Vestibular and cochlear nerve enhancement on MRI and its correlation with vestibulocochlear functional deficits in patients with Ramsay Hunt syndrome.

OBJECTIVE: The correlation between enhancement of the vestibulocochlear nerves on gadolinium-enhanced magnetic resonance imaging (MRI) and vestibulocochlear functional deficits was examined in patients with Ramsay Hunt syndrome (RHS). METHODS: Nineteen patients with RHS who showed herpes zoster oticus, peripheral facial palsy, and vertigo were enrolled. Canal paresis (CP) in the caloric test, abnormal response to ocular and cervical vestibular myogenic potentials (oVEMP and cVEMP), and refractory sensorineural hearing loss were evaluated. MRI images perpendicular to the internal auditory canal were reconstructed to identify the superior (SVN) and inferior vestibular nerves (IVN) and the cochlear nerve (CV). The signal intensity increase (SIinc) of the four-nerve enhancement was calculated as an index. RESULTS: Among RHS patients, 79%, 53%, 17% and 26% showed CP in the caloric test, abnormal responses to oVEMP and cVEMP, and refractory sensorineural hearing loss, respectively. SIinc rates of the SVN were significantly increased in RHS patients with CP in the caloric test, and with abnormal responses to oVEMP and cVEMP. SIinc rates of the SVN tended to increase in RHS patients with refractory sensorineural hearing loss (p = 0.052). SIinc rates of the IVN were significantly increased in RHS patients with abnormal responses to oVEMP and cVEMP, and refractory sensorineural hearing loss, but not in those with CP in the caloric test. SIinc rates of the CN were significantly increased in RHS patients with CP in the caloric test, abnormal response to oVEMP and refractory sensorineural hearing loss, but not in those with abnormal response to cVEMP. CONCLUSION: In patients with RHS, the origin of vertigo may be superior vestibular neuritis, which is affected by reactive varicella-zoster virus from the geniculate ganglion of the facial nerve through the faciovestibular anastomosis. The results also suggested that in some RHS patients, inferior vestibular neuritis contributes to the development of vertigo and that the origin of refractory sensorineural hearing loss is cochlear neuritis.

Electroneurography cannot predict when facial synkinesis develops in patients with facial palsy.

The objective of this study is to clarify when facial palsy patients with lower value of Electroneurography (ENoG) should begin the rehabilitation to prevent the development of facial synkinesis. For this purpose, we examined the relationship between the value of ENoG measured 10-14 days after facial palsy onset and the onset day of the development of oral-ocular synkinesis. Sixteen patients with facial palsy including 11 with Bell's palsy and 5 with Ramsay Hunt syndrome (7 men and 9 women ; 15-73 years old ; mean age, 41.6 years) were enrolled in this study. There was no correlation between ENoG value and the onset day of the development of oral-ocular synkinesis (ρ = .09, p = .73). Oral-ocular synkinesis began to develop in 4.0 ±â€…0.7 months (mean ±â€…SD ; range : 3.1-5.0 months) after facial palsy onset regardless of ENoG value. In conclusion, ENoG value cannot predict when facial synkinesis develops in patients with facial palsy. We recommend that facial palsy patients with a high risk for the development of synkinesis begin the biofeedback rehabilitation with mirror to prevent the development of facial synkinesis 3 months after facial palsy onset. J. Med. Invest. 67 : 87-89, February, 2020.

Electroneurography in the acute stage of facial palsy as a predictive factor for the development of facial synkinesis sequela.

OBJECTIVE: We investigated whether the value of ENoG is a predictive factor for the development of facial synkinesis in patients with facial palsy. METHODS: The degree of oral-ocular synkinesis was evaluated quantitatively by an asymmetry of the interpalpebral space width during the mouth movement (% eye opening). Twenty healthy volunteers without a history of facial palsy (12 men and 8 women; 25-65 years old; mean age: 42.3±9.7years) were included in the study to examine the normal range of % eye opening. Fifty-one patients with facial palsy including 38 with Bell palsy and 15 with herpes zoster oticus (28 men and 25 women; 11-86 years old; mean age: 54±19years) were enrolled to examine the relationship between the ENoG value 10-14days after the onset of facial palsy, and the % eye opening 12 months later. Receiver operating characteristic (ROC) curve for the ENoG value was then used to decide the optimum cut-off value as a predictor of the development of oral-ocular synkinesis. RESULTS: We defined a % eye opening inferior to 85% as an index of the development of oral-ocular synkinesis. There was a significant correlation between the values of ENoG 10-14days after the onset of facial palsy and those of % eye opening 12 months later (ρ=0.81, p<0.001). The area under the ROC curve for the ENoG value was the predictor for the development of oral-ocular synkinesis at 0.913 (95%CI: 0.831-0.996, p<0.001). The optimum cut-off value of ENoG 10-14days after the onset of facial palsy was 46.5% to predict the development of oral-ocular synkinesis 12 months after the onset of facial palsy (sensitivity 97.1% and specificity 77.5%). CONCLUSION: The value of ENoG 10-14days after the onset of facial palsy is a predictive factor for the development of facial synkinesis 12 months later. Since facial palsy patients with a ENoG value inferior to 46.5% have a high risk of developing synkinesis, they should receive the facial biofeedback rehabilitation with a mirror as a preventive therapy.