| 1. |
- Brantberg, K, et al.
(författare)
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Age-related changes in vestibular evoked myogenic potentials
- 2007
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Ingår i: Audiology & neuro-otology. - : S. Karger AG. - 1421-9700. ; 12:4, s. 247-253
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Tidskriftsartikel (refereegranskat)abstract
- Vestibular evoked myogenic potentials (VEMP) in response to sound stimulation (500 Hz tone burst, 129 dB SPL) were studied in 1000 consecutive patients. VEMP from the ear with the larger amplitude were evaluated based on the assumption that the majority of the tested patients probably had normal vestibular function in that ear. Patients with known bilateral conductive hearing loss, with known bilateral vestibular disease and those with Tullio phenomenon were not included in the evaluation. It was found that there was an age-related decrease in VEMP amplitude and an increase in VEMP latency that appeared to be rather constant throughout the whole age span. The VEMP data were also compared to an additional group of 10 patients with Tullio phenomenon. Although these 10 patients did have rather large VEMP, equally large VEMP amplitudes were observed in a proportion of unaffected subjects of a similar age group. Thus, the finding of a large VEMP amplitude in response to a high-intensity sound stimulation is not, per se, distinctive for a significant vestibular hypersensitivity to sounds.
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| 2. |
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| 3. |
- Bergenius, J., et al.
(författare)
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The subjective horizontal at different angles of roll-tilt in patients with unilateral vestibular impairment
- 1996
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Ingår i: Brain Research Bulletin. - : Elsevier BV. - 0361-9230 .- 1873-2747. ; 40:5-6, s. 385-390
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 4. |
- Brantberg, K, et al.
(författare)
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Asymmetric optokinetic afterresponse in patients with small acoustic neurinomas
- 1990
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Ingår i: Journal of Vestibular Research: Equilibrium and Orientation. - 0957-4271. ; 1:3, s. 299-307
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Tidskriftsartikel (refereegranskat)abstract
- Directional asymmetry of primary and secondary optokinetic afternystagmus (OKAN I and OKAN II, respectively) was studied in 20 patients with small acoustic neurinomas (< or = 20 mm), and results were compared to those for 24 normal controls. The optokinetic afterresponse was induced by 60 s of horizontal whole-field optokinetic stimulation in both directions. Among patients, the optokinetic afterresponse was asymmetric, OKAN I and OKAN II beating toward the lesioned ear being significantly weaker than the OKAN I and OKAN II beating toward the healthy ear. Hence, in these patients with gradual deterioration of vestibular function, the vestibular side-difference was reflected both in OKAN I and OKAN II. Although asymmetry in OKAN I was frequently observed among controls, it was significantly more pronounced among the patients. Moreover, patients could be distinguished by the occurrence of OKAN II, as it did not occur at all among controls exposed to the same stimulation.
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| 5. |
- Brantberg, K, et al.
(författare)
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Asymmetric optokinetic afterresponse in patients with vestibular neuritis
- 1990
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Ingår i: Journal of Vestibular Research: Equilibrium and Orientation. - 0957-4271. ; 1:3, s. 89-279
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Tidskriftsartikel (refereegranskat)abstract
- The symmetry of primary and secondary optokinetic afternystagmus (OKAN I and OKAN II, respectively) was studied in 14 patients with vestibular neuritis, as well as in 50 normals. The patients were examined at onset of symptoms and at follow-up 3 and 12 months later. At onset, OKAN was found mainly to reflect the spontaneous nystagmus. Although the spontaneous nystagmus disappeared in all patients within 3 months, both OKAN I and OKAN II was asymmetric at the 3- and 12-month check-ups. OKAN beating toward the lesioned ear was weaker than the OKAN beating toward the healthy ear. Thus, the asymmetric vestibular function was reflected not only in the OKAN I, but also by an asymmetry in OKAN II. Between the 3- and 12-month check-ups, asymmetry in OKAN declined, even among those patients who showed no improvement in caloric response during that time. The decreasing asymmetry in OKAN with time after lesion was, however, related to the disappearance of a positional nystagmus. Hence, the results may be interpreted as suggesting OKAN not only to be affected by vestibular side-difference, but also to be modified by the process responsible for vestibular compensation following a peripheral vestibular lesion.
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