Abstract
High-resolution sonography is capable of depicting peripheral nerves with excellent visual quality. However, it is unknown whether changes related to aging can be detected by sonography. The aim of this study was to examine the power of sonography to detect aging. For sonography, a high-frequency linear array transducer (central frequency, 12 MHz) was used. We examined the median nerve by measuring motor conduction velocity (MCV), fascicular cross-sectional area (CSA) at the levels of the wrist and elbow, and anteroposterior diameter at the levels of the forearm, lunate and capitate bones in 34 healthy subjects (12 males, 22 females; median age, 34.5 years; age range, 22−78). MCV tended to decrease with aging; however, CSA was not significantly different among age subgroups. A significant correlation between MCV and CSA was observed in the subgroups of twenties and thirties, but not in the subgroups over 40. This is probably due to the fact that CSA of the median nerve measured by sonography does not change with aging, whereas MCV decreases with aging because of nerve degeneration. In this study, sonography depicted physiological size differences of the median nerve at the carpal tunnel but not age-related changes.
