Surgical treatment of vertigo

Long-Term Balance Outcomes in Vestibular Ablative Surgeries

Objective:

To evaluate the long-term balance outcomes of vestibular nerve section (VNS) and labyrinthectomy (L) operations. The indirect outcomes will be the correlation of objective and subjective test results and an analysis of anterior-posterior versus medial-lateral computerized posturography (CP) scores.

Methods:

This retrospective study evaluated objective CP and subjective Dizziness Handicap Inventory (DHI) results of patients who underwent VNS and L surgeries for Ménière’s disease.

Results:

A total of 55 (31 VNS and 24 L) patients were included in the study. The two operation groups were similar in terms of age, and mean time between surgery and the tests (p=0.465 and p=0.616) respectively. The vestibular and global scores at anterior-posterior CP showed statistically significant differences between the groups (p=0.000 and p=0.007) respectively in favor of the VNS group. In addition, the comparison of the vestibular CP scores of anterior-posterior and medial-lateral evaluations of the entire study population was lower in the medial-lateral evaluation (p=0.000). The mean DHI scores did not show statistically significant differences (p=0.359) between operation groups, nor did the correlation analysis between CP and DHI scores reveal statistical significance (p values >0.05).

Conclusion:

In the long term, objective balance outcomes are better for VNS patients than for L patients. Additionally, medial-lateral balance outcomes are more affected than anterior-posterior balance outcomes from unilateral ablative surgeries. Subjective balance perception is not different between the two surgery groups, and DHI scores do not show a correlation with CP scores.

Neurotologic surgery and tinnitus

Otologic surgeons have long searched for a predictable surgical procedure for the control of tinnitus, but without success. Yet periodically, surgical procedures employed primarily for other purposes serendipitously produce relief of associated tinnitus. An effort will be made to study this aspect of tinnitus. The recent literature on the subject will be surveyed briefly. The effect upon tinnitus in 332 patients by the use of various neurotologic surgical procedures, performed primarily for other purposes, will be presented and discussed.

Vestibular function after acoustic neuroma removal with preservation of one branch of the vestibular nerve

BACKGROUND

Vestibular compensation after acoustic neuroma surgery is affected by many parameters. Apart from surgical approach, age of the patient, and comorbidity, the use of rehabilitative vestibular training and the degree of preoperative vestibular compensation play their respective roles.

OBJECTIVE

To examine whether and how surgical preservation of one branch of the vestibular nerve affects the compensation process in patients after acoustic neuroma removal.

STUDY DESIGN

Prospective study involving 29 patients with acoustic neuromas. In 15 patients operated on by the middle fossa or retrosigmoid approach, one branch of the vestibular nerve could be preserved intraoperatively, and the course of the compensation process was followed (Group 1). Fourteen other patients with acoustic neuroma, who were operated on via a translabyrinthine approach, served as a control group (Group 2).

MAIN OUTCOME MEASURE

The evaluation of vestibular compensation was accomplished clinically, by electronystagmography, and by dynamic posturography.

RESULTS

An accelerated vestibular compensation was found in all examinations for Group 1, and 3 months after surgery 47% of the patients in this group were back to work without substantial restrictions, compared with 29% of Group 2. At the end of 6 months, however, there was no more significant difference between the two groups.

CONCLUSION

The long-term results of vestibular compensation do not seem to be influenced by partial preservation of the vestibular nerve, whereas the compensation process seems to be accelerated when the nerve is partially preserved.

Outcomes in vestibular ablative procedures

OBJECTIVE

To assess dizziness handicap and postural recovery in 17 patients undergoing a vestibular ablative procedure.

STUDY DESIGN

Outcomes were compared between nine patients who underwent selective vestibular neurectomy and eight patients who underwent a transmastoid labyrinthectomy.

SETTING

Patients underwent ablative procedures at a tertiary care facility.

METHODS

Patients were tested with posturography (sensory organization test [SOT]) and the Dizziness Handicap Inventory (DHI) before and 4 to 5 weeks after their procedure.

RESULTS

The mean change scores for each of the DHI subscales and the total DHI score showed significant improvement for the labyrinthectomy group. For the neurectomy group, only the emotional DHI subscale change score showed significant improvement. No difference was noted between preprocedure and postprocedure SOT scores for either group. The results indicated that the largest proportion of significant correlations existed between DHI and the somatosensory and vestibular subtests of platform posturography. In regression analyses, a model with age (p = 0.04) and vestibular score (p = 0.001) fitted the data well and explained 52.9% of the variance. Persons who were less than 69 years old were three times more likely to report persistent episodes of dizziness after the ablative procedure, and those who had neurectomies were 2.3 times more likely to report episodes of dizziness than those who underwent transmastoid labyrinthectomy.

CONCLUSION

Dizziness handicap after an ablative procedure is influenced by the type of procedure (labyrinthectomy versus neurectomy), age, and preoperative vestibular score on the SOT. Preoperative vestibular SOT score is highly associated with the emotional, physical, and functional domains of perceived handicap and quality of life after the surgery.

Neural conservation in skull base surgery

Surgical treatment of lesions of the skull base carries significant risk to the functioning of the cerebral hemispheres, the brain stem and the cranial nerves. This risk is due both, to problems associated with maintaining an adequate blood flow while exposing and removing the tumor and to direct or indirect trauma to the brain, perineural tissues and cranial nerves. These risks may be reduced if information about possible implications of surgical maneuvers on the cerebral blood flow and on the function of the patients central nervous system and cranial nerves is available and can be monitored during surgery of the skull base. The use of electromyographic neuromonitoring for the facial nerve and of BERA-monitoring for the auditory nerve have been described and are now standard methods to achieve these goals. In acoustic tumors in the last several years beside preservation of the function of the facial nerve hearing preservation especially in small tumors has been one of the primary goals in acoustic neuroma surgery. Computer assisted surgery and intraoperative imaging for lateral skull base surgery are still in their infancy but promise to allow further improvement of neural conservation.

Tinnitus

Tinnitus is a common otologic symptom secondary to numerous etiologies, such as noise exposure, otitis, Meniere's disease, otosclerosis, trauma, medications, and presbycusis. A thorough evaluation is necessary to rule out less common causes, which may include acoustic neuromas, glomus tumors, atherosclerosis of the carotid arteries, arteriovenous fistulae (AVFs), arteriovenous fistulae malformations (AVMs), and intracranial hypertension. Treating physicians need to have a very compassionate attitude towards these patients, and statements such as "there is nothing that can be done" are very inappropriate and should be strongly condemned. Reassurance, hearing aids, masking devices, retraining methods, antidepressants, intratympanic medications, and management of underlying pathologies such as carotid artery atherosclerosis, skull base tumors, intracranial hypertension, and AVMs/AVFs provide relief for the majority of these patients.

The Role of Vestibular Nerve Section in Meniere's Disease

The role of vestibular nerve section (VNS) surgery in the management of Meniere's disease is considered by prospective analysis of a large series of 531 patients treated by the author over a period of 11 years. Twenty-seven percent were referred by their primary care physicians, while the rest were secondary (45.6%) or tertiary (27.3%) referrals. Overall, 62 (11.7%) Meniere's patients underwent 63 VNS procedures. This surgery was undertaken more frequently in the secondary and tertiary referral patients (14.2%) than in the primary referrals (5.5%). The retrolabyrinthine technique was the preferred approach in almost 90% of ears. The results and complications of these and other surgical options are discussed in an attempt to define the present role of VNS in intractable Meniere's disease. Vertigo was abolished after VNS in 93% of cases. Compensation was significantly impaired in 12.9%. All these patients had contralateral Meniere's disease or marked labyrinthine hypofunction. Although highly effective and associated with few postoperative complications, VNS is generally reserved for sac failures, though may be appropriate as a primary procedure in severe unilateral cases.

Selective cochlear neurectomy for debilitating tinnitus

Eighth nerve sections have been performed to control debilitating tinnitus, with various success rates (45% to 76%). Patients with a unilateral profound sensorineural hearing loss and disabling tinnitus perceived in that ear are candidates for such surgery. The concept of a selective cochlear neurectomy with preservation of the vestibular nerve is introduced with two case presentations. The indications for surgery, surgical technique, and results are described. Advantages of preserving the vestibular nerve fibers include the lack of postoperative vertigo and disequilibrium and thus a shorter length of hospital stay, and the conservation of a symmetric vestibular input, obviating the lengthy compensation process that might otherwise be needed, particularly in the elderly. A selective cochlear neurectomy for the control of debilitating tinnitus has proven to be successful in controlling tinnitus in the two patients presented, with the added advantage of preservation of their vestibular function. Further controlled studies are necessary to confirm the advantages and effectiveness of this technique.

Relief of severe hyperacusis and diplacusis in a deafened ear by cochlear labyrinthectomy

A professional musician with intolerable hyperacusis and dysharmonic diplacusis in a severely deafened ear was successfully relieved of his symptoms by deliberate destruction of the cochlea.

Recovery from unilateral vestibular nerve section in human subjects evaluated by physiological, psychological and questionnaire assessments

Patients undergoing vestibular nerve section for vertigo or acoustic neuroma surgery were compared pre- and post-operatively and during long-term follow-up using a range of tests including: nystagmography, impulsive rotational testing of the vestibulo-ocular reflex (VOR), ability to estimate and reproduce imposed rotational displacements, validated questionnaires rating vertigo, imbalance, autonomic reactivity and somatisation, and clinical and self-assessment scales of overall outcome in terms of symptoms and disability. Correlations were found between rating scale assessments, questionnaire scores and estimates of self-rotation. Neither nystagmography nor VOR tests correlated with the presence or severity of vertigo or imbalance. Post-operatively, vertigo patients reported that they had received significant relief, although they had higher incidences of residual complaints of imbalance and vertigo than patients after acoustic neuroma surgery. Factors impeding rehabilitation in patients with vertigo are discussed.

Bilateral vestibular neurectomy for treatment of vertigo

The effects of bilateral vestibular neurectomy on equilibrium and vestibular function were clinically evaluated in two patients more than 15 years after surgery. Both patients had bilateral Menière's disease and their vertiginous spells were permanently resolved after the second vestibular neurectomy. Symptoms of disequilibrium were absent in one patient and mild in the other. Reflexive horizontal eye movements on whole body rotation in darkness were absent on low angular accelerations (2 degrees/s2), but could be elicited with angular accelerations of 20 degrees/s2 or higher. Extravestibular cues generating these eye movements seemed to be unlikely because a "control" patient with complete peripheral vestibular ablation after bilateral subtotal petrosectomy did not present reflexive eye movements under the same stimulus paradigms. An incomplete deafferentiation of the vestibular end organ (rather than regeneration of vestibular nerve fibers) and a consecutive impairment of the central velocity storage mechanism may explain the good functional outcome in our bilateral neurectomized patients.

Chemical labyrinthectomy with NaCl. Menière's disease treatment with deposition of NaCl in the vestibule

Thirteen individuals with unilateral Menière's disease were chosen for experimental chemical labyrinthectomy. All subjects suffered from frequent attacks of disabling vertigo and had mean pure-tone thresholds greater than 50 dB in the affected ear. The surgical procedure was similar to stapedectomy; after removal of the stapes, several crystals of NaCl were placed in the vestibule which was then covered with a vein graft. Postoperative recovery was rapid, allowing patients to be discharged 4-6 days after surgery. Of the 13 subjects, all reported complete relief from vertigo. Tinnitus was cured in 7 subjects, greatly improved in 4 and unchanged in 2. Most patients complaining of aural fullness preoperatively reported relief from this symptom following surgery. To date (up to 4 years post-surgery) none of the subjects has shown any significant alteration in audiologic or vestibular function in the contralateral ear. The ease and safety of this procedure make it an attractive method when cochleovestibular deafferentation is indicated.

The state of tinnitus after inner ear surgery

A retrospective study of several procedures--for either treatment of vertigo or resection of acoustic neuromas--was performed to determine their effect on tinnitus. Subjective ratings of the state of tinnitus (resolution, improvement, maintenance, or deterioration) were obtained by questionnaire. Surgical procedures performed for correction of vertigo frequently alter tinnitus. In general, procedures that conserve hearing--namely, retrolabyrinthine vestibular neurectomy (RVN), middle fossa vestibular neurectomy (MFVN), and endolymphatic shunt procedures (ELS)--have a 50% to 65% chance of helping relieve tinnitus and up to a 22% chance of worsening tinnitus. When there is no serviceable hearing, cochleovestibular neurectomy (CVN) offers the best cure rate for tinnitus (76%) and the least chance of worsening tinnitus (3%). When hearing is minimal and the patient complains of tinnitus, a CVN--rather than a labyrinthectomy--should be recommended. However, when useful hearing is present, a CVN is not usually recommended for relief of tinnitus, since the actual cure rates are only 35%. When vertigo is not a complaint, there is currently no surgical procedure known that can be recommended for the treatment of tinnitus.

Experiences with ESR (endolymphatic sac revascularization) in cases of sensorineural hearing-loss

Experience based on 14 cases of severe-to-total sensorineural deafness, treated with endolymphatic sac revascularization, operation, is presented. Changes seen in the endolymphatic sacs and lateral sinuses of these patients have been detailed. Irrespective of the degree and duration of deafness, significant hearing gain (with good improvement in speech discrimination) was obtained in nine out of 14 cases (64.28 per cent). There was no improvement at all in one out of 14 (7.14 per cent), and there was a relapse of the hearing-loss two months post-operatively in one case (7.14 per cent). Tinnitus disappeared in the operated ear in three out of five cases (60 per cent) and vertigo improved considerably in four out of six cases (66.66 per cent). The follow-up in this series has been up to two years.

Meniere's disease at the University of Iowa: 1973 to 1980

The goals of treatment in Meniere's disease are hearing preservation and control of vertigo. Controversy abounds with regard to the most expeditious and efficacious means of attaining these goals. Low-salt diet, diuretic therapy, endolymphatic-mastoid shunt, and middle cranial fossa vestibular neurectomy are all modes of treatment employed for Meniere's disease at the University of Iowa. This review of our experience from 1973 to 1980 summarizes the efficacy of each therapeutic option.

Vestibular neurectomy and saccus decompression surgery in Meniere's disease

Results of vestibular neurectomy, total eighth nerve section, and saccus decompression in 42 patients with Meniere's disease are reported. Vestibular nerve section was found in isolated cases to be a very effective method of abolishing the symptom of vertigo. Hearing is not affected but may be lost owing to opening of the vertical canal or disruption of blood supply. Saccus surgery might be the surgical treatment of choice in early cases with good hearing but in patients with fixed non-fluctuating hearing loss, rehabilitation can be effected only by vestibular neurectomy. In bilateral cases either sac surgery or the use of vestibulotoxic drugs is advised.

Cochlear and vestibular lesions in capsular otosclerosis as seen in microdissection

In 24 temporal bones from patients with otosclerosis prepared by the method of microdissection and surface preparations, otosclerotic foci could be clearly seen during removal of the otic capsule. The state of activity of each focus was estimated on the basis of its consistency and vascularity. Small anterior foci constituted the most common form of involvement of the otic capsule. All were judged to be inactive, and none of them appeared to have caused obvious sensorineural degeneration. No cases of "pure cochlear otosclerosis" were seen. Sensorineural degeneration was associated with large anterior foci which reached the upper basal turn. One specimen displayed a circumscribed sensorineural degeneration in the upper basal turn, with an almost exact correspondence between the location and extent of the cochlear lesion and the site of invasion by the otosclerotic process in the bone and endosteum bordering on scala media and scala tympani. It is postulated that a toxic factor had diffused from the focus and acted directly on the organ of Corti. When multiple foci were present they were usually poorly defined. The otosclerotic process involved the round window, with new lamellar bone formation in the scala tympant of the lower half of the basal turn. The most extensive sensorineural degeneration in the entire material was seen in this group. One specimen also had severe cochlear hydrops. In three specimens large shunts were observed to connect the otosclerotic foci with the cochlear vasculature, which was severely dilated. Where otosclerosis involved the endosteum of the scala tympani, loss of vessels was observed. One specimum with extensive active capsular otosclerosis had severe sensorineural degeneration of the vestibular system. Vestibular pathology in fenestrated ears is also described. In a specimen from a patient with no caloric reaction, numerous hair cells were present in the macular organs.

Vestibular nerve section for Ménière's disease

In summary: (i) the fact that VNS spares auditory function makes it preferable to labyrinthectomy. A comparison of VNS and the "conservative" operations on the inner ear shown that they have much the same effect on hearing. VNS by controlling vertigo may also provide an additional benefit by eliminating one of the stress factors concerned in the perpetuation of hydrops; (2) in the treatment of vertigo, VNS is now the most effective method of treatment. Because of elimination of vertigo is what chiefly concerns most of our patients, we suggest that when medical treatment fails to control vertigo, VNS is the surgical method of choice.