EIM Via the Myolex mScan as an ALS Biomarker

Inclusion Criteria: * Sporadic or familial ALS diagnosed as clinically possible, probable, lab-supported probable, or definite ALS defined by revised El Escorial criteria * Capable of providing informed consent and complying with study procedures in the investigator's opinion * Time since ALS symptom onset ≤36 months * Vital Capacity of ≥40% of predicted capacity as measured by forced vital capacity or slow vital capacity * Must have a study partner for home visits * Access to the internet for data upload * Age 18 years or older Exclusion Criteria: * Clinically significant unstable medical condition (other than ALS) that would affect the participant's ability to participate, according to the investigator's judgment * Patient with pure upper motor neuron disease (PLS) * Known history of unstable psychiatric disease, cognitive impairment, dementia, or active substance abuse * Significant pitting edema (2+ or more) that would interfere with EIM measures * Active cancer or history of cancer treated with chemotherapy and/or radiation * BMI \>35