Home · MCP YouTube · MCP Twitter · MCP Facebook · rss feed Masseter Muscle Rigidity and Nondepolarizing Neuromuscular Blocking Agents . nerve stimulator; however, no effect was noted on the degree of masseter muscle spasm. .. 6Petersen, WC and Crouch, ER Jr. Anesthesia-induced rigidity, unrelated to. This is a constant experience for people with spasticity. Spasticity is a muscle control disorder. It causes tight or stiff muscles and an inability for. skilled in diagnosing and treating movement disorders such as Parkinson's disease. Parkinson's disease; Torticollis; Spasticity; Essential tremor; Dystonia . Original Article from The New England Journal of Medicine — Intramuscular Injection of Botulinum Toxin for the Treatment of Wrist and Finger Spasticity after a.