A novel muscle for electroneurography in peripheral facial palsy: occipitalis

Electroneurography (ENoG) is one of the most objective tests in grading the damage and prediction of prognosis in peripheral facial palsy (PFP). We aimed to determine temporal changes of ENoG recorded over occipitalis muscle in acute idiopathic PFP. Consecutive 21 patients with unilateral acute idiopathic PFP and age- and sex-matched 15 healthy volunteers were included in the study. Nasal and occipital ENoG values were recorded once in the control group and the same procedure was repeated daily between the second and eight days of the disorder in the PFP group. Occipital ENoG value began to increase on the third day while nasal ENoG value was still within the normal range (27.04 vs 7.69 %, p = 0.0001). In the fourth, fifth and sixth days, occipital ENoG value was significantly high compared to nasal ENoG value (p = 0.0001 for each day) whereas nasal and occipital ENoG values were very similar in the seventh and eighth days (p = 0.181 and p = 0.584, respectively). Our study presents further support for technical possibility of occipital ENoG which may reflect the degree of fiber degeneration earlier than the nasalis muscle in PFP.