Introduction

Patients with dizziness resistant to various treatments are so difficult to conduct as patients that have high levels of tinnitus disturbance. These symptoms are extremely common in the clinical practice and can occur simultaneously or independently. Whereas dizziness affects about 10% of the world population in all age ranges and over 40% of the adults have already had some episodes in their lives 1, tinnitus is reported by 17% of the population 2. The occurrence of both together tends to increase in elderly adults.

Many other similarities bring both symptoms together: etiology can be undefined or multiple, there may be aggravating emotional factors and they also restrict the routine activities of the subjects.

We preferably treat the etiology 3 and when it is not possible or enough to eliminate tinnitus and dizziness, patients are indicated to treatment regimes that include habituation: in the case of dizziness, Vestibular Rehabilitation (VR) and for tinnitus, TRT - Tinnitus Retraining Therapy.

Vestibular rehabilitation was developed by Cawthorn and Cooksey4. McCabe4 emphasized its value describing the physiological rationale and the therapy methodology whose objective is to accelerate the central compensation mechanisms of balance disorders. Normally, there are three equally important steps: 1. counseling, in which the patients and the families are informed about basic balance functioning, symptoms and proposed treatment; 2. training session, comprising repetitive eye, head and trunk movement and gait; 3. follow-up period in which the progression of the patients is monitored and counseling is emphasized, normally for a 3-month period. VR is considered a safe, affordable and extremely efficient option 3, 5, 6.

The difficulties to have an objective register both of tinnitus and dizziness many times frustrate the attempts to apply the scientific studies that confirm the efficacy of the referred treatment, and therefore, effectiveness is generally based on clinical observations 7, 8.

In the literature, we could find one study that correlated tinnitus relief with use of vestibular rehabilitation, but only for single and specific use of release maneuvers (Semont and/or Epley), used in treating benign paroxysmal posture vertigo. The studied patients presented improvement of tinnitus both in cases associated with dizziness and in those without vestibular symptoms 9.

Considering the non-intentional clinical improvement of tinnitus after vestibular rehabilitation, we decided to conduct a retrospective study to analyze the behavior of this symptom pre and post-rehabilitation. Our study reports the preliminary results of the VR application at the Division of Otoneurology, Service of Otorhinolaryngology, Hospital das Clínicas, UNICAMP, focusing on the unexpected improvement of tinnitus.

MATERIAL AND METHOD

We conducted a survey of the assessment forms (Annex 1) and reassessment forms (Annex II) in the medical charts of patients submitted to VR in the ambulatory of Otoneurology, Discipline of Otorhinolaryngology, UNICAMP, within a period of 1 year and 2 months. Out of the 30 studies patients, we excluded medical charts of patients that were absent for more than 2 session of VR, those that remained in treatment, subjects without tinnitus, and incomplete medical charts, amounting to a total of 12 studied patients. Table 1 shows the distribution of subjects based on age and gender and Table 2 shows the results of otoneurological examinations.

The duration of dizziness or vertigo in these patients ranged from 4 months to 15 years, mean of 5.72 years (EP = 1.49).

The grade and type of hearing loss is shown in Tables 3 and 4.
We observed that 58.2 (n=7) of the subjects presented unilateral tinnitus, 25% (n=3) had bilateral symptoms and 16.7% (n=2) had diffuse head tinnitus. Sixty-seven percent of the patients (n=8) reported auditory hypersensitivity.

In addition to auditory complaints, we observed that 83.3% (n=10) of the patients were considered anxious and 50% (n=6) presented previous or current history of depression.

Vestibular Rehabilitation
The method adopted to conduct the vestibular rehabilitation was based on recommendations of the Consensus on Vertigo 3 prepared by the Brazilian Society of ENT. It comprises the following steps:

 assessment;
 clarifications about symptoms and treatment proposed;
 suggestion of changes of inappropriate habits (posture, dependency, physical activity), if present;
 training practice comprising eyes, head and trunk movements, gait, motor coordination and neck relaxation;
 15-day or monthly follow-up sessions (depending on availability and need of the patient) for approximately 3 months.

The treatment duration ranged from 2 to 3 months to 50% of the patients (n=6) and it lasted more than 3 months to the other 50% (n=6).

The improvement criteria were based on patients' self-report about grade of general improvement, Thus, we considered significant improvement if subjects reported improvement equal or better than 70%, partial improvement between 40 and 70%, and dissatisfactory evolution below 40%.





Results

Seventy-five percent (n=9) of the patients reported significant improvement of dizziness after VR and 25% (n=3) reported partial improvement. The rate of compliance with complete treatment for the analyzed subjects was 91.7% (n=11), being that the patient that did not conclude treatment had reported significant improvement of dizziness in the last session.

The mean differences between pre and post-treatment values of the analog-visual scale (0 to 5) to dizziness, tinnitus, auditory hypersensitivity and hearing are shown in Table 5.

There was reduction of the level of discomfort with tinnitus measured with the analog visual scale score (0-5) for 58% of the subjects (n=7) after vestibular rehabilitation. We did not detect changes in the subjects who had not reported discomfort with the symptoms at the beginning of VR (25%, n=3) and to 2 other subjects (16.7%). Out of the subjects with auditory hypersensitivity (n=8), 75% reported some level of improvement of the symptom (n=6) and 25% had unaltered complaint (n=2).






Discussion

The comparison of the difference between pre and post-treatment values of the analog visual scale score in each patient evidenced that in addition to the expected improvement of dizziness, the complaints of tinnitus and auditory hypersensitivity were reduced. We believe that since patients informed there was no hearing improvement (as expected, since hearing loss in most patients was sensorineural), it evidences the reliability of the data obtained in other items.

The correlation between psychiatric disorders, especially anxiety, and dizziness has been known for a long time10. Tinnitus presents an important interface with psycho-affective disorders, especially by the association of depression and negative reactions to stress and anxiety 11. It is possible that tinnitus improvement was related to control or reduction of possible psychiatric disorders, either by dizziness itself or reached by VR exercises, as well as by better understanding symptoms and the treatment, thanks to the counseling sessions. The same effect of reducing the discomfort of tinnitus is achieved by TRT-Tinnitus Retraining Therapy in counseling sessions 2, even though it does not lead to dizziness improvement.

Many issues have originated from the analysis of our results: how does labyrinth compensation mechanism influence the process of tinnitus habituation? Do the results achieved with VR confirm the involvement of the sensorial-motor system in the generation and modulation of tinnitus?12 Would the improvement in auditory hypersensitivity be due to the same reasons that had led to improvement of tinnitus?

Despite the limited knowledge about it, the identification of multiple vestibular cortical areas in electrophysiological experiments in animal models and in human studies indicates there is not an isolated vestibular cortex compared to that of the visual and auditory systems 13.

It is believed that most cortical vestibular functions would not be specifically vestibular, but rather related to many different systems in a way that it is not fully understood yet 14. There are important cortical interactions that are already known between the central vestibular, visual and somato-sensitive processing and, yet, the study of the influence of the vestibular signs in cortical vestibular processing is still very limited 14.

Whereas research studies involving the brainstem are directed to the function of motor control, adaptation, learning and vestibular reflexes, future investigations directed to the cerebral vestibular cortex will probably examine the cognitive and perceptive processes related to this system 14.
We do not suggest the use of VR as a treatment approach for tinnitus, but our results encourage the investigation about the possible synergy with VR, tinnitus drug treatment and TRT in patients that have associated vestibular and tinnitus complaints.

Even though we had a limited number of cases, we consider that the absence of literature reports showing the concomitant improvement of tinnitus in vestibular rehabilitation conveys a character of innovation to our study and suggests the need for further studies addressing this therapy issue.

Conclusions

We observed reduction of tinnitus complaint in patients with dizziness and tinnitus submitted to vestibular rehabilitation. By better understanding the influence of the cortical vestibular system over other sensorial modalities, in addition to spatial and movement perceptions, we can provide explanations to our findings.

References

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14. Andersen RA, Shenoy KV, Snyder LH, Bradley DC, Crowell JÁ. The Contributions of Vestibular Signals to the Representations of Space in the Posterior Parietal Cortex.. In: Otolith function in spatial orientation and moviment: Annals of the New York Academy of Sciences; May 1999; New York; 1999. p. 282-92.

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1 Speech Therapist, Master in Sciences, Medical School, University of São Paulo, Responsible for the
Division of Vestibular Rehabilitation, Hospital das Clínicas, UNICAMP.
2 Assistant Physician, Division of Otoneurology and Skull Base Surgery, Discipline of Otorhinolaryngology, Medical School, UNICAMP.
3 Assistant Physician, Division of Otoneurology, Discipline of Otorhinolaryngology, Medical School, UNICAMP.
4 Collaborating Physician, Discipline of Otorhinolaryngology, Medical School, University of São Paulo.
Affiliation: Study conducted at the Department of Ophthalmology and Otorhinolaryngology, Hospital das Clínicas, Medical School, UNICAMP.
Free communication nominated for Special Citation and presented at 36º Congresso Brasileiro de
Otorrinolaringologia, held on November 19 - 23, 2002 in Florianópolis, SC.
Address correspondence to: Keila Alessandra Baraldi Knobel -
R. Joaquim Novaes, 60/132 Campinas SP 13015-140 - Tel/fax (55 19) 3255 1234 - E-mail: keila@gabengenharia.com.br
Article submitted on June 09, 2003. Article accepted on July 01, 2003.