Muscle Twitching (Fasciculations)

Fasciculations are involuntary muscle twitches that can be benign (BFS) or indicate motor neuron disease (ALS). Context matters: benign fasciculations occur in isolation, while ALS fasciculations accompany progressive weakness and atrophy.

Body System: Neuromuscular

Related Diseases

• ALS — Fasciculations with progressive weakness and upper motor neuron signs are a diagnostic feature of ALS.

Related Compounds

• Riluzole
• Masitinib

Frequently Asked Questions

Are muscle twitches a sign of ALS?

Most fasciculations are benign (BFS — benign fasciculation syndrome), especially in the absence of weakness, atrophy, or abnormal reflexes. ALS fasciculations are accompanied by progressive weakness, muscle wasting, and upper motor neuron signs. EMG can help differentiate by showing denervation in ALS.

What causes benign fasciculations?

Caffeine, stress, sleep deprivation, electrolyte imbalances (magnesium, potassium), intense exercise, and anxiety are common triggers. Benign fasciculations are extremely common and rarely indicate serious disease. They typically resolve with lifestyle modifications.