Is spasticity always a symptom of ALS?

Spasticity is a common but not uniform symptom of ALS. Overall, flaccid paralysis (peripheral paresis) and muscle wasting (myopathy) predominate in ALS, while spasticity is usually a secondary symptom. A common pattern is the occurrence of flaccid paralysis in the arms, while the legs exhibit spasticity. In more than 20% of ALS patients, spasticity is absent throughout the entire course of the disease.