Facial nerve palsy at sternomastoid canal can cause-

Below stylomastoid foramen, facial nerve gives following branches: - Posterior auricular branch, muscular branches (stylohyoid & posterior belly of digastric) and terminal (peripheral) branches. Lesion at sternomastoid foramen : - i)    Will spare Greater superficial petrosal nerve → Lacrimation present. Nerve to stapedius → Normal stapedial reflex and no hyperacusis. Chorda tympani → Normal salivation and a taste sensation in anterior 2/3 of the tongue. ii) Will involve Terminal (peripheral) branches → Paralysis of muscles of facial expression. Corneal reflex will also be lost because efferent fibres of corneal reflex are derived from peripheral branches of the facial nerve.