Restricted motion of the median nerve in carpal tunnel syndrome

Peripheral nerve motion measurement with spectral Doppler sonography: a reliability study

This study evaluates single operator test-retest reliability of spectral Doppler ultrasound measurement of median nerve excursion during wrist extension. Longitudinal motion of the median nerve was measured at the elbow on three occasions in both upper limbs of 16 healthy subjects using a standard colour Doppler ultrasound system. The mean of the three maximum velocity time integrals was calculated from the spectral Doppler sonogram of each test. Analysis of data with intraclass correlation coefficient indicated a high degree of repeatability (0.92). Spectral Doppler ultrasound may provide a valuable method for measurement of peripheral nerve motion and may have a role in the clinical assessment of entrapment syndromes.

US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs

The diagnosis of nerve entrapment at osteofibrous tunnels relies primarily on clinical and electrodiagnostic findings. Recently, the refinement of high-frequency broadband transducers with a range of 5-15 MHz, sophisticated focusing in the near field, and sensitive color and power Doppler technology have improved the ability to evaluate peripheral nerve entrapment in osteofibrous tunnels with ultrasonography (US). In the upper limb, osteofibrous tunnels amenable to US examination include the carpal tunnel for the median nerve and the cubital and Guyon tunnels for the ulnar nerve. In the lower limb, these tunnels include the fibular neck for the common peroneal nerve, the tarsal tunnel for the posterior tibial nerve, and the intermetatarsal spaces for the interdigital nerves. High-resolution US allows direct imaging of the involved nerves, as well as documentation of changes in nerve shape and echotexture that occur in compressive syndromes. A spectrum of extrinsic causes of entrapment, such as tenosynovitis, ganglia, soft-tissue tumors, bone and joint abnormalities, and anomalous muscles, can also be diagnosed with US. With continued experience, it is likely that this technique will be increasingly used to evaluate nerve entrapment syndromes.

Measuring longitudinal nerve motion using ultrasonography

While it is known that peripheral nerves slide longitudinally in response to limb movements, the clinical relevance of this phenomenon remains largely speculative. This technical note introduces a new application for noninvasive measurement of longitudinal movement of peripheral nerves. The rationale for developing the technique is given including a brief overview of nerve motion theories and how these are related to clinical practice. Current ultrasound applications for nerves and tissue motion are outlined and details of the Doppler measurement procedure are described. Limitations of the technique and potential future applications are discussed. Spectral Doppler ultrasound may provide an effective method for noninvasive quantification of longitudinal nerve motion.

Ultrasonography of peripheral nerves

With recent improvements in ultrasound (US) imaging equipment and refinements in scanning technique, an increasing number of peripheral nerves and related pathologic conditions can be identified. US imaging can support clinical and electrophysiologic testing for detection of nerve abnormalities caused by trauma, tumors, and a variety of nonneoplastic conditions, including entrapment neuropathies. This article addresses the normal US appearance of peripheral nerves and discusses the potential role of US nerve imaging in specific clinical settings. A series of US images of diverse pathologic processes involving peripheral nerves is presented.

Tendon and nerve sonography

The refinement of high frequency transducers has improved the ability of ultrasound (US) to detect fine textural abnormalities of tendons and nerves and to identify a variety of pathologic conditions. Characteristic echotextural patterns, closely resembling the histologic ones, are typically depicted in these structures using high US frequencies. In tendon imaging, US can identify tendon dislocations, degenerative changes, differentiate partial from complete tears and determine whether the patient has to be treated surgically or conservatively. A spectrum of findings in inflammatory conditions, including paratendonitis and tenosynovitis, and tendon tumors also can be detected. In nerve imaging, US can support clinical and electrophysiologic testing for detection of compressing lesions caused by nerve entrapment in a variety of osteofibrous tunnels of the limbs and extremities. Nerve tears and tumors also can be diagnosed. Overall, US is an effective technique for imaging tendons and nerves.