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Background: Generally, vertical component of the skull vibratory nystagmus (VCN) is ignored in the clinical practise. Thus, the relative contribution of the vestibular organs in the presence of VCN remains unknown. Objectives: To determine the association between vertical semicircular canal (vSCC) function and the presence of VCN. Material and methods: Comparisons were made between Video Head Impulse Test and SVINT (100 Hz) results at the time of the acute peripheral vestibular lesion (PVL) and at the post-acute phase in patients diagnosed PVL. Later on, a paired analysis was performed restricting the assessments to patients with vestibular explorations in both the acute and post-acute phases. Results: In an univariable analysis, larger mean total gain differences (TGD) between vSCC VOR gains, significantly related with the appearance of VCN in nystagmography in the acute phase (p =.001), unlike the post-acute phase (p =.46). After a multivariate analysis, mean TGD was the only predictive factor of the VCN (p =.013). In the paired analysis, we found an increase in the post-acute phase mean TGD, approaching zero value. Conclusions and significance: Global relation between all vertical canals has at least a contributory role in the presence of the vertical component of nystagmus in SVINT. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate the vestibulo-ocular reflex (VOR) gain and the saccade regrouping pattern PR score of the Video Head Impulse Test (vHIT) and its relationship with the slow-phase velocity (SPV) of skull vibration-induced nystagmus (SVIN) in recovery after a unilateral vestibular loss (UVL). A total of 36 patients suffering from vestibular neuritis (VN) were recruited and followed up for twelve months. In every visit, horizontal vHIT and an SVIN were performed, as well as VOR gain; PR score and the SPV of SVIN were measured. We observed a positive association between the VOR gain difference and the SPV of SVIN over time (probability greater than 0.86). Additionally, we obtained a positive association between the SPV of SVIN and the PR score in successive visits (odds ratio (OR) = −0.048; CI [0.898, 1.01]), with a probability of 0.95. Our results confirm that SPV of SVIN; VOR gain difference; and PR score decrease over time after a UVL. Both tests are useful in the follow-up of VN, as they could reflect its clinical compensation or partial recovery. [ABSTRACT FROM AUTHOR]

As described by Dumas, an 80–100 Hz vibration applied to the mastoid produces a horizontal nystagmus, with quick phases beating away from the affected side in patients with unilateral vestibular loss (UVL). To elucidate the characteristics of skull vibration-induced nystagmus (SVIN) in patients suffering from vestibular neuritis and how these characteristics are related to information provided by the video head impulse test (vHIT). Sixty-three patients were enrolled to perform a vHIT to measure the gain in both ears. SVIN was induced with stimulation at 30 Hz, 60 Hz, and 100 Hz. The slow phase velocity (SPV) of the SVIN was measured. The SVIN test was positive in 25/63 patients at 30 Hz, 36/63 at 60 Hz and 46/63 at 100 Hz. Mean gain difference between both ears to obtain a positive SVIN at 30 Hz was observed to be 0.38 ± 0.25, decreasing to 0.35 ± 0.23 at 60 Hz, and 0.31 ± 0.24 at 100 Hz (p =.025). We found a significant positive linear correlation between the gain asymmetry measured using horizontal vHIT and SPV in SVIN at 100 Hz. There is a close relationship between the difference in the gains of both ears as measured using VHIT and the SPV of the nystagmus induced by SVIN at 100 Hz [ABSTRACT FROM AUTHOR]

Background: Acquired periodic alternating nystagmus (PAN) is a rare but well-defined syndrome that consists of a horizontal nystagmus that cyclically reverses its direction. PAN can be caused by degenerative, neoplastic, or toxic diseases of the cerebellum and, in a few cases, by subacute cerebellar ataxia of immune origin.Case Presentation: A 44-year-old man came to our attention because of rapidly progressive gait instability and blurred vision. Clinical examination showed PAN and a mild pancerebellar syndrome. Eye movement recordings disclosed a short cycle PAN with significant slow-phase velocity only in darkness. Under the effect of a γ-aminobutyric acid type B (GABAB) agonist, PAN was not modified. Right after treatment with intravenous immunoglobulin (IVIg) was started, PAN was essentially eliminated. Three months after last dose of IVIg, this nystagmus reappeared.Conclusions: IVIg resolved PAN in this patient. This finding may point to an autoimmune mechanism underlying this patient's nystagmus. This case suggests that the usefulness of IVIg at treating PAN might be worth a consideration in similar clinical settings. [ABSTRACT FROM AUTHOR]