Surgical labyrinthectomy in the older patient.

OBJECTIVE: Ablation of vestibular function is a highly efficacious option in the treatment of disabling vertigo arising from unilateral labyrinthine dysfunction. Regardless of the method used to ablate vestibular function, permanent posttreatment impairment of the balance function will develop in a number of treated patients. Many physicians who are involved in the care of the older patient with episodic vertigo are reluctant to recommend or perform a vestibular ablation procedure, because this treatment may result in permanent disequilibrium, which may be more detrimental to the older patient than the episodic vertigo. This study evaluates the outcome in older patients who underwent unilateral surgical labyrinthine ablation. METHODS: A retrospective analysis was done of the cases of 30 patients, all more than 60 years old, who underwent unilateral vestibular ablation because of disabling episodic vertigo by either transmastoid labyrinthectomy (n=22) or transcanal labyrinthectomy (n=8). RESULTS: Episodic vertigo was controlled in 95.5% of the patients in the transmastoid labyrinthectomy group and in 100% of those in the transcanal labyrinthectomy group. Postoperative imbalance was present in 22.7% of patients in the transmastoid labyrinthectomy group and in 62.5% of those in the transcanal labyrinthectomy group. CONCLUSIONS: Vestibular ablation is a viable option in the treatment of disabling vertigo in the older patient. A transmastoid labyrinthectomy may be preferable to a transcanal labyrinthectomy because the incidence of permanent posttreatment imbalance is less with a transmastoid labyrinthectomy.

Sensorineural hearing loss with delayed onset of vertigo.

Sensorineural hearing loss with delayed onset of vertigo is a syndrome in which episodic vertigo arises in a person who has preexisting unilateral severe-to-profound sensorineural hearing loss. This syndrome has an ipsilateral form in which the vertigo arises from the poorer hearing ear and a contralateral form in which the aural symptoms arise from the better hearing ear. The existence of this syndrome has only been noted within the past two decades. This report details our clinical experience with 17 persons with the ipsilateral form of this disorder. The onset of the vertigo after the occurrence of the hearing loss was quite variable. It ranged from 1 to 60 years after the development of the hearing loss. The hearing loss occurred for several reasons. Most patients had hearing loss due to an unknown cause. The development of the vertigo and the timing of the onset of the vertigo were not related to the cause of the hearing loss. Bithermal caloric testing identified the offending labyrinth in most patients who underwent ablative vestibular surgery. Ablative vestibular surgery was performed in 13 of the 17 persons in this study because of disabling symptoms. In all 13 cases, the episodic vertigo was eliminated. Surgical treatment for sensorineural hearing loss with delayed-onset vertigo, as with all surgery for vertigo, should be based on the severity of the afflicted person's symptoms.

Surgery for vertigo in the nonserviceable hearing ear: transmastoid labyrinthectomy or translabyrinthine vestibular nerve section.

Two of the surgical options that exist for the treatment of disabling vertigo arising from an ear with nonserviceable hearing are a transmastoid labyrinthectomy (TL) and a translabyrinthine vestibular nerve section (TLVNS). The major difference between the two operations is a section of the vestibular nerves with the TLVNS which removes all preganglionic vestibular tissue from the diseased inner ear. It has been inferred that a TLVNS should be the procedure of choice if hearing is not to be spared, because a TL results in an incomplete removal of preganglionic vestibular tissue, and that this remaining tissue might have continued or recurrent physiologic function resulting in further vertigo. The clinical outcome of 58 patients who had either TL or TLVNS for disabling vertigo arising from a nonserviceable hearing ear was investigated with respect to the control of vertigo and the development of postoperative balance dysfunction. The control of vertigo in the TLVNS and TL groups was 100% and 95.3%, respectively. This difference was not statistically significant. There was a tendency for postoperative dysequilibrium to be more frequent in the TLVNS group, but this finding did not reach statistical significance. A TL appears to offer the same benefit as TLVNS in the control of intractable episodic vertigo without the additional risks of TLVNS.

Revision stapedectomy.

The need for revision stapedectomy surgery still exists despite the many changes that have occurred in the surgical technique for the treatment of stapedial otosclerosis over the past 30 years. Sixty-six revision stapes operations were analyzed to determine the causes of failure of previously operated cases of stapedial otosclerosis, and to evaluate the hearing results following a revision stapedectomy. Failure was most often due to erosion of the incus (41%), displacement of the prosthesis from the incus (24%), or migration of the prosthesis from the center portion of the oval window (24%). Postoperative improvement of hearing was observed in 81% of ears operated on for a conductive hearing loss. Closure to within 10 dB, however, occurred in 61%. Two ears suffered a deterioration in the sensorineural hearing level following the revision surgery. Speech discrimination scores following revision surgery were improved in 5% of ears and unchanged in the remainder. Although the overall hearing results are less favorable than those seen in primary stapedectomy, revision stapedectomy surgery should continue to be offered to patients whose primary stapes surgery failed or whose initial good result declined over time.

Ceravital versus plastipore in tympanoplasty: a randomized prospective trial.

The hearing results and extrusion rates for ossicular chain reconstruction using a new material called Ceravital, a bioactive glass ceramic, were compared with those for Plastipore, a porous polyethylene that is our standard for synthetic materials. Our null hypothesis was that the results of the two materials were similar. A Ceravital or a Plastipore prosthesis was randomly assigned to 112 consecutive patients. We had 6-month follow-up on 100 patients and 3-year follow-up on 80 patients. The average air-bone gap at 4,000 Hz was 6 dB less with Plastipore than with Ceravital (p = .036). Patients were twice as likely to have an air-bone gap of 15 dB or less with Plastipore than with Ceravital (40% versus 21%; p = .061). Two of the 38 patients with Ceravital prostheses had a late hearing-result failure due to resorption of the prosthesis material. The materials had similar extrusion rates. We rejected our null hypothesis. The Plastipore group had better hearing results than did the Ceravital group.

The tracheoesophageal diversion and laryngotracheal separation procedures for treatment of intractable aspiration.

Intractable aspiration is a severe and often fatal complication in patients with impaired protective function of the larynx. This problem is usually a result of central nervous system disorders such as cerebrovascular accident, trauma, neoplasms, or degenerative disease. Surgical separation of the upper respiratory tract from the digestive tract can prevent recurrent contamination of the respiratory system in these patients. Two such procedures are the tracheoesophageal diversion procedure and a modification of this operation, the laryngotracheal separation procedure. The Virginia Mason Medical Center experience with these procedures, their indications, technique, and outcome are presented. In addition, cases of successful surgical reversal of the diversion procedures are discussed.

Indications for the tracheoesophageal diversion procedure and the laryngotracheal separation procedure.

Impaired protective function of the larynx can lead to intractable aspiration, a severe and potentially fatal disorder. If medical therapy fails to prevent intractable aspiration, surgical separation of the upper respiratory tract from the digestive tract is necessary to prevent recurrent contamination of the respiratory system in these patients. Two such surgical procedures are the tracheoesophageal diversion procedure and the laryngotracheal separation procedure. Our approach to patients with intractable aspiration and the indications for the use of these surgical procedures for the prevention of aspiration are discussed.

Discriminative phonation in macaques: effects of anterior mesial cortex damage.

Lesion damage of the anterior midline hemisphere in M. mulatta results in impaired discriminative vocal activity. Destruction of the supplementary motor area (SMA) or pre-SMA greatly increases vocal response latency without similar changes in a non-vocal response. Discrimination and efficiency in performing the vocal and non-vocal responses are unaffected by this damage. The behavioral deficit reflects a specific loss in initiating vocal signals.

Evaluation of tensor tympani muscle dominance in the biphasic acoustic reflex.

The Acoustic reflex frequently causes a biphasic change in impedance at onset. Understanding the cause of the biphasic response is important for establishing a physiological basis for the clinical measurement of reflex latency. The decrease in impedance at onset may be due to uncoupling of impedance contributed by the cochlea. Subsequent increases in impedance predominantly reflect stapedius muscle activity. The clinical implications of this physiologic model are discussed.

Primate phonation: unilateral and bilateral cingulate lesion effects.

Four juvenile Macaca mulatta were trained on a multiple schedule to perform discriminative vocalization and lever press tasks. Sequential unilateral and bilateral lesions of the anterior cingulate gyrus were made with testing of vocalization and lever press at each stage. Performance of the two behavioral tasks was assessed in terms of total responses, latency, efficiency and error index. Unilateral damage had a profound effect on vocal performance in one monkey. There was a significant deficit in total vocal responses and an increase of vocal response latency. No such impairment occurred from equivalent damage in the 3 remaining animals, despite comparable lesions. None of the 4 suffered changes in discriminative lever press following unilateral lesions. The second lesion (producing bilateral damage) had little further effect on the animal that exhibited an initial deficit from a unilateral insult. In contrast, this step in the remaining monkeys produced latency and total vocal response scores that approximated the scores obtained from the monkey with a single, unilateral hemisphere lesion. The evidence indicates there is lateral asymmetry in vocal mechanisms involving anterior cingulate cortex. This may be related to the hemisphere controlling the preferred hand. The principal effect of anterior cingulate damage involves impaired response initiation.

The negative acoustic reflex in retrocochlear disorders.

The most frequent impedance abnormality of an acoustic tumor is an absent reflex. However, this finding also occurs with middle ear disorders and is therefore nonspecific. This study recorded the contralateral acoustic reflex of human subjects suspected of having an acoustic tumor. Many tumor subjects, by visual inspection of the impedance bridge balance meter, appeared to have an absent reflex. Most of these subjects, in fact, had small amplitude negative reflexes by offline analysis on an averaging computer. Recognition of these negative reflexes increases the specificity and sensitivity of the reflex test for acoustic tumors. We recommend reflex testing with averaging computer monitoring to ensure their recognition.

Stapedius reflex quantification in acoustic tumor patients.

This investigation is a human application of previously reported work from our laboratories on experimental acoustic tumor effects on the stapedius reflex in monkeys. In this study, the contralateral stapedius reflex was elicited in human controls and in subjects with an acoustic tumor. Acoustic impedance was recorded on magnetic tape for offline analysis of reflex threshold, latency, rise, amplitude, decay, and relaxation. Typical tumor effects on threshold and decay were observed. Most important was the demonstration that decay measured at 20 db SL was more sensitive and more specific for tumor than decay measured at the conventional 10 db SL. Stapedius reflex latency, rise, and amplitude were more sensitive to the presence of a tumor than were measures of threshold and decay. These data indicate that qualification of the reflex will increase the utility of the test.

Somatic reflex development in infant macaques.

Thirty infant monkeys have been tested on a protocol of 19 measures of somatic reflex development. The sample includes four cesarean-derived premature infants of 150-160 days gestational age, and 26 term infants ranging in age from four to 48 days.

Temporal bone trauma and facial paralysis.

Temporal bone trauma includes a wide range of injuries of greater and lesser severity, most of which require the immediate attention of an otolaryngologist. The most common temporal bone injuries encountered in an emergency room setting include longitudinal and transverse fractures of the temporal bone with and without facial paralysis, labyrinthine concussion, foreign bodies in the external canal, penetrating injuries via the external auditory canal, and pressure injuries, including otitic barotrauma, water skiing accidents, blows or slaps to the ear or side of the head, and severe impact noise. A brief but inclusive examination can be performed within the limitations necessarily imposed by an emergency room setting. Cranial nerve screening, balance testing, hearing, and vestibular evaluation can be accomplished with a considerable degree of accuracy. To a large extent, the long term result reflects the quality of the initial examination.