Blanco Melissa, Monopoli-Roca Chiara, Álvarez de Linera-Alperi Marta, Menéndez Fernández-Miranda Pablo, Molina Bárbara, Batuecas-Caletrío Angel, Pérez-Fernández Nicolás
Department of Otorhinolaryngology, Clinica Universidad de Navarra, 28047 Madrid, Spain.
Otoneurology Unit, Department of Otorhinolaryngology, Complejo Asistencial Universitario de Salamanca, IBSAL, University of Salamanca, 37008 Salamanca, Spain.
Audiol Res. 2024 Jun 24;14(4):562-571. doi: 10.3390/audiolres14040047.
Nystagmus induced by applying an intense vibratory stimulus to the skull (SVIN) indicates vestibular functional asymmetry. In unilateral vestibular loss, a 100 Hz bone-conducted vibration given to either mastoid immediately causes a primarily horizontal nystagmus. The test is performed in darkness to avoid visual fixation (VF) but there are no data about how much VF affects the often-intense SVIN. The aim is to analyze the amount of reduction in SVIN when VF is allowed during testing. Thus, all patients seen in a tertiary hospital for vertigo or dizziness with positive SVIN were included. SVIN was recorded for 10 s for each condition: without VF (aSVINwo) and with VF (aSVINw). We obtained an aSVINwo and an aSVINw as average slow-phase velocities (SPV) without and with VF. VF index (FI) was calculated as the ratio of SPV. Among the 124 patients included, spontaneous nystagmus (SN) was found in 25% and the median slow phase velocity (mSPV) (without VF) of SN was 2.6 ± 2.4°/s. Mean FI was 0.27 ± 0.29. FI was 0 in 42 patients, and FI between 0 and 1 was found in 82 (mean FI 0.39 ± 0.02). Fixation suppression was found in all patients with SVIN in cases of peripheral vestibulopathy. FI clearly delineates two populations of patients: with or without a complete visual reduction in nystagmus.
通过对颅骨施加强烈振动刺激诱发的眼球震颤（SVIN）表明前庭功能不对称。在单侧前庭丧失的情况下，对任一乳突给予100Hz的骨传导振动会立即引发主要为水平方向的眼球震颤。该测试在黑暗中进行以避免视觉注视（VF），但尚无关于VF对通常强烈的SVIN影响程度的数据。目的是分析测试期间允许VF时SVIN减少的量。因此，纳入了在三级医院因眩晕或头晕且SVIN阳性而就诊的所有患者。针对每种情况记录SVIN 10秒：无VF（aSVINwo）和有VF（aSVINw）。我们获得了无VF和有VF时作为平均慢相速度（SPV）的aSVINwo和aSVINw。VF指数（FI）计算为SPV的比值。在纳入的124例患者中，25%发现有自发性眼球震颤（SN），SN的中位慢相速度（mSPV）（无VF）为2.6±2.4°/秒。平均FI为0.27±0.29。42例患者的FI为0，82例患者的FI在0至1之间（平均FI 0.39±0.02）。在所有外周前庭病变导致SVIN的患者中均发现有注视抑制。FI清楚地划分出两类患者：眼球震颤视觉抑制完全与否。
