Recurrent facial palsy: Characteristics of ipsilateral and alternative palsies of 104 cases.

OBJECTIVE: Recurrent facial palsy is relatively rare and its clinical details of recurrent facial palsy are not well known. We analyzed recurrent facial palsy cases and clarified its characteristics, especially the difference between ipsilateral and alternative palsies. The analysis aimed to obtain information about recurrent facial palsy that would be useful for delivering explanations to patients and help improve recurrent facial palsy treatments based on the etiology. METHODS: We picked up data from the chart and analyzed the clinical characteristics of patients with recurrent facial palsy from 1243 facial palsy patients (Bell's palsy, VZV-related palsy (Ramsay Hunt syndrome and zoster sine herpete [ZSH])) between 2006 and 2020. RESULTS: Recurrent facial palsy was observed in 104 of 1243 patients (8.4%). There were 35 cases (34%) of ipsilateral palsy and 69 cases (66%) of alternative palsy. The mean age at the onset of the first palsy was 38.9 years old in the ipsilateral group and 48.4 years old in the alternative group, and a significant difference was observed between them. The number of recurrences ranged from 1 to 4. Among the ipsilateral group, 6 patients experienced more than second recurrence. In two cases, the condition failed to resolve after the second recurrence. A serological examination confirmed that 4 cases had recurrent VZV-related palsy (both the first and second palsies were VZV-related) and all of them initially had ZSH: no cases had Hunt syndrome as the first palsy. CONCLUSIONS: The VZV-specific immunity obtained with ZSH might be insufficient to suppress VZV reactivation, and VZV vaccination should be recommended for ZSH patients to prevent further recurrence of VZV-related facial palsy. More than 2 ipsilateral recurrent episodes may be a risk factor for incomplete recovery.

Facial nerve course in the temporal bone: Anatomical relationship between the tympanic and mastoid portions for safe ear surgery.

OBJECTIVE: Avoidance of iatrogenic injury to the facial nerve is crucial during ear surgery. The anatomical relationship between the tympanic portion of the facial canal (FC) and the mastoid portion of the facial nerve was analyzed using multi-slice computed tomography (CT) scans to avoid iatrogenic facial nerve injury. METHODS: In total, 364 ears of 351 patients who underwent CT scans were enrolled. The 364 ears were divided into two groups: 281 ears with middle ear inflammation (MEI) and 83 ears without middle ear inflammation (non-MEI). The anatomical relationship between the tympanic portion of the FC and mastoid portion of the facial nerve was analyzed on multi-slice CT images. The ears were categorized into three subgroups based on the course of the mastoid portion of the facial nerve to the tympanic portion of the FC: ("lateral running course", LRC), "on the tympanic line course" (OL), and "medial running course" (MRC). The proportions of ears in each subgroup were compared between the MEI and non-MEI groups. RESULTS: Overall, 15% of ears were categorized as LRC, 30% were OL, and 55% were MRC. In the MEI group, the proportions of LRC, OL, and MRC ears were 17%, 32%, and 51%, respectively, whereas they were 7%, 24%, and 69% in the non-MEI group. The proportion of LRC ears in the MEI group was significantly higher than that in the non-MEI group. CONCLUSIONS: Especially in patients with MEI, a more LRC for the facial nerve increases the risk of facial nerve injury during posterior tympanotomy or canal wall down mastoidectomy. The course of the facial nerve in the temporal bone should be evaluated before surgery on multi-slice CT images.