Journal of Vestibular Research

Healthy controls exhibit spontaneous and positional nystagmus which needs to be distinguished from pathological nystagmus.

Define nystagmus characteristics of healthy controls using portable video-oculography.

One-hundred and one asymptomatic community-dwelling adults were prospectively recruited. Participants answered questions regarding their audio-vestibular and headache history and were sub-categorized into migraine/non-migraine groups. Portable video-oculography was conducted in the upright, supine, left- and right-lateral positions, using miniature take-home video glasses.

Upright position spontaneous nystagmus was found in 30.7% of subjects (slow-phase velocity (SPV)), mean 1.1±2.2 degrees per second (°/s) (range 0.0 – 9.3). Upright position spontaneous nystagmus was horizontal, up-beating or down-beating in 16.7, 7.9 and 5.9% of subjects. Nystagmus in at least one lying position was found in 70.3% of subjects with 56.4% showing nystagmus while supine, and 63.4% in at least one lateral position. While supine, 20.8% of subjects showed up-beating nystagmus, 8.9% showed down-beating, and 26.7% had horizontal nystagmus. In the lateral positions combined, 37.1% displayed horizontal nystagmus on at least one side, while 6.4% showed up-beating, 6.4% showed down-beating. Mean nystagmus SPVs in the supine, right and left lateral positions were 2.2±2.8, 2.7±3.4, and 2.1±3.2°/s. No significant difference was found between migraine and non-migraine groups for nystagmus SPVs, prevalence, vertical vs horizontal fast-phase, or low- vs high-velocity nystagmus (<5 vs > 5°/s).

Healthy controls without a history of spontaneous vertigo show low velocity spontaneous and positional nystagmus, highlighting the importance of interictal nystagmus measures when assessing the acutely symptomatic patient.

This study aimed to investigate the underlying pathogenesis of acute unilateral vestibulopathy (AUV) using gene expression profiling combined with bioinformatics analysis.

Total RNA was extracted from the peripheral blood mononuclear cells of ten AUV patients in the acute phase and from ten controls. The differentially expressed genes (DEGs) between these two groups were screened using microarray analysis with the cut-off criteria (|fold changes| > 1.5 and p-value < 0.05). Functional enrichment analysis of DEGs was performed using Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analysis, and the protein-protein interaction (PPI) network was constructed using the STRING (Search Tool for the Retrieval of Interacting Genes) database.

There were 57 DEGs (50 up-regulated and 7 down-regulated) identified in the AUV group. Functional enrichment analysis showed that most of the up-regulated DEGs were significantly enriched in terms related to the neutrophil-mediated immune pathway. From the PPI network, the top ten hub genes were extracted by calculating four topological properties, and most of them were related to the innate immune system, inflammatory processes and vascular disorders. The complete blood count tests showed that the neutrophil-to-lymphocyte ratio was significantly higher in the 72 AUV patients than in the age-matched controls (2.93±2.25 vs 1.54±0.61, p < 0.001).

This study showed that the neutrophil-mediated immune pathway may contribute to the development of AUV by mediating inflammatory and thrombotic changes in the vestibular organ.

Benign paroxysmal positional vertigo (BPPV) has a reported recurrence ranging from 26.8 to 50%. Osteoporosis and Vitamin D deficiency seems to have an impact on recurrence of BPPV.

to evaluate the impact of osteoporosis and Vitamin D deficiency on recurrence of BPPV.

73 consecutive patients were divided in two groups according to the presence (group 1) or absence (group 0) of a recurrent episode. BMD, femoral and lumbar T-scores and Vitamin D levels were recorded. Statistical analysis was performed to investigate correlations.

patients in group 1 had statistically significant lower values of both femoral (–1,62±1,06 vs. –0,53±1,51; p = 0,001), lumbar T-score (–2,10±1,19 vs –0, 53±1.51, p = 0.001) and Vitamin D (19.53±15.33). The values of femoral T-score and Vitamin D could be combined in a model able to properly classify 65.8% of the cases (p = 0.002) as isolated or recurrent BPPV, with high accuracy (AUC 0.710 [0.590 –0.830]).

present data show a probable correlation between osteoporosis and Vitamin D with recurrent BPPV.

Few studies have suggested a relationship between vestibular system and sleep deprivation. The aim of the present study is to investigate the effects of acute sleep deprivation lasting 24 hours or more on the postural balance and the visual abilities related to the vestibular system in healthy young adults.

Thirty-one healthy young adults (8 males, 23 female; ages 18– 36 years) who had experienced at least 24 hours of sleep deprivation were included in the study. Subjects made two visits to the test laboratory. One visit was scheduled during a sleep deprivation (SD) condition, and the other was scheduled during a daily life (DL) condition. Five tests— the Sensory Organization Test (SOT), Static Visual Acuity Test (SVA), Minimum Perception Time Test (mPT), Dynamic Visual Acuity Test (DVA), and Gaze Stabilization Test (GST)— were performed using a Computerized Dynamic Posturography System.

A statistically significant difference was found between SD and DL measurements in somatosensorial (p = 0.003), visual (p = 0.037), vestibular (p = 0.008) ratios, and composite scores (p = 0.001) in SOT. The mPT results showed a statistically significant difference between SD and DL conditions (p = 0.001). No significant difference was found between SD and DL conditions in the comparison of the mean SVA (p = 0.466), DVA (p = 0.192), and GST head velocity values (p = 0.160).

Sleep deprivation has a considerable impact on the vestibular system and visual perception time in young adults. Increased risk of accidents and performance loss after SD were thought to be due to the postural control and visual processing parameters rather than dynamic visual parameters of the vestibular system.

Susac syndrome (retino-cochleo-cerebral vasculopathy, SuS) is an autoimmune endotheliopathy characterized by the clinical triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. In contrast to data regarding auditory function, data measuring vestibular function is sparse and the cervical vestibular-evoked myogenic potentials (cVEMPs).

To determine whether the video head impulse test (vHIT) can serve as a confirmatory assessment of vestibulocochlear dysfunction in cases of suspected SuS.

Seven patients diagnosed with SuS underwent pure tone audiometry, a word recognition test, cVEMPs and the vHIT.

Five patients were diagnosed with definite SuS, and two with probable SuS. Two patients were asymptomatic for hearing loss or tinnitus, and no sensorineural hearing loss was detected by audiograms. Four patients complained of tinnitus, and three patients reported experiencing vertigo. Three patients had abnormal cVEMPs results. All seven patients’ vHIT results were normal, except for patient #2, who was one of the three who complained of vertigo. The calculated gain of her left anterior semicircular canal was 0.5, without saccades.

This is the first study to describe the results of the vHIT and cVEMPs among a group of patients with SuS. The results suggest that the vHIT should not be the only exam used to assess the function of the vestibular system of SuS patients.