Thoracoabdominal aortic aneurysm in Cogan's syndrome.
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Cogan's syndrome is an autoimmune disease of unknown etiology, clinically manifested as non-syphilitic interstitial keratitis and audiovestibular symptoms. Increasing evidence suggests that Cogan's may be a systemic vasculitis. In this report, we review the vascular manifestations of Cogan's syndrome and report two cases of thoracoabdominal aortic aneurysm in patients with this disorder. (+info)
Adaptation to oscillopsia: a psychophysical and questionnaire investigation.
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In this study we explore the reasons why patients with bilateral vestibular failure report disparate degrees of oscillopsia. Twelve bilateral labyrinthine-defective (LD) subjects and twelve normal healthy controls were tested using a self- versus visual-motion psychophysical experiment. The LD subjects also completed a questionnaire designed to quantify the severity of handicap caused by oscillopsia. Additional standardized questionnaires were completed to identify the role of personality, personal beliefs and affective factors in adaptation to oscillopsia. During the psychophysical experiment subjects sat on a motorized Barany chair whilst viewing a large-field projected video image displayed on a screen in front of them. The chair and video image oscillated sinusoidally at 1 Hz in counter-phase at variable amplitudes which were controlled by the subject but constrained, so that the net relative motion of the chair and video image always resulted in a sinusoid with a peak velocity of 50 degrees /s. The subject's task was to find the ratio of chair versus video image motion that subjectively produced the 'most comfortable visual image'. Eye movements were recorded during the experiment in order that the net retinal image slip at the point of maximum visual comfort could be measured. The main findings in the LD subjects were that, as a group, they selected lower chair motion amplitude settings to obtain visual comfort than did the normal control subjects. Responses to the questionnaires highlighted considerable variation in reported handicap due to oscillopsia. Greater oscillopsia handicap scores were significantly correlated with a greater external locus of control (i.e. the perception of having little control over one's health). Retinal slip speed was negatively correlated with oscillopsia handicap score so that patients who suffered the greatest retinal slip were those least handicapped by oscillopsia. The results suggest that adaptation to oscillopsia is partly related to the patient's personal attitude to the recovery process and partly associated with the development of tolerance to the movement of images on the retina during self-motion. The latter is likely to be related to previously described changes in visual motion sensitivity in these patients. (+info)
Relationship among balance impairments, functional performance, and disability in people with peripheral vestibular hypofunction.
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BACKGROUND AND PURPOSE: Physical therapy interventions are often based on assumed relationships among impairments, functional performance, and disability. The purposes of this study were (1) to describe balance impairments, functional performance, and disability in subjects with unilateral peripheral vestibular hypofunction (UVH) and bilateral peripheral vestibular hypofunction (BVH), (2) to examine the relationship among these factors, and (3) to determine whether disability can be explained by commonly used tests of balance and functional performance. SUBJECTS: Participants were 85 subjects (mean age=62.5 years, SD=16.5) with UVH (n=41) or BVH (n=44) diagnosed by vestibular function tests and clinical examination. METHODS: Each subject completed the Dizziness Handicap Inventory (DHI) to obtain a measure of disability. Functional performance was measured with a modified Timed Up & Go Test (TUG). Balance impairments were measured with computerized posturography and balance tests. Descriptive statistics, correlational analyses, and stepwise regressions were performed. RESULTS: Subjects with BVH had poorer balance but similar TUG scores and perceived levels of disability, as compared with subjects with UVH. Weak to moderate correlations existed among balance measurements, TUG scores, and DHI scores. Balance impairments and TUG scores together explained 78% of the variance in DHI scores of the subjects with BVH, whereas balance impairments alone explained 13% of the variance in DHI scores of the subjects with UVH. CONCLUSION AND DISCUSSION: Balance impairments and functional performance appear to be more closely related to disability in individuals with BVH as compared with those with UVH. Clinical tests of balance impairments and functional performance appear to be useful in explaining disability. (+info)
Falls in elderly.
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Falls are common in elderly. They cause morbidily, mortality and financial hardship. They can be prevented with minimum cost. All steps should be taken. Remove the cause or causes as far as it is possible in the environment. (+info)
Targeted disruption of mouse Pds provides insight about the inner-ear defects encountered in Pendred syndrome.
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Following the positional cloning of PDS, the gene mutated in the deafness/goitre disorder Pendred syndrome (PS), numerous studies have focused on defining the role of PDS in deafness and PS as well as elucidating the function of the PDS-encoded protein (pendrin). To facilitate these efforts and to provide a system for more detailed study of the inner-ear defects that occur in the absence of pendrin, we have generated a Pds-knockout mouse. Pds(-/-) mice are completely deaf and also display signs of vestibular dysfunction. The inner ears of these mice appear to develop normally until embryonic day 15, after which time severe endolymphatic dilatation occurs, reminiscent of that seen radiologically in deaf individuals with PDS mutations. Additionally, in the second postnatal week, severe degeneration of sensory cells and malformation of otoconia and otoconial membranes occur, as revealed by scanning electron and fluorescence confocal microscopy. The ultrastructural defects seen in the Pds(-/-) mice provide important clues about the mechanisms responsible for the inner-ear pathology associated with PDS mutations. (+info)
Vertigo and vestibular rehabilitation.
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The role of rehabilitation in the management of vertigo is limited to a very specific group of conditions. An Occupational therapist who is a part of the multidisciplinary team treating the vertiginous patient, with the knowledge of physiology and therapeutic benefit of vestibular rehabilitation can widen the rehabilitation spectrum for various diseases producing vertigo and dysequilibrium, to resolve or minimise these symptoms. The present article reviews the need for vestibular rehabilitation and the different conditions needing the same along with its characteristics, physiology and various exercises prescribed. (+info)
Effects of postural changes and vestibular lesions on diaphragm and rectus abdominis activity in awake cats.
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Changes in posture can affect the resting length of the diaphragm, requiring alterations in the activity of both the abdominal muscles and the diaphragm to maintain stable ventilation. To determine the role of the vestibular system in regulating respiratory muscle discharges during postural changes, spontaneous diaphragm and rectus abdominis activity and modulation of the firing of these muscles during nose-up and ear-down tilt were compared before and after removal of labyrinthine inputs in awake cats. In vestibular-intact animals, nose-up and ear-down tilts from the prone position altered rectus abdominis firing, whereas the effects of body rotation on diaphragm activity were not statistically significant. After peripheral vestibular lesions, spontaneous diaphragm and rectus abdominis discharges increased significantly (by approximately 170%), and augmentation of rectus abdominis activity during nose-up body rotation was diminished. However, spontaneous muscle activity and responses to tilt began to recover after a few days after the lesions, presumably because of plasticity in the central vestibular system. These data suggest that the vestibular system provides tonic inhibitory influences on rectus abdominis and the diaphragm and in addition contributes to eliciting increases in abdominal muscle activity during some changes in body orientation. (+info)
Interference between postural control and mental task performance in patients with vestibular disorder and healthy controls.
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OBJECTIVES: To determine whether interference between postural control and mental task performance in patients with balance system impairment and healthy subjects is due to general capacity limitations, motor control interference, competition for spatial processing resources, or a combination of these. METHOD: Postural stability was assessed in 48 patients with vestibular disorder and 24 healthy controls while they were standing with eyes closed on (a) a stable and (b) a moving platform. Mental task performance was measured by accuracy and reaction time on mental tasks, comprising high and low load, spatial and non-spatial tasks. Interference between balancing and performing mental tasks was assessed by comparing baseline (single task) levels of sway and mental task performance with levels while concurrently balancing and carrying out mental tasks. RESULTS: As the balancing task increased in difficulty, reaction times on both low load mental tasks grew progressively longer and accuracy on both high load tasks declined in patients and controls. Postural sway was essentially unaffected by mental activity in patients and controls. CONCLUSIONS: It is unlikely that dual task interference between balancing and mental activity is due to competition for spatial processing resources, as levels of interference were similar in patients with vestibular disorder and healthy controls, and were also similar for spatial and non-spatial tasks. Moreover, the finding that accuracy declined on the high load tasks when balancing cannot be attributed to motor control interference, as no motor control processing is involved in maintaining accuracy of responses. Therefore, interference between mental activity and postural control can be attributed principally to general capacity limitations, and is hence proportional to the attentional demands of both tasks. (+info)