Jason M. Hanson

Management of stage II (T2N0M0) glottic carcinoma by radiotherapy and conservation surgery.

The best therapeutic approach for the treatment of stage II (T2N0M0) glottic carcinoma is controversial.

Posturographic Evidence of Nonorganic Sway Patterns in Normal Subjects, Patients, and Suspected Malingerers

During the last 10 years, computerized dynamic posturography has yielded various patterns of sway on the sensory organization test and the motor control test that have been associated with a variety of organic balance disorders. Some aspects of performance during computerized dynamic posturography, however, are under conscious control. Voluntary movements not indicative of physiologic response to balance system stimulation can also affect computerized dynamic posturography results. Quantification of nonorganic or “aphysiologic” response patterns in normal subjects, patients, and suspected malingerers is crucial to justify use of computerized dynamic posturography for identification of physiologically inconsistent results. For this purpose the computerized dynamic posturography records of 122 normal subjects, 347 patients with known or suspected balance disorders, and 72 subjects instructed to feign a balance disturbance were critically evaluated by use of seven measurement criteria, which were postulated as indicating aphysiologic sway. Each criterion was scored with a standard calculation of the raw data in a random, blinded fashion. The results of this multicenter study show that three of the seven criteria are significantly different in the suspected “malingerer” group when compared with either the normal or patient group. The relative strength of each criterion in discerning organic from nonorganic sway provides the examiner with a measure of reliability during platform posture testing. This study demonstrates that computerized dynamic posturography can accurately identify and document nonorganic sway patterns during routine assessment of posture control.

Idiopathic Bilateral Vestibular Loss

We describe the clinical and laboratory features of 13 patients with bilateral loss of peripheral vestibular sensitivity of no known cause. In the office, screening for this condition was possible using illegible e-testing and examination of the patient for refixation saccades after brisk head movements while attempting visual fixation. Diagnosis was confirmed by bilaterally reduced caloric responses (< 20 degrees/second on all 4 caloric irrigations) and abnormally low gain of the vestibulo-ocular reflex on rotational chair testing. The mean age of the patients was 68 years. We noted two patterns of symptom onset: onset associated with vertigo (10 patients) and insidious progressive disequilibrium not associated with vertigo (3 patients). Only 38% of the patients complained of subjective oscillopsia. The subjects performed poorly on platform posturography, particularly when deprived of visual and somatosensory feedback. When associated with vertigo, bilateral vestibular loss may be the result of bilateral sequential vestibular neuritis; when not associated with vertigo, disequilibrium may be caused by slow, symmetrical loss of peripheral function as a result of aging. Although the subjects in this report were elderly, idiopathic bilateral vestibular loss has been reported in patients of all ages.

Interlaboratory variability of rotational chair test results II: analysis of simulated data.

Standardization of rotational chair testing across laboratories has not been achieved because of differences in test protocol and analysis algorithms. The Interlaboratory Rotational Chair Study Group was formed to investigate these differences. Its first study demonstrated significant variability in calculated results using actual patient data files. No estimation of accuracy could be made, however, because the “true” values of response parameters were unknown. In this study we used simulated “patient” data files to further explore the differences among analysis algorithms. We found a high degree of agreement and accuracy across laboratories using automated analysis of high signal-to-noise/low-artifact data for gain, phase, and asymmetry. Variability increased significantly for the lower signal-to-noise ratio/higher artifact files. Operator intervention generally improved accuracy and decreased variability, but there were cases in which operator intervention reduced accuracy. (Otolaryngol Head Neck Surg 2000;122:23–30.)

Manual rotational testing of the vestibulo-ocular reflex

Objectives/Hypothesis Manual whole‐body and head‐on‐body rotational testing of the vestibulo‐ocular reflex (VOR) is comparable to conventional rotary chair methods with and without visual fixation from 0.025 to 1 Hz.

Interlaboratory Variability of Rotational Chair Test Results

Test-retest reliability of rotational chair testing for a single facility has previously been examined by others. The actual data analysis methods, however, have received far less attention. The variety of both hardware and software currently used theoretically may affect the results for a given subject tested at different facilities. The purposes of this study were, first, to quantify the amount of variability in the analysis of Identical raw data files at multiple rotational chair testing facilities by using automated analysis; second, to evaluate the effect of operator intervention on the anaiysis; and third, to identify possible sources of variability. Raw data were collected from 10 normal subjects at 0.05 Hz and 0.5 Hz (50 degrees per second peak velocity). Diskettes containing raw electro-oculogram data files were then distributed to eight participating laboratories for analysis by two methods: (1) using automated analysis algorithms and (2) using the same algorithms but allowing operator intervention into the analysis. Response parameters calculated were gain and phase (re: velocity). The SD of gain values per subject for automated analysis ranged from 0.01 to 0.32 gain units and of phase values from 0.4 to 13.7 degrees. For analysis with operator Intervention, the SD of gain values ranged from 0.02 to 0.10 gain units and of phase values from 0.4 to 4.4 degrees. The difference between automated analysis and analysis with operator intervention was significant for gain calculations (p < 0.02) but not for phase calculations (p > 0.05). This study demonstrates significant variability in automated analysis of rotational chair raw data for gain and phase. Operator intervention into the analysis significantly reduces variability for gain but not for phase.

Prevalence of Nonorganic Sway Patterns in Normal Subjects, Patients, and Suspected Malingerers

the physic;_an evaluating a patient with signs and symptoms suggestive of retrocochlear pathology. Cost-per-tumor analysis reveals a significant expense if standard, full-head magnetic resonance imaging (MRI) is routinely applied in every patient with such findings. Although less expensive, an ABRbased diagnostic scheme risks missing up to 24% of small tumors. This study reviews a 1-year experience with a diagnostic scheme for cerebellopontine angle evaluation on the basis of screening, enhanced MRI. Our imaging protocol includes Tt-weighted, 3-ram contiguous slices through the internal auditory canal and the region of the cerebellopontine angle. Total scanning time is about 11 minutes, with an estimated cost of approximately

Idiopathic Bilateral Vestibular Loss: Diagnosis and Management

300 including contrast. Compared with ABR, screening MRI offers advantages of a near-zero false-negative rate and markedly improved specificity. By el iminat ing the need for follow-up audiometric or electrophysiologic studies, a screening MRI-based diagnostic scheme is actually more effective on a cost-per-tumor basis as well as a cost-per-diagnosis basis. We conclude that a screening MRI-based diagnostic scheme without ABR offers a definitive and cost-effective diagnostic approach for patients with possible retrocochlear pathology.

Stage I (T1 N0 M0) squamous cell carcinoma of the laryngeal glottis : Therapeutic results and voice preservation

Reconstruction of scutal defects following canal wall up mastoidectomies with cartilage remains controversial. Theoretically the cartilage is used to reinforce the scutal defect and thus prevent future retraction pockets and recurrence of cholesteatoma. To evaluate whether cartilage reconstruction of the scutum is useful in our hands, we performed a retrospective chart review of all patients who underwent a canal wall up mastoidectomy from 1980 to 1993 for cholesteatoma. A total of 103 canal wall up mastoidectomies were performed in this time period. Of these 103 mastoidectomies, the scutum was reconstructed with cartilage in 37 cases, whereas in 66 cases the scutum was not reconstructed. Of the 37 patients who underwent reconstruction with cartilage, 66% did not develop further retraction pockets. Of the 33% that did develop a retraction pocket, only one third required further surgery. Of the 66 patients who did not undergo reconstruction, 47% did not develop retraction pockets. Of the 53% who did develop a retraction pocket, one third required further surgery. Age was assessed as a variable but did not seem to change the outcome of these results. Thus it would appear that reconstruction of scutal defects with cartilage may be of some benefit in preventing future retraction pockets and recurrence of cholesteatoma in our hands.