Which of the following is a sign of Lidocaine toxicity?

Lidocaine toxicity primarily affects the central nervous system and the cardiovascular system, with muscle twitching being one of the hallmark signs. This symptom occurs due to increased excitability of the neurons in the brain caused by elevated levels of lidocaine. As lidocaine is a local anesthetic and antiarrhythmic agent, its toxicity can lead to neurological disturbances, including seizures and muscle twitching. This increased neural excitability is often one of the first indicators of lidocaine's adverse effects.

While other signs, such as nausea and vomiting or cardiovascular changes like hypotension and increased heart rate, are also associated with different aspects of lidocaine toxicity or other conditions, muscle twitching specifically is a prominent and direct manifestation of lidocaine affecting the neuromuscular system. Recognizing muscle twitching is crucial for timely management and intervention when assessing a patient suspected of experiencing lidocaine toxicity.