Bell's palsy is a peripheral palsy of the facial nerve that results in muscle weakness on one side of the face. Affected patients develop unilateral facial paralysis over one to three days with forehead involvement and no other neurologic abnormalities.
The cause of Bell's palsy is unknown but is thought to be caused by inflammation affecting the body's immune system. It is associated with other conditions such as diabetes. Symptoms of facial weakness or paralysis get worse over the first few days and start to improve in about 2 weeks.
A lower motor neurone lesion occurs with Bell's palsy, whereas an upper motor neurone lesion is associated with a cerebrovascular accident. A lower motor neurone lesion causes weakness of all the muscles of facial expression. The angle of the mouth falls. Weakness of frontalis occurs, and eye closure is weak.
ICD-10 | Bell's palsy (G51. 0)
When a patient is diagnosed with facial paralysis, a cause for the paralysis can be identified. In this instance, facial paralysis can be linked to a tumor, infection, or nerve damage. In cases of Bell's palsy, the disorder appears without any reason.
There's no specific test for Bell's palsy. Your health care provider will look at your face and ask you to move your facial muscles by closing your eyes, lifting your brow, showing your teeth and frowning, among other movements.
Patients with a Bell's Palsy will present with varying severity of painless unilateral lower motor neuron (LMN) weakness of the facial muscles (Fig. 2). Depending on the severity and the proximity of the nerve affected, it can also result in: Inability to close their eye (temporal and zygomatic branches)
The constellation of motor pathways within the human central and peripheral nervous system involves two entities that guide voluntary movement: upper motor neurons (UMN) and lower motor neurons (LMN). Although these entities share familiar nomenclature, they each serve distinct functions in steering spinal mechanics.
Bell's palsy is an isolated lower motor neuron lesion of the whole facial nerve. The cause is usually unknown. Most children recover completely. Assessment of Bell's palsy is aimed at confirming the diagnosis and excluding the other important causes of facial weakness.
ICD-10-CM Code for Facial weakness R29. 810.
Hemiplegia, unspecified affecting left dominant side The 2022 edition of ICD-10-CM G81. 92 became effective on October 1, 2021. This is the American ICD-10-CM version of G81.
1 - Atypical facial pain. G50. 1 - Atypical facial pain is a topic covered in the ICD-10-CM.