Anterior subannular T-tube for prolonged middle ear ventilation during tympanoplasty: evaluation of efficacy and complications.

OBJECTIVE: We previously described the use of anterior subannular T-tubes (n = 20) for long-term middle ear ventilation. In the current study, we examine a larger patient population (n = 38) and a longer follow-up interval (average >2 years) to evaluate the efficacy and safety of anterior subannular tympanostomy. STUDY DESIGN: Retrospective nonrandomized case review. SETTING: Tertiary referral hospital. PATIENTS: Our series consisted of 38 consecutive patients with a diagnosis of eustachian tube dysfunction, adhesive otitis media, or chronic otitis media with a perforation who underwent a tympanoplasty. INTERVENTION: A subannular T-tube was placed anteriorly at the time of tympanoplasty to provide long-term middle ear ventilation. MAIN OUTCOME MEASURES: The main outcomes of this study are tube position, tube patency, and middle ear ventilation. In addition, hearing was evaluated both preoperatively and postoperatively and any complications were noted. RESULTS: There were 38 patients and 38 ears that received an anterior subannular T-tube at the time of tympanoplasty. The study group consisted of 24 female patients and 14 male patents with a median age of 36 years (range, 10-75 yr). All 38 patients had eustachian tube dysfunction, 22 had adhesive otitis media, 23 had chronic otitis media, 13 had a cholesteatoma, 11 had tympanic membrane perforations, and 3 patients had a cleft palate. All patients underwent tympanoplasty. Eighteen patients had a concomitant ossiculoplasty and 7 had a mastoidectomy. Follow-up ranged from 1 month to 48 months (average, 26 mo). Three tubes had extruded within 2 years, in 1 case resulting in a persistent perforation. Postoperative complications included 1 patient with a partially extruded prosthesis, 2 patients with tipped prosthesis and persistent tympanic membrane retraction, and 1 patient with a plugged tube. All other tubes were patent and showed no evidence of migration. Furthermore, there were no cases of anterior canal blunting or ingrowth of epithelium around the tube. CONCLUSION: Anterior subannular tympanostomy is a safe and effective method for long-term middle ear ventilation in patients with chronic eustachian tube dysfunction.

Clinical experience with a surgical approach to hydrops.

This work was based upon the need to look at the role of surgical intervention in cases of presumed hydrops encountered in usual medical practice. A retrospective cohort study of 292 consecutive cases diagnosed as Meniere's disease was used to identify subjects severely enough affected to elect surgical relief. Two nested case-control design studies were subsequently conducted: one to compare surgical failures (4 cases) with successes (15 controls); and the other to compare the surgical group (19 cases) with a uniform random sample of all presenting Meniere's disease cases (10 controls). These data suggest the following testable hypotheses: (1) the younger the age of onset, the higher the probability that surgical intervention will be required to control episodic vertigo; (2) the younger the age of onset, the higher the probability of the failure of nondestructive surgery; and (3) patients destined for surgical intervention are likely to require at least twice as much office-based medical care as the general group of presenting Meniere's patients. A biological question arising from these data is, Does age influence the putative homeostatic pathophysiology implicated in hydrops?

Tutorials in clinical research: part III. Selecting a research approach to best answer a clinical question.

OBJECTIVE: This is the third in a series of sequential "Tutorials in Clinical Research." The objectives of this specific report are to enable the reader to rapidly dissect a clinical question or article to efficiently determine what critical mass of information is required to answer the question and what study design is likely to produce the answer. STUDY DESIGN: Tutorial. METHODS: The authors met weekly for 3 months exploring clinical problems and systematically recording the logic and procedural pathways from multiple clinical questions to the selection of proper research approaches. The basic elements required to understand the processes of selection were catalogued and field tested, and a report was produced to define and explain these elements. RESULTS: Fundamental to a research approach is the assembly of subjects and the allocation of exposures. An algorithm leading to the selection of an approach is presented. The report is organized into three parts. The tables serve as a rapid reference section. The initial two-part narrative explains the process of approach selection. The examples section illustrates the application of the selection algorithm. CONCLUSIONS: Selecting the proper research approach has six steps: the question, logic and ethics,identification of variables, data display considerations, original data source considerations, and selection of prototypical approaches for assembly of subjects. Field tests of this approach consistently demonstrated its utility.

Building the powerful 10-minute office visit: Part II. Beginning a critical literature review.

OBJECTIVE: This is the second part in a series of sequential Tutorials in Clinical Research. The objective of this tutorial is to introduce methods of searching the vast stores of information now available, to review some of the computer resources available, to reintroduce the concept of an a priori design for the search, and to reveal the need for assessment of the clinical importance and validity of each pertinent article found. STUDY DESIGN: Tutorial. METHODS: An open working group has been formed with the specific aim of surveying and translating the large volume of complex information on research design and statistics into easily understood, useable, and non-threatening tutorials for the busy practitioner. The hypotheses under which this work is conducted are highly intelligent, but extremely busy, surgeons are interested in evidence-based medicine and will increase personal participation in critical reading of the literature, pending an expanded familiarity with clinical research design and statistics. RESULTS: Available resources for literature searching, methods of quick personal overviews, and quick question-specific reviews are discussed. Additionally, the methods, with examples, of beginning a critical literature review are presented. CONCLUSIONS: Rapid, personal, critical literature review requires succinct formulation of the question, efficient search for the best available evidence, and critical appraisal of the pertinent individual articles to determine if sufficient evidence exists to support a clinical contention.

Rapid simultaneous comparison system for subjective grading scales grading scales for facial paralysis.

OBJECTIVE: The senior authors developed a computer-assisted rapid, simultaneous comparison system for nine international grading scales for facial paralysis. The purpose of this study is to present the system and to compare the agreement of hand-performed House-Brackmann and Sunnybrook scales, two frequently used scales herein taken as the concurrent criterion test standards, with those like scales done simultaneously in the computed system. STUDY DESIGN: The study design was a prospective concurrent criterion validity study. Test-retest reliability and interobserver agreement were assessed using the kappa statistic (k) for ordinal data and the intraclass correlation coefficient (ICC) for semidimensional data. SETTING: The study was conducted at a university practice. PATIENTS: Ten consecutive consenting subjects with varying degrees of facial paralysis were studied. INTERVENTION: Each subject was measured, in random order, twice by each method by each of two independent observers. MAIN OUTCOME MEASURES: House-Brackmann score, Sunnybrook score, and like-scale scores done simultaneously in the computed system were measured. RESULTS: Agreement between the computed system and hand-performed criterion standards was equal to each scale compared against itself; for the House-Brackmann, agreement was moderate (k = 0.554); for the Sunnybrook, agreement was excellent (ICC = 0.976). CONCLUSIONS: The computed system has the advantage of allowing an examiner to view a rapid, simultaneous display of multiple grading scale scores at a keystroke from one clinical assessment input, obviating the labor of repeating measures by hand.

In vivo measures of cochlear length and insertion depth of nucleus cochlear implant electrode arrays.

Three-dimensional cochlear canal lengths, electrode array intracochlear insertion depths, and characteristic frequency ranges were estimated for 20 Nucleus implant recipients on the basis of in vivo computed tomography (CT) scans. Ultra-high resolution images were reconstructed from spiral CT data with 0.1-mm slicing and expanded attenuation scales. Canal length estimates (mean 33.01 mm; SD 2.31) were consistent with previous findings for normal human temporal bones. Intracochlear array insertion depths estimated by 3-dimensional (3-D) spiral calculations (mean 20.19 mm; SD 2.86) and by a computerized array tracking algorithm (mean 20.36 mm; SD 2.66) were not significantly different. Estimates from surgical observations were significantly longer (mean 21.03 mm; SD 2.31) because array compressions were not detectable. Characteristic frequencies at apical electrodes estimated from Greenwood's equations ranged from 387 Hz to 2,596 Hz. The results show that significant variations in cochlear anatomy and array distribution among implant patients that may impact implant performance can be reliably detected and quantified by using in vivo high-resolution CT and 3-D reconstructions.

Validation of objective measures for facial paralysis.

A shift from subjective scales to objective measures of facial paralysis requires physical models against which to validate and calibrate the new objective techniques. The purpose of this report was to demonstrate such a model and to test the capacity of an objective computer system to accurately measure physical change. The physical model consisted of an advancing edge of a spreading gelatin film. The model was measured in submillimeter increments. Concurrent measurements were made using the computed system. Ten trials were conducted. The objective system proved to be exquisitely sensitive (0.03 mm) and highly correlated with the physical criterion model (Pearson's product moment correlation coefficient [r]=0.9849). Sensitive and calibrated objective methods of analysis of facial motion are crucial to the design of clinical trials, clinical studies of nerve regeneration, and comparisons of reanimation techniques.

Patterns of facial nerve synkinesis.

Facial nerve synkinesis is an extremely distressing sequela of facial paralysis, and its prevention and treatment are less than adequate. Improved therapeutic interventions await better understanding of its pathogenesis. In this study, 11 patients with synkinesis and 11 normal control subjects were quantitatively assessed using a new computer-assisted, motion-sensitive system. Two additional, informative cases presenting at the completion of the study are also briefly reported. The observed synkinetic patterns appear predictable and nonrandom. In addition, these observations tend to raise doubts that the aberrant fiber regeneration hypothesis is the sole explanation of synkinesis. They further implicate facial nuclear hyperexcitability as an explanation in at least some cases of synkinesis. Understanding these patterns enhances clinical detection and evaluation and may lead to a better knowledge of the fundamental pathophysiology of synkinesis and its prevention.

Quantitative assessment of the variation within grades of facial paralysis.

A completely objective, unambiguous outcome measure of facial function is now available. A new automated computer-assisted clinimetric system combines the crucial detection capabilities of the human observer and the unique capacity of the computer to quantify the image light reflectance difference observed during facial expression. The new system was applied to 27 patients with a variety of diseases affecting the facial nerve. All subjects could be individually and objectively ranked, and disease-specific profiles could be constructed. These tasks are not possible with the House-Brackmann scale, because of the wide variation within grades and the ambiguity between grades. With the automated objective, unambiguous outcome measure, it may be possible to define individual case progression, recovery, and outcome over the course of disease.

Defining functional limitation, disability, and societal limitations in patients with facial paresis: initial pilot questionnaire.

Experiences with patients with facial paralysis over the last 25 years and recent efforts to develop objective measures of paresis and synkinesis led us to three hypotheses: (a) dysfunction in certain regions of the face is more disturbing than that in others, (b) there are major psychosocial impacts of facial paralysis, and (c) the impact of facial paralysis is underestimated. An initial questionnaire of 10 open-ended items was submitted to 11 subjects stabilized after acoustic tumor resection. Responses were tabulated qualitatively, and frequency counts were made of responses. These results show that the region of the face that is most disturbing is the mouth; however, early in the time course of paralysis, the eye is most disturbing. Synkinesis above the eye is ultimately more disturbing than paresis in that region, and it may worsen. Major psychosocial impacts of paralysis appear common and underestimated. These pilot data qualitatively support the hypotheses.

Computer-assisted clinimetric tool for the study of facial expression: a pilot validity study.

Clinimetrics is the measurement of clinical phenomena; more specifically, it is mensuration, the act of acquiring and labeling basic raw data that is used to describe or measure symptoms, signs, and other distinctly clinical phenomena. Over the last 5 years, a new computer method for measuring facial expression has been developed. Refinement and validation of this technique are necessary before clinical applications are appropriate. Four hundred fifty data points from two human observers and the computed method were compared with one another by using indices of location, dispersion, and association within the framework of the logical construct of validity. These results suggest that the computed method is valid. This new method may be nearly ready for clinical applications as a primary or adjunctive clinimetric tool.

Use of distortion product otoacoustic emissions to assess middle ear transducers in rhesus monkeys.

Distortion product otoacoustic emissions (DPOAEs) can provide an objective and noninvasive assessment of the peripheral cochlear function. Auditory brainstem responses measured from implanted rhesus monkeys have shown that middle ear transducers, coupled directly to the incus, are capable of delivering the signals to the central auditory system. The DPOAEs were used as a noninvasive method of assessing the frequency specificity of this mechanical transduction. In two rhesus monkeys implanted with the middle ear transducers, one primary stimulating tone (f1) was presented acoustically, and the other primary tone (f2) was presented by the transducer, which converted the signal into a mechanical motion of the probe tip attached to the body of the incus. The nonlinear characteristics of the cochlea produced the distortion product responses at the expected frequencies (2f1 - f2). This demonstrates the fidelity of the middle ear implant signal transduction in vivo. The DPOAEs also indicate minimal changes in the post-implant middle ear transmission. This study demonstrates that the DPOAEs can be used to assess the function of implanted middle ear transducers objectively and noninvasively.

Four cases of acoustic neuromas with normal hearing.

In 95 percent of the cases, patients with acoustic neuromas will have some magnitude of hearing loss in the affected ear. This paper reports on four patients who had acoustic neuromas and normal hearing. Results from the case history, audiometric evaluation, auditory brainstem response (ABR), electroneurography (ENOG), and vestibular evaluation are reported for each patient. For all patients, the presence of unilateral tinnitus was the most common complaint. Audiologically, elevated or absent acoustic reflex thresholds and abnormal ABR findings were the most powerful diagnostic tools.

Computer-stimulated test fitting of an implantable hearing aid using implantable hearing aid using three-dimensional CT scans of the temporal bone: preliminary study.

In preparation for future implantation of the implantable middle ear transducer in patients, a method was sought for preoperatively test fitting a model of the device, using computer generated three-dimensional (3-D) temporal bone images derived from spiral computed tomography (CT) data. A 3-D model of the implantable middle ear transducer was designed using NIH Image software on a Macintosh computer. High resolution human temporal bone CT scans were obtained using a spiral CT scanner (Siemens Somatom Plus S). The 3-D transducer model was superimposed onto 3-D reconstructions of the temporal bone using ANALYZE software on a computer graphics workstation (Sun SPARCstation 10), showing the transducer "implanted" in the temporal bone. Measurements were validated using a cadaver temporal bone. This process produced images demonstrating the "fit" of the current transducer design in the mastoid region of the adult temporal bone. It permitted assessment of the proximity of surrounding structures such as the external auditory meatus, dura, or sigmoid sinus. Preliminary cadaver validation measurements confirmed the accuracy of this method. Three-dimensional CT is a feasible method for preoperative planning of the surgical implantation of devices in the temporal bone. This method of 3-D test fitting will be used in the future to determine optimum orientation and size limitations for human implantable devices.

Variations in maximum amplitude of facial expressions between and within normal subjects.

Definitive proof of efficacy of preventions and therapeutic interventions, and of risk factors in lower motor neuron facial paralyses continue to be confounded by the lack of repeatable quantitative measures of outcome. Clinical and research experience with human facial expression repeatedly demonstrates wide variations between subjects. To our knowledge, little information is available to isolate and describe the differences in dynamic facial expression between and within normal subjects. The purpose of this study is to use a statistical model to analyze the components of the observed variations of maximum amplitude measurement of image change during normal human subject facial expressions. Seventeen consecutive normal adult human subjects with no current or past evidence of facial nerve or ear disease were studied. Videotapes of command facial expressions were taken using specific and standardized conditions. The tapes were analyzed using a new computer-assisted image-change analysis program capable of generating dimensional data for the maximum amplitude of expression. These data were statistically analyzed using a General Linear Model with Nested variables to isolate and define component variations and errors. The General Linear Model predicted 88% of the observed total variation (p < 0.05).* A model performance this high suggests that most of the important independent variables were being studied. The major component of the variations was the difference among (between) subjects. Seventy-seven percent of the predicted variation was due to this difference (p < 0.05). Little of the variation (1%) seemed to be within-subjects. Test-retest agreement was acceptable.(ABSTRACT TRUNCATED AT 250 WORDS)

Literature review articles as a research form.

The purpose of this article has been to outline the JOURNAL format, to present some methodologic suggestions for this new section, and, hopefully, to excite and challenge authors to this form of research. Fundamental to a quality overview are A PRIORI EXPLICIT CRITERIA for each component of the review process. Details of what this means have been presented. The length of the review will depend on the objectives; however, approximately 20 double-spaced manuscript pages (about eight published pages) should be considered close to maximal for a readable review. References may be too extensive for full publication; one way to manage this is to choose about 50 or less key references for publication and suggest to the readers that a full bibliography is available, upon request, from the corresponding author. We hope this new section will be exciting and will be of benefit.

Induction of heat shock protein in interdental cells by hyperthermia.

The effect of hyperthermia on induction of the 72 kilodalton (kDa) heat shock protein (HSP72) was examined in interdental cells of the guinea pig cochlea. After being immersed in a water bath of either normal body temperature (37 degrees C, control condition) or 43 degrees C (hyperthermic condition), animals were killed either 0, 1, 2, 6, or 18 hours later. Cochlear sections were incubated with a monoclonal antibody raised against HSP72 and relative staining densities were quantified with a light microscopic image analysis system. Optical densities of the interdental cell region of animals receiving hyperthermia treatment were significantly greater than those of animals in the control group. Further analysis revealed that levels of HSP72 immunoreactivity began increasing by 1 hour after hyperthermia and continued to increase thereafter, to reach maximal levels at 6 hours. The maximal levels were maintained for the rest of the experiment--18 hours. The results indicate that hyperthermia leads to an increase in the synthesis of HSP72 in guinea pig interdental cells.