Mi Joo Kim

Clinical use of subjective visual horizontal and vertical in patients of unilateral vestibular neuritis.

Objectives: Subjective visual horizontal (SVH) and subjective visual vertical (SVV) used to assess otolith dysfunction and ipsilesional deviation of SVV and SVH in unilateral vestibular dysfunction is well known. The goal of this study was to investigate the clinical use of SVH/SVV and a dizziness scale in the clinical setting of acute unilateral vestibular neuritis. Methods: Thirty-five patients with unilateral vestibular neuritis were investigated. Every patient was diagnosed by physical examination and electronystagmography. Subjective visual horizontal and SVV were assessed during the acute or subacute period; the Dizziness Handicap Inventory (DHI) and Vestibular Disorder Activities of Daily Living Scale (VADL) were used for a self-dizziness scale at the same time. All patients underwent rehabilitation therapy. Subjective visual horizontal/SVV and DHI/VADL were assessed again approximately 4 weeks later. Postrehabilitation SVH/SVV and DHI/VADL data were compared with initial data. Results: Dizziness Handicap Inventory and VADL were improved after 4 weeks of rehabilitation, and the deviation toward ipsilesional side SVH and SVV was also improved. Conclusion: These results demonstrate that SVH and SVV correlated with clinical dizziness symptoms in patients with acute unilateral vestibular neuritis. Therefore, SVH and SVV would be useful tools for the evaluation of clinical manifestations of unilateral vestibular neuritis.

A quantitative analysis of gait patterns in vestibular neuritis patients using gyroscope sensor and a continuous walking protocol

BackgroundLocomotion involves an integration of vision, proprioception, and vestibular information. The parieto-insular vestibular cortex is known to affect the supra-spinal rhythm generators, and the vestibular system regulates anti- gravity muscle tone of the lower leg in the same side to maintain an upright posture through the extra-pyramidal track. To demonstrate the relationship between locomotion and vestibular function, we evaluated the differences in gait patterns between vestibular neuritis (VN) patients and normal subjects using a gyroscope sensor and long-way walking protocol.MethodsGyroscope sensors were attached to both shanks of healthy controls (n=10) and age-matched VN patients (n = 10). We then asked the participants to walk 88.8 m along a corridor. Through the summation of gait cycle data, we measured gait frequency (Hz), normalized angular velocity (NAV) of each axis for legs, maximum and minimum NAV, up-slope and down-slope of NAV in swing phase, stride-swing-stance time (s), and stance to stride ratio (%).ResultsThe most dominant walking frequency in the VN group was not different compared to normal control. The NAVs of z-axis (pitch motion) were significantly larger than the others (x-, y-axis) and the values in VN patients tended to decrease in both legs and the difference of NAV between both group was significant in the ipsi- lesion side in the VN group only (p=0.03). Additionally, the gait velocity of these individuals was decreased relatively to controls (1.11 ± 0.120 and 0.84 ± 0.061 m/s in control and VN group respectively, p<0.01), which seems to be related to the significantly increased stance and stride time of the ipsi- lesion side. Moreover, in the VN group, the maximum NAV of the lesion side was less, and the minimum one was higher than control group. Furthermore, the down-slope and up-slope of NAV decreased on the impaired side.ConclusionThe walking pattern of VN patients was highly phase-dependent, and NAV of pitch motion was significantly decreased in the ipsi- lesion side. The change of gait rhythm, stance and stride time, and maximum/minimum NAV of the ipsi- lesion side were characteristics of individuals with VN.

Ambulatory balance monitoring using a wireless attachable three-axis accelerometer

BACKGROUND AND OBJECTIVES The ability of conventional diagnostic equipment to monitor feelings of dizziness experienced during daily activities is limited. Our goal is to develop an ambulatory multipurpose device for monitoring balance to prevent falling in daily life. MATERIALS AND METHODS A three-axis accelerometers and gyroscope sensors were attached to the head, pelvis, and legs of vestibular neuritis (VN) patients or age-, height-, and body weight-matched healthy volunteers. The sum of the deviations for the scalar value of acceleration [signal vector magnitude, SVM (g)] and angular velocity (°/s) was measured using the modified Romberg test. RESULTS The repeated measure ANOVA model with acceleration showed a greater group difference (p < 0.001) than that with angular velocity (p < 0.01). There was no significant interaction effect within-subjects factor between replication and groups (p < 0.178). SVM within the VN group significantly increased for all sensor locations compared to the control group (p < 0.01). Strong correlations between measurements taken at head and pelvis as sensor location were observed for both groups (VN/control, r=0.68/r=072). CONCLUS ION The SVM appears to accurately assess balance while standing, even repetitive measurement or any location in body.