Perilymph fistula: an important cause of deafness and dizziness in children.

This study underscores the importance of considering a perilymph fistula, an abnormal communication between the inner and middle ear, in any child with a progressive sensorineural hearing loss. A concomitant complaint of intermittent dizziness or observed spells of imbalance (56%) is another indication of the disease. Six of 16 patients (37.5%) with proven fistulas were less than 2 years of age at the onset of symptoms. Unless the fistula is identified and repaired by grafting, the ear may become totally deaf. This would be disastrous in the presence of bilateral fistulas, which occur commonly in children (56% of patients had symptoms of bilateral disease). Our experience in recognizing and treating fistulas and thereby saving and restoring hearing is described.

Human experience with canal plugging.

Canal occlusion/plugging is a very effective technique with a low risk to hearing. The series of posterior semicircular canal occlusions described in this review now becomes the largest in the literature to date. It continues to support this procedure as the treatment of choice for intractable benign paroxysmal positional vertigo (BPPV). All 44 operated ears were relieved of BPPV, with one patient having an atypical late recurrence. Of the 40 ears with normal preoperative hearing, one had a delayed (3-month) sudden and permanent profound loss, while one other had a mild (20 dB) loss. Six patients had protracted courses of imbalance and motion sensitivity. Canal plugging has led to several new and innovative developments including the partial labyrinthectomy for difficult-to-access skull base lesions and superior semicircular canal plugging for dehiscence. These new procedures and their development are reviewed in this paper.

Free-floating endolymph particles: a new operative finding during posterior semicircular canal occlusion.

Most clinicians accept cupulolithiasis as the pathophysiological mechanism underlying benign paroxysmal positional vertigo (BPPV.) According to this theory, a cupular deposit induces a gravitational effect on the posterior canal crista. Posterior semicircular canal occlusion is a new operative procedure for treating incapacitating BPPV. It is postulated that canal occlusion abolishes endolymph movement within the canal, effectively fixing the cupula and rendering it unresponsive to both angular and linear acceleration (gravity). During two recent canal occlusions, abundant "free-floating particles" were identified within the posterior canal endolymph. When changing the position of the canal in the earth vertical plane, these free-floating particles would move under the influence of gravity. The hydrodynamic drag of the particles would induce endolymph movement with cupular displacement leading to the typical response. This finding supports an alternate explanation to cupulolithiasis as the pathophysiological mechanism underlying BPPV.

Irritative spontaneous nystagmus following intratympanic gentamicin for Menière's disease.

Intratympanic aminoglycosides were first used to treat unilateral intractable Meniere's disease over 30 years ago. Gentamicin, the current drug of choice, provides excellent vertigo control with a low incidence of hearing loss. Its salutory effect results from direct damage to both the sensory neuroepithelium and the dark cells of the labyrinth. This latter effect may reverse the degree of endolymphatic hydrops. Twelve patients with unilateral Meniere's disease were treated and prospectively studied. Although further follow-up is necessary, 10 patients have complete vertigo control, while 2 remain significantly improved. Three patients developed a spontaneous "irritative" nystagmus during the early post-treatment period. This new unique finding may represent a recovery phenomenon resulting from a temporary reversible ototoxic effect in the treatment ear. Despite our patients having a somewhat higher incidence of hearing loss compared to the reported rate, the results of this treatment are encouraging.

Percutaneous embolization for control of nasal blood circulation.

Percutaneous embolization to control the nasal blood circulation was used in 19 patients with vascular nasal disorders. Embolization was the initial treatment for intractable posterior epistaxis in 11 patients, 9 (82%) of whom were controlled without further treatment. Used as an adjunct to surgery on vascular nasal tumors, embolization reduced intraoperative blood loss in four patients to an average of 800 cc. In four patients with Osler-Weber-Rendu disease, treatment with embolization did not significantly alter the course of their disease. Overall, however, this relatively new technique enhances successful management of difficult epistaxis cases.

Magnetic resonance imaging of facial nerve neuromas.

Facial nerve neuromas are uncommon tumors often confused with other tumors of the temporal bone and cerebellopontine angle. Radiologically, it may be impossible to differentiate an intracanalicular facial nerve neuroma from an acoustic neuroma. We present three case reports of facial nerve neuromas arising within the internal auditory canal to show the important magnetic resonance imaging features of these tumors. One tumor extended into the cerebellopontine angle, middle cranial fossa, and middle ear. Another filled the internal auditory canal and extended through the cerebellopontine angle to the brain stem. The third occurred in a patient who had neurofibromatosis as well as numerous other intracranial tumors. We feel that gadolinium-enhanced magnetic resonance imaging provides the most useful information in the preoperative assessment of this disorder.

Corticosteroid pharmacokinetics in the inner ear fluids: an animal study followed by clinical application.

OBJECTIVE: Autoimmune disease (e.g., Cogan syndrome) and other inflammatory inner ear diseases may ravage the labyrinth if not treated aggressively with antiinflammatory medication. Corticosteroids are the mainstay of treatment, yet, partly because of the existence of the blood-labyrinthine barrier, the ideal drug, dose, and route of administration are currently unknown. STUDY DESIGN: In the present study, we established cochlear fluid pharmacokinetic profiles of hydrocortisone, methylprednisolone, and dexamethasone in the guinea pig following oral, intravenous, and topical (intratympanic) administration. High-performance liquid chromatography was used to determine the drug concentrations, and comparisons were made with simultaneous pharmacokinetic profiles from blood and cerebrospinal fluid. RESULTS: Our findings demonstrated a much higher penetration of all three drugs into the cochlear fluids following topical application as compared with systemic administration, with methylprednisolone showing the best profile. DISCUSSION: The results suggested that intratympanic administration of corticosteroids might be more efficacious while avoiding high blood levels and therefore the deleterious side effects of systemic use. CLINICAL APPLICATION: Thirty-seven patients with various inner ear disorders causing sensorineural hearing loss were subsequently treated using intratympanic corticosteroids, 20 with dexamethasone, and 17 with methlyprednisolone. Patients with immune-mediated hearing losses showed the best results, with notable improvement also seen in several cases of a "sudden deafness." No benefit was seen in patients with cochlear hydrops or those with sudden deterioration of a preexisting hearing loss. Three patients developed a transient otitis media related to the treatments, easily controlled with antibiotics. There were no cases of treatment-induced hearing loss and no permanent tympanic membrane perforations. CONCLUSIONS: Overall injection of intratympanic corticosteroids for the treatment of hearing loss in inner ear disorders appears to be both safe and highly effective for certain disorders. The concept of this technique is supported by animal experimental data. The findings from the present study warrant further clinical application and experimental investigation.

Particulate matter in the posterior semicircular canal.

The pathoetiology of benign paroxysmal positional vertigo (BPPV) is controversial. Particulate matter within the posterior semicircular canal has been identified intraoperatively in patients with BPPV but has also been reported in non-BPPV patients at the time of translabyrinthine surgery (Parnes LS, McClure JA. Free-floating endolymphatic particles: a new operative finding during posterior semicircular canal occlusion. Laryngoscope 1992;102:988-92; Schuknecht HF, Ruby RRF. Cupulolithiasis. Adv Otorhinolaryngol 1973;20: 434-43; Kveton JF, Kashgarian M. Particulate matter within the membranous labyrinth: pathologic or normal? Am J Otol 1994;15:173-6). The nature of the particulate matter remains unknown. The purpose of this study was to prospectively examine the posterior semicircular canal of patients with and without a clinical history of BPPV for the presence of particulate matter. Seventy-three patients without BPPV symptoms undergoing labyrinthine surgery (vestibular schwannoma excision or labyrinthectomy) and 26 patients with BPPV undergoing the posterior semicircular canal occlusion procedure were compared. Additionally, 70 archived temporal bones without a history of BPPV were examined microscopically for the presence of particulate matter within the lumen of the membranous labyrinth. No particles were observed intraoperatively in any of the 73 patients without a history of BPPV. Particulate matter was observed in 8 of 26 patients at the time of the posterior semicircular canal occlusion procedure for intractable BPPV. Of the 70 temporal bones examined, 31 did not show significant postmortem changes and also did not demonstrate cupulolithiasis or canalithiasis. Particulate matter from within the membranous posterior semicircular canal was removed from one patient at the time of posterior semicircular canal occlusion for intractable BPPV symptoms and was examined by scanning electron microscopy. The particulate matter appeared morphologically consistent with degenerating otoconia. These data show a statistically significant association between the presence of particles within the posterior semicircular canal in this study and the symptom complex of BPPV.

Therapeutic embolization in the treatment of intractable epistaxis.

OBJECTIVE: To determine the effectiveness of therapeutic embolization in the treatment of intractable epistaxis. DESIGN: Cohort. SETTING: Tertiary care hospital. PATIENTS: Consecutive referred sample of 57 patients with intractable epistaxis. INTERVENTION: Percutaneous transfemoral catheterization and angiography of the internal maxillary arteries. Embolization of the most distal branches with 0.1- to 0.9- cm3 medium-sized polyvinyl alcohol particles on the suspected side of bleeding. OUTCOME: Outcome was successful if no further interventional treatment was required for epistaxis. RESULTS: Anatomical abnormalities precluded embolization in three patients. Three of the remaining 54 patients required supplementry embolization. Including these three patients, 52 (96%) of 54 patients had successful control epistaxis. The major neurologic complication rate was 6% (three of 54 patients), with no permanent deficits. CONCLUSIONS: Therapeutic embolization is an effective and safe technique and should be considered as the primary treatment modality in severe epistaxis.

Posterior semicircular canal occlusion in the normal hearing ear.

This report outlines our experience with posterior semicircular canal occlusion, a new operative procedure for intractable benign paroxysmal positional vertigo (BPPV). We postulate that the resulting solid canal "plug" prevents endolymph movement within the posterior canal, which effectively fixes the cupula. This selectively abolishes the receptivity of the posterior canal to both angular acceleration and gravity without influencing the other inner ear receptors. We previously reported the success of this procedure in two patients with BPPV and a co-existing profound sensorineural hearing loss in the affected ear. Since that report, a slightly modified technique has been used to occlude six more posterior canals--five in normal hearing ears. While our follow-up times range from only 3 to 18 months, all eight patients continue to be relieved of their BPPV. Temporary mixed hearing losses occurred in three of the five ears with normal preoperative hearing. Hearing in all five patients ultimately returned to the preoperative state. We believe this procedure is a simpler and safer alternative to singular neurectomy for the treatment of intractable benign paroxysmal positional vertigo.

Comparison of open, percutaneous, and translaryngeal tracheostomies.

INTRODUCTION: With 3 tracheostomy techniques currently available, controversy exists regarding which is safest and most economical. Percutaneous (PDT) and the new translaryngeal (TLT) tracheostomies are cited as more cost-effective than the traditional open surgical procedure because they are bedside techniques. Our objective was to compare the perioperative and postoperative complications of the 3 techniques. STUDY DESIGN: This was a prospective trial involving 100 consecutive patients who underwent tracheostomy between April and December of 1997 at the London Health Sciences Centre and St Joseph's Health Centre in London, Canada. RESULTS: Fifty open tracheostomies were performed. Indications included prolonged ventilation (n = 42), airway protection (n = 5), pulmonary hygiene (n = 2), and sleep apnea (n = 1). A tension pneumothorax was the one significant intraoperative complication. Fifteen postoperative complications occurred, most notable of which was a 2-L hemorrhage at 24 hours. Thirty-seven TLTs were performed, 20 in patients with coagulopathy. Indications were prolonged intubation (n = 27), airway protection (n = 9), and pulmonary hygiene (n = 1). One intraoperative complication of accidental decannulation occurred. One postoperative complication, a pretracheal abscess, occurred in a decannulated transplant patient 2 weeks after the procedure. Thirteen PDTs were performed. Indications were prolonged intubation (n = 6), airway protection (n = 6), and tracheal toilet (n = 1). No significant complications occurred. CONCLUSIONS: TLT and PDT have fewer complications than the traditional open technique. TLT appears to have the greatest utility in the coagulopathic patient.

Approach to the vestibular patient and driving: A patient perspective.

OBJECTIVES: To learn about the impact of dizziness on driving from a patient perspective and to present an approach to the vestibular patient and driving. DESIGN: An anonymous questionnaire completed by 265 dizzy patients at 3 different centers. RESULTS: The participants were experienced drivers who needed to drive to function normally (83%). Those with constant or severe dizziness comprised a higher risk group of drivers. Although few had ever been warned not to drive, 52% said that if they were warned to stop driving, they would not. Most thought that it was the doctor's role to report unsafe drivers to the authorities (P < 0.001, chi2 = 87.2670). CONCLUSIONS: The diagnosis of a vestibular disorder should not alone be grounds to suspend a patient's driver's license. Legislation should be amended to better reflect the views of doctors and patients alike.

Posterior semicircular canal occlusion for intractable benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is most often a self-limited disorder arising from the posterior semicircular canal of the undermost ear in the Hallpike position. Some individuals with this disorder have severe and protracted symptoms requiring more than expectant therapy. We describe two patients with intractable BPPV and profound sensorineural hearing loss in the affected ear treated by transmastoid posterior semicircular canal occlusion. Postoperatively, both were relieved of their BPPV and demonstrated preserved lateral semicircular canal function as measured by electronystagmography. We feel this new procedure provides a simpler and possibly safer alternative to singular neurectomy and should be given future consideration in the treatment of intractable BPPV in a normal-hearing ear.

Bilateral semicircular canal aplasia with near-normal cochlear development. Two case reports.

Congenital malformations of the vestibular labyrinth (pars superior) are rare. We present two patients with computed tomographic findings of bilateral semicircular canal aplasia with normal or near-normal cochleas. Initial bone conduction thresholds were within normal limits, although both patients had significant conductive hearing losses due to congenital middle ear malformations. Bithermal caloric responses were absent in both. To our knowledge these are the first reports of vestibular aplasia concomitant with normal or near-normal cochlear development. These findings conflict with conventional hypotheses that state that inner ear malformations result from arrested development during the normal stages of inner ear embryogenesis.

Chronic perilymph fistula in the guinea pig with implications in the human.

To improve understanding of the pathophysiology of perilymph fistulas, a predictable animal model of a chronic fistula was developed. Our findings suggest that guinea pig fistulas do not remain patent for prolonged periods. By extrapolating these findings to humans, we postulate that the symptoms and signs of perilymph fistula are possibly due not to one prolonged constant fistula, but rather a series of "blowouts" from an inherent congenital or posttraumatic weak spot in either the round or oval window. We feel that a diagnosis of perilymph fistula must be considered in any patient presenting with a Meniere's-like symptom set concomitant with a congenital inner ear deformity or a history of inner ear trauma.

Particle repositioning maneuver for benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo is a common, most often self-limited, vestibular end organ disorder that in some cases may be quite disabling. Recent evidence suggests that some, if not most, cases result from free-floating posterior semicircular canal endolymph particles. We postulate that the particle repositioning maneuver displaces these particles from the posterior canal through the common crus into the utricle, where they no longer induce pathologic responses. Our report focuses on 38 consecutive patients treated with this simple bedside technique during a 10-month period. On follow-up, 26 patients (68.4%) were free of disease, 4 (10.5%) were significantly improved, 4(10.5%) remained unchanged, and 4(10.5%) were lost to follow-up. Of the 4 patients who remained unchanged, 2 underwent successful posterior semicircular canal occlusions. The direction of the nystagmus during the second stage of the maneuver appears important in predicting the efficacy, with reversal of nystagmus denoting a poor response. These findings provide additional insight into the pathophysiology of this disorder.

Comparative perilymph permeability of cephalosporins and its significance in the treatment and prevention of suppurative labyrinthitis.

Cephalosporins are nonototoxic antibiotics that provide excellent coverage for almost all bacteria that can cause suppurative labyrinthitis. In this study we performed comparative perilymph permeability determinations of the three cephalosporins that we deemed to have the most clinical potential in these varied situations. Perilymph pharmacokinetic profiles were established for ceftazidime, cefuroxime, and cefotaxime and its metabolite desacetylcefotaxime in 36 guinea pigs by using the technique of high-performance liquid chromatography. At 1, 2, 3, 4, and 6 hours after intravenous administration of the three cephalosporins at a dose of 100 mg/kg of body weight, ceftazidime consistently exhibited the highest perilymph concentration. Desacetylcefotaxime showed the next highest capacity for penetration into perilymph. Keeping in mind that the choice of drug for the treatment of suppurative labyrinthitis should be based foremost on culture and sensitivity studies, we consider ceftazidime to be the first-line agent for treatment and prevention of both meningogenic labyrinthitis and labyrinthitis complicating acute or chronic otitis media.

Aerodynamic assessment of the speech of adults undergoing multichannel cochlear implantation.

This investigation was designed to evaluate the aerodynamic characteristics of the speech of adult multichannel cochlear implant (Nucleus, 21-channel) recipients. Five adults with an acquired profound sensorineural hearing loss were tested before implantation, immediately following implantation, and 3, 6, 9, and 12 months after implantation. A commercially available computerized pressure-flow instrumentation system was employed to assess the respiratory, laryngeal, velopharyngeal, and oral articulatory subsystems of speech of the implantees. The results of the investigation indicated 1) a slight increase in airflow rate values for sustained vowel /a/phonation after implantation, 2) a slight increase in duration of sustained vowel phonation from the preimplant period to the last postimplant period, 3) an increase in laryngeal airway resistance after implantation that resulted from a larger increase in estimated transglottal pressure than in transglottal airflow, 4) maintenance of normal velopharyngeal closure in oral-nasal contrastive contexts, and 5) slight increases in oral orifice area for fricative syllable utterances following implantation. Individual strategies for coordinated control of the speech mechanism appear to be potent variables to consider when assessing speech production.

Effectiveness of an intensive speech perception training program for adult cochlear implant recipients.

A staggered multiple baseline single-subject experimental design was used to assess the effectiveness of a postimplant intensive aural rehabilitation program. Four adults with an acquired profound hearing loss were provided with a Nucleus 22-channel cochlear implant. The subjects completed a speech perception test protocol once before their cochlear implant operation and at 3-month intervals for a period of 12 months postimplantation. Each subject participated in a 12-week postimplant intensive aural rehabilitation program. A comparison of the prerehabilitation and postrehabilitation results failed to reveal any systematic improvements in performance on the speech perception tests that could be attributed unequivocally to the aural rehabilitation program.

Middle cranial fossa acoustic neuroma excision: results and complications.

The middle cranial fossa surgical approach has been used for the removal of acoustic neuromas in 43 patients at the University of Iowa since 1974. Hearing was maintained in 50% of patients with tumors 1.5 cm or less outside the porus acusticus. Postoperative hearing, facial nerve function, and complications were similar to reports using the suboccipital or retrosigmoid approach to preserve hearing for this size tumor. The character of the tumor appears to dictate the postoperative outcome rather than the surgical approach.