Neurophysiology Practice Test

A 34-year-old man undergoes a dental procedure. The dentist injects lidocaine, a local anesthetic, into the gingival tissue. The patient reports a loss of sensation in the area, allowing the procedure to be completed without pain.

A 2-year-old boy presents with recurrent, difficult-to-control seizures. Genetic testing reveals a gain-of-function mutation in a gene encoding a neuronal voltage-gated sodium channel. The mutation results in incomplete and delayed channel inactivation following depolarization.