Intratympanic versus intravenous delivery of dexamethasone and dexamethasone sodium phosphate to cochlear perilymph.

OBJECTIVE: To measure dexamethasone concentrations in the plasma and perilymph of the human ear after intravenous (IV) and intratympanic (IT) administration and to compare these with previous studies with methylprednisolone. METHODS: Patients were administered dexamethasone by the IT or IV routes approximately 0.5 to 2 hours before cochlear implantation. The IT dose of 1.6 to 7.2 mg (0.4-1.8 ml of a 4 mg/ml solution) of dexamethasone sodium phosphate was administered by injection into the middle ear cavity through the external auditory canal via a 27-gauge needle passed through a small anterosuperior myringotomy. The IV dose of dexamethasone sodium phosphate was 0.17 mg/kg given as a single injection for 30 seconds. A sample of perilymph (approximately 20 µl) was collected using a needle passed through the round window, and blood was sampled simultaneously. Concentrations of free dexamethasone and dexamethasone sodium phosphate were measured using a validated liquid chromatography-tandem mass spectrometry method. RESULTS: In the 22 patients studied, 22 perilymph samples and 19 plasma samples were available and suitable for measurement. The median perilymph concentration of dexamethasone after IV injection of 0.17 mg/kg was 0.016 mg/L (n = 9; range, 0.008-0.17), and 1.4 mg/L (n = 13; range, 0.1-16.3) after IT administration of approximately 4 mg. Perilymph concentrations were approximately 88-fold higher after IT compared with IV administration (p = 0.0004) or approximately 260 fold after correction for dosage. The median plasma concentration of dexamethasone after IV injection was 0.12 mg/L (n = 7; range, 0.07-0.14) and 0.003 mg/L (n = 12; range, <0.0005-0.005) after IT injection. Plasma concentrations were approximately 40-fold lower (p = 0.0005) or approximately 13-fold lower after dose correction. Concentrations of dexamethasone sodium phosphate were more variable and were even higher in perilymph and lower in plasma. CONCLUSION: Administration of dexamethasone IT results in much higher perilymph concentrations and much lower plasma concentrations compared with IV administration.

An audit of referrals to the Southern Cochlear Implant Paediatric Programme.

AIM: To audit the age at referral and time to assessment and implantation in children presenting to the Southern Cochlear Implant Paediatric Programme and identify any delay in implantation, particularly in individuals with pre-lingual sensorineural hearing loss. METHODS: All paediatric referrals to the Southern Cochlear Implant Programme from March 2003-March 2008 were evaluated retrospectively. The Student t-test was used to compare median time intervals between those with and without risk factors for Sensorineural hearing loss. RESULTS: Seventy five children were referred, 42 with pre-lingual deafness and 33 with post-lingual deafness. The median age of referral was 17 months with a range of 1 to 203 months. Thirty-five children with pre-lingual deafness were accepted as candidates and implanted, 6 were declined as they were too old to receive benefit from cochlear implantation. Of these 6 children who were declined, 4 had not been adequately diagnosed despite having risk factors for sensorineural hearing loss. There was no significant difference in the age of referral in pre-lingually deafened children between those with risk factors and those without risk factors. CONCLUSION: The age at referral of pre-lingually deafened children to the Southern Cochlear Implant Programme is unacceptably high, particularly in those children who have known risk factors for sensorineural hearing loss.

Cochlear Implantation in children with CHARGE syndrome.

UNLABELLED: CHARGE syndrome is a rare congenital condition that manifests with anomalies of coloboma, heart defects, choanal atresia, mental retardation, genitourinary and ear anomalies that can affect almost any part of the auditory pathway. In those patients with a significant sensorineural hearing loss, cochlear implantation has become a potential therapeutic option. METHODS: Chart review of three cases from the Southern Cochlear Implant Programme. OUTCOMES: All patients met clinical diagnostic criteria of CHARGE syndrome, and had abnormal inner ear anatomy with profound sensorineural hearing loss. One child had previously undergone cochlear implantation which was unsuccessful due to increasing non-auditory stimulation. All patients had successful cochlear implantation with full insertion of a Nucleus Freedom Implant with contour Advance. All patients showed improvement in their audiological function; one child has high functioning verbal communication, one child uses both sign and verbal communication with improved speech quality and ability to speech read, and one child responds reliably to sound, understands short phrases and attempts to vocalize, but this is limited by tracheostomy. CONCLUSION: Cochlear implantation faces numerous challenges in children with CHARGE syndrome, but with appropriate patient selection can result in successful audiologic and quality of life outcomes.

Intratympanic versus intravenous delivery of methylprednisolone to cochlear perilymph.

OBJECTIVE: To compare methylprednisolone concentrations in the perilymph of the human ear and in plasma after intratympanic (IT) or intravenous (IV) administration. METHODS: Methylprednisolone concentrations in the perilymph of patients during cochlear implantation were compared after 3 dosing strategies of methylprednisolone solution for injection (40 mg/ml): 1) IT administration of up to 40 mg was injected into the middle ear through the external auditory canal via a 27-gauge needle passed through a small anterosuperior myringotomy; 2) IV administration of 1 mg/kg was given as a single injection over 30 seconds; 3) IV administration of 10 mg/kg was infused over 30 minutes. Perilymph (single sample, approximately 20 microL) was sampled using a needle passed through the round window membrane, from 0.5 to 3 hours after dosing. In most patients, simultaneous blood sampling was performed. Methylprednisolone concentrations were measured by high-performance liquid chromatography with a limit of quantification of 0.001 mg/L. RESULTS: In 39 patients studied, 33 perilymph samples were suitable for measurement, along with 26 plasma samples. Median perilymph concentrations were 6.7 mg/L (n = 18; range, 0.2-89.4 mg/L) after IT administration, 0.053 mg/L (n = 8; range, 0-0.47 mg/L) after IV injection of 1 mg/kg, and 0.2 mg/L (n = 7; range, 0.067-3.1 mg/L) after IV infusion of 10 mg/kg. The median perilymph concentrations were 126-fold higher after the IT administration than after 1 mg/kg IV (p = 0.0003) and 33-fold higher than after 10 mg/kg IV infusion (p = 0.0045). Plasma concentrations after IT administration were 16-fold lower than after IV administration of 1 mg/kg (p = 0.0006), and 136-fold lower than after IV infusion of 10 mg/kg (p = 0.0006). CONCLUSION: IT administration of methylprednisolone in humans results in much higher perilymph concentrations and much lower systemic concentrations than IV administration.

Preservation of the superficial lobe for deep-lobe parotid tumors: a better aesthetic outcome.

Deep-lobe parotid tumors are relatively uncommon. Most of these tumors present as external masses. They can also present in the oral cavity or oropharynx. Magnetic resonance imaging and ultrasound-guided fine-needle aspiration for biopsy and cytology have made it possible to establish a definitive diagnosis and identify the exact location of the tumor in almost all cases before surgery. Traditionally, deep-lobe tumors have been managed by a formal superficial parotidectomy and identification and preservation of the facial nerve, followed by removal of the deep lobe that contains the tumor Superficialparotidectomy is associated in most cases with periauricular depression secondary to a loss of volume, leading to variable aesthetic deformities. A complete parotidectomy is more likely to be associated with a larger aesthetic deficit secondary to a greater loss of tissue volume. The incidence of gustatory sweating is high after superficial parotidectomy, particularly in the early postoperative period. We hypothesize that if the superficial lobe is preserved, there is less likelihood of gustatory sweating because of the interposition of tissue between the skin and the cut ends of the secretomotor fibers. Approximately 80% of parotid tissue volume is made up of the superficial lobe, and therefore preservation of the superficial lobe should be associated with less postparotidectomy depression. Therefore, we decided to preserve the superficial lobe of the gland for deep-lobe tumors. Nine patients underwent deep-lobe parotidectomy with preservation of the superficial lobe over a 6-year period. Patients were studied prospectively with regard to technical difficulty, complications, and cosmetic outcome. Follow-up ranged from 12 months to 6 years. We did not experience any undue technical difficulty, and there were no cases of facial weakness. One patient developed gustatory sweating, which almost completely resolved over a 2-year period. There were no cases of post parotidectomy depression, and both patients and surgeons were satisfied with the cosmetic appearance. We present our technique and experience.

Modified submandibular sialoadenectomy.

Submandibular sialoadenectomy is a common head and neck procedure. Indications include the presence of benign and malignant tumors and inflammatory disease with or without intraglandular sialolithiasis. The standard technique involves a variably sized incision. The facial artery and vein are usually ligated and transected during the procedure, and either suction or nonsuction wound drainage is generally instituted. We describe a modified sialoadenectomy technique that involves a minimal incision, preserves the facial artery and vein, and does not require wound drainage because the surgical site is closed in three layers. We performed this procedure on 19 patients and observed only 1 postoperative complication--mild paresis of the right marginal mandibular branch of the facial nerve following the excision of a Warthin's tumor: This patient recovered fully 3 months postoperatively.

Extra-abdominal fibromatosis: a case report.

Head and neck fibromatosis is a rare disease with a variable clinical picture. We report the case of a 40-year-old woman who had a 1-week history of a painless mass overlying her right neck. Histology confirmed a diagnosis of extra-abdominal fibromatosis. Two unusual features of this case were the site of the lesion and its rapid growth. In this article, we discuss the clinical picture of head and neck fibromatosis, its etiology and pathology, and current opinion regarding its treatment.