THE ROLE OF MOTOR UNIT NUMBER ESTIMATION (MUNE) IN SMA ADULTS

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. This is a research study to collect information about adult patients with spinal muscular atrophy (SMA). This disease is charcterized by loss of motor nerve cells from the spinal cord. These nerves supply the muscle of the body and their loss results in weakness and loss of motor function. The disease is a genetic disease, and patients are born with it. To help plan future theraputic trials, information about ways to determine the severity of the disease and its progression are needed. In this study we plan to use an electrical study to estimate the number of the surviving motor nerves and see how this number changes over time in patients. This is done by measuring how big the muscle size is in the little finger through recording the electrical response generated by the muscle after stimulation with electrode and a slight electrical shock. We will also compare these results with measures of muscle strength obtained manually (ie, by pushing and pulling on the muslces) or through computerized testing. We also plan to look at muscle functional abilities, quality of life questionaires, and measurements of lung function. The study requires six half day visits to the outpatient clinic in a two-year period; at 0,3,6,12,18, and 24 months. The hope is that this technique will provide physicians and researchers with a useful method to document the progression of the disease as well as the effects of any therapy on the disease. This study is based on the hypothesis that the electrophysiological technique of motor unit number estimation (MUNE) may be superior to the compound muscle action potential (CMAP) in assessing the severity and progression of disease in adults with SMA. There are four specific aims: 1. To determine how MUNE values and CMAP amplitudes in adult patients with SMA compare to the values of these parameters found in normal age and sex-matched controls; 2. To assess whether there are differences in MUNE and CMAP values between types 2 and type 3 adults with SMA; 3. To explore how MUNE and CMAP values correlate with other measures of disease severity in these patients, including muscle strength [determined by both manual and computerized (fixed and hand-held dynamometry) testing], functional rating scales, pulmonary function, and a self-assessed quality of life instrument; 4. How do MUNE and CMAP change over time, and how do these compare to changes in the other parameters mentioned in Specific Aim 3.