Focal neuropathies of the hand are among the most common diseases treated by neurologists. The two most common are median neuropathy at the wrist (carpal tunnel syndrome) and ulnar neuropathy at the elbow. The current electrophysiological methods of assessment of focal neuropathies can be painful, and include nerve conduction studies and electromyography. Electrical impedance myography (EIM) is a new technique that can be used to assess neuromuscular disease. We have had success in using EIM in small muscles in animals, and limited experience using EIM in small muscles in human studies. We plan to refine these techniques in this proposal, while studying focal neuropathies of the hand. The long-term goal of this proposal is to make EIM a valuable tool for the assessment of neuromuscular disease. Establishing standards for use in small muscles will complement the known utility of EIM in larger muscles and help make it such a tool. We have three specific aims for this study. First, we aim to establish a range of normality for EIM for the three hand muscles that are tested most commonly in standard neurophysiologic assessment: the abductor digiti minimi, first dorsal interosseous, and abductor pollicis brevis. Second, we will evaluate EIM parameters in a group of patients with median or ulnar neuropathy, predicting that EIM parameters recorded from affected muscles in patients with median and ulnar neuropathy will differ from normal subjects due to the underlying architectural alterations in the muscle caused by neurogenic injury. Third, in order to determine the ability of EIM to judge lesion severity, we seek to determine the correlation between EIM parameters with standard electromyography (EMG) parameters in patients with focal neuropathy. Relevance to public health: Focal neuropathies of the hand, which include median neuropathy at the wrist (carpal tunnel syndrome) and ulnar neuropathy at the elbow, occur in approximately 10% of people. The standard neurophysiologic assessment of these problems includes electromyography and nerve conduction studies, both of which may be poorly tolerated. We are developing electrical impedance myography as a painless, noninvasive, quantifiable technique to assess focal neuropathies of the hand, and neuromuscular diseases in general. ? ? ?
| Tarulli, Andrew W; Duggal, Naven; Esper, Gregory J et al. (2009) Electrical impedance myography in the assessment of disuse atrophy. Arch Phys Med Rehabil 90:1806-10 |
