CASE REPORT Delayed Facial Nerve Palsy after Endolymphatic Sac Surgery
Int. Adv. Otol
Introduction Delayed facial nerve palsy (DFP) can occasionally occur several days after temporal bone surgery, despite no direct contact with the facial nerve during operative procedures [1,2]. DFP was reported to actually occur after otologicical and neurotological surgeries including tympanoplasty with mastoidectomy, stapes surgery, and cochlear implant [1-13]. DPF only occurs on the same side as that operated, and is rare following other types of ENT surgery such as to the head and neck,
... head and neck, suggesting a direct role of temporal bone surgery procedures. However, the underlying cause of DFP remains unclear. Herein, we report a novel case of DFP after endolymphatic sac surgery, and review the pathogenesis of DFP after otological and neurotological surgeries. Case Report The incidence of DFP after endolymphatic sac surgery from 1998 to 2008 at our hospital was 0.67% (1 out of 150 cases). A 44-year old male patient presented to our hospital in July, 2004 with complaints of repeated vertigo with cochlear symptoms including tinnitus and hearing loss in the right ear. He had been suffering from these symptoms since February, 2004, and had received medication at his former hospital without any affect. We diagnosed this case as intractable Meniere's disease and performed endolymphatic sac surgery on his right ear in September, 2004 to prevent from intractable vertigo attack and progressive sensorineural hearing loss. The technical details of endolymphatic sac surgery (termed endolymphatic sac drainage and steroid-instillation surgery: EDSS) were previously reported [14-16]. In brief, a simple mastoidectomy was performed, clearly exposing the endolymphatic sac in the area between the sigmoid sinus and the inferior margin of the posterior semicircular canal (Figure 1A). The sac was opened with an L-shaped incision made along the posterior and distal margins of the lateral wall. The sac was then filled with a solid mass of 20 mg prednisolone powder (Figure 1B). While dissolving the mass in the sac, we prepared a bundle of absorbable gelatin films (approximately five 4×20×0.7 mm sheets) with fan-and stick-shaped ends (Figures 1C, 1D). These films were tied together with a 130 Objective: Delayed facial nerve palsy (DFP) after otological and neurotological surgeries is always observed ipsilateral to the operated side, while it is rare in other types of ENT surgery including head and neck, suggesting that DFP may result from procedures selective to temporal bone surgery. Herein, we present a rare case of DFP after endolymphatic sac surgery, and review the pathogenesis and prevention of DFP after otological and neurotological surgeries. Materials and Methods: The incidence of DFP after endolymphatic sac surgery from 1998 to 2008 at our hospital was 0.67% (1 out of 150 cases). A 44-year-old male with complaints of repeated vertigo attacks and cochlear symptoms such as persistent tinnitus and fluctuating hearing loss of the right ear. The patient received endolymphatic sac surgery on the right ear for treatment of intractable Meniere's disease, resulting in the onset of DFP. Results: DFP onset occurred at post-operative day 8, with the House-Brackmann grade III. HSV and VZV serum tests were negative. Conclusion: The later onset DFP observed in the present case after endolymphatic sac surgery might relate to the reactiva-tion of a virus other than HSV and VZV in the geniculate ganglion induced by surgery.