What are the diagnostic criteria of myopathy and inflammatory myositis by electromyography?

Diagnostic criteria of myopathy and inflammatory myositis by electromyography

Myopathy and inflammatory myositis are suspected if the diagnostic triad is found on Electromyography:
1. Spontaneous fibrillation
2. Short-duration action potentials in a polyphasic disorganised outline
3. Repetitive bouts of high-voltage oscillations on needle contact with diseased muscle