Predicting the Prognosis of Bell’s Palsy in Infants and Young Children Using the Nerve Excitability Test

OBJECTIVE: To evaluate whether the nerve excitability test using a 10 mA pulse current (NET10 mA) can serve as a simple and reliable method of predicting the prognosis of Bell's palsy in infants and young children, and to compare its diagnostic value with that of electroneurography (ENoG). METHODS: This retrospective study included 19 pediatric patients aged 0 to 5 years with Bell's palsy who underwent both a NET and ENoG 8 days to 3 weeks after paralysis onset. During the NET, the marginal mandibular branch of the facial nerve was stimulated with a 10-mA pulse current, and any movement in the depressor anguli oris muscle was recorded. ENoG values were expressed as a percentage of the compound action potential amplitude on the affected side relative to that on the healthy side. Prognostic accuracy was evaluated using sensitivity, specificity, predictive values, and likelihood ratios. RESULTS: All 8 patients with both a positive NET10 mA and ENoG ≥ 10% achieved full recovery (positive predictive value: 100%). In 11 patients with a negative result on NET10 mA or ENoG < 10%, only 2 achieved full recovery. The sensitivity and specificity of NET10 mA was 0.8 and 1.0, respectively. The results of NET10 mA closely corresponded with the ENoG 10% cutoff ( κ = 0.89). The median recovery time was significantly shorter in patients with NET10 mA+ ENoG ≥ 10% (3 vs. 12 mo; P < 0.001). CONCLUSION: NET10 mA provided a simple, minimally invasive, and clinically reliable means of predicting the prognosis of Bell's palsy in infants and young children and closely mirrored the degree of nerve degeneration indicated by ENoG.