Facial nerve palsy Abstract 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 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.
Carcinomatous or leukemic nerve invasion Chronic meningitis Cerebellopontine angle or glomus jugulare tumors Diabetes The other disorders that cause peripheral facial nerve palsy typically develop more slowly than idiopathic facial nerve palsy and may have other distinguishing symptoms or signs. Thus, if patients have any other neurologic symptoms or signs or if symptoms developed gradually, MRI should be done. In idiopathic facial nerve palsy, MRI may show contrast enhancement of the facial nerve at or near the geniculate ganglion or along the entire course of the nerve. However, its enhancement may reflect other causes, such as meningeal tumor. If the paralysis progresses over weeks to months, the likelihood of a tumor eg, most commonly schwannoma compressing the facial nerve increases.
Bell's palsy Bell's palsy is the most common cause of acute facial nerve paralysis. There is no known cause of Bell's palsy,   although it has been associated with herpes simplex infection. Bell's palsy may develop over several days, and may last several months, in the majority of cases recovering spontaneously. It is typically diagnosed clinically, in patients with no risk factors for other causes, without vesicles in the ear, and with no other neurological signs.
Print Overview Bell's palsy causes sudden, temporary weakness in your facial muscles. This makes half of your face appear to droop. Your smile is one-sided, and your eye on that side resists closing. Bell's palsy, also known as facial palsy, can occur at any age. The exact cause is unknown.