Ramsay Hunt first described this condition in 1907, and it has since been referred to as Ramsay Hunt Syndrome (RHS). The syndrome is characterized by ear pain, ear vesicles, and peripheral facial paralysis.
Incidence Rate
Ramsay Hunt Syndrome is the second most common cause of non-traumatic facial paralysis, with an incidence rate of 5 per 100,000 people.
Etiology
Ramsay Hunt Syndrome is caused by an infection with the varicella-zoster virus (herpes zoster virus). The primary site of infection in the facial nerve is the geniculate ganglion.
Pathology and Pathogenesis
Infection with the varicella-zoster virus leads to facial nerve edema and degeneration. Due to the limited volume of the facial nerve canal, increased intrasheath pressure results in impaired excitatory conduction of the facial nerve, leading to facial paralysis. Prolonged edema compressing the facial nerve may cause ischemia and degeneration, with severe cases potentially resulting in nerve necrosis. Additionally, demyelinating lesions caused by viral infection may also result in chronic or permanent facial paralysis.
Clinical Features
Facial Paralysis
Symptoms include deviation of the mouth commissure and difficulty closing the eye; abnormal lacrimal gland secretion;
Static findings include loss of forehead wrinkles on the affected side, flattening or disappearance of the nasolabial fold, and a widened palpebral fissure.
Dynamic findings include inability to raise the eyebrow, incomplete eyelid closure, and deviation of the mouth commissure toward the unaffected side during smiling or showing teeth. Facial paralysis may initially present as partial paralysis and later progress to complete facial paralysis. In some cases, paralysis is complete at onset.
Ear Pain
Severe ear pain often occurs in the early stage of the condition.
Ear Vesicles
Vesicles may appear on the concha, external auditory canal, and occasionally extend to the surrounding ear area, face, or tympanic membrane.
Other Symptoms
Some patients experience vertigo, tinnitus, nausea, vomiting, or even hearing loss. In rare cases, paralysis of cranial nerves VI, IX, XI, and XII may also be observed.
Diagnosis and Differential Diagnosis
Diagnosis is primarily based on the medical history and clinical findings. It should be noted that early-stage Ramsay Hunt Syndrome is prone to misdiagnosis, particularly in patients without ear vesicles. Serological testing for viruses may show a fourfold increase in varicella-zoster virus antibodies in patients with Ramsay Hunt Syndrome. Varicella-zoster virus DNA may be detected in skin vesicles, middle ear fluid, or peripheral blood mononuclear cells.
Atypical cases may require CT or MRI to exclude other potential causes of peripheral facial paralysis, such as facial nerve tumors, internal auditory canal tumors, otitis media, or middle ear cholesteatoma. Electroneurography and electromyography can provide insights into the severity of facial paralysis.
Treatment
Facial paralysis caused by herpes zoster tends to be severe, with most patients experiencing irreversible facial paralysis and only a small proportion achieving complete spontaneous recovery.
Pharmacological Treatment
Studies have shown that the combination of corticosteroids and antiviral drugs provides better facial nerve function recovery compared to corticosteroids alone. The use of antiviral drugs combined with prednisone within three days of onset significantly improves outcomes. According to the literature, timely treatment within three days of onset leads to complete recovery of facial nerve function in 75% of cases. However, when treatment is initiated more than seven days after onset, only 30% of patients achieve complete recovery of facial nerve function.
The standard dosing protocols involve oral administration of acyclovir (800 mg, five times daily) or oral valacyclovir (0.5 g to 1 g, two to three times daily) for 7–10 days. If contraindications to corticosteroid use are excluded, prednisone can be administered orally [1 mg/(kg·day)] for five days, followed by a gradual tapering of the dose. For external ear vesicles, topical acyclovir or valacyclovir ointments can be applied.
In cases of Ramsay Hunt Syndrome with complete facial paralysis, attention must be given to the prevention and management of ocular complications. Artificial tears can be used during the day, and ophthalmic ointments can be applied at night to protect the cornea, thereby reducing the risk of exposure keratitis and corneal ulcers.
Facial Nerve Decompression Surgery
The degree of facial nerve paralysis in Ramsay Hunt Syndrome is more severe. Whether facial nerve decompression surgery should be performed in Ramsay Hunt Syndrome remains controversial, with general consensus suggesting the surgical outcome may be limited. The limited volume of the facial nerve canal exacerbates edema and degeneration in the early stages, increasing intracanal pressure and further compressing the facial nerve, which may lead to ischemia, degeneration, or even necrosis. From this perspective, timely surgical decompression may theoretically alleviate nerve damage. Comprehensive decompression surgery involving the entire facial nerve, including the geniculate ganglion and the labyrinthine segment, has been proposed as a potential approach. However, evidence supporting this practice remains lacking due to insufficient research in evidence-based medicine.