Study of Electrical Impedance Myography (EIM) in ALS

This is a multicenter, 9-month study evaluating the effectiveness of electrical impedance myography (EIM) as a diagnostic and disease-tracking tool. In addition, the following will be studied: 1. Determine EIM device's ability to discriminate between ALS and "look-alike" non-fatal, motor-predominant syndromes; 2. Track EIM progression over time and determine the best summary EIM measure that could serve as an endpoint in future clinical trials and individual patient care; and, 3. Determine whether EIM progression is predictive of a combined outcome of survival and progression as measured by ALS Functional Rating Scale, Revised (ALSFRS-R), Hand-held Dynamometry (HHD) and Vital Capacity (VC) measures.