<unk>  (colloquially referred to as<unk>  seven) is a symptom or finding characterized by paralysis or paresis of the lower half of one side of the face. It usually results from damage to upper motor neurons of the facial nerve. The facial motor nucleus has dorsal and<unk>  divisions that contain lower motor neurons supplying the muscles of the upper and lower face, respectively. The dorsal division receives bilateral upper motor neuron input (i.e. from both sides of the brain) while the<unk>  division receives only<unk> ateral input (i.e. from the opposite side of the brain). Thus, lesions of the corticobulbar tract between the cerebral cortex and pons and the facial motor nucleus destroy or reduce input to the<unk>  division, but ipsilateral input (i.e. from the same side) to the dorsal division is retained. As a result,<unk>  is characterized by hemiparalysis or hemiparesis of the<unk> ateral muscles of facial expression, but not the muscles of the forehead.
Central facial palsy
Facial nerve paralysis
Bilateral vestibulopathy
Bulbar palsy
Pseudobulbar palsy
Oculoauricular syndrome
Trigeminal trophic syndrome
Sixth nerve palsy