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.     

Long-lasting deviation of the subjective visual horizontal after complete unilateral vestibular deafferentation by subtotal resection of the temporal bone.

OBJECTIVE: This study examined whether subjective visual horizontal (SVH) could be compensated in patients with complete loss of unilateral vestibular function. PATIENTS: Patients comprised two men and three women who underwent subtotal resection of the unilateral temporal bone due to squamous cell carcinoma of the middle or external ear. Mean patient age was 63.2 years (range, 59-69 yr). INTERVENTION: Diagnostic. MAIN OUTCOME MEASURES: Patients were tested postoperatively (mean, 4 yr 5 mo after the surgery; range, 2 yr 9 mo to 8 yr 6 mo). The task for patients involved adjusting a laser projection bar four times to SVH in darkness. RESULTS: All patients displayed marked deviation of SVH toward the operated side-down. Mean deviation from four trials for each subject was 4.5, 2.9, 3.7, 3.0, and 3.4 degrees. CONCLUSION: Deviation of SVH in patients with definite unilateral vestibular deafferentation can be long term, lasting more than 2 years at least.     

Idiosyncratic compensation of the subjective visual horizontal and vertical in 60 patients after unilateral vestibular deafferentation

Objective To investigate long-term compensation mechanisms of utricular function after translabyrinthine surgery for vestibular schwannoma. Correlations between the subjective visual horizontal (SVH) and subjective visual vertical (SVV) and other parameters of vestibular compensation were studied. The correlation between the SVH and SVV was also investigated to see whether these measurements are compatible for patients.

Material and Methods Sixty consecutive patients were investigated 3 months before and 6 months after surgery by means of electronystagmography and SVH and SVV tests. Tumor size was measured using MRI.

Results The SVH and SVV increased significantly towards the ipsilesional side postoperatively. Preoperative tilt correlated with age. Postoperative tilt correlated weakly with preoperative caloric sensitivity and inversely with tumor size. The correlation between the SVH and SVV was high both before and after surgery (r_s>0.74; p<0.001).

Conclusions The long-term compensation of static tilt perception was dependent on age and not on dynamic canal functions. We propose an idiosyncrasy in the SVH and SVV compensation after unilateral vestibular deafferentation, incongruous with the general course of vestibular compensation. The results suggest a probable dependence on non-vestibular information, i.e. proprioception, in facilitating compensation of static vestibular deficits. The similarity between the SVH and SVV measurements confirms that either test can be used clinically for patients with vestibular lesions.     

Idiosyncratic compensation of the subjective visual horizontal and vertical in 60 patients after unilateral vestibular deafferentation

OBJECTIVE: To investigate long-term compensation mechanisms of utricular function after translabyrinthine surgery for vestibular schwannoma. Correlations between the subjective visual horizontal (SVH) and subjective visual vertical (SVV) and other parameters of vestibular compensation were studied. The correlation between the SVH and SVV was also investigated to see whether these measurements are compatible for patients. MATERIAL AND METHODS: Sixty consecutive patients were investigated 3 months before and 6 months after surgery by means of electronystagmography and SVH and SVV tests. Tumor size was measured using MRI. RESULTS: The SVH and SVV increased significantly towards the ipsilesional side postoperatively. Preoperative tilt correlated with age. Postoperative tilt correlated weakly with preoperative caloric sensitivity and inversely with tumor size. The correlation between the SVH and SVV was high both before and after surgery (r(s) > 0.74; p < 0.001). CONCLUSIONS: The long-term compensation of static tilt perception was dependent on age and not on dynamic canal functions. We propose an idiosyncrasy in the SVH and SVV compensation after unilateral vestibular deafferentation, incongruous with the general course of vestibular compensation. The results suggest a probable dependence on non-vestibular information, i.e. proprioception, in facilitating compensation of static vestibular deficits. The similarity between the SVH and SVV measurements confirms that either test can be used clinically for patients with vestibular lesions.     

Subjective visual vertical and subjective visual horizontal measures in patients with chronic dizziness

OBJECTIVES: We aimed to find the frequency of otolith organ pathologies in the clinical picture of common dizziness etiologies in the chronic stage. METHOD: Subjective visual vertical and subjective visual horizontal measures were assessed in patients who had persistent or recurrent dizziness at least 2 months after the acute period. Every patient was tested in three head positions: neutral, right, or left deviation in the roll plane. Test results were compared with those of the control group. RESULTS: Seventy-three patients and 18 controls were examined. Fifty-eight of the patients had peripheral vestibular disease; 15 of them had central vestibular disease. Left subjective visual horizontal (SVH) and right SVH measures of the peripheral group were significantly different from those of the control group (p < .01). There was no difference in any test between the peripheral and central groups. When we put a cut off point for abnormality (0, 1) according to mean +/- 2 SD of the control group, the peripheral and central groups had very high significant differences from the control group. Approximately 25 to 50% of our patients had pathologic subjective visual vertical or SVH measures according to test type. CONCLUSION: These results showed that the otolith system must be evaluated in the chronic period of dizziness, especially in patients who frequently visit their physician, and modifications in treatment programs must be conducted.     

Subjective visual vertical deviation in patients with early-onset direction-changing horizontal positional nystagmus

ObjectiveOtolithic dysfunction is investigated in cases of direction-changing horizontal positional nystagmus (DCHPN) due to peripheral vestibular disorders.MethodsThe static-subjective visual vertical (S-SVV) was conducted in DCHPN cases within 48 h after onset.ResultsThe absolute values of S-SVV deviations of patients with Light cupula and lateral canal-benign paroxysmal positional vertigo-cupulolithiasis (L-BPPV-Cup) were significantly different from those of healthy subjects (p < 0.001, p < 0.05, respectively), whereas there were no significant differences in those of patients with L-BPPV-Canalolithiasis-geotropic (L-BPPV-Can-g) or L-BPPV-Can-ageotropic (L-BPPV-Can-a) versus healthy subjects. Significant differences were found in S-SVV (+: deviation to the affected side, ?: deviation to the unaffected side) between patients with Light cupula and those with L-BPPV-Can-g, L-BPPV-Can-a and L-BPPV-Cup (p < 0.01, p < 0.05, and p < 0.001, respectively), as well as between those with L-BPPV-Can-g and L-BPPV-Cup (p < 0.01). The S-SVV in patients with Light cupula, L-BPPV-Can-g, and L-BPPV-Can-a deviated more to the affected side, whereas that in patients with L-BPPV-Cup deviated more to the unaffected side.ConclusionMild otolithic dysfunctions were found in patients with DCHPN due to the presence of peripheral vestibular disorders within 48 h after onset. The extent of otolithic (utricular) disorders in patients with DCHPN is estimated in decreasing order as follows: Light cupula > L-BPPV-Cup > L-BPPV-Can-g and L-BPPV-Can-a. Many patients with L-BPPV-Cup likely suffer from disorders of the pars externa of the utricular macula, whereas many patients with L-BPPV-Can-g likely suffer from disorders of the pars interna of the utricular macula. L-BPPV-Can-a and L-BPPV-Can-g must be induced by a common mild utricular disorder.     

Preoperative postural control of patients with vestibular schwannoma assessed by visual feedback posturography

BACKGROUND: The need for an objective method to describe the functional postural control of patients with vestibular schwannoma in agreement with their subjective sensation of balance. Objectives: The objective was to compare the postural control of 49 patients with unilateral vestibular schwannoma (VS) with that of healthy subjects by using visual feedback posturography (VFP). We aimed to find out if preoperative postural control of the patients correlates with their subjective sensation of balance. METHODS: In the VFP, while standing on the platform, patients were instructed to move their center of gravity (COG) marker to the targets as fast and accurately as possible. Hit delay (HD) to the targets, hold percentage (HP) within the targets, COG marker velocity (CMV) to the targets, and balance index (BI) were calculated. We rated intensity of balance disturbance using a 5-point qualitative scale. RESULTS: Twenty-two (45%) patients had at least one abnormal VFP parameter, and 49% of patients were simultaneously symptomatic. Mean hit delay (HD), hold percentage (HP), and balance index (BI) were significantly worsened in patients with VS (p < 0.05). Increased HD and BI correlated significantly with subjective sensation of imbalance (p = 0.02). CONCLUSIONS: The overall deficit in preoperative postural control of the VS patients was not severe, and this finding agreed well with their subjective sensations.     

Recovery of subjective visual horizontal after unilateral vestibular deafferentation by intratympanic instillation of gentamicin

The time course of the recovery of subjective visual horizontal (SVH) after unilateral vestibular deafferentation by intratympanic instillation of gentamicin was studied. Six patients who underwent intratympanic gentamicin instillation therapy for Meniere's disease (1 man and 5 women, 32 to 69 years of age) were enrolled in this study. For comparison, SVH in 23 healthy subjects (12 men and 11 woman, 23 to 48 years of age) was also measured. The mean +/- SD of SVH in healthy subjects was 0.0 +/- 1.1 deg. All of the 6 patients showed significantly deviated SVH toward the injected side-down at the early stage after the therapy. Although one patient showed recovery of SVH to the normal range 25 days after the injection, the other patients required more time for recovery. Three patients did not show recovery to the normal range after 1 year. On the other hand, spontaneous nystagmus observed using an infrared CCD camera in total dark disappeared after 35 days (median). Patients who had normal vestibular evoked myogenic potentials before the therapy showed a tendency of delay of recovery of SVH. The reasons why the recovery of SVH took longer than the disappearance of spontaneous nystagmus are discussed in this report.     

Effects of visual input on galvanic body sway test of unilateral vestibular deficiency in patients with unilateral vestibular schwannoma

OBJECTIVE: Galvanic body sway tests (GBSTs) are performed with eyes fixed and closed. However, quantitative effect of fixation on GBST has been unknown. The purpose of this study is to address this question. METHODS: We evaluated GBSTs of patients with unilateral vestibular schwannomas and normal controls, while their eyes were open and closed. We evaluated three GBST parameters: maximum amplitude of the response, velocity and latency of the onset of response. RESULTS: Closing the eyes diminished stability, resulting in increased amplitude and velocity of the responses. However, apparent contribution to the latency of response could not be found. Contribution of visual fixation seems to be greater in apparatus with vestibular hypo-function than without it. Unilateral weakness (UW) was calculated for each parameter, and significant correlation, between with eyes fixed and closed, was found only for velocity parameter. CONCLUSION: Fixation would stabilize the body of subjects, and diminish GBST responses. GBST with and without fixation can be evaluated together, using certain coefficient. On the other hand, fixation would not have any contribution to the latency of the GBST response. When we evaluate vestibular dysfunction of patients with unilateral vestibular schwannomas, velocity parameter should be employed.     

Vibration-induced shift of the subjective visual horizontal: a sign of unilateral vestibular deficit.

BACKGROUND: Vibration to the head or neck excites vestibular and neck muscle spindle afferents. Can such vibrations improve the sensitivity of the subjective visual horizontal (SVH) test to chronic unilateral deficit of the vestibular system? DESIGN: Controlled experimental study. SETTING: Tertiary referral center. PATIENTS AND CONTROLS: Thirteen healthy subjects and 23 patients with chronic unilateral vestibular deficits after vestibular neurectomy or neurolabyrinthitis. Results of head-impulse test showed unilateral loss of function of all 3 semicircular canals in 14 patients and loss of anterior and lateral semicircular canals in 9 patients. INTERVENTION: Unilateral vibration (92 Hz; 0.6-mm amplitude) applied to sternocleidomastoid muscle (SCM) or mastoid bone. MAIN OUTCOME MEASURE: Results of SVH test (in degrees). RESULTS: Without vibration, 13 of 23 patients and all healthy subjects had SVH of less than 3 degrees (sensitivity, 43%; specificity, 100%). During vibration to the ipsilesional SCM, SVH increased to greater than 3 degrees in 21 of 23 patients but in only 1 of 13 healthy subjects (sensitivity, 91%; specificity, 92%). The patient group had significantly greater SVH shifts to the ipsilesional side than did healthy subjects in response to SCM and mastoid bone vibration on either side. The SVH shift during vibration to the ipsilesional SCM was significantly greater than that during vibration to the contralesional muscle (P<.001) or to the mastoid bone on either side (P<.05). The vibration-induced SVH shift was significantly greater in those patients with loss of 3 semicircular canals than in those with loss of 2 (P<.01). CONCLUSIONS: The sensitivity of the SVH test to chronic unilateral vestibular deficits can be improved by applying vibration to the SCM. The magnitude of vibratory SVH shift is related to the extent of unilateral deficit of the otolithic organs, vertical canals, or both.     

Subjective visual horizontal and stabilometer findings in patients with unilateral severe vestibular dysfunction

The records of both stabilometer and subjective visual horizontal (SVH) testing can be used to evaluate vestibular compensation. When results of SVH testing have a strong significant correlation to those of stabilometer testing, clinicians can omit one of two tests from the test battery. To investigate the correlation, results of these two tests of patients with unilateral severe vestibular dysfunction were studied. Twenty-eight patients, 20 men and 8 women, with unilateral severe vestibular dysfunction were enrolled in this study. The correlation between these two tests was considered not significant according to the results. In conclusion, we cannot omit either stabilometer testing or SVH testing for the evaluation of patients with vestibular dysfunction.     

Head-shaking nystagmus in patients with a vestibular schwannoma

The aim of this study was to calculate the sensitivity of the head-shake test for peripheral and central vestibular dysfunction associated with unilateral sporadic vestibular schwannoma and to discuss the feasibility of using the head-shake test as a screening test. The study group consisted of 102 patients with unilateral sporadic vestibular schwannomas, who were seen consecutively for preoperative vestibular assessment, including the head-shake test. The sensitivity of the head-shake test for vestibular schwannoma was found to be 22%, and the sensitivity and specificity of the head-shake test for canal paresis (>/=25%) were found to be 27% and 88%, respectively. Patients with abnormalities in the central vestibular system and with a greater canal paresis were more likely to have head-shake nystagmus, although, even for severe canal paresis, the sensitivity of the test remained low at 36%. The direction of nystagmus was found to be contra-lateral to the side of the tumour in 86% of patients. It was concluded that the head-shake test is of insufficient sensitivity to be used as a screening test either for vestibular schwannoma or for vestibular-system abnormalities associated with vestibular schwannoma. The deduction is made that the head-shake test is of insufficient sensitivity or specificity to be of clinical value as a screening test for vestibular dysfunction in a general population with symptoms of imbalance.     

Exercise with visual feedback improves postural stability after vestibular schwannoma surgery

We analyzed the effect of 2-week individualized visual feedback-based balance training on the postural control of patients undergoing retrosigmoid microsurgical removal of vestibular schwannoma. We performed prospective evaluation of 17 patients allocated into two groups: feedback group (9 patients, mean age 37 years) and standard physiotherapy group (8 patients, mean age 44 years). Patients in both the groups were treated once per day by intensive rehabilitation from 5th to 14th postoperative day. Rehabilitation of patients in the feedback group was performed using the visual feedback and force platform. Results were evaluated on the beginning and at the end of rehabilitation program (e.g. 5th and 14th postoperative day). Outcome measures included posturography during quiet stance under four different conditions by the modified Clinical Test for Sensory Interaction of Balance. Body sway was evaluated from center of foot pressure. Compensation of Center of pressure (CoP) parameters in stance on firm surface was similar in the control and feedback groups. However, in stance on foam surface with eyes closed the patients from the feedback group were better compensated and CoP parameters differed significantly (p < 0.05). This prospective clinical study suggests that specific exercises with visual feedback improve vestibulospinal compensation in patients after vestibular schwannoma surgery and thus can improve their quality of life.     

Postural control after vestibular schwannoma resection measured with visual feedback posturography

BACKGROUND: Vestibular symptoms after surgery diminish rapidly, but the simultaneous progress in active postural control has not been fully addressed. OBJECTIVES: The aim was to evaluate the progress in postural control in operated vestibular schwannoma (VS) patients with visual feedback posturography (VFP). METHODS: 36 consecutive patients with unilateral VS were studied with the VFP pre-operatively, 1 month and 3 months after the surgery. The accuracy and velocity of active postural control movements to distant targets in VFP was measured and compared to that of healthy controls. RESULTS: The hold percentage within the targets was significantly reduced in the VS patients compared to the controls (pre-operatively p = 0.005; postoperatively at 1 month p = 0.002 and at 3 months p = 0.017). The sway velocity (SV) within the targets among patients with VS was significantly increased pre-operatively (p = 0.009), at the 1-month (p = 0.004) and at the 3-month follow-up visits (p = 0.016). All the postural control parameters except SV tended to improve slightly postoperatively. The consecutive VFP measurements in individual VS patients correlated statistically significantly (p < 0.001 for all parameters). The abnormality in the pre-operative VFP results correlated statistically significantly with that of postoperative VFP (p = 0.001). CONCLUSIONS: The VFP is an objective and repeatable method, which can be used to assess and follow up the active postural control in individual patients with VS. Persisting abnormality in the VFP seems to be an indication for more aggressive vestibular rehabilitation to normalize the disturbed postural control.     

Motorized head impulse rotator in patients with vestibular schwannoma

Conclusion. Motorized head impulse rotator is an effective technique to assess peripheral vestibular function. Approximately a quarter of patients with vestibular schwannoma (VS) had preserved preoperative responses. Vestibular disability could not be predicted based on vestibulo-ocular reflex (VOR) performance during motion stimuli, or in the caloric test. Objectives. To explore motorized head impulse rotator for evaluation of angular horizontal VOR in patients with VS, and to compare these responses to those of the caloric test and the symptoms. Patients and methods. We prospectively recorded head and eye position during unpredictable motorized head impulses in 38 patients with VS. We calculated gain and asymmetry of VOR (mean±95% CI), and the results were compared to those of the caloric test and a questionnaire regarding dizziness, hearing and quality of life. Results. The VOR during motorized impulses was abnormal in 71% of patients. Asymmetry in gain correlated significantly (p<0.001) with unilateral weakness in the caloric test. Preoperative gain was significantly lowered to 0.83±0.08 on the ipsilateral side compared to 0.98±0.06 on the contralateral side. Postoperative gain on the operated side of 0.53±0.05 was significantly different from preoperative gain (p<0.001). Findings in vestibular tests did not correlate with subjective sensation of dizziness.     

BoneBridge implantation in patients with single-sided deafness resulting from vestibular schwannoma resection: objective and subjective benefit evaluations

Abstract

Background: The BoneBridge could rehabilitate hearing for patients with single-sided deafness (SSD).

Objectives: To evaluate the objective and subjective benefits of BoneBridge implantation in patients after vestibular Schwannoma resection and to explore the factors affecting the benefits.

Material and methods: We prospectively enrolled all 15 patients implanted with BoneBridge after VS resection from January to June 2017. The primary outcome was the ability to hear in noisy conditions. The secondary outcomes were the soft-band BoneBridge try-on rate, the frequency of BB use, the sound source localization test result, and questionnaire measures of quality of life (QoL).

Results: Patients showed better speech recognition ability in the presence of noise with the BoneBridge. The BoneBridge provided no help in sound localization, although most patients reported subjective sound localization benefits. The results of QoL questionnaires showed significant satisfaction with BoneBridge implantation. The unilateral hearing deprivation duration and high education levels had significant impacts on the subjective benefits of patients.

Conclusions: The BoneBridge could improve speech recognition performance in complex auditory backgrounds, as well as QoL, especially in patients with short unilateral hearing deprivation durations and high education levels.

Significance: The BoneBridge is an effective hearing aid for single-sided deafness patients after VS removal.     

Hearing deterioration in patients with a non-growing vestibular schwannoma

OBJECTIVE: The aim of this study was to document and analyse the course of several audiometric parameters in 49 patients with a non-growing unilateral vestibular schwannoma (VS). MATERIAL AND METHODS: Patients received conservative management and absence of tumour growth was ascertained by means of serial magnetic imaging studies. Pure-tone audiometry and speech audiometry were performed at yearly intervals. RESULTS: Pure-tone audiometry revealed a significant increase in thresholds at all frequencies, except for 8.0 kHz. The maximum yearly threshold increase was 2.4 dB hearing level at 1.0 and 2.0 kHz. Speech audiometry revealed a significant decrease in maximum discrimination over the course of time. No significant changes were observed in the following parameters: the intensity level at which maximum discrimination was achieved; the roll-over index; the speech reception threshold; and the slope of the curve in the speech audiogram. No change was observed in the relation between pure-tone audiometry thresholds and speech audiometry scores. Apparently, the deterioration of pure-tone perception and speech discrimination ran parallel courses. CONCLUSIONS: The results of this study indicate that hearing loss is a predominant symptom in patients with a non-growing VS, as is also known in patients with a growing lesion. Moreover, it seems unlikely that the hearing loss in VS patients is merely the result of mechanical influences on retrocochlear neural or vascular structures.