Symptoms experienced by patients with peripheral vestibular disorders: evaluation of the Vertigo Symptom Scale for clinical application

OBJECTIVES

To describe symptoms during an episode of dizziness in a sample of patients suffering from peripheral vestibular disorders and to compare them with the items in the Vertigo Symptom Scale.

DESIGN

A descriptive study from a sample of patients with peripheral vestibular disorders.

SETTING

Patients visiting a department of audiology at a university hospital.

PARTICIPANTS

Twenty patients with peripheral vestibular disorders. The inclusion criteria were that the patient had had at least three spontaneous attacks of vertigo and/or was constantly unsteady during the last 3 months for at least 75% of the time when awake.

MAIN OUTCOME MEASURES

Patients were instructed to complete a diary where they recorded symptoms that arose during an episode of dizziness. These symptoms were compared with the content of the Vertigo Symptom Scale.

RESULTS

The most frequent symptoms as mentioned by the patients in their diaries were a feeling that things are spinning or moving around, nausea, feeling unsteady/about to lose one's balance, fatigue, headache, a feeling as if the ground you walk on is distant and ear-related such as tinnitus and a feeling of pressure in the ear. Pain in the heart or chest region, a heavy feeling in the arms or legs, pain in the lower part of the back and excessive sweating were not mentioned at all or by very few patients. Analysis showed that some of the symptoms included in the Vertigo Symptom Scale occurred less during an episode of dizziness than others in this sample of patients with peripheral vestibular disorders.

CONCLUSION

It was found that the Vertigo Symptom Scale is an adequate base but may need to be developed for use in patients diagnosed with peripheral vestibular symptoms to be able to evaluate care and treatment.

Patients' subjective evaluations of quality of life related to disease-specific symptoms, sense of coherence, and treatment in Ménière's disease

OBJECTIVE

To evaluate the self-rated quality of life associated with vertigo, hearing loss, and tinnitus in Ménière's patients, and to identify potential relationships between these findings, treatment regimens, and sense of coherence in comparison to the classification of the American Academy of Otolaryngology-Head and Neck Surgery (AAO/HNS).

STUDY DESIGN

Cross-sectional.

SETTING

Tertiary referral hospital centers.

PATIENTS

112 patients with Méniére's disease, who had undergone endolymphatic sac surgery or intratympanic gentamicin injections, or were surgically untreated.

MAIN OUTCOME MEASURE

Questionnaires concerning quality of life aspects and symptom-specific instruments: the Vertigo Symptom Scale (VSS), the Hearing Disability Handicap scale (HDHS), the Tinnitus Severity Questionnaire (TSQ), the AAO/HNS criteria for reporting results of treatment of Ménière's disease, and the Sense of Coherence Scale.

RESULTS

A majority of the patients reported their quality of life in general as very good or good. There was no difference in general quality of life, present hearing loss, or tinnitus between the three treatment groups, but the gentamicin-treated patients had less vertigo than did the other groups. Sense of coherence showed a strong correlation to reported quality of life in all measurements.

CONCLUSIONS

Even though the gentamicin-treated patients had less vertigo, no difference in overall quality of life was found between the surgically treated and untreated patients. The sense of coherence seems to be an important factor in the patient's experience of quality of life. Quality of life instruments can measure both specific symptoms and related aspects on quality of life and may give complementary information to the AAO/HNS classification in evaluating the treatment of patients with Ménière's disease.

The sense of coherence: a tool for evaluating patients with peripheral vestibular disorders

Peripheral vestibular disorders may result in physical as well as psychosocial dysfunction. Such a situation demands a capacity to cope which lately has been discussed as an important factor in the health outcome. Antonovsky has described the concept of sense of coherence (SOC) as such a trait and has developed a questionnaire (the SOC Scale) to measure it. The aim of this study was to describe the patients' self-rated degree of SOC and to set this in relation to their perception of the self-rated quality of life. The results showed that patients with a strong SOC scored statistically less self-rated handicap, less emotional distress, less impact on working capacity and sleep and rest and less psychosocial dysfunction than those with weak SOC scores. It is suggested that the SOC Scale may serve as a tool to identify patients who are at risk of poorer quality of life and in need of supportive care.

Symptoms, findings and treatment in patients with dehiscence of the superior semicircular canal

Recently Minor and co-workers described patients with sound- and pressure-induced vertigo due to dehiscence of the superior semicircular canal. Identifying patients with this 'new' vestibular entity is important, not only because the symptoms are sometimes very incapacitating, but also because they can be treated. We present symptoms and findings in eight such patients, all of whom reported pressure-induced vertigo that increased during periods of upper respiratory infections. Pulse-synchronous tinnitus and gaze instability during head movements were also common complaints. All patients lateralized Weber's test to the symptomatic ear. In some of the patients the audiogram also revealed a small conductive hearing loss. However, the stapedius reflexes were always normal. A vertical/torsional eye movement related to the superior semicircular canal was seen in most of the patients in response to pressure changes and/or sound stimulation. One patient also had superior canal-related positioning nystagmus. Testing vestibular evoked myogenic potentials revealed in all patients a vestibular hypersensitivity to sounds. In the coronal high-resolution 1-mm section CT scans the dehiscence was visible on 1 to 4 sections. Moreover, the skull base was rather thin in this area and cortical bone separating the middle ear and the antrum from the middle cranial fossa was absent in many of the patients. Two of the patients have undergone plugging of the superior semicircular canal using a transmastoid approach and both patients were relieved of the pressure-induced symptoms.

Nystagmus findings in healthy subjects examined with infrared videonystagmoscopy

The increased use of video systems for the detection of nystagmus is a new diagnostic tool in the diagnosis of patients with vestibular disorders. Small video cameras mounted in a light sealed mask visualize the eyes which are illuminated with infrared light. Compared to the well-established use of Frenzel glasses the patient has no visual references at all. This new technique requires standards for normal limits. Thirty subjects between 20 and 78 years of age with no history of vestibular disorders were examined with infrared video-oculoscopy with the gaze in primary position, after head-shake and in supine position with head torsion and Dix-Hallpike positions backward and forward according to a standardized procedure at our department. Two subjects had spontaneous nystagmus, but nystagmus after head-shake was not found in any. No subject had torsional nystagmus in the Dix-Hallpike positions. In the elderly subjects horizontal nystagmus in head hanging position was a frequent finding.

Vestibular neuritis: a follow-up study

Seven to eight years after a disease period of vestibular neuritis 19 patients previously examined at our department were given a questionnaire about whether they had experienced any audiovestibular symptoms since they first fell ill. All 19 patients responded and 18 consented to participate in the long-term follow-up study. The patients were subjected to a clinical evaluation, a bithermal caloric test and audiological examinations with stapedius reflex measurements with use of the same technique as at the first examinations. Ten of the 18 patients had experienced recurrent vestibular symptoms with sensation of dysequilibrium and vertigo. Six of these 10 patients also had periods of positional vertigo. The remaining nine patients were free of symptoms. None of the patients had noticed any change in their hearing ability. The mean caloric side difference at the 7- or 8-year follow-up was not significantly higher in the group of patients with symptoms than in the group without symptoms. Neither did the group of patients with pathologically elevated stapedius reflex thresholds at onset display a larger mean caloric side difference than the group of patients with normal thresholds. However, a small caloric side difference at onset of the disease served as a predictor for residual vestibular symptoms. It is speculated whether the group of patients with residual symptoms had a different pathophysiological localization of their disease within the vestibular system than the group of patients with no symptoms at follow-up.

Vestibular-evoked myogenic potentials in patients with dehiscence of the superior semicircular canal

Recently Minor and co-workers described patients with sound- and pressure-induced vertigo due to dehiscence of bone overlying the superior semicircular canal. Identifying patients with this "new" vestibular entity is important, not only because the symptoms can be very incapacitating, but also because they are surgically treatable. We present symptoms and findings for three such patients. On exposure to sounds, especially in the frequency range 0.5-1 kHz, they showed vertical/torsional eye movements analogous to a stimulation of the superior semicircular canal. They also showed abnormally large sound-induced vestibular-evoked myogenic potentials (VEMP), i.e. the short latency sternomastoid muscle response considered to be of saccular origin. The VEMP also had a low threshold, especially in the frequency range 0.5-1 kHz. However, in response to saccular stimulation by skull taps, i.e. when the middle ear route was bypassed, the VEMP were not enlarged. This suggests that the relation between the sound-induced and the skull tap-induced responses can differentiate a large but normal VEMP from an abnormally large response due to dehiscence of bone overlying the labyrinth, because only the latter would produce large sound-induced VEMP compared to those induced by skull taps.

Dizziness symptom severity and impact on daily living as perceived by patients suffering from peripheral vestibular disorder

The purpose of this study was to describe quality-of-life aspects in a group of patients (n = 99) suffering from peripheral vestibular disorder, using three different self-rated instruments, the Vertigo Symptom Scale (VSS), the Vertigo Handicap Questionnaire (VHQ) and the Sickness Impact Profile (SIP). The results showed that the type of dizziness that most influenced the quality-of-life aspects were: frequent short- or long-term dizziness, nausea, and the feeling that the ground was distant or as though the patient were walking on clouds. However, several of the impairments in daily life were neither related to the disease itself nor the demographic data. This verifies the necessity of investigating other factors such as personality and coping capacity. The results of this study also demonstrate the patients' need of psychosocial support. A comprehensive assessment and evaluation is important in order to identify each patient's needs.

Subjective visual horizontal during follow-up after unilateral vestibular deafferentation with gentamicin

The subjective visual horizontal (SVH) was measured by means of a small, rotatable, luminous line in darkness in the upright head and body position and at 10, 20 and 30 degrees of tilt to the right and left before, and repeatedly during a follow-up period of 1 year after intratympanic gentamicin instillations in 12 patients with recurrent vertigo attacks. This treatment caused a loss of the bithermal caloric responses on the diseased side. Shortly after treatment there was a significant tilt of SVH towards the treated side (group mean = 10.6 degrees). Repeated testing made it possible to characterize mathematically the changes with time for SVH. For the group of patients as a whole this otolithic component of vestibular compensation was best described by a power function, SVH = 8.65t(-0.16) degrees, where t is time in days after maximum tilt of SVH. After 1 year, SVH was still significantly tilted towards the treated side (group mean = 3.16 degrees). Gentamicin treatment also caused a significant reduction in the perception of head and body tilt towards the deafferented side, while the perception of tilt towards the healthy side did not show any significant changes. During follow-up there was a gradual improvement in the perception of tilt towards the treated side. However, a significant asymmetry in roll-tilt perception was still present 1 year after deafferentation. There was no correlation between SVH in the upright position and roll-tilt perception, suggesting that these parameters are to some extent dependent on different afferent input from the vestibular organ. They were also found to be complementary for the detection of vestibular disturbance.

The subjective visual horizontal after stapedotomy: evidence for an increased resting activity in otolithic afferents

The subjective visual horizontal (SVH) was measured by means of a small rotatable luminous line in darkness in the upright body position and at 10, 20 and 30 degrees of body tilt to the right and left prior to, and during a follow-up period after, stapedotomy in 12 patients with otosclerosis. In the acute stage after surgery, SVH in the upright body position was significantly tilted away from the operated side. In addition, the perception of roll tilt towards the operated side (Kop) was significantly increased after stapedotomy, while the perception of roll tilt towards the healthy side (Khe) showed a slight but not significant reduction. After exclusion of two outliers, a statistically significant correlation was found between changes in Kop and in Khe. The slope of the regression line was 1.8:1, probably corresponding to a preference of the utricle for ipsilateral as opposed to contralateral head tilt. In four patients there was a weak ( < 1 degrees/s) spontaneous nystagmus, not systematically related to the side of surgery, while in most cases there were no nystagmus or subjective vertigo symptoms. These specific changes in the subjective horizontal show that the otolithic effects on perception can be dissociated from canal effects. Further, the results are opposite to those for patients with unilateral loss of vestibular function. The tilt of SVH after stapedotomy indicates an increase in resting activity of utricular afferents. In addition, based on recent theories on otolith function, we suggest that an increased activity in saccular afferents is of major importance for the changes in roll-tilt perception because of its interaction with the utricle on the central nervous level.

Living with dizziness: an explorative study

A qualitative study was conducted for the purpose of exploring how patients with dizziness manage their daily living. Ten patients with history of dizziness were recruited from the out-patient clinic, Department of Audiology, in a hospital in Stockholm. Collection and analysis of data were inspired by the method of grounded theory. Four themes were developed that described the experience of living with dizziness: vulnerable reactions, affirmation and non-affirmation, finding ways to carry on daily living, and expressing the need for health care support. These themes seem to conceptualize these patients' difficulties and needs in relationship to living with dizziness and, given the small sample, have implications for nursing practice and provide a framework for a broader study.

When and how to use gentamicin in the treatment of Menière's disease

Gentamicin given as local therapy for severe Menière's disease is of considerable value in the control of vertigo. The ototoxic antibiotic is instilled through the tympanic membrane causing a peripheral vestibular loss and possibly also diminished endolymph production. In order to achieve the best results with gentamicin treatment it is of utmost importance that the diagnosis is correct. Given to a patient with vertigo of other than peripheral origin, the outcome would be worsening of the existing symptoms and addition of new ones. The method should be used only by physicians who are very familiar with vertigo and otology, and only in patients with such a disturbing degree of vertigo that they are well motivated to receive treatment. Thorough information regarding the disease, the treatment procedure and the symptoms caused by a unilateral peripheral vestibular loss should be given to the patient. Vestibular rehabilitation, including movement therapy, should be given by the physician or preferably, a well trained physiotherapist on an individual basis or in patient groups together with written practice programmes for use at home. Vertigo attacks are usually relieved in 95% of patients. Twenty percent of patients experience an added hearing loss in the treated ear, although this number is reduced if the treatment is given as a single installment on consecutive days with extra installments given one month later if the vertigo remains.

Further studies on a male monozygotic triplet with schizophrenia: cytogenetical and neurobiological assessments in the patients and their parents

We previously described a Swedish set of male schizophrenic monozygotic triplets. In this study the patients as well as their parents were further characterized. By high-resolution chromosomal analysis an extra band at chromosome 15p was found in all the triplets and the father. Microdissection, degenerate oligonucleotide-primed PCR (DOP-PCR) amplification and reverse painting indicates that the extra band probably contains only repetitive DNA sequences with no known effect on the phenotype. Magnetic resonance imaging (MRI) showed similar borderline ventricular enlargement and widened subarachnoid spaces over frontoparietal and basal regions as well as around the pituitary gland (empty sella) in all the triplets. The father also had widened subarachnoid spaces over the frontal and basal regions. The mother had an empty sella indicating widened subarachnoid spaces. All the boys also had a right-sided conductive hearing defect, probably due to malformation and fixation of the ossicular chain. The parents did not present any otological abnormalities. Neuropsychological assessment demonstrated similar marked reductions of attentional, mnestic, and executive functions in all the triplets, but the mother showed a normal pattern. Possible joint etiological mechanisms for the psychological and somatic abnormalities recorded in the triplets are discussed.

Gentamicin treatment in peripheral vestibular disorders other than Ménière's disease

Intratympanic instillation of gentamicin may not exclusively be a treatment for Ménière's disease. We present case reports of successful vertigo control in peripheral vestibular disorders other than Ménère's disease. Cases 1 and 2 illustrate treatment of vertigo attacks caused by vestibular dysfunction in deaf ears. Case 3 illustrates treatment of brief sensations of linear acceleration in a patient who had suffered idiopathic sudden hearing loss a few years earlier. Case 4 illustrates treatment of disabling benign paroxysmal positioning vertigo. Case 5 illustrates treatment of severe and frequent attacks of vertigo in an elderly patient with a medium-sized acoustic neuroma who did not want surgical extirpation of the tumor.

Tilt Suppression, OKAN, and Head-Shaking Nystagmus at Long-Term Follow-Up After Unilateral Vestibular Neurectomy1

The functional status of the velocity storage mechanism was studied in patients at long-term follow-up (2 to 4 years) after unilateral vestibular neurectomy. The time constant of the vestibulo-ocular reflex (VORtc), the effect of head tilt on postrotatory nystagmus, optokinetic after-nystagmus (OKAN), and nystagmus after rapid head shaking were studied in 10 patients. In agreement with previous findings, VORtc was found to be short and most patients manifested OKAN, suggesting that unilateral peripheral vestibular loss is associated with a complete loss of storage within the the VOR but only a partial loss of velocity storage for visual input. However, at postrotatory head tilt the VOR time constant was further shortened, supposedly due to discharge of functioning velocity storage. Moreover, most patients manifested nystagmus after head shaking. These findings on tilt suppression and head-shaking nystagmus suggest that velocity storage within the VOR may function even in patients with complete unilateral vestibular lesions.

Tilt suppression, OKAN, and head-shaking nystagmus at long-term follow-up after unilateral vestibular neurectomy

The functional status of the velocity storage mechanism was studied in patients at long-term follow-up (2 to 4 years) after unilateral vestibular neurectomy. The time constant of the vestibulo-ocular reflex (VORtc), the effect of head tilt on postrotatory nystagmus, optokinetic after-nystagmus (OKAN), and nystagmus after rapid head shaking were studied in 10 patients. In agreement with previous findings, VORtc was found to be short and most patients manifested OKAN, suggesting that unilateral peripheral vestibular loss is associated with a complete loss of storage within the the VOR but only a partial loss of velocity storage for visual input. However, at postrotatory head tilt the VOR time constant was further shortened, supposedly due to discharge of functioning velocity storage. Moreover, most patients manifested nystagmus after head shaking. These findings on tilt suppression and head-shaking nystagmus suggest that velocity storage within the VOR may function even in patients with complete unilateral vestibular lesions.

The subjective horizontal at different angles of roll-tilt in patients with unilateral vestibular impairment

The subjective visual horizontal is mainly dependent on the otolithic system. A group of 11 patients with sudden unilateral vestibular impairment were asked to set a dimly illuminated bar according to their subjective horizontal when they were seated upright and tilted 10, 20, and 30 degrees to the right and left in a completely darkened room (Bias test). The patients were examined within 1 week, after 3 and 6 weeks, and 9 patients consented to the 11-week follow-up. The results were compared with ENG examinations. In the acute stage of the disease all patients, when they were in upright position, set the light bar tilted towards the affected side. At roll tilt to the affected side, 9 of the 11 patients set the light bar in the same direction as their body tilt (undercorrection). At a tilt to the unaffected side 6 of the 11 patients made an undercorrection. For the group of patients the magnitude of undercorrection was larger at tilt to the affected side than to the unaffected side. The patients' ability to correctly align the light bar with the true horizontal gradually improved but was found normal in both upright and tilted positions in only three of the nine patients at the last follow-up. In four of the six patients who still demonstrated pathologic results, these were met only in tilted positions. No significant correlation was found between the intensity of spontaneous nystagmus or the degree of caloric side difference and the deviation in setting of the light bar in upright or tilted positions. The large asymmetric perceptual responses at tilt found at onset might be explained by the two-directional organisation of the utricle.

Surgical treatment of vertigo--the Karolinska Hospital policy

Results are reported for 40 patients with disabling vestibular symptoms, treated with endolymphatic sac surgery (ELS), gentamicin injections in the middle ear, or vestibular neurectomy by the middle fossa approach. If ELS failed, an additional treatment with a second ELS procedure or gentamicin instillations was performed. If the gentamicin treatment failed, the patients were treated with a second series of gentamicin instillations or vestibular neurectomy or both. The results in relieving the patients of their vertigo were found to be almost the same with each of the treatment modalities: approximately 82% of the patients in each group reported total or substantial relief of vestibular symptoms, whereas the rate of complications differed between the groups. After ELS, one patient had a possible complication in that she became deaf 10 days after surgery. After gentamicin injections, 12 of the 14 patients with preoperatively measurable hearing had significantly decreased hearing, but no other complications were reported. After vestibular neurectomy, five of 11 patients had complications in the form of hearing loss, infections, or transient facial paralysis. No effect on tinnitus was seen after any of the methods. When evaluating the outcome after the final surgical treatment of the 40 patients, it was found that 38 patients (95%) reported total or substantial relief of vestibular symptoms. A future policy for surgical treatment of vertigo is discussed.

The subjective visual horizontal for different body tilts in the roll plane: characterization of normal subjects

In order to establish a method for estimation of the perceptual horizontal as a test of otolith function in diagnosis of atypical vertigo, in a first study we have standardized a test procedure and characterized a body of normal material consisting of 72 healthy subjects, 24 of them examined with tests followed by retests. The perceptual visual horizontal in darkness was estimated in the upright body position and at body tilts of 10, 20, and 30 degrees to the right and to the left by means of a narrow luminous bar. The deviation of the perceptual horizontal relative to the gravitational horizontal is expressed as a function of body tilt. In the upright body position, 95% had a perceptual horizontal within the range of +/- 2.5 degrees. In the tilted positions, there was a tendency to set the light bar tilted oppositely with respect to the body tilt. The results suggest that roll tilt to the right and to the left is sensed by two independent functional units. Furthermore, the results imply that some other factor might be of importance and that the perceptual horizontal in the upright position and tilt perception are complementary in reflecting vestibular function. Differences between individuals were great in comparison with intraindividual variability and the test-retest variability. The results are discussed against the background of the extensive literature.

Short vestibulo-ocular reflex time-constant in complete unilateral vestibular lesions

The time-constant of the vestibulo-ocular reflex (VORtc) in response to short accelerations was studied in 18 patients with complete unilateral vestibular lesions: 12 patients with incomplete lesions and 9 healthy controls. The marked group differences in VORtc, which was short in patients with complete lesions and long (i.e., > or = 10 s) in the controls and some patients with incomplete lesions, suggests the finding of a long VORtc in a patient with a unilateral vestibular lesion to indicate the presence of an incomplete lesion. Moreover, one analytic method (where the initial phase of decay is weighted) showed the VORtc to be longer following stimulation toward the healthy ear than following stimulation toward the lesioned ear, whereas other analytic methods showed no direction asymmetry in VORtc.

Mefloquine Prophylaxis and Hearing, Postural Control, and Vestibular Functions

Background: Mefloquine (MQ) is an important antimalarial drug. Dizziness and other adverse neuropsychiatric reactions have however restricted its use. Method: Ten healthy adult volunteers were given MQ (Lariam) 250 mg once weekly for 16 weeks. Measurement of postural sway (posturography), nystagmus recording, determinations of hearing thresholds (Bekesy audiometry), and determinations of drug concentrations were done before, after 4, 32, and 109 days of weekly MQ intake and 3 months after the last dose. Results: All volunteers were able to continue their professional work and normal daily activities. Several mild symptoms were reported. In at least one of the volunteers, these symptoms were probably caused by the MQ intake. Hearing thresholds remained normal. No significant changes were noted in the nystagmus tests. The recorded values of sway index were within the normal range (99% confidence interval) in all volunteers in all test situations, and no differences were seen at the time of maximal drug concentrations (day 109) compared to before or after the study. There was no correlation between the plasma concentrations of MQ, the two MQ enantiomers (RS and SR), or the main mefloquine metabolite and the sway index. Conclusion: Although no effect was seen on the vestibular system in the present study, further tests in a flight simulator will be needed before MQ can be recommended for pilots. (J Travel Med 2:66-69, 1995)

"Dumping" of activity within the VOR is possible after unilateral vestibular neurectomy

The effect of head tilt on postrotatory nystagmus was studied in patients at long time follow-up of complete unilateral vestibular lesions. Ten patients were tested 2-4 years after unilateral vestibular neurectomy. They were all found to have short VOR time constants. However, at postrotatory head tilt the VOR time constant was further shortened. This suggests that the velocity storage mechanisms may function even in cases with complete unilateral vestibular lesions.

Oculomotor and nystagmus tests in subjects with strabismus

Smooth pursuit (SP) and saccades (SC) as well as nystagmus were recorded with electro-oculography in 21 healthy subjects with manifest non-paralytic strabismus. A normal SP function under binocular conditions could be recorded in 67% of the subjects and complementary monocular recordings increased the figure to 81%. The corresponding figure for the SC test was 38 and 67%, respectively. However, a minority of the subjects presented a normal test result under both binocular and monocular conditions. Spontaneous nystagmus and/or nystagmus after headshaking was present in 67%. These findings may indicate that subjects with strabismus have a combination of a 'subclinical' vestibular and oculomotor dysfunction.

Inner ear effects of topical gentamicin treatment in patients with Menière's disease

Several efforts have been made to treat patients with Menière's disease with ototoxic drugs. Lately the aminoglycoside antibiotic, gentamicin, has been favored. Several reports have proved its efficacy. In a series of 12 patients treated at the Karolinska Hospital in Stockholm, two patients failed to show improvement regarding their vertigo in spite of repeated courses of treatment. These patients both underwent labyrinthectomy where their vestibular sensory epithelia as well as portions of the cochlea were removed. The findings in these two cases were quite unanimous in that the vestibular sensory epithelia were retained showing advanced signs of degeneration. The organ of Corti in the cochlea was totally absent in all specimens examined. These findings indicate that gentamicin seems to affect the cochlea more than the vestibular sensory epithelia that also was clinically proven since both patients totally lost their hearing in the affected ear. Possible routes and actions of the drug in the inner ear are discussed.

The relationship between caloric response, oculomotor dysfunction and size of cerebello-pontine angle tumours

Seventy-nine consecutive patients, 70 patients with acoustic neurinomas (ACN) and 9 patients with cerebello-pontine angle tumours of other etiology (o-CPA) were analysed with respect to tumour size and the result of the caloric and oculomotor tests. The size of the tumour was judged by the largest diameter calculated from the computerized tomography. A highly significant linear relationship between tumour size and caloric side difference was found for the group of ACN patients who had normal oculomotor function. A unilateral loss of caloric response on the tumour side was found in 75% of the ACN patients with tumours larger than 20 mm, but not in any of the ACN patients with tumours smaller than 10 mm. Oculomotor dysfunction (OMD), defined as disturbed pursuit eye movements and/or gaze nystagmus was frequently found in the patients with ACN larger than 20 mm (77%), and was present in all but one of the o-CPA patients. However, the caloric response on the tumour side was significantly more impaired in the group of ACN patients with OMD than in the o-CPA group. A combined view of the oculomotor and caloric test results offers a possibility to obtain a rough estimate of tumour size as well as to distinguish ACNs from other types of tumours in the cerebello-pontine angle.

Drop attacks in Menière's disease

An inner ear etiology for drop attacks is easily overlooked and seldom mentioned in the literature. Cardiovascular pathology is what generally is looked for, e.g. transitory ischemic attacks. Twenty-nine patients with frequent and severe Meniere attacks were treated with gentamicin intratympanally, when they had reached a stage of incapacitation due to vertigo and dread of further attacks and all medical treatments had failed. All but one patient were suffering from more or less frequent drop attacks. The attacks of vertigo were successfully cured in all patients except 2, who had recurrence of the inner ear problem. The drop attacks disappeared in all patients, which indicates that they had an inner ear origin.

Some considerations on caloric test results

The caloric test procedure as suggested by Fitzgerald & Hallpike is still widely used. With a carefully standardized procedure it is well suited to identify the affected side in patients with unilateral vestibular impairments. By repeated testing it is also possible to follow the course of a vestibular affection.

Saccade abnormalities in patients with ocular flutter

In a group of 8 patients with opsoclonus or ocular flutter, the eye movements were recorded by electro-oculography (EOG). The spontaneous eye movement pattern and the amplitude and peak velocity of the refixation saccade were analysed. The EOG recording demonstrated frequent bursts of horizontally and vertically directed saccades elicited without any intersaccadic interval. Three patients also demonstrated an increased frequency of square waves. In 6 of the 8 patients the peak velocity of the voluntary saccades was increased; in 5 patients this condition was found for saccades in both directions. Over-shooting oscillations or slightly hypermetric voluntary saccades occurred in 5 patients. It is proposed that the ocular flutter and the increased saccadic velocities found in the present series of patients is caused by a disorder of the burst cells in the brain stem saccadic control system.

Vestibular findings in sensorineural hearing disorders. Results of caloric, oculomotor and hearing tests in 205 patients with unilateral hearing dysfunction

In 205 patients with unilateral hearing loss, 117 of cochlear and 88 of retrocochlear origin, thorough audiovestibular examinations were performed to establish the occurrence and severity of vestibular dysfunction. The results were also analysed with the aim of determining the relationships between the severity of the hearing loss, the etiology and the topical location of the hearing disorder, on the one hand, and vestibular dysfunction, recorded as reduced caloric sensitivity and occurrence of oculomotor disturbances, on the other. No correlation was found between severity of hearing loss and recordable vestibular dysfunction, in either the cochlear or retrocochlear group of patients, or in the etiological subgroups of these main groups. With respect to the relations between the topic locations of the lesions and the results of vestibular tests, distinct characteristics were observed. In the affected ears, totally extinguished caloric reactions were more than six times as frequent in the retrocochlear group as in the cochlear group and appeared as a specific but rather insensitive sign of acoustic neurinoma. Oculomotor disturbances were only exceptionally observed in patients with cochlear lesions, but were noted in nearly half of the retrocochlear group; when only those patients with lesions of the brain stem or cerebellum were considered, all were found to exhibit such disturbances. The relations between audiometric hearing test pattern, caloric sensitivity and oculomotor disturbances seem to form interesting diagnostic paradigms of great value for the topical localization of audiovestibular disorders.

Computerized analysis of voluntary eye movements. A clinical method for evaluation of smooth pursuit and saccades in oto-neurological diagnosis

To permit rapid and exact quantification of the oculomotor function in clinical practice, a computerized program has been designed for the recording and analysis of pursuit eye movements and voluntary saccades. In a pursuit sequence the subject tracks a moving target, projected onto a screen at a constant speed of 20 degrees/sec over a horizontal visual angle of 60 degrees. The pursuit sequence is followed by a refixation saccade when the subject rapidly shifts his gaze back to the starting point of the target. A complete test procedure consists of ten consecutive pursuit sequences and refixation saccades in each direction. The EOG signal is fed to a PDP11/23 computer for storage and analysis. The pursuit eye movements are quantified and arranged in five velocity intervals: less than 8, 8-16, 16-24, 24-32 and greater than 32 degrees/sec. The relative distribution of the velocity content is calculated for these intervals and presented in histogram form. Saccades superimposing on the smooth pursuit are identified and grouped according to amplitude and direction. The refixation saccades are quantified as mean peak velocities and also the highest and lowest velocities of the refixation saccades are determined. In a material of 70 healthy subjects, normative data and limits for pathological function were established. In the smooth pursuit, 69% of the velocity values were located within the 16-24 degrees/sec interval. Pathological limits were set for each velocity interval and impaired pursuit tracking ability was considered to be present when those limits were reached in at least three of the five intervals. Normal mean peak eye velocity of the refixation saccade was found to be 460 degrees/sec with a range of 354-575 degrees/sec. Application of the test procedure and method of analysis is described in two patients with impairment of the oculomotor function due to a disturbance in the cerebellar brain stem area.

Audio-vestibular findings in patients with vestibular neuritis

19 patients with the clinical diagnosis vestibular neuritis, i.e., cases with unilaterally ENG verified abolished or reduced caloric reactions but without symptoms of central nervous involvement or hearing impairment, participated in the study. In addition to ENG examinations and Békésy audiometry all patients were submitted to stapedius reflex tests and auditory brainstem response examinations (ABR) for signs of subclinical auditory nerve engagement. In all but one of the 19 patients the caloric reactions improved; 8 of the 13 patients available for tests after one year recovered completely. The ABR was normal in all cases but the stapedius reflex thresholds were pathologically elevated and remained so in about half of the subjects throughout the observation time; reflex decay was not present in anyone. Cases with pathologically elevated stapedius reflex thresholds showed a tendency to slower recovery of the vestibular function than the group with the normal reflexes. The results were interpreted to indicate lack of eighth nerve or CNS engagement. The possibility that subjects with reflex threshold elevation may constitute a group with constitutional weakness of the audio-vestibular apparatus disposed for vestibular disease is discussed.

[Head trauma with resultant irreversible deafness on one side and reversible hearing impairment on the other side. A case report]

Following a severe head trauma, a 27-year-old man immediately suffered from bilateral hearing loss and impaired balance. On examination there was a complete loss of hearing on the right side. On the left side a subtotal hearing loss of sensorineural origin occurred and became total after a few days. The vestibular function was absent on both sides. Following treatment with prednisolone, hearing recovered in the left ear and reached an average tone threshold of 55 dB. The vestibular function remained lost from the onset of the trauma. At follow up two years later the subtotal hearing loss in the left ear was unchanged as was also the vestibular impairment.

Stapedius reflex test, brainstem audiometry and opto-vestibular tests in diagnosis of acoustic neurinomas. A comparison of test sensitivity in patients with moderate hearing loss

The stapedius reflex test, brainstem audiometry and the opto-vestibular tests for identifying acoustic neurinomas (AN) were evaluated and compared in a study of 21 patients with radiologically or surgically verified AN and a pure tone average not exceeding 60 dB HL. The stapedius reflex test results were interpreted according to the criteria developed at this clinic. The stimuli for the auditory brainstem response (ABR) were 2 kHz haversine waves and 4 kHz square waves. The vestibular examination consisted of a caloric test and the recording of eye-tracking and gaze nystagmus. In the cases studied the stapedius reflex test gave 1 false-negative result and ABR none. The ENG gave 3 false-negatives whereas the results of speech discrimination tests were misleading in no fewer than 1/3 of the cases. The results of the different tests were directly correlated but correlation coefficients did not exceed 0.65. Tumours larger than 15-20 mm showed a different test pattern than those below that size: stapedius reflex response, ABR and caloric response were eliminated and all of these patients had abnormal optomotor function. It is suggested that an optimal routine test procedure should consist of a pure tone audiogram, supplemented by ABR or the stapedius reflex test. Opto-vestibular tests may be of value in a preliminary estimation of tumour size.

Automatic analysis of electro-oculographic (EOG) recordings. Application to audio-vestibular diagnosis

An automatic, computerized system for analysis of the ocular movements in nystagmus, slow pursuit and saccades is presented. The performance of the system has been tested in healthy subjects, as well as in patients with peripheral or brainstem audio-vestibular disorders. The automatized procedure enables an extended application of opto-motor tests in the clinical examination of patients with suspected retrocochlear and brainstem involvement.