoccurred, she had been followed closely without any treatment.…”

“…to distal and CMAP < 20% below lower limit of normal values[2]; MCV < 70% below lower limit of normal values[2]. electrophysiological examinations, genetic analysis to exclude HMSN or other genetic neuropathic disorders, other autoimmune pathogenetic analysis, and responsiveness to immunotherapy, in order to define the diagnosis of CIDP.…”