Herpes zoster oticus: correlations between clinical and MRI findings

Many gadolinium-enhanced magnetic resonance imaging (MRI) studies focusing on the anatomy and pathology of the 7th cranial nerve have already been published. However, only scattered cases of herpes zoster oticus (HZO) have been described and only the MRI appearance of the soft temporal bone structures has been reported. Enhanced MRI was performed in 4 patients with HZO observed at the Department of Otorhinolaryngology of the University of Pisa. A good correlation was found between the clinical data and MRI findings in both the acute and chronic stages of the disease. The 2 cases with complete facial palsy presented prominent and diffuse enhancement of the 7th and 8th cranial nerves on postcontrast MRI, while the patient with grade III facial palsy showed more limited nerve enhancement. The patient with grade II facial palsy presented no MRI abnormalities. In our series, enhancement limited to the geniculate ganglion and to the labyrinthine segment of the facial nerve indicates a good prognosis while a widespread enhancement correlates with a poor prognosis. In conclusion, MRI with contrast may be useful during the acute stage of HZO because it can confirm the diagnosis and can provide prognostic information on the facial function.