Dexamethasone pharmacokinetics in the inner ear: Comparison of route of administration and use of facilitating agentsThere is growing otologic interest in treating inner ear disorders, such as sudden sensorineural hearing loss and acute or unremitting Meniere's disease, with intratympanic dexamethasone (IT-DEX). Although anecdotally reported, there are no scientific clinical papers and few prior laboratory research publications on the subject. This study compares perilymph dexamethasone concentrations after systemic and intratympanic administration and assesses the role of 3 potential transport facilitators of IT-DEX into perilymph. Forty guinea pigs (79 ears) were randomly separated into 5 groups. Dexamethasone levels were measured by radioimmunoassay. IT-DEX resulted in higher perilymph steroid levels than intravenous dexamethasone (P < 0.05). Histamine facilitator resulted in significantly higher perilymph steroid levels than IT-DEX alone (P < 0.05). Neither hyaluronic acid nor dimethylsulfoxide was a potent facilitator. This study demonstrates that IT-DEX administration results in superior perilymph levels within 1 hour of administration and does not result in systemic absorption. Histamine is a potent facilitating agent. The clinical implications are considerable.
Skull base osteomyelitis secondary to malignant otitis externaGangadhar S Sreepada, Jed A. Kwartler|Current Opinion in Otolaryngology & Head & Neck Surgery|2003 PURPOSE OF REVIEW: Skull base osteomyelitis secondary to malignant otitis externa was first described in 1959. Since then, advances have been made in the diagnosis, treatment, and clinical outcomes of this condition. RECENT FINDINGS: This review discusses the pathophysiology and microbiology of malignant otitis externa. The review highlights the sometimes subtle presenting symptoms and recent advances in imaging and their practical application to diagnosing and monitoring the disease. Therapy for malignant otitis externa has changed since this entity was first described; this article reviews the medical, surgical, and adjuvant therapies and the relevant controversies. SUMMARY: The review discusses the history, pathogenesis, diagnosis, and treatment of skull base osteomyelitis in the context of malignant otitis externa with particular emphasis on HIV, children, and other immunodeficient states.
Glomus tympanicum tumors: A clinical perspectiveSince Guild first discovered glomus bodies in the middle ear, the diagnostic evaluation and therapy of glomus tympanicum tumors have remained challenging. This study describes 73 cases diagnosed as glomus tympanicum tumors over the past 30 years. During this period, imaging techniques have markedly improved, and surgical approaches have evolved and been refined. These 73 cases were reviewed from a clinical perspective involving presentation, diagnostic evaluation, and therapeutic management. Pulsatile tinnitus was the primary symptom in over half the patients, followed by hearing loss in one third. The physical exam rarely revealed a circumferential view of the lesion, emphasizing the necessity of further diagnostic evaluation. High-resolution computerized tomography (CT) is currently the radiographic study of choice. A transmastoid surgical approach with extended facial recess was most commonly employed. Extension to the jugular bulb or internal carotid was rare, and no intraoperative complications of catecholamine secretion were noted. Postoperative complications were few, and the overall residual/recurrence rate was less than 5%. Additional clinical insights may assist in the management of these rare but fascinating tumors.
Predicting Long‐Term Facial Nerve Outcome after Acoustic Neuroma SurgeryAlthough anatomic preservation of the facial nerve is achieved in nearly 90% of reported cases after acoustic neuroma surgery, postoperative long-term facial function is of most concern to the patient. This study examines long-term facial nerve function in relation to the immediate postoperative function and the function at time of discharge from the hospital. Subjects included 515 patients who underwent primary acoustic neuroma removal at House Ear Clinic from 1982 through 1989 and who had normal preoperative facial function, an intact facial nerve after surgery, and a House-Brackmann facial nerve grade available immediately postoperatively, at time of hospital discharge, and at least 1 year postoperatively. Rate of acceptable facial function (House grades I-IV) differed significantly (p < or = 0.001) at the three postoperative time intervals: 85.2%, immediate; 73.6%, discharge; 93.8%, long-term. Of those with good immediate function (grades I-II), 98.6% had acceptable long-term function. Of those with poor immediate function (grades V-VI), 69.8% had acceptable long-term function. We conclude that facial nerve recovery after acoustic neuroma surgery is characterized by slight deterioration in the immediate postoperative period, but subsequent improvement in the long-term. Patients can be reliably counseled that acceptable function immediately after surgery is associated with a favorable long-term outcome; poor function immediately after surgery, despite an intact nerve, has a more guarded prognosis.
Transcanal infracochlear approach to the petrous apexComputerized tomography and magnetic resonance imaging have now made it possible to reliably differentiate cholesteatoma from cholesterol granuloma of the petrous apex. The treatment for cholesteatoma is complete surgical excision when possible, whereas cholesterol granuloma needs only adequate drainage for control. A new transcanal infracochlear approach for drainage of cholesterol granuloma involving the anterior petrous apex is described. Absolute measurements from 10 cadaveric temporal bones were obtained to determine the distances between the cochlea, jugular bulb, carotid artery, and facial nerve. In all specimens the petrous apex was entered without invading the cochlea, carotid, or jugular bulb. Advantages of this technique include a more direct route to the petrous apex, dependent drainage, and preservation of the normal hearing mechanism, including the tympanic membrane. Clinical indications for this technique include failure of other treatment approaches and a high jugular bulb obstructing an infralabyrinthine approach. Experience to date shows that patients experience little difficulty from the procedure.