Classification of Menière's disease

To create a rational treatment system for Meniere's disease, it is helpful to divide Meniere's disease into five stages according to the signs, symptoms, pathology, and natural history by recalling what is known for certain and what is probably true about Meniere's disease. It is known that Meniere's disease is attributable to endolymphatic hydrops, caused by a small, malfunctioning endolymphatic sac, abnormally placed since birth, and Meniere's disease is therefore a congenital disorder of the endolymphatic sac. It is probably true that there is often an immune, viral, metabolic, or other insult to the inner ear, that disturbs the balance between the cochlea, where endolymph is produced, and the endolymphatic sac, where most of it is absorbed. Using this five-stage classification, it is possible to separate Meniere's disease into the first three stages, for which different but reasonable treatments are possible, and the last two stages, for which no treatments are effective.

Transtympanic electrocochleography in Menière's disease using clicks and tone-bursts

Transtympanic electrocochleography (ECoG), using clicks and tone-bursts at 500, 1000, and 2000 Hz, was employed to study 80 patients with Meniere's disease and 25 non-Meniere's patients. The magnitude of the negative summating potential and the summating potential:action potential ratio (SP:AP) were examined in both groups. Groups were further divided based upon degree of hearing loss and audiometric configuration. An elevated SP:AP ratio was found in 83.7 percent of the Meniere's ears and 12 percent of the non-Meniere's. The likelihood of obtaining a positive ECoG in Meniere's patients was strongly related to degree of hearing loss but not audiometric configuration.

Otoneuroscience and space vestibulo-neuroscience in the new century

From a clinically oriented point of view, efforts of otoneuroscience should be directed toward an improvement of the management of dizzy and vertiginous patients. At present, the main obstacles in this field are: (1) the lack of specific therapies for many of the clinical diagnoses. This reduces the necessity of clinical vestibular diagnosis to a pragmatic exclusion of the few diseases with therapeutic consequences; (2) the lack of feedback to confirm or disprove clinical diagnoses; (3) poor knowledge of the pathophysiology of many of the otoneurological diseases; experiments in animal models may be helpful in this respect; (4) most progress in medicine originates from the results of numerous, poorly controlled 'unscientific' trial and error experiments obtained during treatment of patients; training clinicians in more scientific, critical thinking would help to increase the profits that can be realized from this important source of information; and (5) to date, information obtained during zero-gravity experiments in space have not yet led to important consequences in treatment of patients under 1-g conditions, but are important for a possible evolutionary step of mammals adapting to a new environment.

[Therapy of vestibular vertigo]

The non-surgical treatment of vestibular disorders must be based on current knowledge of vestibular pathophysiology. It is generally accepted that after vestibular lesions a self-repair mechanism exists that allows a more or less complete recovery. In cases of persisting vestibular complaints the physician's duty consists in stimulation of these pre-existing mechanisms. This can be done by physical exercises, as has been recommended since the work of Cawthorne and Cooksey in 1946. This concept is meanwhile supported by modern neurophysiological research. This article describes a short training program consisting of exercises for fixation during rotations, smooth pursuit, optokinetic nystagmus and motor learning mechanisms. Physical exercises can be reinforced by nootropic drugs.

Intratympanic gentamicin instillation as treatment of unilateral Menière's disease: update of an ongoing study

A prospective study using intratympanic gentamicin instillation as treatment for disabling unilateral Meniere's disease has been ongoing at our institution for 4 years. Treatment effectiveness is evaluated based on the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) 1985 guidelines. This report is based on 30 patients who have become eligible for assessment. We conclude that gentamicin intratympanic instillation as currently used in our protocol is an effective, safe, and easily administered method of achieving a predictable measure of vertigo control.

[Effects of a change in environmental pressure on spontaneous nystagmus in patients with cochleovestibular diseases]

Cochlear and vestibular effects of variation of middle ear pressure have been discussed for more than 50 years. In 1975, Densert reported on temporary improvement of hearing threshold in patients suffering from Ménière's disease after reduction of air pressure in a pressure chamber. One year later Ingelstedt observed reduction of spontaneous nystagmus under this condition. The transmission of relative overpressure from the middle ear to the labyrinth with consecutive decongestion of the hydropic endolymphatic system to the saccus was thought to be the cause of this phenomenon. Meanwhile a direct effect of labyrinthine pressure on the activity of the inner ear and labyrinth in healthy subjects and animals has been described. In order to gain further information on the phenomenon observed by Densert and Ingelstedt we performed investigations on patients suffering from several cochleovestibular diseases. Chamber pressure was altered and simultaneous electronystagmographic recording was performed. As a striking result, we observed a reduction of the pathological spontaneous nystagmus in a majority of patients with vestibular damage during and after the reduction of chamber pressure. Many of these subjects showed a partial restitution of nystagmus if the chamber pressure was increased again. This observation was made in patients with Méni ere's disease, vestibular neuritis and sudden hearing loss with vestibular involvement. Hence, we conclude that this phenomenon is not specific for Ménière's disease. A transmission of middle ear pressure to the labyrinth may be an explanation of our observations.

[Results of 100 consecutively operated patients with acoustic neuroma]

The results from 100 patients with 103 acoustic neurinomas who were operated on between February 1979 and April 1992 are presented. All patients were placed in the half-sitting position and operated on by the same surgeon using the suboccipital-trans-meatal approach. Postoperative facial nerve function was good in 56%, moderate in 20% and poor in 24% of our patients. Preservation of useful hearing was achieved in 21%: the smaller the tumor, the better the functional result. However, the early symptoms of acoustic neuromas (tinnitus, dizziness, feeling of unsteadiness) were only slightly improved by the operation. The result concerning tinnitus seemed to be better after sacrificing the cochlear nerve. The number of patients with ataxia increased postoperatively, although objective ataxia decreased. Dizziness improved regardless of the tumor size.

[Psycho-physiological study by contingent negative variation (CNV) in otolaryngological diseases]

Contingent negative variations (CNV) were recorded in patients with tinnitus (N = 20), abnormal sensations of the pharynx and larynx (ASPL) (N = 26) and Meniere's disease (N = 19), and compared with those of healthy adults (N = 20) in order to investigate the characteristics of their information processing mechanisms in the brain. Patients were also subjected to psychological tests: Depression Score and the Cornell Medical Index test. CNV (an event-related potential) is a slow negative cortical potential shift and can be recorded during two stimuli presented at a constant interval under conditions in which the subjects are told to press a key as quickly as possible upon an imperative stimulus (S2) following a warning stimulus (S1). S1 was a 1kHz tone burst of 300 msec duration at a level of 85dB HL. S2 was a light flash. The interstimulus (S1-S2) interval was set at 2 seconds. The CNV can be divided into three components, early, middle, and late, according to latency. Statistical analysis of CNV amplitudes of the three components showed the following differences between groups. In tinnitus patients, the mean amplitudes of both the early and middle component were significantly greater than those in healthy adults (P < 0.05). In ASPL patients, the mean amplitudes of the middle component were significantly greater than those in healthy adults (P < 0.05). In Menière's disease, the mean amplitudes of both the middle and late component were significantly greater than those in healthy adults (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Ocular tilt reaction resulting from vestibuloacoustic nerve surgery

The ocular tilt reaction (OTR) is a triad of head-eye synkinesis composed of head tilt, conjugate ocular torsion in the direction of head tilt, and skew deviation. The OTR represents a normal compensatory response to lateral head tilts and is produced by activation of the utricle of the lowermost ear. A pathological OTR results when otolith activity is unopposed as the result of injury to the opposite utricle or its nerve. Vertical diplopia may be the only symptom of OTR in patients who have undergone surgery involving the vestibuloacoustic nerve. We report a series of patients with OTR after surgery for acoustic neuroma or Meniere's disease. In each patient, the manifesting symptom was vertical diplopia. Bedside neuro-ophthalmological testing readily excluded a brain stem cause for the double vision. We conclude that OTR after vestibuloacoustic surgery is a benign condition with spontaneous resolution of symptoms within several months.

Otoneurological functioning in panic disorder patients with prominent dizziness

Fifteen panic disorder patients with prominent dizziness underwent audiologic, caloric, and vestibuloocular reflex activity testing and were compared with normal controls. There were no abnormalities detected on audiologic and caloric tests. Compared with normal controls, panickers with dizziness showed a greater discrepancy between eye and head movements on vestibulo-ocular reflex activity in the dark. Panickers with prominent dizziness did not differ from a second control group of panickers with severe heart palpitations on a number of psychological tests. The results did not support the hypothesis that organic dizziness is etiologically important in the causation of panic or agoraphobia, but do suggest that vestibuloocular reflex activity should be further studied in panic disorder.

Diagnosis of vestibular Menière's disease with electrocochleography

The existence of vestibular Menière's disease, once considered a variant of classic Menière's disease, but without hearing loss, has been questioned because of lack of objective evidence that endolymphatic hydrops is involved with the disease process. Transtympanic electrocochleography (TT ECoG) has emerged as a useful tool for electrophysiologic monitoring of the inner ear, and is especially valuable in assessing endolymphatic hydrops. A retrospective chart review was performed to identify those patients with a diagnosis consistent with vestibular Menière's disease in order to determine the presence or absence of endolymphatic hydrops using TT ECoG. A total of 15 patients were identified. Using established norms for the summating to action potential ratio (SP:AP) with click stimulus, 73 percent demonstrated values consistent with endolymphatic hydrops. The most commonly associated symptom was aural fullness (60%), followed by tinnitus (33%), and the disease was bilateral 53 percent of the time. The similarities between this clinical entity and classic Menière's disease are noted, and theoretic considerations are made.

Microvascular decompression of the eighth nerve in patients with disabling positional vertigo: selection criteria and operative results in 207 patients

Two-hundred seven patients who were operated on consecutively between January 1983 and December 1990 to relieve disabling positional vertigo (DPV) using the microvascular decompression (MVD) procedure were studied. Selection of the patients for MVD operations was based on both case history and the results of otoneurological tests. Of the 177 patients with unilateral symptoms, 8 were excluded because of previous vestibular nerve section, and 6 did not return for follow-up; of the remaining 163 patients, 129 (79%) were free of symptoms or markedly improved following MVD, and none became worse. Thirty patients had symptoms and signs of bilateral DPV, and of these 1 was excluded because of previous vestibular nerve section and 3 because of multiple operations. Of the remaining 26 patients, 20 (77%) were free of symptoms or markedly improved following MVD. Eleven of these patients had more than 2 operations. The follow-up time was an average of 38 months, ranging from 3 months to 10 years. The cure rate (about 80%) of MVD for DPV is similar to that reported for MVD for trigeminal neuralgia and hemifacial spasm. The cure rate of MVD for DPV was not related to gender or to the duration of the symptoms. Following a total of 254 operations that these 207 patients underwent, 4 patients (1.6%) lost hearing and 4 (1.6%) suffered marked hearing loss. Three patients suffered temporary deficits of other cranial nerves. There were no other complications to these operations.

[Autonomic nervous function of vertiginous patients--assessment by spectral analysis of heart rate variability]

Autonomic nervous function in 68 vertiginous patients and 33 controls was studied using power spectral analysis of heart rate variability. First, a system was developed which computes the power spectral density (PSD) of beat-to-beat heart intervals using a continuous non-invasive finger blood pressure recording obtained with the FINAPRESS device. A fast-Fourier transform algorithm was used to compute the PSD. In frequencies up to 0.5 Hz, the PSD of heart rate variability contains three major components: a low frequency (P1), a middle frequency (P2) and a high frequency (P3). Each component was normalized by dividing the absolute values by total power (T), and then used as an index of each component. Second, the effects of passive tilt, respiratory frequency and specific pharmacological sympathetic or parasympathetic blockade on the indices of these components were evaluated in the control group. The following results were obtained. 1. During passive tilt, the normalized power of P2 was increased, whereas that of P3 was decreased. 2. The peak frequency of P3 was consistent with the frequency of respiration. 3. Sympathetic blockade decreased the normalized power of P2, whereas parasympathetic blockade decreased the normalized power of P3. From these results, I concluded that the normalized power of P2 and P3 are quantitative markers of sympathetic and vagal nervous activities, respectively. Third, the results of spectral analysis in patients were compared with those in controls. The following characteristics of autonomic nervous function in vertiginous patients were noted. 1. The normalized power of P3 in patients was lower than that in controls, suggesting that parasympathetic nervous activity at rest was suppressed in patients. 2. The increase of normalized power of P2 with passive tilt was suppressed in patients, suggesting suppression of sympathetic response to passive tilt. 3. In patients with Meniere's disease, during the active period of vertigo attacks, the normalized power of P2, which is an index of sympathetic activity, was higher than that in the intervals between vertigo attacks. Fourth, with caloric stimulation in the control group, an increase of the normalized power of P2 was observed during or after the stimulation, which suggests that vestibular stimulation increases sympathetic activity. I therefore suggest the following: 1. Decreased parasympathetic activity and suppression of sympathetic response were present in the vertiginous patients. 2. Sympathetic activity was increased by vertigo attacks in the patients with Meniere's disease.

Dynamic properties of feed back control of human posture in subjects with vestibular neuritis

Postural control was studied in 22 subjects with vestibular neruitis within 14 days after the onset of symptoms. Dynamic feed back control of posture were evaluated by analyzing the postural responses to vibration toward calf muscles applied according to a PRBS schedule. Properties of the dynamic control was normalized as swiftness, stiffness and damping of the responses. There was no prominent group differences between the 22 subjects with vestibular neuritis and 17 normal subjects. However, when studying the change in parameters evoked by presence or absence of visual information it was found that the abundant changes of control parameters, especially in stiffness, met in normal subjects had declined in subjects with vestibular neuritis. The present finding suggests that although subjects after an acute vestibular lesion may achieve a sufficient postural control by utilizing information from other somatosensory receptors, this is concomitant with changes of the feed back control.

Electrocochleography in syphilitic hearing loss

Syphilitic labyrinthitis presents such symptoms as hearing loss, tinnitus, vertigo and/or dizziness, and is well known as one of the endolymphatic hydropic diseases. In order to elucidate the relationship between syphilitic hydrops and ECochG findings, we performed ECochG in patients with syphilis following our previously reported study of patients with Meniere's disease. Twenty-two patients who have been serologically and clinically diagnosed as having syphilitic labyrinthitis were examined with ECochG between December, 1982 and November, 1991. Of the 27 ears tested with ECochG, 2 showed no response due to severe hearing loss, and increased SP (SP/AP ratio > 0.37) was observed in 14 (56.0%) out of the remaining 25 ears. The SP/AP ratio of patients with syphilitic labyrinthitis was not significantly different from that of the patients with Meniere's disease or delayed endolymphatic hydrops, while it was significantly higher than that of the patients with sudden deafness and other types of sensorineural hearing loss. We conclude that the electrocochleographic features of endolymphatic syphilitic lesions resemble those in Meniere's disease.

A clinical observation of benign paroxysmal positional vertigo (BPPV) after vestibular neuronitis (VN)

We observed 9 cases of BPPV developed after vestibular neuronitis. The interval between the onset of BPPV and vestibular neuronitis ranged from 2 weeks to 20 years. All cases were examined for critical head position which provoked vertigo, non-gaze nystagmus, positional and positioning nystagmus and caloric nystagmus. No characteristic signs and symptoms could be observed. The function of the posterior canal is thought to be necessary to provoke positional vertigo. Thus in BPPV after vestibular neuronitis the function of the posterior canal would presumably have been preserved to some degree. The first possibility is that the function of the posterior canal was not impaired in spite of the damage of the lateral canal. The fact that each canal differs in involvement in vestibular neuronitis may be explained by the difference in the blood supply or the innervation between lateral and posterior canals. If only the artery or nerve which is related to the lateral canal is damaged and the artery or nerve to the posterior canal is not involved, then the function of the posterior canal is preserved. So BPPV may occur soon after the disappearance of severe vertigo. The second possibility is that if the posterior canal had been damaged together with the lateral canal and the functions are recovering, BPPV may occur some time after the onset of vestibular neuronitis. The locus of vestibular neuronitis is in the peripheral vestibular system and the extent and degree of the lesion vary, which may explain why there can be time difference of the recovery between the two canals.

Vestibular nerve disorder in patients suffering from sudden deafness with vertigo and/or vestibular dysfunction

Vestibular nerve disorder (VND) in cases suffering from sudden deafness with vertigo was studied. Between 1987 and 1991, we observed 46 patients suffering from sudden deafness with or without vertigo, who had undergone the caloric test and galvanic body sway test (GBST). Twenty-seven patients had vertigo and canal paresis (CP) upon the caloric test, 6 vertigo without CP and 13 CP without vertigo. VND was detected in 12 of the 46 patients. All those with VND had vertigo and CP upon the caloric test, 12/27 (44%). The degree of hearing loss in those with VND was significantly (p < 0.05) more severe and their recovery of hearing loss was poorer than in patients without VND. These results indicate that VND is a common finding in cases of sudden deafness with vertigo especially in those with severe hearing loss.

Evaluation of vestibular function by dynamic posturography and other equilibrium examinations

We evaluated the significance of dynamic posturography (EquiTest) in vestibular function assessment by comparing it with our routine equilibrium examinations comprised of nystagmographic data and other postural tests. Fifty-two patients with unilateral peripheral vestibular disorders were examined. Differences in test results between pendular rotation test and dynamic posturography were found in 23 out of 52 (44%) patients with unilateral peripheral vestibular disorders. In 5 patients, no abnormality of vestibular function could be detected by means of a three-test battery (spontaneous and positional nystagmus and pendular rotation test) used for evaluating vestibular compensation. In spite of these results, the patients complained of vertigo of dizziness and showed abnormal results in dynamic posturography. Dynamic posturography was superior to other postural tests in the detection of pathology corresponding with the patients' complaints. From these results, dynamic posturography (EquiTest) appeared to provide new information about such conditions of vestibular patients which other equilibrium examinations have not heretofore been able to detect.

Intraoperative electrocochleography of endolymphatic hydrops surgery using clicks and tone bursts

Seventy-seven ears of patients with Menière's disease (n = 69) and other ears with secondary endolymphatic hydrops (n = 8) underwent valved shunt surgery, and were monitored with intraoperative electrocochleography (ECoG) using clicks stimuli (n = 77), and both clicks and tone bursts (n = 37). Of the 41 ears in which the "baseline" measurement was > 35% summating potential to action potential (SP/AP) amplitude click ratio, 23 ears (56%) showed a significant ratio decrease (improvement). Twenty-six ears out of the 37 that were monitored by both clicks and tone bursts had abnormal absolute SP tone bursts amplitudes at "baseline" and 8 ears (31%) changed to normal at "closing". When tone burst ECoG information is combined with click stimuli, our basic understanding of click ECoG is enhanced and our ability to assess electrophysiologic changes intraoperatively is improved.

Interpretation of the combined galvanic test. Findings from cases with vestibular neuronitis

The combined galvanic test (CGT) was developed in our department for simultaneous recording of galvanic eye movement test (GEMT) and galvanic body sway test (GBST). Twelve cases of vestibular neuronitis were studied first with the caloric test, and then with the CGT. The findings of the caloric test corresponded to those of the GEMT, but did not always correspond to those of the GBST. Thus we suggest that the GBST reflects an abnormality in a system different from that reflected by the caloric test and GEMT. It is likely that the caloric response mainly originates from the semicircular canal system. Thus the GEMT may reflect an abnormality in the semicircular canal system, while the GBST reflects an abnormality in the otolithic system. The CGT may thus be a feasible method of differentiating the disorders of the semicircular canal system from those of the otolithic system in the vestibular nervous system.

Neuroborreliosis in the etiology of vestibular neuronitis

Symptoms and incidence of neuroborreliosis (NB) were studied in ambulatory patients visiting the ENT clinic in Helsinki. Especially we tried to search for possible markers indicating the connection between vestibular neuronitis and NB. A total of 350 patients were screened with the enzyme-linked immunosorbent assay (ELISA) technique for possible antibodies against Borrelia burgdorferi (BB). Twelve patients had positive serological reactions for BB with sera titer levels ranging from 640-14700 (normal < 500). In 2 additional cases, NB was clinically confirmed. In 7 cases a history of tick bite and in 4 cases erythema chronicum migrans was confirmed. In 9 cases, vertigo was the predominant symptom, and in 3 cases the symptoms were linked to facial nerve paresis. Six patients suffered from hearing loss. In 7 cases, the diagnosis was initially settled as vestibular neuronitis. NB seems to be present in about 4% of cases with apparent otologic diseases in Finland. In the majority of the cases, the disease resembles vestibular neuronitis in the acute stage. Since NB is tractable, all patients visiting the ENT clinic, especially those with vertigo, should be screened.

Vestibular neuritis: an overview using a classical case

Although acute unilateral and/or bilateral vestibular paralysis, known as vestibular neuronitis, is the second most common cause of vertigo (the most common is benign paroxysmal positional vertigo (BPPV), it is fraught with controversies. The clinical symptoms and methods of treatment of vestibular neuronitis are well defined; however, the etiology and pathophysiology of this disorder are still sketchy. Furthermore, there are no specific diagnostic tests available, and unfortunately, there are no animal models for this disorder. The purpose of this paper is to present an overview of those controversies using a classical case of vestibular neuronitis.

Autonomic nervous system disturbance as etiological background of vertigo and dizziness

In order to investigate whether dysautonomia lies behind vertigo and/or dizziness in the neurotological clinic, an electrocardiogram (ECG) R-peak to R-peak test (R-R test) along with the Schellong test were simultaneously performed in 136 subjects. ECG data were analyzed by a microcomputer, and R-R intervals were calculated. In a dynamic test performed during postural changes from the supine to the standing position, there were 23 of 55 (41.8%) positive test results in patients with peripheral vestibular disorders, 28 of 51 (54.9%) with central vestibular disorders, and 15 of 18 (83.3%) with spinocerebellar degeneration. In a static test with the patient in the standing position, there were 13 of 55 (29.1%) positive test results in patients with peripheral vestibular disorders, 16 of 51 with central vestibular disorders, and 8 of 18 (44.4%) with spinocerebellar degeneration. A significant difference in the positive rate between spinocerebellar degeneration and both other central and peripheral vestibular disorders in the dynamic test was observed. These results also demonstrated that dysautonomia upon postural changes might play an important role in the development of vertigo and dizziness and that it is provoked by disorders of the autoregulatory mechanisms of the cerebral blood flow. This test is presumed to be excellent for detecting dysautonomia by virtue of being non-invasive, having good reproducibility and being readily available to quantitative evaluation by using a microcomputer.

The role of summating potential in the diagnosis and management of Menière's disease

To assess the role of a negative summating potential (-SP) in the clinical diagnosis and management of Menière's disease, the relationship of -SP abnormality to clinical symptoms, hearing level and caloric test results was examined in 70 patients with unilateral Meniere's disease. The click-induced -SP and action potential (AP) were recorded by extratympanic electrocochleography. When SP/AP ratio exceeded 0.43, the -SP was considered to be abnormal. No significant relationship was found between abnormal -SP and clinical symptoms (the duration of cochlear and vestibular symptoms, recent hearing fluctuation and recent vertigo attack). Ears with abnormal -SP had a significantly worse hearing loss at high frequencies (2-8 kHz) than ears with normal -SP, whereas there was no significant difference in hearing loss at low frequencies (0.25-1 kHz) between both ears. No significant relation was found between abnormal -SP and abnormal unilateral weakness in caloric test. The results indicate that the click-induced -SP reflects the pathophysiology of Menière's disease basically in the cochlear partition at high frequencies.