There are certain causes responsible for muscle twitching like diet deficiency, drug
overdose, and side
effects of diuretics, corticosteroids, estrogens, exercise, benign twitches, and nervous system conditions like amyotrophic lateral sclerosis or ALS, muscle dystrophy, spinal muscular atrophy and myopathy. Your neurologist needs to look into these conditions one by one. The other possible cause could be multiple sclerosis and is a diagnosis of exclusion.