Infections of the Temporal Bone Flashcards
Petrous Apicitis: Important Points
1) Rare in the antibiotic era
2) Triad of Symptoms (Gradenigo’s Syndrome):
- Otorrhea
- Retroorbital pain
- Diplopia caused by CN VI palsy
3) IV Antibiotics are the first line of therapy
4) Petrous apicectomy should be considered if infection does not improve or intracranial complications are suspected
5) If due to Chronic Otitis Media with cholesteatoma
- Give IV antibiotics first
- Surgical management of the cholesteatoma when acute infection resolved
Ramsay Hunt Syndrome - Treatment
I. Systemic steroids
1. Reduces post Herpetic neuralgia
2. Effect of steroids on facial nerve paralysis is controversial
3. Early institution of steroids seems to relieve acute pain, reduces vertigo, and decreases the incidence of postherpetic neuralgia
II. Acyclovir
1. Acyclovir is a nucleotide analog that interferes with virus DNA polymerase and inhibits DNA replication. It is preferentially taken up by HSV-infected cells, making it nontoxic to noninfected cells.
III. Standard Treatment Protocol
1. Valacyclovir: give 1 gram TID for 7-10 days
2. Prednisone (1mg/kg for 5 days without a taper
3. In severe cases (eg, vertigo, tinnitus, or hearing loss), IV therapy can be initiated and the patient can then be transitioned to an oral antiviral agent when the skin lesions begin to crust
- Give IV Acyclovir in severe cases (10mg/kg IV every 8 hours)
IV. Miscellaneous
1. Eye protection - use eye bubble and lube/artificial tears
Note: the current consensus is that herpes zoster-associated facial paralysis should be treated with both steroids and antivirals.
Ramsay Hunt Syndrome/Herpes Zoster Oticus
I. RHS reflects reactivation of latent VZV in the geniculate ganglion with subsequent spread of the infection to the eighth cranial nerve.
- Is associated with VZV as shown by rising titers of antibodies to VZV
- RHS may rarely occur as a component of multiple cranial nerve involvement, especially cranial nerves V, IX, and X.
II. Compared to Bell’s palsy, Ramsay Hunt syndrome generally causes more severe symptoms and patients have a higher risk of complete nerve degeneration developing.
1. Symptoms are worse and the prognosis is poorer in RHS compared to Bell’s palsy
- Increased rates of late neural denervation and decreased probability of complete recovery.
2. Ramsay Hunt syndrome includes the triad of
- Ipsilateral facial paralysis
- Ear pain
- Vesicles in the auditory canal or on the auricle
- Ipsilateral altered taste perception and tongue lesions, hearing abnormalities (hearing loss, tinnitus, hyperacusis), lacrimation, and vertigo are also frequently reported.
III. Ramsay Hunt Syndrome can be difficult to diagnose
1. In 10% of patients, the vesicular rash appears well after the initial facial paralysis, and many patients have a rise in antibody titer to the VZV without ever having cutaneous or mucous membrane vesicles develop (zoster sine herpete)
IV. Varicella/Chicken pox is the manifestation of the primary infection by VZV (HSV, varicella) in a nonimmune host. Herpes zoster infection is the manifestation of this same virus in a partially immune host. VZV is most likely a reactivation of a latent virus. In the primary infection, the virus traves to the dorsal root to extramedullary cranial nerve ganglia.
1. Reactivation generally occurs during a period of decreased cell-mediated immunity. The increased incidence in the elderly is secondary to an age-related decrease in cellular immune response to VZV.
V. Be aware of possible herpes zoster ophthalmicus
1. Complications include uveitis, keratoconjunctivitis, ophthalmic neuritis, and glaucoma.
2. These complications are almost always associated with involvement of the ophthalmic division of the trigeminal nerve.
3. Herpes zoster ophthalmicus may be difficult to differentiate from localized skin rash associated with HSV.
- Although both conditions may cause keratitis, differentiation btwn them is very important bcs topical steroids are used to manage herpes zoster infection, but are contraindicated in HSV. You should consult with Ophthalmology.
