1,721,047 research outputs found
Sensitivity and specificity of mastoid vibration test in detection of effects of vestibular neuritis [Sensibilità e specificità del test della vibrazione mastoidea nella individuazione degli esiti della neurite vestibolare]
Full text linkAim of this study was to determine sensitivity and specificity of the mastoid vibration test in patients who had suffered an attack of vestibular neuritis. Results were compared with the caloric test and two bedside tests of vestibular function (head shaking test and head thrust test). Results are reported in 28 patients who had a residual vestibular deficit 6 months after acute neuritis and in 25 healthy subjects. Mastoid vibration nystagmus was evoked in 21 patients but not in controls. In these patients, mastoid vibration test had a sensitivity of 75% and specificity of 100%. Since one patient had inverted mastoid vibration nystagmus, specificity of identification on the pathological side was 95%. Sensitivity of the test increased with increasing severity of the vestibular lesion. Indeed, mastoid vibration nystagmus was induced in 93% of patients with caloric paralysis and in 58% of those with caloric paresis. Nystagmus could usually be modulated or elicited by stimulation of either mastoid. In the few patients in whom mastoid vibration nystagmus was elicited only from one side, or when there was a clear difference in intensity of the nystagmus induced on the two sides, the stimulated side was more often the affected side. Four patients still showed spontaneous nystagmus. The caloric test was abnormal in 26/28 patients (93%) with paralysis in 16 and paresis in 12; 71% of patients had a head shaking induced nystagmus: 64% had an asymmetrical response in head thrust test. In conclusion, mastoid vibration test was overall more sensitive than head thrust test. Mastoid vibration test was slightly less sensitive than head shaking test in patients with severe residual deficit and more sensitive in patients with partial deficit. Mastoid vibration test, a valid, low cost clinical screening test for rapid detection of asymmetrical vestibular function, does not cause patient discomfort. It is suggested that this test be included in the diagnostic workup of all patients with suspected vestibular dysfunction
The effects of caloric vestibular stimulation on the soleus alpha motoneurons reinvestigated in man.
No full textInhibition of vestibulo-ocular reflex by tonic stimulation of the posterior neck region in man.
No full textThe effect of posterior neck stimulation on vestibulo-ocular reflex (VOR) was studied in 10 healthy subjects. The experimental situation was designed to minimise all afferent inputs except from the neck; each subject was placed in supine position with body fixed to a tilting table inclinable in a vertical plane. The head was immovably secured at 30 degrees to an independent non-inclinable rigid frame. In this situation the body could be mechanically moved upwards in the vertical plane (ventriflexion), producing symmetrical and selective stretch of the posterior neck region. The VOR elicited by caloric monoaural stimulation was evaluated for each of the following static positions: 0 degree and 50 degrees of ventriflexion and vice versa. We observed a significant decrease in the slow-phase angular velocity of induced nystagmus as the body was tilted upwards and a significant opposite effect when the body was returned to the original position. Similar changes in VOR were observed in 4 selected patients with spontaneous 'peripheral nystagmus'. Mechanisms involved in the cervical control of VOR are discussed
Benign Paroxysmal Positional Vertigo: What We Do and Do Not Know
No full textBenign paroxysmal positional vertigo (BPPV) is common, sometimes terrifying, but rarely portends serious disease. It is usually easily diagnosed and treated, and both the patient and the physician are immediately gratified. While much has been learned about the pathogenesis of BPPV in the past decades, many of its features remain mysterious, and one must still be wary of the rare times it mimics a dangerous brain disorder. Here we review common, relatively well understood clinical features of BPPV but also emphasize what we do not know and when the physician must look deeper for a more ominous cause. © 2020 Georg Thieme Verlag. All rights reserved
Compensation in vestibular neuronitis [Il compenso nella neurite vestibolare]
No full textAfter a vestibular neuronitis, the majority of patients with functional residual deficit reach a static vestibular compensation. Only in 16% of patients in fact a spontaneous nystagmus after 6 months is detectable. Contrarily vestibular dynamic signs tend to persist probably because mechanisms of adaptation hardly succeed to be effective when we use high velocity stimulus, particularly if the peripheral organ is heavily damaged. Generally patients with a vestibular persistent caloric areflexia show a deficit in vestibule-oculomotor reflex during a rapid rotation of the head or a persistent nystagmus induced by Head Shaking (HSTest). Instead in 50% of patients with residual hyporeflectivity after 6 months we can observe a dynamic compensation. From the analysis of our data, it appears that the caloric test, though considered a gold standard in detection of peripheral vestibular deficit, can supply missleading negative results, even if this is rare. In our survey, in fact, there are patients that present a normal caloric test after 3 and 6 months of deficit, but an HST pathologic
Benign Positional Paroxysmal Vertigo Treatment: a Practical Update
No full textPurpose of the review: To define the best up-to-date practical approach to treat benign paroxysmal positional vertigo (BPPV). Recent findings: Both posterior and horizontal canal BPPV canalith repositioning maneuvers (Semont, Epley, and Gufoni’s maneuvers) are level 1 evidence treatment for evidence-based medicine. The choice of maneuver (since their efficacy is comparable) is up to the clinician’s preferences, failure of the previous maneuver, or movement restrictions of the patient. Maneuvers for controversial variants, such as anterior canal and apogeotropic posterior canal BPPV, have weaker evidence of efficacy. Despite this, these variants are increasingly diagnosed and treated. Maneuvers also play a role in the differential diagnosis with central vestibular disorders. Chair-assisted treatment may be of help if available while surgical canal plugging should be indicated in selected same-canal, same-side intractable severe BPPV. Summary: The primary evidence-based treatment strategy for BPPV should be physical therapy through maneuvers. Despite the high success rate of liberatory maneuvers, there is a low percentage of subjects who have unsatisfactory outcomes. These patients need to be investigated to identify recurrences, multiple canal involvement, associated comorbidities (migraine, persistent postural perceptual dizziness), or risk factors for recurrences (low vitamin D serum level). Future research should also identify the optimum maneuvers for variants whose diagnosis and treatment are still a matter of some debate. © 2019, Springer Science+Business Media, LLC, part of Springer Nature
Cochleovestibular investigation in progressive myoclonus epilepsy
No full textA cochleovestibular investigation including tone audiometry, speech audiometry, impedance tests, stapedial reflex threshold, tone decay test, spontaneous nystagmus, tracking, caloric stimulation and visual suppression test, was performed in 13 patients affected by different types of progressive familial myoclonus epilepsy. The electronystagmographic study shows signs of lesion in the cerebellar system. In some cases the lesion seemed to be cerebellar, whereas in others there was also evidence of brainstem involvement
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