Red chorda tympani nerve and Bell's palsy.

Abstract

AbstractThis is the first report of a red chorda tympani nerve observed in association with Bell's palsy. A prospective study was designed to determine the frequency and significance of this sign in association with Bell's palsy. Twenty‐eight patients were evaluated within two days of onset of paralysis. The red chorda tympani sign was correlated with alterations in chorda tympani function in terms of taste and submandibular salivary flow as well as response of the extracranial facial nerve to the maximal stimulation test. The chorda tympani was red in 10 of 20 patients (50 percent) where the nerve could be seen through the tympanic membrane. This finding is discussed in terms of a viral‐inflammatory involvement of the chorda tympani as part of the pathogenesis of Bell's palsy. In addition, the red chorda tympani sign was clinically significant. It indicated a more severe involvement of the chorda tympani than in those patients where the nerve was normal. The patients with the finding had a greater incidence of loss of taste by history and testing. In addition, 4 of the 10 patients with a red chorda tympani on the side of the facial paralysis had a salivary flow of less than 25 percent as compared to only 1 of 10 patients with a normal chorda tympani on the ipsilateral side. The study suggested a worse prognosis for patients with a red chorda tympani, although the difference was not statistically significant. The most important clinical significance of the red chorda tympani was its exclusive association with Bell's palsy and, therefore, may be an important diagnostic sign.