title: Transient facial nerve palsy after topical papaverine application during vestibular schwannoma surgery. Case report.
abstract: Some evidence in the literature supports the topical application of papaverine to the cochlear nerve to prevent internal auditory artery vasospasm and cochlear ischemia as a method of enhancing the ability to preserve hearing during acoustic neuroma surgery. The authors report a case of transient facial nerve palsy that occurred after papaverine was topically applied during a hearing preservation acoustic neuroma removal. A 58-year-old woman presented with tinnitus and serviceable sensorineural hearing loss in her right ear (speech reception threshold 15 dB, speech discrimination score 100%). Magnetic resonance imaging demonstrated a 1.5-cm acoustic neuroma in the right cerebellopontine angle (CPA). A retrosigmoid approach was performed to achieve gross-total resection of the tumor. During tumor removal, a solution of 3% papaverine soaked in a Gelfoam pledget was placed over the cochlear nerve. Shortly thereafter, the quality of the facial nerve stimulation deteriorated markedly. Electrical stimulation of the facial nerve did not elicit a response at the level of the brainstem but was observed to elicit a robust response more peripherally. There were no changes in auditory brainstem responses. Immediately after surgery, the patient had a House-Brackmann Grade V facial palsy on the right side. After several hours, this improved to a Grade I. At the 1-month follow-up examination, the patient exhibited normal facial nerve function and stable hearing. Intracisternal papaverine may cause a transient facial nerve palsy by producing a temporary conduction block of the facial nerve. This adverse effect should be recognized when topical papaverine is used during CPA surgery.
authors.affiliation: Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Evanston Northwestern Healthcare, Evanston, Illinois 60201, USA. jliu@enh.org
authors.forename: James K
authors.initials: JK
authors.lastname: Liu
authors.forename: Christina M
authors.initials: CM
authors.lastname: Sayama
authors.forename: Clough
authors.initials: C
authors.lastname: Shelton
authors.forename: Joel D
authors.initials: JD
authors.lastname: MacDonald
mesh_terms: D000287:Administration, Topical; D005158:Facial Paralysis / Q000139:chemically induced*; D005260:Female; D006801:Humans; D007431:Intraoperative Complications; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000601:surgery*; D010208:Papaverine / Q000008:administration & dosage / Q000009:adverse effects*; D014665:Vasodilator Agents / Q000008:administration & dosage / Q000009:adverse effects*
chemical_list: D014665:Vasodilator Agents; D010208:Papaverine