Ramsay Hunt Syndrome

Definition

1. Ipsilateral peripheral facial nerve palsy
2. Otalgia (ear pain)
3. Vesicular eruption in the distribution of the sensory branch of the facial nerve (pinna, external auditory canal, conchal bowl, and occasionally oral mucosa)

• Cummings Otolaryngology Head and Neck Surgery
• Shambaugh Surgery of the Ear

Etiopathogenesis

• Causative agent: Varicella-Zoster Virus (VZV) - a member of the Herpesviridae family.
• Primary infection: Chickenpox (varicella) in a non-immune host.
• Latency: After primary infection, VZV travels to the dorsal root and extramedullary cranial nerve ganglia (particularly the geniculate ganglion of CN VII) where it remains dormant.
• Reactivation: Occurs during periods of decreased cell-mediated immunity - such as old age, malignancy, trauma, radiotherapy, chemotherapy, or immunosuppression.
• The virus then tracks along the sensory (and motor) branches of CN VII, producing neuritis, demyelination, and axonal degeneration.
• Incidence: ~30 cases per 100,000 persons. Dramatically increases in patients over 60 years old.

Clinical Features

The Classic Triad:

1. Otalgia - Severe, often the presenting symptom; may precede vesicular eruption by 3-5 days (prodrome)
2. Vesicular eruption - In the external auditory canal, conchal bowl, pinna, retroauricular area, face, or oral mucosa (soft palate, anterior 2/3 of tongue)
3. Peripheral facial nerve palsy - Rapidly progressive; affects all branches of CN VII (upper and lower face - differentiating it from UMN lesions)

Additional Features (up to 50% of patients):

• Sensorineural hearing loss (SNHL) - due to involvement of the cochlea and auditory nerve
• Tinnitus
• Vertigo and vestibular dysfunction - due to involvement of the vestibular labyrinth
• Hyperacusis
• Decreased lacrimation (involvement of greater superficial petrosal nerve via geniculate ganglion)

Cranial Nerve Involvement:

• CN V (trigeminal) - Facial pain, numbness
• CN IX, X, XI, XII - Dysphagia, hoarseness, shoulder weakness (in more severe cases)

Special Variants:

• Zoster sine herpete: VZV reactivation causing facial palsy WITHOUT any visible vesicular rash. Diagnosed by PCR detection of VZV DNA in blood/skin/middle ear fluid, or a fourfold rise in VZV antibody titers. It can be mistaken for Bell's palsy.
• In ~10% of patients, the vesicular rash appears well after initial facial paralysis.
• In ~25% of cases, vesicles precede paralysis - these patients have a better prognosis.

Diagnosis

Clinical:

• Based on the classic triad; the rash confirms the diagnosis.
• In 15% of cases, vesicles may appear after the onset of palsy - delaying recognition.

Laboratory:

• Tzanck smear: Shows multinucleated giant cells at the base of a ruptured vesicle
• PCR: Detection of VZV DNA in vesicular fluid, blood mononuclear cells, or middle ear fluid - most sensitive and specific; also useful for zoster sine herpete
• Viral antibody titers: Rising titers to VZV (fourfold rise confirmatory)
• Viral culture from vesicular fluid

Imaging:

• MRI with gadolinium: Reveals enhancement along the intratemporal facial nerve (geniculate ganglion and labyrinthine/tympanic segments). Enhancement also occurs in Bell's palsy, so it is not exclusively diagnostic.

Histopathology

• Inflammatory cells within the auditory nerve and modiolus
• Degeneration of the spiral ganglion neurons, stria vascularis, and organ of Corti
• Atrophy of the semicircular canal sensory epithelia
• Notably, the geniculate ganglion itself may show relatively little change in some cases, while the labyrinthine and tympanic segments show atrophy and degeneration.

Differential Diagnosis

Treatment

1. Corticosteroids:

• Prednisone: 1 mg/kg/day (usually 60-80 mg/day) for 5 days, followed by a 10-day taper
• Reduces acute otalgia, vertigo, and post-herpetic neuralgia
• The utility in improving facial nerve recovery is controversial, but early institution is generally recommended.

2. Antiviral Agents:

• Acyclovir: 800 mg five times daily orally for 7-10 days; OR IV acyclovir 250 mg three times daily (for severe cases)
• Valacyclovir: 1000 mg every 8 hours for 7 days (preferred due to better bioavailability)
• Acts by inhibiting VZV DNA polymerase (nucleotide analogue); preferentially taken up by VZV-infected cells.
• Combination therapy (steroids + antivirals) is more effective than steroids alone.
• Since the active phase of RHS persists longer than Bell's palsy, treatment duration is longer: 3 weeks vs. 2 weeks.

3. Additional Measures:

• Eye care: Artificial tears, lubricating eye drops, or taping the eyelid shut at night to prevent exposure keratopathy (due to lagophthalmos from facial palsy)
• Gabapentin: For post-herpetic neuralgia
• Oral antibiotics: If bacterial superinfection of vesicles occurs

4. Surgical Decompression:

• NOT indicated in Ramsay Hunt syndrome.
• Reason: Neural degeneration is widespread (diffuse neuritis with "skip" regions) rather than localized to a single segment (as in Bell's palsy); therefore surgical decompression is not expected to benefit.

Prognosis

• Significantly worse than Bell's palsy.
• Without treatment:
  • Complete recovery in only 10% after complete facial paralysis
  • Complete recovery in ~66% after incomplete palsy
  • Persistent weakness in 30-50% of patients overall
• Peitersen (1995): Full recovery in only 22%; Devriese: complete recovery in 16%
• KJ Lee: Only 60% regain normal facial function overall
• Favorable prognostic factors:
  • Incomplete (vs. complete) palsy at presentation
  • Early treatment (within 72 hours)
  • Vesicular eruption preceding paralysis (rather than following it)
• Complications: Post-herpetic neuralgia, synkinesis, hemifacial spasm, permanent SNHL, permanent vestibular dysfunction, and Frey's syndrome.

Prevention

• Varicella vaccine (in children): Prevents primary VZV infection
• Herpes zoster vaccine (Shingrix - recombinant zoster vaccine): Recommended for adults ≥50 years; shown to prevent herpes zoster and post-herpetic neuralgia.