Patients' experiences of living with superior canal dehiscence syndrome.

OBJECTIVE: The study investigated how the symptoms of superior canal dehiscence syndrome (SCDS) affected patients in their daily life, and how patients coped with the disease. DESIGN: This was a qualitative study; semi-structured interviews were performed and analysed according to the systematic text condensation method. STUDY SAMPLE: Twelve of 13 identified patients with SCDS in the county of Norrbotten, Sweden, were included in the study. RESULTS: Five main categories were created based on the patients' experiences of living with SCDS: (1) Experiencing strange symptoms: One "new" symptom was identified - mental fatigue. (2) A restricted life socially, physically and at work: All patients experienced some extent of limitation in their daily life. (3) To accept and to protect oneself: All patients had developed strategies to protect their ears from noise. (4) Misunderstood in health care: The diagnosis was sometimes delayed several years due to lack of knowledge among healthcare workers. (5) Carefully considering treatment (surgery): Symptoms were weighed against the risk of side effects. CONCLUSIONS: SCDS was rendered an invisible disability. In the present study, we identified mental fatigue as a symptom not previously considered in the literature.

The Reliability and Validity of "Dokuz Eylül University Meniere's Disease Disability Scale".

OBJECTIVE: Ménière's Disease (MD) is a chronic, non-life threatening inner ear disease, with attacks of disabling vertigo, progressive hearing loss, and tinnitus as the major symptoms. All three symptoms, separately or in combination, cause great distress and have a considerable impact on the quality of life of the patients. The aims of this study were to develop a disease-specific quality of life survey for patients with MD and to analyze the relationships between the audiovestibular findings and the survey. MATERIALS AND METHODS: Following Ear-Nose-Throat examination and audiovestibular tests, the Dokuz Eylül University Meniere's Disease Disability Scale (DEU-MDDS) and Turkish version of the Dizziness Handicap Inventory (DHI-T) were administered to 93 patients with definite MD. Reliability and validity analyses of the scale were performed. RESULTS: There were 45 (48.4%) male and 48 (51.6%) female patients and the mean age was 48.9±12.1 years. Cronbach's alpha was 0.92 and intraclass correlation coefficients of the DEU-MMDS were significant (p<0.001). Results of the Goodness of Fit Statistics showed that the expression levels of the items were high and the correlation coefficients of each item with the scale were sufficient. There was a statistically significant correlation between DHI-T scores and MDDS. DEU-MDDS was not related to the vestibular tests, age or gender (p>0.05). CONCLUSION: The MDDS is a valid and reliable scale as a disease-specific quality of life questionnaire for patients with MD.

Perception of slow pitch and roll body tilts in bilateral labyrinthine-defective subjects.

The aim of the present study was to examine whether the perception of slow body tilts in total darkness was affected by a complete loss of vestibular function. Four blindfolded bilateral labyrinthine-defective subjects (LDs) and 12 normal subjects (Normals) were seated and immobilized with large straps against the back of a rotating L-shaped platform, and were passively displaced from the upright at 0.05 degrees x s(-1) in the pitch and roll dimensions. Subjects were asked to detect the slow change in their body orientation, by indicating as soon as possible the direction of tilt. After a brief period of practice observed for all LDs at the beginning of the session, results showed no significant difference between LDs and Normals in the mean detection threshold recorded for each direction of tilt. The mean perceptual threshold was 4.4 versus 5.1 degrees in the roll dimension, and 6.1 versus 6.1 degrees in the pitch dimension, for the LDs and Normals, respectively. These findings indicate that the accurate perception of body orientation in quasi-static conditions is mainly allowed by somatosensory information rather than by otolithic inputs.

Coriolis-force-induced trajectory and endpoint deviations in the reaching movements of labyrinthine-defective subjects.

When reaching movements are made during passive constant velocity body rotation, inertial Coriolis accelerations are generated that displace both movement paths and endpoints in their direction. These findings directly contradict equilibrium point theories of movement control. However, it has been argued that these movement errors relate to subjects sensing their body rotation through continuing vestibular activity and making corrective movements. In the present study, we evaluated the reaching movements of five labyrinthine-defective subjects (lacking both semicircular canal and otolith function) who cannot sense passive body rotation in the dark and five age-matched, normal control subjects. Each pointed 40 times in complete darkness to the location of a just extinguished visual target before, during, and after constant velocity rotation at 10 rpm in the center of a fully enclosed slow rotation room. All subjects, including the normal controls, always felt completely stationary when making their movements. During rotation, both groups initially showed large deviations of their movement paths and endpoints in the direction of the transient Coriolis forces generated by their movements. With additional per-rotation movements, both groups showed complete adaptation of movement curvature (restoration of straight-line reaches) during rotation. The labyrinthine-defective subjects, however, failed to regain fully accurate movement endpoints after 40 reaches, unlike the control subjects who did so within 11 reaches. Postrotation, both groups' movements initially had mirror image curvatures to their initial per-rotation reaches; the endpoint aftereffects were significantly different from prerotation baseline for the control subjects but not for the labyrinthine-defective subjects reflecting the smaller amount of endpoint adaptation they achieved during rotation. The labyrinthine-defective subjects' movements had significantly lower peak velocity, higher peak elevation, lower terminal velocity, and a more vertical touchdown than those of the control subjects. Thus the way their reaches terminated denied them the somatosensory contact cues necessary for full endpoint adaptation. These findings fully contradict equilibrium point theories of movement control. They emphasize the importance of contact cues in adaptive movement control and indicate that movement errors generated by Coriolis perturbations of limb movements reveal characteristics of motor planning and adaptation in both healthy and clinical populations.

Do musical hallucinations always arise from the inner ear?

It has been known for some time that musical hallucinations occur in deaf patients. This has been ignored, as it has been believed that neurological and psychiatric causes predominate. However, despite specific appeals, no one with musical hallucinations and a lesion in the brain but not in the ear has been produced. The postulated otological basis is a hyperactive state of the ear, a slight endolymphatic hydrops or pre-Meniere's disease. The hallucinations probably develop out of rhythmic tinnitus. A review of all the very disparate states and diseases supposedly causing musical hallucinations shows that peripheral ear symptoms are always present. It therefore seems that they always have the same simple otological trigger.

Application of tetra-ataxiametric posturography in clinical and developmental diagnosis.

Tetra-ataxiametric posturography is based on the measurement and computerized elaboration of electronic signals emitted by four footplates, one for each heel and toe, respectively. These are sensitive to vertical pressure produced by a subject standing straight but in various positions (feet parallel, in tandem, eyes closed, on pads, etc.). The method yields additional parameters not obtained by the traditional monoplate stabilometers, namely, weight-distribution patterns and correlations among six combinations of paired outputs from the two heels, two toes, heel/toe of each foot, and the two diagonals (tetra-ataxiametric synchronisations). Comparing age-matched learning disabled, mentally retarded, autistic, and hearing impaired (with and without labyrinthine hypofunction) with normal children, significant and clinically meaningful differences were detected between the tetra-ataxiametric measures of stability, interaction between Fourier Spectral Power Ranges of body sway, weight distributions, and synchronisations of toe parts. The same parameters correlated significantly with cognitive school readiness in normal populations. While the stability and spectral quotients show significant developmental changes, weight distribution and toe synchronisations are stable from 5 years onwards. The method is suitable for young subjects and attractive to children who may ordinarily be reluctant to cooperate, such as the autistic ones. The equipment is portable and tests can be conveniently carried out in a child's familiar educational setting.

The perilymph fistula syndrome defined in mild head trauma.

Neurological and neuro-otological studies were carried out on 102 adults with mild cranio-cervical trauma productive of positional vertigo and perilymph fistula as confirmed by laboratory tests, and by the finding of perilymph fistula at tympanotomy in the surgically managed group. In this patient group, all other neurological and neuro-otological diagnoses were excluded, e.g. epilepsy, cerebral palsy, multiple sclerosis, retardation; and for the neuro-otological group those with a history of ototoxicity, labyrinthitis, Meniere's disease, chronic ear infections, or developmental or familial disorders. Emphasis in this study was on mild trauma: fewer than half of the sample had been rendered unconscious in the injury of record, and a third of the cases were of whiplash type, with no loss of consciousness (LOC) and no remembered headstrike. These concomitant lesions comprise the perilymph fistula syndrome (PLFS) with a unique profile of neurological, perceptual, and cognitive deficits resembling a post-concussion injury. A complete description of the clinical picture is given, including psychological, cognitive and diagnostic tests, and the outcome of bedrest vs. surgical management. PLFS can arise from minor trauma, fistula are frequently bilateral (71/102), a mild sensorineural hearing loss is of variable occurrence (53%), secondary hydrops is not uncommon, and women appear more vulnerable than men for developing the syndrome. As based upon combined laboratory techniques and clinical symptomology, fistula were correctly predicted in 61 of 65 laser-operated ears. The positional vertigo component of PLFS was in all cases managed according to a special physical therapy program utilizing exercises for vestibular symptom habituation. Even when diagnosed late, a good-to-excellent outcome was achieved in 70% of treated patients.

Psychiatric morbidity in subjects with inner ear disease.

A prospective assessment of psychiatric morbidity in a sample of 207 patients with inner ear disorders, attending an ENT clinic, was carried out. As a group, they were found to have higher psychiatric morbidity on the general health questionnaire (GHQ) than either normal samples or samples affected by other forms of physical disease. Within the sample tinnitus patients scored the highest, and presbyacusis patients the lowest. High GHQ scores predicted an exaggerated self-rating of symptom severity in a visual analogue scale. Past psychiatric history did not play a role in the development of psychiatric morbidity. Elderly subjects complained more often of fear of collapsing in the street but this was not related, as has been suggested, to the subsequent development of agoraphobic symptoms. Factor analysis of GHQ items for the 'cases' yielded 'depression', 'anxiety' and 'personality' factors. No correlation was found between these factors and the rest of the clinical variables. It is concluded that tinnitus shows the clearest association with psychiatric morbidity and hence merits detailed psychological analysis. Such a study has been started at Addenbrooke's Hospital.

Influence of vestibular and cerebellar dysfunction on the performance of alcoholics on the Rod-and-Frame Test.

The hypothesis of vestibuloocular or cerebellooccular motor dysfunction as a possible cause of the field-dependent behavior of alcoholics on the Rod-and-Frame Test could not be verified.

Constant error of visual egocentric orientation in patients with acute vestibular disorder.

Errors of visual egocentric localization are well-known in patients with paresis of ocular muscles or paresis of conjugate gaze. In the present paper a series of patients with unilateral vestibular disorder disclosed a constant lateralization of the visual agocentre in the absence of any ocular paresis. The perceptual illusion is associated with an altered resting position of the eyes caused by the vestibular imbalance. The disturbance of visual, egocentric localization was revealed only after elimination of the visual frame of reference and the extent of lateralization of the visual egocentre was proportional to the degree of resting deviation of the eyes. Although the findings are of limited clinical importance they have a considerable theoretical interest. From the clinical point of view they may provide a basis for further understnading of the complex-perceptual illusions which may accompany disorders affecting central vestibulo-ocular connections. The results indicate that the perceptual effects are related to an altered central evaluation of the oculomotor programme and thus depend upon the operation of an 'efference copy'. This hypothesis is discussed with reference to earlier and current theories of visual localization.

The additive effects of two mutant genes on otolith formation in mice: an animal model to assess otolith function.

This study examined the additive effects of two mutant genes, pallid (pa) and tilted head (th), on otolith formation in mice. Four strains of mice were bred: (1) a control strain, heterozygous for both pa and th. (2) a pallid strain, homozygous for pa, (3) a tilted head strain, homozygous for th, and (4) a double mutant strain, homozygous for both pa and th. The results were confirmed (1) behaviorally, by the animals' ability to swim, and (2) by histological examination of the inner ear. The findings suggest significant differences in mean otolith scores between all possible pairs of strains. As expected, the controls had normal otoliths and the pa/th strain the most severe otolith defects. Furthermore, there was a significant directional asymmetry in mean otolith scores between the utricle and saccule of the R and L ears for both pa and th strains. The results also showed a highly significant linear relationship between poor swimming ability and reduction of otoconia (r = 0.94, F = 92.14, p less than .001).