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

• Published in: Auris, nasus, larynx Vol. 45; no. 4; pp. 728 - 731
• Main Authors: Azuma, Takahiro, Nakamura, Katsuhiko, Takahashi, Mika, Miyoshi, Hitomi, Toda, Naoki, Iwasaki, Hidetaka, Takeda, Noriaki
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.08.2018
• Subjects: Adolescent; Adult; Aged; Aged, 80 and over; Bell Palsy - complications; Bell Palsy - physiopathology; Case-Control Studies; Child; Disease Progression; Electroneurography; eye-opening; Facial palsy; Facial Paralysis - complications; Facial Paralysis - physiopathology; Facial synkinesis; Female; Herpes Zoster Oticus - complications; Herpes Zoster Oticus - physiopathology; Humans; Male; Middle Aged; Neural Conduction - physiology; Predictive factor; Prognosis; ROC Curve; Synkinesis - etiology; Synkinesis - physiopathology; Young Adult; Facial synkinesis; Facial palsy; Predictive factor; Electroneurography; eye-opening
• ISSN: 0385-8146; 1879-1476
• DOI: 10.1016/j.anl.2017.09.016

We investigated whether the value of ENoG is a predictive factor for the development of facial synkinesis in patients with facial palsy. 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. 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%). 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.