Intermuscular Coherence: A Biomarker for Early Diagnosis and Follow-up of ALS
The specific aims of this study are to: 1. Determine if a painless and quick measurement of muscle activity using surface electrodes can help with the diagnosis of ALS. Specifically, we ask if a measure of intermuscular coherence (IMC-βγ), when added to current diagnostic criteria (Awaji criteria), can differentiate ALS from mimic diseases more accurately and earlier than currently possible. 2. Characterize IMC-βγ in neurotypical subjects by age, sex, race, and ethnicity. 3. Follow a cohort of ALS patients longitudinally to determine if IMC-βγ changes with ALS disease progression and whether such changes correlate with functional and clinical scores, or survival.
• AIM 1: Patients with arm or leg weakness, spastic gait, muscle wasting and/or fasciculations (muscle twitching), dysphagia (difficulty swallowing), dysarthria (difficulty speaking), shortness of breath, hyperreflexia or pathological reflexes, or findings of muscle denervation in previous needle electromyography (EMG) studies.
• AIM 2: Subjects between 20 and 90 years of age.
• AIM 3: Subjects will be selected from among Aim 1 patients who carry an Awaji (without IMC) category of Possible, Probable, or Definite ALS.