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.

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.

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.

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.

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.

Intratympanic gentamicin titration therapy for intractable Meniere's disease

OBJECTIVE

This study aimed to assess the efficacy and morbidity of intratympanic gentamicin titration therapy on patients with intractable unilateral Meniere's disease.

STUDY DESIGN

The study design was a retrospective chart review and patient interviews.

SETTING

The study was conducted at a tertiary referral ambulatory dizziness clinic at the London Health Sciences Centre, University Campus, from July 1992 to June 1997.

INTERVENTION

Eighty-three patients received weekly intratympanic gentamicin injections in their diseased ear. Treatments were terminated after four injections or sooner if patients met clinical or audiologic criteria. Sixty-eight patients were available for detailed follow-up.

MAIN OUTCOME MEASURES

Vertigo frequency, hearing status, personal disability ratings, tinnitus level, and caloric responses before and after gentamicin therapy were measured.

RESULTS

Eighty-four percent of patients showed complete, and an additional 6% showed substantial, vertigo control. At 24 months, 17% of patients demonstrated a clinically significant (10-dB) reduction in hearing, but 26% showed a significant hearing improvement. Overall, the group showed no combined statistically significant changes in any of the hearing parameters. No patients had an "extreme" drop in hearing (>30 dB).

CONCLUSIONS

Intratympanic gentamicin titration therapy provides excellent vertigo control with a low incidence of hearing loss.

Molecular analysis of the POU3F4 gene in patients with clinical and radiographic evidence of X-linked mixed deafness with perilymphatic gusher

The molecular defect in some patients with X-linked mixed deafness with perilymphatic gusher at stapes surgery (DFN3) was recently attributed to mutations in the POU3F4 gene. In this manuscript we describe the molecular analysis of the POU3F4 gene in 5 patients with clinical and radiographic evidence of DFN3. Novel mutations were found in 2 of the 5 patients analyzed, while 3 had an entirely normal protein coding sequence. The fact that 3 of the 5 patients with clinical histories and radiographic abnormalities characteristic of X-linked mixed deafness with perilymphatic gusher displayed normal POU3F4 gene sequences supports the possibility that not all patients with the characteristic phenotype have involvement of the POU3F4 gene.

Reporting of vestibular patients who are unfit to drive: survey of Canadian otolaryngologists

OBJECTIVES

The objectives of this study were (1) to learn about the concerns and current practices of Canadian otolaryngologists with regard to the reporting of vestibular patients; and (2) to examine the three different reporting mandates in Canada by surveying otolaryngologists in Ontario, Alberta, and British Columbia, and to assess the level of satisfaction with reporting methods.

METHOD

A survey was mailed to all members of the Canadian Society of Otolaryngology-Head and Neck Surgery in Ontario, Alberta, and British Columbia, using a modified version of the "Dillman Total Survey Design Method."

RESULTS

The survey had an overall response rate of 62.8%. Although many respondents have considered reporting vestibular patients (82.2%) and have warned patients not to drive without reporting them (84.2%), only 25.3% actually have. The great majority (91.8%) felt that unfit drivers should be brought to the attention of the transportation authority. There was no consensus of opinion on the best method of reporting, but only 23.3% of those surveyed supported mandatory physician reporting. Ontario otolaryngologists were significantly less satisfied with the fitness-to-drive legislation in their province than were those from Alberta or British Columbia (chi 2 = 22.7, p = .001). Almost three times as many Ontario respondents have actually reported a vestibular patient (chi 2 = 6.7, p = .01).

CONCLUSIONS

The study results suggest that mandatory physician reporting is not a satisfactory method of reporting unfit-to-drive vestibular patients. It is highly recommended that all physicians become familiar with the reporting guidelines in their province or territory and comply with their legal obligations.

Impact of vestibular disorders on fitness to drive: a census of the American Neurotology Society

BACKGROUND

Legislation for reporting unfit-to-drive patients by physicians varies dramatically among U.S. states and Canadian provinces. The impact of vestibular disease on driving safety is not well described in the literature.

OBJECTIVES

(1) to learn more about the critical issues and current practices of neurotologists regarding reporting of vestibular patients and (2) to make recommendations for reporting patients with vestibular disorders.

STUDY DESIGN

A mailed census of members of the American Neurotology Society using a questionnaire based on a modified Dillman Total Design Survey Method.

RESULTS

Most respondents are aware of the potential safety risks of patients who drive with vestibular diseases, most notably those with Tumarkins' attacks. Although many have counselled patients (94%) and considered reporting vestibular patients (75%), few actually have (14%). There was no consensus of opinion on a method of reporting unfit-to-drive patients. Only 18.9% of respondents supported mandatory physician reporting. Respondents who live in states where reporting is not mandatory and who are aware of this fact are (a) more satisfied with their state's legislation (chi 2 = 60.1, p = 0.001) and (b) less likely to report patients who they consider unfit-to-drive (chi 2 = 10.6, p = 0.03).

CONCLUSIONS

In that there is no general consensus amongst respondents and the relative safety risks seem low in comparison to other disorders, at present we do not advocate mandatory reporting of patients with vestibular disorders.

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.

Identification of a hot spot for microdeletions in patients with X-linked deafness type 3 (DFN3) 900 kb proximal to the DFN3 gene POU3F4

Small mutations in the POU domain gene POU3F4 were recently shown to cause X-linked deafness type 3 (DFN3) in nine unrelated males. The POU3F4 gene was found to be located outside four of five deletions associated with DFN3. Two of these deletions were situated more than 400 kb proximal to POU3F4. Employing PCR analysis of sequence tagged sites from this region we initially identified novel deletions in two DFN3 patients. To investigate this chromosomal segment in more detail, we extended a previously established 850 kb cosmid contig in the centromeric direction to a total size of 1500 kb. Cosmids from this contig were hybridized to DNA of 11 unrelated males with DFN3. In two patients, we identified deletions encompassing the POU3F4 gene and variably sized segments of Xq21.1. In six of the nine remaining patients which lacked mutations in the POU3F4 gene, smaller deletions were identified which, with one exception, overlap in a 8 kb segment 900 kb proximal to the POU3F4 gene. In one patient, we identified several small deletions in the vicinity of the 8 kb DNA segment. Together, deletions account for 56% (13/23) of all known DFN3 mutations, most (10/13) of which do not encompass the POU3F4 gene. The combined molecular data suggest that the deletion hot spot region in Xq21.1 contains another DFN3 gene or, alternatively, a sequence element involved in transcriptional regulation of POU3F4.

Update on posterior canal occlusion for benign paroxysmal positional vertigo

Most, if not all, cases of BPPV appear to result from free-floating posterior semicircular canal endolymph particles. Particle repositioning alleviates symptoms and findings in the vast majority of patients. For the small intractable group of nonresponders, posterior semicircular canal occlusion remains a safe and highly efficacious procedure. This new technique has also paved the way for even newer and most invasive inner ear procedures.

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.

Intratympanic gentamicin therapy for Menière's disease: preliminary comparison of two regimens

Selective chemical ablation of the vestibular endorgan using intratympanic gentamicin is an effective and safe treatment for incapacitating vertigo in patients with unilateral Menière's disease. A major risk of the treatment is sensorineural hearing loss. In this retrospective study, two different regimens of intratympanic gentamicin therapy are compared. In one group, multiple daily doses were administered in hospital over 4 consecutive days. The other group received single treatments at weekly intervals on an outpatient basis, following pretreatment audiometric and clinical assessment. We adopted the weekly protocol to theoretically reduce the incidence of treatment-related hearing loss by a more controlled titration of dosing. Preliminary results indicate that the weekly interval treatment offers equivalent efficacy with considerably less risk to hearing.

Pharmacokinetic profiles of ceftazidime in cochlear perilymph, cerebrospinal fluid and plasma: a high-performance liquid chromatographic study

A pharmacokinetic profile of the antibiotic ceftazidime was established for perilymph, cerbrospinal fluid (CSF) and plasma in 12 guinea pigs using the technique of high-performance liquid chromatography. The mean peak levels of 13.35 mg/l in perilymph and 140.54 mg/l in plasma were reached within the first hour after a single intravenous dose of 100 mg/kg. The CSF mean peak level of 5.36 mg/l, however, was not attained until 3 h after injection. The half-life was about 4 h in perilymph, more than 6 h in CSF and less than 2 h in plasma. Six hours following administration, the perilymph drug concentration remained higher than the plasma level. The study indicates that ceftazidime has excellent penetration into perilymph. It is concluded that ceftazidime should be a very useful agent in the treatment of bacterial labyrinthitis caused by susceptible organisms.

Teratoma of the middle ear

Teratomas are true tumours derived from ectoderm, mesoderm, and endoderm, which differentiate into identifiable tissues and organs. Teratomas of the temporal bone are exceedingly rare, but should be considered in the differential diagnosis of a temporal bone mass at birth or during childhood. We present a case of a temporal bone teratoma involving the middle ear, judge the imaging capabilities of computed tomography in the diagnosis, and review the literature.

Acoustic neuroma management: a six-year review

The purpose of this investigation is to review the outcome of 83 consecutive acoustic neuroma patients, managed solely or in part by the Department of Otolaryngology at University Hospital, London, Ontario, over a 6-year period (1987 to 1993). The majority of patients underwent operative intervention, utilizing the middle cranial fossa, suboccipital, or most commonly, the translabyrinthine approach depending on the tumour size and level of residual hearing. Demographic, preoperative, intraoperative, and postoperative data are analyzed including complications of surgery. As well, we report on our experience with the use of fibrin glue in the dural closure following translabyrinthine resections and the resultant impact on the postoperative CSF leak rate. Overall, our results and complications are comparable to other large acoustic neuroma series in the literature. In addition, we feel that further study is merited in the use of fibrin glue in dural repair and its relationship to postoperative cerebrospinal fluid fistula.

Cefuroxime: pharmacokinetics in cochlear perilymph, cerebrospinal fluid, and plasma

Very little is known about the permeability of contemporary antibiotics through the blood:perilymph barrier. In this study, we measure the concentration of cefuroxime in perilymph, cerebrospinal fluid (CSF), and plasma in the guinea pig following intravenous administration by using the technique of high-performance liquid chromatography. The results of our study demonstrate a higher permeability of cefuroxime in perilymph than in CSF with a similar concentration profile over time in both fluids. This suggests that each of the two fluid compartments has its own drug barrier, with little or no free passage from CSF to perilymph. On the basis of these experimental findings, we feel that cefuroxime has considerable potential as an antibacterial agent for the treatment or prevention of bacterial labyrinthitis.

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.

A cure for benign positional vertigo

Benign positional vertigo is a common clinical entity encountered in any dizzy clinic. It is easily diagnosed on the basis of historical information and a positive Dix-Hallpike position test. The available evidence suggests that this condition is due to involvement of the posterior semicircular canal. The pathophysiology of this condition can be explained theoretically on the basis of free-floating particles within the endolymph of the posterior semicircular canal that move under the influence of gravity with certain provocative positional changes. Based on this theoretical model, a variety of particle-repositioning manoeuvres have been developed that attempt to relocate the loose particles from the posterior semicircular canal to the utricular sac. If the particles are kept in the utricular sac for a period of 48 h by maintaining the patient in an upright position, the clinical symptoms are relieved in a high proportion of patients. If the manoeuvre is unsuccessful on a first attempt, or if the benign positional vertigo recurs at a later date, the condition can usually be relieved by a second manoeuvre. Bilateral benign positional vertigo can be treated by performing a manoeuvre on one side followed by a manoeuvre on the other side at a later date. On occasion, posterior canal benign positional vertigo is converted to horizontal canal benign positional vertigo, but this subsides readily within the 48-h post-manoeuvre period.

Cochlear implants and otitis media: considerations in two cleft palate patients

Cochlear implantation is a safe and effective means of rehabilitating profound sensory deafness. The implications of coincident chronic middle ear disease upon the operative procedure and auditory results have received little attention in the literature. We describe two patients, each with congenital cleft lip and palate and secondary chronic otitis media with effusion, who received multichannel cochlear implants following bacterial meningitis. One patient (a three-year-old girl) was implanted in the standard fashion while the other (a 38-year-old-man) underwent middle ear and mastoid obliteration. Our findings suggest that chronic otitis media should not be a deterrent to cochlear implantation.

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.

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.

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.

Medial meatal fibrosis: the University of Western Ontario experience

Medial meatal fibrosis is an uncommon but surgically treatable cause of conductive hearing loss. A review of 10 years experience with this entity at The University of Western Ontario revealed a total of 15 cases involving nine patients. Each of them was treated by one of four otologists. This disease may arise from either recurring or chronic infection or from chronic dermatitis, and it frequently presents with bilateral involvement. It may occur at virtually any age, and to our knowledge, this series includes the first cases of this disease to be described in children. The medical and surgical management of this condition is described in detail and the results are summarized.

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.

Tuberculous mastoiditis

The prevalence of Mycobacterium tuberculosis is increasing due in part to the rising incidence of immunocompromised hosts. Although Mycobacterium tuberculosis is a well-documented pathogen in otitis media and mastoiditis, its extremely low incidence often precludes consideration when treating these infections. This is especially true when concomitant pulmonary symptoms are absent. We describe two patients who initially presented after prolonged unsuccessful medical and surgical therapy for chronic mastoiditis. In both, the diagnosis of Mycobacterium tuberculosis mastoiditis was made after the onset of complete facial paralysis. On subsequent investigations, one had an asymptomatic pulmonary focus while the other was felt to have primary mastoid disease. Both patients had normal immunological profiles. This report underscores the importance of considering a tuberculous infection in all cases of otitis media and mastoiditis which do not initially respond to conventional antibacterial therapy. This holds true in both immunocompromised and immunocompetent hosts. Early diagnosis with prompt institution of antituberculous therapy is essential to avoid facial nerve paralysis and other grave complications.

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.

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.

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.

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.

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.

Vascular relationships of the vestibulocochlear nerve on magnetic resonance imaging

Vascular compression of the vestibulocochlear (VIIIth) nerve may cause constant or recurrent positional vertigo, tinnitus, and/or hearing loss. At present the diagnosis is based upon history, physical findings, audiologic assessment, vestibular function testing, and auditory brainstem evoked responses. Delineation of the vascular and neural anatomy within the cerebellopontine angle (CPA) has not been part of the preoperative assessment. We recently treated a patient demonstrating the clinical features of this syndrome. A magnetic resonance imaging (MRI) study revealed a vascular loop of the anterior inferior cerebellar artery intimately associated with the VIIIth nerve at the porus acusticus. To better define the significance of this finding, we retrospectively reviewed the CPA neurovascular anatomy of 100 (200 sides) otherwise normal MRI scans performed for unrelated disorders. Vessels were identified on 59.9 percent of sides while nerves were seen on 40 percent of sides. Contact between vessel and nerve occurred on 12.5 percent of sides and when both nerve and vessels were seen concurrently, they were in contact 50 percent of the time. These findings may preclude the use of MRI as the definitive diagnostic test in the preoperative assessment of vascular VIIIth nerve compression.

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.

Rotatory recovery nystagmus: an important localizing sign in endolymphatic hydrops

Localizing the ear responsible for vertigo attacks may be exceedingly difficult in patients with delayed endolymphatic hydrops, vestibular Ménière's disease or bilateral Ménière's disease. This has important clinical implications when planning operative treatment. We present a case of delayed endolymphatic hydrops to exemplify these difficulties and demonstrate the localizing value of recovery nystagmus. We stress the importance when possible of monitoring patients with endolymphatic hydrops for recovery nystagmus during acute vertigo attacks. Monitoring should include direct eye observation as pure rotatory nystagmus escapes detection on electronystagmography.

Mycotic sinusitis: a management protocol

There has been a recent increase in reported cases of fungal sinusitis. This may be due to better awareness and improved histopathological methods as well as increasing numbers of immunologically compromised patients. We present a case of mycotic sinusitis in an immunocompetent individual to emphasize the clinical features of this disease. The pathology and microbiology are analyzed and a management protocol is discussed.

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.

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.

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.

Effect on brainstem auditory evoked responses of posterior semicircular canal occlusion in guinea pigs

The site of origin of benign paroxysmal positional vertigo is the posterior semicircular canal and when persistent, the condition is known as cupulolithiasis. Singular neurectomy is the current procedure of choice for the treatment of incapacitating cupulolithiasis. The neurectomy is difficult to learn and carries a significant risk of hearing loss. An alternative procedure, whereby the posterior canal is occluded, is discussed. This was performed on 11 guinea pigs and the effect on hearing was measured using brainstem evoked audiometry. Eight animals showed no hearing loss while the other three had a mild to moderate loss of hearing due to intra-operative complications. The effect of canal plugging on hearing compares favorably with the hearing results obtained with singular neurectomy. Posterior semicircular canal occlusion is suggested as a safer and technically easier treatment for incapacitating cupulolithiasis.