Peripheral nerves that originate from the brain are called cranial nerves, and they're in charge of motor and sensory innervation of the head and neck.
Acquired include 1. Neurogenic Basically, there is an innervation defect of the muscles, and because nerves supplying the muscles are not working, the muscles will be unable to work properly.
In some people, there's also dryness of the affected eye or mouth because the facial nerve innervates the lacrimal, submandibular, and sublingual glands.
If the muscle does not receive any nerve fibers within twelve months, the muscle fibers are replaced by fibrous connective tissue, and the muscle is permanently lost.