1

Introduction

The facial nerve via the chorda tympani is responsible for controlling the taste in the anterior two-thirds of the tongue on each side. The chorda tympani runs close to the annulus of the tympanic membrane, crossing the tympanic cavity between the incus and the malleus, and is initially encountered at this location when elevating the annulus . Iatrogenic injury or damage to the chorda tympani is a well-documented complication resulting from middle-ear surgery . McManus et al. reported the overall prevalence of related symptoms after such injury to be between 15% and 22%, consisting of mostly changes in taste (dysgeusia) and dryness of the mouth. On occasions, the dysgeusia can be refractory to treatment, with patients seeking opinions from multiple providers without relief. We present a report on successful medical management of the dysgeusia after tympanoplasty using amitriptyline.

2

Case reports

Patient is a 59-year-old white man evaluated in November, 2012 for abnormal taste sensation since January of 2012 following a left lateral graft tympanoplasty. His past medical history is significant for chronic left otitis media, diabetes mellitus, diabetic retinopathy, hypertension, erectile dysfunction, cervical spondylosis with C6-7 anterior cervical discectomy and fusion, and no known drug allergies. On the initial encounter, he was afebrile with stable vital signs, and he had a non-focal neurological examination.

Patient was initially seen by otolaryngology for left otitis externa and recurrent otitis media. He subsequently developed mixed hearing loss documented on audiogram, and was noted to have a perforated left tympanic membrane. In January, 2012 patient underwent left lateral graft tympanoplasty with temporalis fascia autograft harvesting under general endotracheal anesthesia. The intubation was difficult, requiring fiberoptic assistance. After the postauricular region was injected with local anesthetic, the intraoperative microscope was brought into the field, and the external auditory canal (EAC) was also infiltrated with local anesthetic. The canal cuts were made along the tympanosquamous and tympanomastoid suture lines. Next, the postauricular incision was carried down to the temporalis fascia, which was then harvested. The muscular periosteal flap was elevated anteriorly until the bony posterior EAC was encountered. The vascular strip was identified, and elevated towards the tympanic membrane. After the bony cartilaginous junction was identified, the anterior canal was incised and elevated down to the fibrous annulus with most of the remaining epithelial layer of the tympanic membrane removed in the continuity with the anterior canal wall. The canal plasty was performed, and the spine of Henle was removed. The tympanomastoid and the tympanosquamous sutures, and the overhanging anterior bony EAC wall were removed. This provided 360° view of the fibrous annulus. The chorda tympani was not visualized during the procedure. The EAC was thoroughly inspected to ensure that no epithelium remained. After copious irrigation, a bed of Gelfoam was placed down in the middle ear space, the already trimmed fascial graft was placed onto the fibrous annulus anteriorly, and the notch for the malleus was placed under the manubrium of the malleus. Once the fascial graft was appropriately positioned, the anterior canal wall skin was replaced just overlaying the fascia graft anteriorly by couple of millimeters. A cigar shaped Gelfoam was placed to recreate the anterior sulcus. The remaining anterior EAC skin and the anterior portion of the graft were covered with Gelfoam soaked in Ciprodex. A marker piece of Gelfoam was placed into the EAC, and the vascular strip was placed onto the marker piece of Gelfoam. Muscular periosteal flaps were reapproximated; the marker piece of Gelfoam was removed from the EAC, while the vascular strip was laid flat on the bony EAC. The remaining EAC was carefully packed with Ciprodex soaked Gelfoam. The postauricular incision was closed with multiple interrupted sutures. A cotton ball coated in bacitracin was placed in the EAC, followed by sterile mastoid dressing. Intraoperatively, he was noted to have approximately 45%–50% of the inferior tympanic membrane perforated. His ossicular chain was intact and mobile. He was discharged home the same day with prescription for Ciprodex drops and pain medication.

One week following surgery, the patient told his otolaryngologist that he was doing well without otalgia or otorrhea. In March, 2012 he reported left aural fullness without otorrhea or otalgia. His overall subjective hearing was improving. On physical examination the left post-auricular incision was healing well without any evidence of infection. The left EAC was healing well, and the tympanic membrane was intact and healing, too. No middle ear effusion was noted. He was instructed to continue to use Ciprodex drops for three more weeks postoperatively. In October, 2012 during a routine visit with his primary care provider, he mentioned that he had an abnormal sensation on the left side of his tongue, which he described as constantly having a “salt tablet in his mouth,” dating back to just after his middle-ear surgery. He was referred for further neurologic evaluation, during which he reported experiencing a salty taste on the left side of his tongue, along with a metallic taste on the tip of his tongue; he stated the onset was shortly after the tympanoplasty. The dysgeusia was accompanied by increased salivation and difficulty with staying asleep. He denied having dysgeusia on the right side of his tongue. He was started on Amitriptyline 50 mg by mouth at bedtime with the plan to increase the dose up to 150 mg if no improvement was noted on further follow-up. Symptoms improved over the course of several weeks. In November, 2014, during a telephone follow-up, he reported taking only Amitriptyline 50 mg at bedtime. The dysgeusia had completely resolved during the day while taking the medication, although he noticed mild return in symptoms towards the end of the work day. If he had skipped a dose of Amitriptyline, the dysgeusia returned to its original severity. Overall, he felt significantly better while taking Amitriptyline.

2

Case reports

Patient is a 59-year-old white man evaluated in November, 2012 for abnormal taste sensation since January of 2012 following a left lateral graft tympanoplasty. His past medical history is significant for chronic left otitis media, diabetes mellitus, diabetic retinopathy, hypertension, erectile dysfunction, cervical spondylosis with C6-7 anterior cervical discectomy and fusion, and no known drug allergies. On the initial encounter, he was afebrile with stable vital signs, and he had a non-focal neurological examination.

Patient was initially seen by otolaryngology for left otitis externa and recurrent otitis media. He subsequently developed mixed hearing loss documented on audiogram, and was noted to have a perforated left tympanic membrane. In January, 2012 patient underwent left lateral graft tympanoplasty with temporalis fascia autograft harvesting under general endotracheal anesthesia. The intubation was difficult, requiring fiberoptic assistance. After the postauricular region was injected with local anesthetic, the intraoperative microscope was brought into the field, and the external auditory canal (EAC) was also infiltrated with local anesthetic. The canal cuts were made along the tympanosquamous and tympanomastoid suture lines. Next, the postauricular incision was carried down to the temporalis fascia, which was then harvested. The muscular periosteal flap was elevated anteriorly until the bony posterior EAC was encountered. The vascular strip was identified, and elevated towards the tympanic membrane. After the bony cartilaginous junction was identified, the anterior canal was incised and elevated down to the fibrous annulus with most of the remaining epithelial layer of the tympanic membrane removed in the continuity with the anterior canal wall. The canal plasty was performed, and the spine of Henle was removed. The tympanomastoid and the tympanosquamous sutures, and the overhanging anterior bony EAC wall were removed. This provided 360° view of the fibrous annulus. The chorda tympani was not visualized during the procedure. The EAC was thoroughly inspected to ensure that no epithelium remained. After copious irrigation, a bed of Gelfoam was placed down in the middle ear space, the already trimmed fascial graft was placed onto the fibrous annulus anteriorly, and the notch for the malleus was placed under the manubrium of the malleus. Once the fascial graft was appropriately positioned, the anterior canal wall skin was replaced just overlaying the fascia graft anteriorly by couple of millimeters. A cigar shaped Gelfoam was placed to recreate the anterior sulcus. The remaining anterior EAC skin and the anterior portion of the graft were covered with Gelfoam soaked in Ciprodex. A marker piece of Gelfoam was placed into the EAC, and the vascular strip was placed onto the marker piece of Gelfoam. Muscular periosteal flaps were reapproximated; the marker piece of Gelfoam was removed from the EAC, while the vascular strip was laid flat on the bony EAC. The remaining EAC was carefully packed with Ciprodex soaked Gelfoam. The postauricular incision was closed with multiple interrupted sutures. A cotton ball coated in bacitracin was placed in the EAC, followed by sterile mastoid dressing. Intraoperatively, he was noted to have approximately 45%–50% of the inferior tympanic membrane perforated. His ossicular chain was intact and mobile. He was discharged home the same day with prescription for Ciprodex drops and pain medication.

One week following surgery, the patient told his otolaryngologist that he was doing well without otalgia or otorrhea. In March, 2012 he reported left aural fullness without otorrhea or otalgia. His overall subjective hearing was improving. On physical examination the left post-auricular incision was healing well without any evidence of infection. The left EAC was healing well, and the tympanic membrane was intact and healing, too. No middle ear effusion was noted. He was instructed to continue to use Ciprodex drops for three more weeks postoperatively. In October, 2012 during a routine visit with his primary care provider, he mentioned that he had an abnormal sensation on the left side of his tongue, which he described as constantly having a “salt tablet in his mouth,” dating back to just after his middle-ear surgery. He was referred for further neurologic evaluation, during which he reported experiencing a salty taste on the left side of his tongue, along with a metallic taste on the tip of his tongue; he stated the onset was shortly after the tympanoplasty. The dysgeusia was accompanied by increased salivation and difficulty with staying asleep. He denied having dysgeusia on the right side of his tongue. He was started on Amitriptyline 50 mg by mouth at bedtime with the plan to increase the dose up to 150 mg if no improvement was noted on further follow-up. Symptoms improved over the course of several weeks. In November, 2014, during a telephone follow-up, he reported taking only Amitriptyline 50 mg at bedtime. The dysgeusia had completely resolved during the day while taking the medication, although he noticed mild return in symptoms towards the end of the work day. If he had skipped a dose of Amitriptyline, the dysgeusia returned to its original severity. Overall, he felt significantly better while taking Amitriptyline.