Facial paralysis is one of the common problem leading to facial deformation. Bell's palsy BP is defined as a lower motor neuron palsy of acute onset and idiopathic origin. BP is regarded as a benign common neurological disorder of unknown cause. It has an acute onset and is almost always a mononeuritis. The facial nerve is a mixed cranial nerve with a predominant motor component, which supplies all muscles concerned with unilateral facial expression. Knowledge of its course is vital for anatomic localization and clinical correlation.
Facial nerve palsy is a neurological condition in which function of the facial nerve cranial nerve VII is partially or completely lost. It is often idiopathic but in some cases, specific causes such as trauma, infections, or metabolic disorders can be identified. Two major types are distinguished: central facial palsy lesion occurs between cortex and nuclei in the brainstem and peripheral facial palsy lesion occurs between nuclei in the brainstem and peripheral organs. Central facial palsy manifests with impairment of the lower contralateral mimic musculature. In contrast, peripheral facial palsy leads to impairment of the ipsilateral mimic muscles and also affects the eyelids and forehead. Additionally, peripheral facial palsy can cause various sensory and autonomic disorders depending on the exact location of the lesion. Diagnosis can usually be made clinically while patient history often helps in evaluating the underlying etiology.
Last updated: November 28, Revisions: A facial palsy is weakness or paralysis of the muscles of the face. The facial nerve arises in the pons formed as separate sensory and motor roots , before travelling in the internal acoustic meatus, very close to the inner ear. As they enter the facial canal, the two roots fuse to form a single facial nerve, before giving off intracranial branches of the greater petrosal nerve, nerve to stapedius, and chorda tympani.
NCBI Bookshelf. Boston: Butterworths; The motor portion, or the facial nerve proper, supplies all the facial musculature.