Facial nerve lesions Flashcards
What is the most common cause of peripheral facial palsy?
Bell’s palsy, usually is idiopathic.
Also from HSV reactivation, Ramsay Hunt syndrome, Lyme disease, or VZV.
What are some causes of peripheral facial nerve palsy other than Bell’s palsy?
sarcoidosis
tumors (e.g., parotid gland)
diabetes mellitus
What is the typical treatment for Bell’s palsy?
Glucocorticoids ± acyclovir.
A lesion in the motor cortex to the facial nucleus in the pons, is called what type of neurological impairment?
an upper motor neuron (UMN) facial nerve lesion
(stroke)
Which muscles are involved in an upper motor neuron lesion?
Lower muscles of facial expression.
A lesion in the motor cortex to the facial nucleus in the pons, will cause issues on what side of the face?
contralateral (opposite side)
How is the forehead affected in an upper motor neuron lesion?
The forehead is spared due to bilateral UMN innervation.
A lesion at the facial nucleus or anywhere along cranial nerve VII, is called … ?
a lower motor neuron (LMN) facial nerve lesion
A lesion at the facial nucleus or anywhere along cranial nerve VII, will cause issues on what side of the face?
ipsilateral (same side)
Which muscles are involved in a lower motor neuron lesion?
Upper and lower muscles of facial expression.
Even though the entire half of the face is impacted, this is less severe because it is more demonstrative of Bell palsy rather than a stroke. A stroke affecting the upper motor neurons in the cortex, which is more severe, would only impact the neurons that innervate the lower portion of the face.
How is the forehead affected in a lower motor neuron lesion?
The forehead is affected, leading to complete facial weakness on the affected side.
What additional symptoms might occur with a lower motor neuron facial nerve lesion?
Incomplete eye closure (dry eyes, corneal ulceration), hyperacusis, and loss of taste sensation to the anterior tongue.
How can an upper motor neuron lesion be distinguished from a lower motor neuron lesion on examination?
UMN lesion: Forehead sparing; contralateral lower face weakness.
LMN lesion: Complete hemifacial weakness including the forehead, ipsilateral to the lesion.
What does the term “Ramsay Hunt syndrome” refer to?
Peripheral facial palsy caused by herpes zoster infection, often with vesicular rash around the ear.
What is the prognosis for most patients with Bell’s palsy?
Gradual recovery of function, although aberrant regeneration can occur.
