Correlations between posturographic findings and symptoms in subjects with fractures of the condylar head of the mandible

Our study examined the posture of 15 patients who had sustained a simple unilateral or bilateral fracture of the condylar head of the mandible as a result of sports or traffic accidents. Following preliminary testing of vestibular function, the patients underwent balance testing: Romberg test with eyes closed (EC), Romberg EC and bite test (ECBT), EC and head retroflexed (ECR). The study parameters were: surface (S) of the statokinesigram, stomatognathic influence index related to S (SSI), and postural oscillations on the frontal plane (X). In keeping with the literature, we felt that the following pattern in static balance suggested a posture destabilised by the stomatognathic system: SSI values of less than 60, reduction of S in the transition from EC to ECR, pathological increase of postural oscillations on the X plane. The study was completed by obtaining a list of new symptoms reported by the patients (altered bite, fullness, tinnitus, pain, loss of balance). The most significant patterns were observed in patients with vestibular dysfunctions and neck pain. It seems that a fracture of the condylar head can affect postural behaviour, although proprioceptive changes alone are not enough to cause true loss of balance and there must be concomitant vestibular dysfunction. The stabilometric pattern is not conditioned by the extent of the trauma or the related treatment. In terms of proprioceptive elements, the presence of muscle pain seems to point to cervical muscle tension as the main culprit in the onset of posttraumatic instability.     

Somatosensory shift of postural control in dizzy patients

Conclusions: Postural control is dependent on the visual system in normal conditions. Shift from visual to somatosensory dependence in dizzy patients suggests that utilizing the stable visual references is recommended for the rehabilitation of dizzy patients. Objectives: To investigate which of the visual or somatosensory system is mainly used for substitution of the impaired spatial orientation in dizzy patients. Methods: We recruited 189 consecutive patients with or without dizziness and vestibular dysfunction. Dizzy patients were divided into three groups: acute, episodic, and chronic dizziness. Vestibular function was assessed by caloric test, traditional head impulse test, and head shaking nystagmus. Visual or somatosensory dependence of spatial orientation was assessed by posturography on a solid surface or on foam in eyes open or closed condition. The foam ratio (posturography with/without foam) when eyes were closed was indicative of somatosensory dependence of postural control, whereas the Romberg ratio on foam showed visual dependence. (Romberg ratio on foam)/(foam ratio with eyes closed) was calculated and used as an index of the visual/somatosensory dependence of postural control. Results: The visual/somatosensory ratio of postural control was significantly lower in dizzy patients as well as patients with vestibular dysfunction, however, no differences were found between acute, episodic, and chronic dizziness.     

Contribution of the Vestibular Apparatus to Postural Control when Rising from a Chair

Objective—The everyday act of rising from a chair is known to require the combined angular control of a number of the body's joints, especially those within the pitch plane. Precisely how this control is exerted, however, remains controversial. The aim of this study was to obtain a better understanding of the contribution made by the vestibular apparatus to postural control of the body and head when an individual rises from a chair.

Material and Methods—A total of 24 healthy controls and 38 patients with varying degrees of vestibular dysfunction were examined. Electromagnetic motion sensors were used to analyze the angular control of the head and body as subjects rose from a chair with their eyes open or closed.

Results—We found that unilateral vestibular dysfunction caused fixation of the head with respect to the body, resulting in a loss of spatial stability of the head which was not compensated for by visual input. Visual input did appear to compensate for bilateral vestibular loss, enabling patients with bilateral vestibular apparatus impairment or central disorders to fix the position of their head in space.

Conclusion—The act of rising from a chair is normally controlled by vestibular and proprioceptive input; the head is aligned according to the gravitational reference so as to obtain stable visual information. In patients with unilateral vestibular hypofunction, posture is still controlled by these two inputs, although the ability to align the head is diminished. In patients with bilateral vestibular hypofunction or a central disorder, head alignment is maintained using visual input, although it may not be the sole or predominant stabilizing force.     

Vestibular dysfunction causing instability in aged patients

Unilateral vestibular hypofunction (UVH) is a common vestibular dysfunction. Its influence upon the vestibulospinal reflex (VSR) is studied by posturography. The postural sway is disturbed when the VSR is disregulated because of the UVH. The degree of disturbance depends on the effectivity of the central compensation. Our results indicate that these adaptive mechanisms become less effective with advancing age. The importance of ocular fixation as a compensatory mechanism is also obvious. The comparison between posturographic recordings made with eyes open and those made with eyes closed, shows that, in elderly people, more abnormal posturographic recordings are found with eyes closed. Accordingly, with regard to the problem of falling in the elderly, the function of the vestibular system must be assessed and especially its influence upon the standing posture. The combination of classical vestibular and posturographic results affords this indispensable information.     

Die graphische Registrierung und rechnergesteuerte Auswertung der Romberg-Tests

Summary In patients with vestibular disturbances the examination of vestibulospinal reflexes belongs to the normal neurotological test-battery. We use Romberg's test, Unterberger's test and WOFEC (walk on floor eyes closed).On one hand, these tests usually are analysed visually and therefore are quoted subjectivly. On the other hand, they are often used by patients to simulate pathologic test-results or aggravate weak pathologic findings.The computer analysis of an electronically performed Romberg test may help to gain more objectivity. It can be shown, that analysis of body motion itself is less effective than the analysis of variations of its velocity.     

Contribution of the vestibular apparatus to postural control when rising from a chair

OBJECTIVE: The everyday act of rising from a chair is known to require the combined angular control of a number of the body's joints, especially those within the pitch plane. Precisely how this control is exerted, however, remains controversial. The aim of this study was to obtain a better understanding of the contribution made by the vestibular apparatus to postural control of the body and head when an individual rises from a chair. MATERIAL AND METHODS: A total of 24 healthy controls and 38 patients with varying degrees of vestibular dysfunction were examined. Electromagnetic motion sensors were used to analyze the angular control of the head and body as subjects rose from a chair with their eyes open or closed. RESULTS: We found that unilateral vestibular dysfunction caused fixation of the head with respect to the body, resulting in a loss of spatial stability of the head which was not compensated for by visual input. Visual input did appear to compensate for bilateral vestibular loss, enabling patients with bilateral vestibular apparatus impairment or central disorders to fix the position of their head in space. CONCLUSION: The act of rising from a chair is normally controlled by vestibular and proprioceptive input; the head is aligned according to the gravitational reference so as to obtain stable visual information. In patients with unilateral vestibular hypofunction, posture is still controlled by these two inputs, although the ability to align the head is diminished. In patients with bilateral vestibular hypofunction or a central disorder, head alignment is maintained using visual input, although it may not be the sole or predominant stabilizing force.     

Head–body righting reflex from the supine position and preparatory eye movements

Conclusion Saccular and utricular maculae can provide information on the supine static position, considering that both have pronounced curved structures with hair cells having a variety of polarization vectors that enable them to sense an inverted position and thus direct the righting reflex.

Objective The vestibular system is essential for the structuring of motor behaviour, senses linear and angular acceleration and has a strong influence on posture and balance at rest, during locomotion and in head–body righting reflexes.

Material and methods Using guinea pigs in the supine position with a symmetrical head and trunk position, the ocular position was analysed to ascertain whether any ocular movement that occurred would adopt a spatial deviation indicative of the subsequent head and body righting. The characteristics of the righting reflex (direction, latency, duration and velocity) were analysed in guinea pigs from position signals obtained from search coils implanted in the eye, head and pelvis. The animals were kept in a supine position for a few seconds or even minutes with the eyes in a stable primary position and the head and body symmetrical and immobile.

Results The righting reflex took place either immediately or after a slow deviation of the eyes. In both cases the righting sequence (eyes, head, body) was stereotyped and consistent. The direction of head and body righting was along the longitudinal axis of the animal and was either clockwise or anticlockwise and the direction of righting was related to the direction of the eye deviation. The ocular deviation and the direction of deviation that initiated and determined the direction of the righting reflex could be explained by possible otolithic activation.     

Time course analysis of angular control of the body and head while rising from a chair

Objective To use time course information to improve understanding of the vestibular contribution to postural control as one rises from a chair.

Material and methods A total of 24 healthy controls and 42 patients with varying degrees of vestibular dysfunction were studied. The time course of the angular motion of the body and head when rising from a chair with eyes open and closed was evaluated. The delay between the onset of the motions of the body and head was compared between subject groups. We also investigated transition points from forward lean of the body to backward reversion and from backward tilt of the head to forward reversion. Results With regard to the onset of chair rise, we found a significant difference in the delay between head and body motion between healthy controls and subjects with bilaterally impaired vestibular deficiency only when the eyes were closed. The time between the transition points of the head and body was stable between these groups.

Conclusion The mechanisms controlling the onset of head and body movements differ between normal subjects and those with bilateral vestibular deficits. In the latter, the loss of a reference of gravity causes a decrease in feed-forward postural control, which is compensated for by a somato-sensory feedback mechanism. Visual input seems to provide an alternative reference of gravity.     

First trial response to sudden support surface displacement: The effect of vestibular compensation

Conclusion: The effect of visual condition is more intense in the first trial response in normal subjects and patients and in last trial response only in patients. The first trial effect is more evident in compensated patients in the eyes open condition with any type of perturbation, and in non-compensated patients with the angular displacements in either visual condition. Objective: The study of body reaction to FTR can help to understand the complex mechanisms involved in the postural response and to develop new therapies to improve stability and prevent falls in unilateral vestibular deficit (UVD). This work describes the adaptation effect and the visual influence on the postural response to repetitive balance perturbation stimulus in normal subjects, compensated, and uncompensated UVD patients. Methods: The magnitude of displacement has been measured when the support surface is linearly or angularly displaced. The differences between results in the first and late trial, and the differences between the eyes open and eyes closed situation have been compared. Results: Compensated patients recover the adaptation ability to unexpected changes on the support surface through visual preference mechanism. Not compensated patients present hypermetric postural response with greater instability in the eyes open and eyes closed situations.     

Short-term Adaptation in the Peripheral Auditory System is Related to the AMPA Receptor

A pattern of sound-induced paroxysms of the eye and head and other spinal motor neuron synkinesis (Tullio's phenomenon) in human subjects always implies either a pathological contiguity of the tympano-ossicular chain and membranous labyrinth or a dehiscence of the bone overlying the superior semicircular canal. However, it has become clear in the last decade that sound-evoked vestibular stimulation is not only a sign of disease but also a physiological phenomenon. The examination of such physiologically sound-induced vestibular (saccular) responses contributes today to the clinical testing of the vestibular organ, mainly in the form of vestibular-evoked myogenic potentials. In this study it was observed that, in a group of 20 normal subjects, a 500 Hz tonal stimulus of high intensity (105 dB HL=118.5 dB SPL), applied monoaurally, elicited postural responses. Each subject was studied under 4 different conditions: (i) head facing forwards, eyes open; (ii) head facing forwards, eyes closed; (iii) head rotated &;#44 90° to the right, eyes closed; and (iv) head rotated 90° to the left, eyes closed. Body sway, measured using a force platform, was recorded in all subjects, with eyes either open or closed. Postural responses, which were also elicited with a 250 Hz tonal stimulus, were not observed with a tone of 2000 Hz, with legs slightly flexed or with binaural stimulation. The postural sway (head facing forwards, eyes open or closed) was in a lateral direction towards the stimulated ear: with the stimulus applied to the right ear the subject had postural sway towards the right, with the stimulus applied to the left ear towards the left. When the head was rotated &;#44 90° sideways and the stimulus was given facing forwards (i.e. head rotated contralaterally to stimulated ear) the postural sway was in a forward direction; when the head was rotated &;#44 90° sideways and the stimulus was given facing backwards (i.e. head rotated ipsilaterally to stimulated ear) the postural sway was in a backward direction. The mean values (mm) of body sway obtained with the head facing forwards and the eyes closed were higher than those with the eyes open (21.7 and 22.8 vs 15.7 and 14.7 for the right and left ears, respectively); higher mean values were obtained with the head turned to the side contralateral to the ear stimulated and the eyes closed (29.3 and 24.8 for the right and left ears, respectively). Under this condition the body sway was mainly in a forward direction. The sound-evoked vestibulopostural reflex seems to be a useful test for exploring the saccular function and, as a click-evoked vestibulocollic reflex, can be considered a physiological Tullio phenomenon.     

Postural Stability Using Different Neck Positions in Normal Subjects and Patients with Neck Trauma

Subjects with neck problems, such as whiplash injuries, often complain of disturbed equilibrium and, in some instances, provocation of the neck position can elicit such problems. The importance of neck proprioceptors for maintaining balance is gaining increased interest, moreover the function or malfunction of the otoliths may disturb equilibrium in certain head positions. The aim of the study was to create a reference material for postural control and its dependence on head position in healthy subjects and to compare this with a set of patients with known neck problems and associated vertiginous problems. A total of 32 healthy subjects (16 men, 16 women; age range 21-58 years) as well as 10 patients age range 27-62 years (mean 44 years) with neck problems and associated balance problems since a whiplash injury were tested for postural control using the EquiTest dynamic posturographic model. The normal subjects were initially split into four age groups in order to estimate the effects of age on performance. The postural stability was evaluated for dependence of support surface conditions (stable or sway-referenced), visual input (eyes open or closed) and head position (neutral, left rotated, right rotated, extended backwards or flexed forward) using analysis of variance (ANOVA) with Tukey's post hoc test in case of a significant factor effect. As expected, visual cues as well as stable support surface improve postural stability (p<0.001). Postural stability is statistically different in the head extended backwards condition compared with the other four head positions (p<0.001 in all cases) in both patients and controls. Eliminating this test condition from the analysis, only a slight (p<0.05) difference between head forwards and head turned left remained. This pattern of results remained if the normal subjects were only split into two age groups instead of four. Finally, the patient group exhibited significantly lower postural performance than all the groups of normal subjects (p<0.01), but none of the normal groups differed significantly from each other. It is concluded that the postural control system is significantly challenged in the head extended backwards condition in both normal subjects and patients with previous whiplash injury and persistent neck problems. The patient group differed statistically from all groups of normal subjects. This suggests that neck problems impair postural control, and that the head extended position is a more challenging task for the postural system to adapt to. Whether this is due to utricular malpositioning, central integrative functions or cervical proprioceptive afferents is not within the scope of this study to answer.     

Clinical applications of correlational vestibular autorotation test

Conclusion: The correlational vestibular autorotation test (VAT) system has the advantages of good test–retest reliability and calibrations of absolute degrees of eye movement are unnecessary when acquiring a cross correlation coefficient (CCC). The approach is able to efficiently detect peripheral vestibulopathies. Objective: A VAT has some drawbacks including poor test–retest reliability and slippage of sensor. This study aimed to develop a correlational VAT system and to evaluate the reliability and applicability of this system. Methods: Twenty healthy participants and 10 vertiginous patients were enrolled. Vertical and horizontal autorotations from 0 to 3 Hz with either closed or open eyes were performed. A small sensor and a wireless transmission technique were used to acquire the electro-ocular graph and head velocity signals. The two signals were analyzed using CCCs to assess the functioning of the vestibular ocular reflex (VOR). Results: The results showed a significantly greater CCC for open-eye versus closed-eye of head autorotations. The CCCs also increased significantly with head rotational frequencies. Moreover, the CCCs significantly correlated with the VOR gains at autorotation frequencies ≥1.0 Hz. The test–retest reliability was good (intraclass correlation coefficients ≥0.85). The vertiginous participants had significantly lower individual CCCs and overall average CCC than age- and-gender matched controls.     

Posture testing (posturography) in the diagnosis of peripheral vestibular pathology

In patients with peripheral vestibular deficiencies, the testing of posture or "posturography" can give specific information about any compensation obtained in the vestibulospinal reflex (VSR). We have used the statokinesimetric parameter of length in this study. Nearly 50% of the patients with unilateral vestibular hypofunction as well as those patients with paroxysmal positional vertigo (PPV) show abnormal results. These findings indicate deficient compensation at the vestibulospinal level, which is independent of any compensation already achieved at the vestibulo-ocular level. The tests used for the latter, such as positioning and rotational tests, are unable to provide information about the degree of compensation reached in the VSR. The examinations used in the different modalities of sensory interaction can show the presence of influences of ocular fixation and changes of head position. We have observed three types of deviant interaction. Our posturographic data have allowed us to assess functional situations in a more precise way. Any rehabilitation exercises used should be adapted according to these data.     

Assessment of head shaking test in neuro-otological practice

The head shaking test (HST) is an important test in neuro-otological diagnosis. In our study of 277 patients complaining of dizziness we verified this importance. The results thus obtained were compared with the results recorded in 73 normal subjects. Head shaking nystagmus was observed in 73 patients. Of these 73 cases, 42 involved central diseases and 31 cases involved peripheral diseases. Head shaking nystagmus was observed in 7 subjects of the control group. A highly significant correlation was noted between head shaking nystagmus and positional nystagmus, between head shaking nystagmus and the caloric test and between head shaking nystagmus and all the other spontaneous types of nystagmus that were investigated (eyes open in light/gaze straight ahead; eyes open behind Frenzel's glasses; eyes closed; eyes open in darkness). No correlation was found between head shaking nystagmus and cervical nystagmus and positioning nystagmus. The sensitivity of head shaking nystagmus, in comparison with other types of spontaneous nystagmus, was found to be slightly higher in cases with peripheral lesions than in those with central lesions. These data confirm the diagnostic importance of this simple test. It is also important to keep in mind that the HST has no importance for topodiagnostic purposes.     

Sound-evoked postural responses in normal subjects

A pattern of sound-induced paroxysms of the eye and head and other spinal motor neuron synkinesis (Tullio's phenomenon) in human subjects always implies either a pathological contiguity of the tympano-ossicular chain and membranous labyrinth or a dehiscence of the bone overlying the superior semicircular canal. However, it has become clear in the last decade that sound-evoked vestibular stimulation is not only a sign of disease but also a physiological phenomenon, The examination of such physiologically sound-induced vestibular (saccular) responses contributes today to the clinical testing of the vestibular organ, mainly in the form of vestibular-evoked myogenic potentials. In this study it was observed that, in a group of 20 normal subjects, a 500 Hz tonal stimulus of high intensity (105 dB HL = 118.5 dB SPL), applied monoaurally, elicited postural responses. Each subject was studied under 4 different conditions: (i) head facing forwards, eyes open; (ii) head facing forwards, eyes closed; (iii) head rotated approximately 90 degrees to the right, eyes closed: and (iv) head rotated approximately 90 degrees to the left, eyes closed. Body sway, measured using a force platform, was recorded in all subjects, with eyes either open or closed. Postural responses, which were also elicited with a 250 Hz tonal stimulus, were not observed with a tone of 2000 Hz, with legs slightly flexed or with binaural stimulation. The postural sway (head facing forwards, eyes open or closed) was in a lateral direction towards the stimulated ear: with the stimulus applied to the right ear the subject had postural sway towards the right, with the stimulus applied to the left ear towards the left. When the head was rotated approximately 90 degrees sideways and the stimulus was given facing forwards (i.e. head rotated contralaterally to stimulated ear) the postural sway was in a forward direction; when the head was rotated approximately 90 degrees sideways and the stimulus was given facing backwards (i.e. head rotated ipsilaterally to stimulated ear) the postural sway was in a backward direction. The mean values (mm) of body sway obtained with the head facing forwards and the eyes closed were higher than those with the eyes open (21.7 and 22.8 vs 15.7 and 14.7 for the right and left ears, respectively); higher mean values were obtained with the head turned to the side contralateral to the ear stimulated and the eyes closed (29.3 and 24.8 for the right and left ears, respectively). Under this condition the body sway was mainly in a forward direction. The sound-evoked vestibulopostural reflex seems to be a useful test for exploring the saccular function and, as a click-evoked vestibulocollic reflex, can be considered a physiological Tullio phenomenon.     

Postural responses evoked by sinusoidal galvanic stimulation of the labyrinth. Influence of head position

In 15 healthy subjects we studied body sway reactions to sinusoidal 0.3 Hz binaural bipolar galvanic current up to 2 mA under three conditions. With the head forward and eyes closed, there is only a periodic lateral displacement of the centre of gravity, following the stimulation with a phase lag. In two other conditions, the head turned to the left or to the right without trunk torsion, the direction of sway was modified in such a way that there were mainly anteroposterior movements. It is thought that this experiment shows the modulatory influence of neck afferents on the direction of vestibulospinal motor effects in man.     

Objective Facial Motion Analysis in Patients With Facial Nerve Dysfunction

Objectives/Hypothesis To objectively measure facial motion at various facial landmarks using a video‐computer interactive system. Study Design Clinical, prospective, non‐randomized. Methods A video‐computer interactive system, The Peak Motus Motion Measurement System, was used to study linear displacement at preselected facial landmarks in the normal and abnormal face. Subjects with normal facial function (n = 34) and patients with abnormal facial function (n = 26) from various etiologies were studied. The sites studied were marked with reflective beads. Of a larger repertoire of expressions, two expressions (eyes closed and closed‐lip smile) were studied in all subjects. The percent asymmetry in facial displacement between the sides of the face was calculated. The sensitivity of this measurement to facial dysfunction was evaluated. The presence of synkinesis was examined by quantifying the displacement at facial sites that were remote to the sites primarily involved in a given facial expression. Test–retest reliability of the percent asymmetry measurement was evaluated with the paired t test. Results The video‐computer interactive approach used accurately detected and quantified gross and subtle changes in facial function. The sensitivity of the percent asymmetry measurement was 95% (both expressions) for patients with apparent facial dysfunction (House‐Brackmann rating >I/VI). In patients with facial nerve dysfunction, displacement on the presumably normal side was significantly excessive in 27% to 35%, depending on the expression. With this interactive computer‐video system, synkinesis was detected in 58% of the pathologic subjects during the eyes closed or closed‐lip smile expressions. The paired t test indicated strong test–retest reliability (r = 0.73–0.99) of the percent asymmetry measurement. Conclusions The present report indicates that this approach to the assessment of facial motion is sensitive to facial dysfunction. This computer‐video interactive system is able to quantify synkinesis. A grading system for the magnitude of synkinesis, based on the magnitude of the displacement at remote facial sites, is proposed. The common occurrence of excessive facial motion on the presumably normal side of affected individuals indicates that patients with facial paralysis often overcompensate by exaggerating the normal side in an effort to move the affected side. This system is of value in the objective measurement of normal facial function and may prove a useful tool to quantify the outcomes of various medical and surgical treatments for facial nerve dysfunction.     

Study in predictive posture control during the performance of actions]

In order to maintain an ordinary upright posture, the body's center of gravity must be predicted and controlled on the supporting surface based on synthesis of multiple-sensory inputs. In order to evaluate the accuracy of predictive (feedforward) posture control during the performance of actions, we measured maximal shifts in the body's center of gravity using a force platform in 6 normal adults under two visual conditions (with eyes open and closed) and four standing conditions (one-legged; heel to toe posture; and both legs together or apart). Subjects were asked to perform five kinds of voluntary actions (static standing; head tilting forward, backward and laterally; head turning; bending forward; and maximal inclinations to the anterior, posterior and lateral directions). The smaller the supporting surface, the more markedly displacement of the body's center of gravity was increased upon closing the eyes. This finding suggests that the accuracy of predictive posture control decreases as a result of the reduction in the number of multisensory inputs which determine spatial orientation. Assessing purposive shifts in center of gravity during voluntary actions, we can conclude that the body's center of gravity is accurately controlled even in the presence of head movements under ordinary standing conditions. To evaluate balance during the performance of routine actions, we must devise a better method of discriminating purposive shifts in center of gravity from control disorder errors as well as a method of quantifying the accuracy of feedforward regulation.     

Posture testing (posturography) in the diagnosis of peripheral vestibular pathology

Summary In patients with peripheral vestibular deficiencies, the testing of posture or posturography can give specific information about any compensation obtained in the vestibulospinal reflex (VSR). We have used the statokinesimetric parameter of length in this study. Nearly 50% of the patients with unilateral vestibular hypofunction as well as those patients with paroxysmal positional vertigo (PPV) show abnormal results. These findings indicate deficient compensation at the vestibulospinal level, which is independent of any compensation already achieved at the vestibulo-ocular level. The tests used for the latter, such as positioning and rotational tests, are unable to provide information about the degree of compensation reached in the VSR. The examinations used in the different modalities of sensory interaction can show the presence of influences of ocular fixation and changes of head position. We have observed three types of deviant interaction. Our posturographic data have allowed us to assess functional situations in a more precise way. Any rehabilitation exercises used should be adapted according to these data.Supported by a grant from the Nationaal Fonds voor Geneeskundig Wetenschappelijk Onderzoek     

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.