1 Introduction
Vestibular function testing aims to objectify the complaints, symptoms, and clinical signs of patients presenting with dizziness and vertigo, serving as a critical methodology for the evaluation of vestibular function and the diagnosis of vestibular disorders. Among these, the rotational chair test is a non-invasive physiological assessment capable of directly evaluating the vestibulo-ocular reflex (VOR) function of the horizontal semicircular canals and their afferent pathways across low-to-mid frequency ranges via precisely calibrated angular acceleration stimuli. Similar to other vestibular assessments such as caloric testing and the video-head impulse test (vHIT), it evaluates vestibular status primarily through oculomotor characteristics—specifically the pattern, frequency, and direction of induced nystagmus. Distinctively, however, the rotational chair test simultaneously stimulates both horizontal semicircular canals to assess the "push-pull mechanism" and the linear characteristics of bilateral labyrinthine synergy. Nonetheless, its clinical accessibility remains limited due to its inability to isolate unilateral semicircular canal function and the high costs associated with the equipment.
The primary limitation of the rotational chair test lies in its simultaneous stimulation of bilateral semicircular canals, which precludes precise lateralization of vestibular lesions. Furthermore, because the vestibular status of patients with dizziness and vertigo is in a state of dynamic flux, results may vary significantly across different stages of the same disease. Paradoxically, this characteristic represents a unique advantage for capturing dynamic fluctuations in vestibular function and monitoring the progress of central compensation. Although clinical adoption remains limited by high operational costs and a lack of standardized normative data, the rotational chair test offers distinct benefits, including precise stimulus delivery and superior patient tolerability. Consequently, it is particularly indicated for cases of bilateral vestibulopathy (BVP), patients unable to undergo caloric or head impulse testing, and individuals with inner ear malformations. Moreover, it remains a critical tool for the evaluation of vestibular compensation and the differential diagnosis of central vestibular lesions
[1,
2].
Consequently, this review delineates the physiological principles, testing protocols, and evaluative parameters of the rotational chair test, while providing an in-depth analysis of its clinical progress across various vestibular disorders. By exploring the application prospects of this modality in different pathological contexts, this paper aims to serve as a comprehensive reference for the standardized clinical implementation and broader dissemination of this diagnostic tool.
2 The Physiological Principle of the Rotational Chair Test
Human stability and gaze stabilization rely primarily on the VOR and the vestibulospinal reflex (VSR), with the semicircular canals and otolith organs serving as the fundamental receptors of the vestibular system. As a rotational assessment conducted around a vertical axis, the rotational chair test specifically evaluates the horizontal semicircular canal-mediated VOR function. Vestibular function testing generally comprises two critical components: the stimulus input and the reactive response output. Regarding the latter, infrared video goggles are typically employed to record eye movements, which are subsequently analyzed by sophisticated computer algorithms to generate a videonystagmogram (VNG). While this output format is consistent with other vestibular assessments such as the vHIT and caloric testing, the core clinical superiority of the rotational chair test lies in the unique precision and physiological nature of its stimulus input.
Current vestibular function tests target distinct frequency domains; however, their stimulus inputs are frequently difficult to standardize. The vHIT utilizes passive, high-velocity head impulses to assess parameters such as gain and symmetry for the evaluation of high-frequency (> 1 Hz) vestibular function; yet, the input remains dependent on the operator’s manual stability. Conversely, the Vestibular Autorotation Test (VAT) requires patients to perform active head oscillations at specific frequencies (2–6 Hz) to evaluate horizontal and vertical semicircular canal function through gain, phase, and asymmetry; this method is often confounded by patient cognition and the lack of motion standardization. While caloric testing employs thermal stimuli to quantitatively assess ultra-low-frequency function, results are susceptible to variations in external auditory canal anatomy, mastoid pneumatization, and the precision of the stimulus temperature. Across these modalities, stimulus input remains inherently uncertain. The rotational chair test effectively addresses the challenge of uncontrollable input variables. While the output remains videonystagmography, the input consists of computer-controlled, precise, and reproducible angular acceleration stimuli covering the physiological frequency range (0.01–0.64 Hz). By simultaneously stimulating bilateral horizontal semicircular canals, where the induced VOR results from the summation of ampullopetal stimulation in the ipsilateral canal and ampullofugal inhibition in the contralateral canal regardless of rotation direction, the rotary chair enables a rigorous assessment of the linear interactions within the vestibular system.
Consequently, the physiological stimulus delivered by the rotational chair test is more precise and less susceptible to technical artifacts. Common rotational paradigms include impulsive and sinusoidal modes—namely, the velocity step test (VST) and Sinusoidal Harmonic Acceleration (SHA). The former is prone to inducing significant vertigo and may not be tolerated by all patients; its limitations include challenges in maintaining constant rotational velocity, high stimulus intensity, and the potential interaction between acceleration and deceleration phases. However, the VST remains essential for determining the VOR Time Constant (Tc). In contrast, SHA is more widely utilized in clinical practice. Although it is less sensitive than caloric testing in detecting mild unilateral vestibular deficits, SHA is superior for the multi-frequency quantitative assessment of bilateral vestibular dysfunction and for the identification of residual vestibular function
[3].
3 Rotational Chair Test Inspection Process and Evaluation Index
3.1 Procedure
Three-dimensional space includes three basic axes of motion: the coronal axis (X-axis), the sagittal axis (Y-axis), and the vertical axis (Z-axis). Rotational chair testing typically involves rotation around the body’s vertical axis (Z-axis) to stimulate the horizontal semicircular canals. First, the subject is secured in a rotary chair within a soundproof and light-shielded darkroom, with the head tilted 30° forward to ensure the horizontal semicircular canals remain parallel to the ground. Second, electrodes are attached to both temples and the center of the forehead; if infrared videonystagmography (VNG) goggles are used, electrodes are no longer necessary. The head must be secured via a headband and chin rest to ensure head movement is perfectly synchronized with the rotary chair. During the test, the patient is in complete darkness to eliminate fixation suppression; the examiner monitors the quality of nystagmus waveforms in real-time via a monitor and closely observes the patient for autonomic reactions such as nausea or sweating.
3.2 Technical requirement
Strict operational requirements and standardized technical specifications are the prerequisites for ensuring accurate and credible results in rotational chair testing. First, the rotational chair test should be conducted in a dark, soundproof, and light-shielded environment with the patient’s eyes open to block the inhibitory effect of visual fixation on the VOR. Second, because the observation indices—particularly gain data—are highly susceptible to the patient’s level of alertness
[4], patients are prone to drowsiness in dark environments, which can lead to a non-pathological reduction in gain. Therefore, mental alertness tasks, such as verbal reminders or tactile stimulation, should be employed to keep the patient in an excited and focused state. This maintains the excitability of the brainstem reticular formation and prevents false-positive results caused by a lack of attention
[5]. Third, in addition to tilting the head forward by 30° to ensure the horizontal semicircular canals are as level as possible, care must be taken to avoid interference from somatosensory stimuli. This includes preventing physical contact with stationary objects or exposure to facial airflow, with a specific focus on the additive effect of upper limb somatosensory input on the VOR
[6]. Furthermore, while the intake of stimulant beverages (such as caffeine or strong tea) does not affect the results of rotational chair tests in healthy individuals, its impact on the elderly and patients with vestibular impairment remains unclear
[7]. It is recommended that standardized medication and dietary guidance be provided for the elderly or those with organic lesions of the vestibular system.
3.3 Parameter setting
The two rotation modes commonly used in clinical rotational chair testing have distinct diagnostic focuses. The VST, also known as the step (impulse) stimulus mode, utilizes an "acceleration-constant velocity-sudden stop" stimulus protocol. The chair accelerates to an angular velocity of 60–240°/s (200°/s is most common) within < 1s, using an angular acceleration of 0.5°/s2 or 1–4°/s2. This velocity is maintained for 60s before coming to a rapid halt within 1s. This mode primarily observes the decay process of post-rotatory nystagmus. Following the cessation of stimulus, parameters such as nystagmus duration, slow-phase velocity (SPV), and the slow-phase velocity asymmetry ratio are evaluated to assess the central velocity storage mechanism. Sinusoidal oscillation modes include a combination of four sinusoidal oscillation tests and the more frequently utilized sinusoidal harmonic acceleration test (SHAT). SHAT consists of a battery of sinusoidal oscillation tests at doubling frequencies (0.01, 0.02, 0.04, 0.08, 0.16, 0.32, and 0.64 Hz), typically with a peak velocity of 50°/s or 60°/s. This mode covers the full frequency range of vestibular function. Specifically: This frequency is the most sensitive for detecting a shortened time constant (manifesting as phase lead) caused by peripheral lesions. These higher frequencies are used to evaluate visual-vestibular interaction and the preservation of high-frequency function. Testing all frequencies can be time-consuming in a clinical setting; currently, 0.32 Hz and 0.64 Hz are the recommended frequencies for standard detection.
3.4 Interpretation of results
In the VST, the SPV of nystagmus is the most stable parameter, and clinical practice frequently employs the slow-phase velocity gain (G) and the time constant (Tc) as primary evaluation indices. The former is defined as the peak slow-phase velocity during or after rotation divided by the chair’s rotational velocity, primarily reflecting nystagmus intensity, while the latter represents the time required for the peak slow-phase velocity to decay to 37% of its maximum value, usually measured in seconds. Additionally, nystagmus duration can be calculated, though it is clinically difficult to determine the exact point of cessation and the metric is easily influenced by age; therefore, while less precise than Tc, both indices reflect central vestibular sensitivity
[8]. Under normal conditions, the central nervous system extends the peripheral signal of approximately 6 s to a duration of 15–20 s. A shortened Tc (< 10 s) typically indicates unilateral or bilateral peripheral vestibular damage, where the center actively inhibits the velocity storage mechanism (VSM) to reduce vertigo, whereas an abnormally prolonged Tc (> 30 s) suggests a state of vestibular hypersensitivity, commonly seen in individuals susceptible to motion sickness or patients with vestibular migraine
[9].
SHAT typically tests frequencies ranging from 0.01 to 0.64 Hz and primarily evaluates three indices: gain, phase, and symmetry, with results considered abnormal if two consecutive frequencies show irregularities. Gain reflects the relationship between vestibular stimulus input and output—specifically the ratio of eye movement velocity to chair velocity—and serves as a measure of the vestibular end-organ’s output; reduced gain is frequently observed in bilateral vestibular damage or acute unilateral vestibular damage. Phase reflects the temporal relationship between compensatory nystagmus (eye movement) and chair movement, serving as a measure of VOR timing; phase lead in the low-frequency range (0.01–0.08 Hz) is a sensitive indicator of peripheral vestibular lesions, while reduced phase may be seen in cases of motion sensitivity
[10]. Symmetry reflects the difference in nystagmus intensity between the left and right directions, comparing the output strength of rotational stimuli in both directions; asymmetry is commonly found during the acute phase of vestibular injury.
Currently, the existing evaluation indices for accessory examinations of semicircular canal function only assess vestibular impairment from specific perspectives, making it difficult to fully capture the complete picture of vestibular dysfunction. Research by Hain et al.
[11] proposed a comprehensive evaluation index known as the Gain-Time Constant product (Gain × Tc). Their findings revealed that, compared to healthy individuals, unilateral vestibular loss has almost no effect on gain but significantly reduces the time constant; conversely, patients with bilateral vestibular loss may present with a normal time constant while their gain is persistently reduced. Consequently, Gain × Tc serves as a better measure for evaluating a patient’s residual vestibular function than considering gain or the time constant in isolation. However, since the vestibular damage in that study was caused by ototoxic drugs or artificial factors, the clinical generalizability of this index requires further consideration
[12]. Furthermore, observing a patient’s equilibrium reactions during the rotational chair test—such as dizziness, nausea, and post-test postural instability—is helpful for a comprehensive assessment of the vestibular system’s capacity for position perception and spatial orientation.
It is noteworthy that one of the primary difficulties in rotational chair testing lies in the standardization of the patient's state. Research by Nourhan et al.
[9] found no significant differences across various age groups regarding SHAT parameters and the time constant for each rotation in the VST; however, the post-rotatory time constant in the VST was significantly prolonged, which is consistent with the findings of Li et al.
[13]. In contrast, the study by Yu et al.
[14] revealed significant differences between age groups in SHAT gain at 0.01 Hz, phase at 0.08–0.64 Hz, and asymmetry at 0.01, 0.16, and 0.64 Hz. Age may be one of the factors negatively impacting the gain of rotational chair tests, particularly in pre-adolescent and elderly groups
[15]. Consequently, given the influence of age on low-frequency phase and gain during rotational chair testing, age-stratified normative data should be established in clinical practice to avoid misdiagnosis.
4 Application of the Rotational Chair Test in Vestibular Diseases
4.1 Bilateral vestibulo pathy
The rotational chair test is one of the most critical diagnostic examinations for identifying BVP and assessing its severity, and it is also one of the auxiliary tests recommended by the Bárány Society’s consensus on BVP diagnosis
[4]. In a SHAT at 0.1 Hz with a peak velocity (Vmax) of 50°/s, a diagnosis of BVP is typically made if the gain is < 0.1 and the phase lead is > 68° (corresponding to a time constant of < 5 s)
[3,
16,
17]; this is also consistent with the research findings of Pérez-Fernández et al.
[18].
Across all frequency bands of the rotational chair test, patients with BVP exhibit more pronounced impairments at lower frequencies; in some cases, phase measurements at 0.01–0.16 Hz are even undetectable
[19], although abnormalities in elderly patients are more commonly observed at higher frequencies, necessitating careful clinical differentiation
[20]. The rotational chair test can evaluate whether there is residual function in the horizontal semicircular canals; specifically, even when caloric testing yields almost no detectable vestibular response, some gain may still be preserved at mid-to-high frequencies (0.32–0.64 Hz)
[17], which carries significant prognostic value for guiding vestibular rehabilitation.
Currently, only vHIT has demonstrated a correlation with the prognosis of BVP patients
[21]. Regarding fall risk assessment in BVP patients, no single vestibular function test can accurately predict outcomes. The Dizziness Handicap Inventory (DHI) and Oscillopsia Severity Questionnaire (OSQ) may be superior options. DHI scores > 47 and OSQ scores > 27.5 may indicate fall risk in BVP patients, with a sensitivity of 70% and specificity of 60% for this predictive indicator
[22].
4.2 Presby vestibular pathy
PVP refers to age-related mild-to-moderate bilateral vestibulopathy and is one of the conditions for which rotational chair testing is recommended under the Bárány Society’s diagnostic consensus. A diagnosis can be confirmed if the patient exhibits a VOR gain of 0.1–0.3 during sinusoidal stimulation at 0.1 Hz with a V max of 50–60°/s
[23]. Due to physiological degenerative changes in the elderly, this threshold is slightly higher than that for BVP; it also effectively distinguishes physiological aging from severe BVP (gain < 0.1). Across all frequency bands of rotational chair testing, research by Allan et al.
[24] recommends using Dynamic Visual Acuity (DVA), sinusoidal rotation tests (gain and phase at 0.5–1 Hz), and transient rotation tests (gain and time constant with an acceleration of 1500°/s
2 and a constant velocity of 50°/s) to evaluate peripheral vestibular function in patients over 50 with benign paroxysmal positional vertigo (BPPV) or vestibular hypofunction. Similarly, Figtree et al.
[25] found that the time constant in rotational chair testing is more suitable for detecting elderly patients with vestibular loss not caused by BPPV. Due to the natural apoptosis of hair cells and neurons in the elderly, high-frequency function (as measured by vHIT) often suffers impairment earlier, whereas the mid-to-low frequency data provided by the rotational chair test can more comprehensively reflect the overall function of the vestibular system. Furthermore, especially for elderly and adolescent populations, the normative data provided by manufacturers cannot serve as an accurate reference
[15]; in clinical practice, care should be taken to integrate these results with vHIT examinations for a combined diagnosis.
4.3 Acute unilateral vestibular impairment
Most acute vestibular injuries are unilateral; when the contralateral function remains normal, the rotational chair test is less sensitive than the vHIT and caloric testing for detecting unilateral vestibular hypofunction. Research by Kim et al.
[26] found that the abnormality rate of the rotational chair test in the group with a canal paresis (CP) value > 25% was 81.5%, significantly higher than the 21.5% observed in the group with a CP value < 25%. Consequently, for patients with unilateral vestibular damage, low-frequency SHAT struggle to reflect the patient’s true vestibular functional state in daily life, and its sensitivity correlates poorly with clinical symptoms. This occurs because, during low-velocity rotation, the healthy labyrinth can drive bidirectional VOR through central compensation; however, the rotational chair test is extremely sensitive to the time constant (Tc). In the acute phase of vestibular neuritis, patients typically exhibit a significantly shortened Tc (< 10 s). Therefore, assessing different stages of unilateral vestibular lesions requires integration with other vestibular function tests to avoid false positives
[17].
Lee et al.
[27] reported acute vestibular asymmetry disorder (AVAD), a form of vestibular neuritis without central involvement. In addition to spontaneous nystagmus persisting for several days and directional preference observed in temperature testing, vHIT revealed no abnormalities. However, the SHAT in the chair test demonstrated unilateral high gain, normal phase, and marked asymmetry. The scholar’s proposal of the AVAD concept highlights the value of the rotational chair test; this phenomenon of frequency-domain dissociation also suggests that patients may suffer from selective damage localized to low-frequency sensitive nerve fibers. Consequently, relying solely on vHIT would result in a missed diagnosis. Regarding disease prognosis, VOR-related tests cannot serve as criteria for balance improvement
[28]. However, phase advance in the low-frequency range (0.04 Hz and 0.16 Hz) during the rotational chair test may predict delayed compensation of static imbalance (PSI) in acute unilateral vestibular dysfunction. Concurrently, the intensity of spontaneous nystagmus should be assessed during the initial disease phase, as it represents one of the key factors influencing prognosis in vestibular neuritis patients
[29].
Additionally, the rotational chair test proves beneficial in assessing vestibular compensation status and monitoring the dynamic recovery of vestibular function. Due to central compensation and peripheral functional recovery, the rotational chair test offers an advantage for acute unilateral peripheral vestibular lesions. It not only tracks VOR recovery on the affected side, similar to HIT testing, but also monitors changes in central compensation on the unaffected side. A gain reduction observed during rotation toward the unaffected side correlates significantly with the CP value, which typically indicates a recovery process (i.e., contralateral disinhibition). Balance is maintained through decreased ipsilateral excitation or contralateral inhibition only when central compensation is active
[30]. This provides valuable insights into the recovery process of central compensation. Moreover, low VOR gain and asymmetry in SHAT (i.e., incomplete vestibular compensation) indicate the state of vestibular compensation, similar to the findings in vHIT saccades. High gain and mismatched spontaneous nystagmus direction with contralateral temperature testing in SHAT may also suggest the patient is in a recovery phase; a comprehensive assessment is required
[31].
4.4 Vestibular disease in children
Hearing loss can cause motor developmental delay in children by affecting vestibular function. The chair test can detect subtle vestibular abnormalities in children with severe or profound sensorineural hearing loss
[32]. A Canadian study found that even when VOR cannot be detected in children with inner ear malformations during early childhood, vestibular compensation may develop over time through the central nervous system and acquired motor skills. This compensation can lead to more pronounced nystagmus than initially observed. However, the study did not account for factors such as genetics and intellectual disability
[33]. A cross-sectional study by Alexandra et al.
[34] found that gain values at 0.01 Hz and 0.05 Hz in the rotational chair test, and the asymmetry rate of vestibular evoked myogenic potential could predict the risk of balance disorders during movement in hearing-impaired children. For children with cochlear implants, the rotational chair test and vHIT demonstrated comparable stability in vestibular function assessment
[35,
36]. In summary, the rotational chair test is the preferred method for assessing vestibular function in children. Accurate and dynamic evaluation of vestibular function in this population is essential to determine optimal rehabilitation strategies.
4.5 Other
Victor et al.
[37] found that phase abnormalities at two consecutive frequencies in the rotational chair test were most common in unilateral Ménière's Disease (MD). However, only when abnormalities occurred at three or more consecutive frequencies (indicating severe vestibular dysfunction) did the test show a stronger correlation with the caloric test, consistent with the findings of Huang et al.
[10]. The rotational chair test exhibited the highest abnormality rate among all vestibular tests in MD patients, possibly due to the disease's primary involvement of the semicircular canals.
Additionally, attention must be paid to the patient’s condition during the rotational chair test. Wurthmann et al.
[38] found that compared to healthy controls, patients with vestibular migraine (VM) exhibited not only a reduced motion perception threshold during and after rotation (7.6/s vs. 29.5/s,
P < 0.001), but also a lower VOR threshold correlated with more severe pre-test headache intensity. However, no differences were observed in mean velocity or slow-phase peak velocity. They also exhibited marked susceptibility to motion sickness, with 60% of VM patients still experiencing autonomic symptoms like nausea, vomiting, or dizziness 5 minutes post-test. Comparisons of Vertigo Symptom Scale (VSS) and Motion Sickness Susceptibility Questionnaire (MSSQ) scores between groups showed differences. However, it remains undetermined whether this can serve as a diagnostic marker distinguishing this condition from migraine.
Although the parameters of the rotational chair test were within normal ranges for patients with persistent postural-perceptual dizziness (PPPD)
[39], their sensitivity to initial rotational movement was significantly higher compared to healthy controls (10.9/s vs. 29.5/s,
P < 0.001). Moreover, during and after rotation, the proportion of PPPD patients experiencing autonomic symptoms such as dizziness, nausea, and vomiting (100%) was significantly higher than that of the control group (30.3%). The degree of increased sensitivity was correlated with disease duration (
P < 0.05)
[40]. Therefore, in addition to traditional reflex assessment, the rotational chair test can be used to determine vestibular perceptual thresholds. Patients with VM and PPPD exhibit lower perceptual thresholds for rotational stimuli compared to healthy individuals, and this hypersensitive state correlates with susceptibility to motion sickness and disease severity. Furthermore, the rotational chair test can, to a certain extent, quantify the state of central sensitization, providing objective evidence for functional vestibular disorders.
5 Expanded Application of the Rotational Chair Test
5.1 Exploration of the physiological mechanisms of the vestibular system
The rotational chair test also serves as a crucial tool for evaluating the physiological function of the VOR, providing insights into the human vestibular motion sensor
[41,
42]. Vision constitutes the stimulus input pathway for the VOR. Nghia et al.
[43] conducted a study using the rotational chair test while simultaneously presenting visual stimuli to subjects. They found that when visual and vestibular inputs conflicted, hemodynamic activity increased in the bilateral medial temporal (MT) region, medial superior temporal (MST) region, and temporoparietal junction (TPJ) region. This indicates that perceptual conflict between visual and vestibular stimuli promotes cognitive processes within the associated cortical networks. The VOR exhibits plasticity when exposed to a specific visual environment for extended periods. Akutsu et al.
[44] conducted a sinusoidal chair test on healthy subjects and found that when the visual pattern aligned with the chair’s rotation direction, the VOR gain decreased significantly. However, when the two stimuli were counter-rotating, no significant difference in gain was observed before and after adaptation due to the plasticity of the VOR. Therefore, future research can artificially create sensory conflicts between visual and vestibular inputs to develop personalized optimal vestibular compensation training protocols tailored to patients with different vestibular disorders.
Additionally, vestibular function exhibits circadian rhythmicity. Martin et al.
[45] used the rotational chair test to evaluate the VOR at different times of day across various age groups. They found that vestibular function is not constant throughout the day, with morning responses being superior to evening responses. Therefore, morning may be the optimal time for vestibular rehabilitation training. Pasquier et al.
[46] investigated the effects of vestibular stimulation induced by a rotating chair on human rest/activity rhythms. They observed a significant decrease in average activity levels during the evening following vestibular stimulation, along with a marked advance in circadian rhythms over the subsequent two days. Consequently, vestibular stimulation can serve as a non-light stimulus capable of influencing circadian rhythms in healthy individuals, while also inducing pronounced motion sickness symptoms.
5.2 Vestibular function testing for non-vestibular disorders
First, because the rotational chair test employs physiological stimuli at varying frequencies within a relatively short timeframe, it is prioritized for assessing vestibular function and compensatory mechanisms in children. It holds significant value in evaluating vestibular compensation during the recovery period following cochlear implantation surgery, enabling dynamic monitoring of changes in vestibular function in pediatric patients
[47]. For evaluating the current vestibular status, the simplicity of vHIT undoubtedly makes it the preferred method. If vHIT results are abnormal, the rotational chair test can be omitted. However, if vHIT results are normal, the rotational chair test can help detect subtle alterations in vestibular loss
[48].
Second, patients with cerebrovascular lesions presenting with instability should undergo a comprehensive vestibular function assessment. Patients with cerebral microvascular lesions exhibit significantly reduced gain across all frequencies and decreased time constants in both SHAT and VST
[49]. Additionally, the chair test for chronic nystagmus in patients with lateral medullary infarction reveals reduced gain on the affected side. The chair test may serve as one method for assessing mild vestibular impairment in such cerebrovascular disease patients
[50].
Additionally, patients with hearing loss due to inner ear malformations may also exhibit vestibular dysfunction. The imaging findings of their vestibular-cochlear anatomy correlate with vestibular function test results (caloric testing and rotational chair testing)
[51]. Among vestibular function assessments for chronic otitis media patients, rotational chair testing demonstrates the highest rate of abnormalities across all vestibular tests. Undoubtedly, rotational chair testing is the preferred choice for evaluating inner ear abnormalities
[52]. Gutkovich et al.
[53] employed vestibular electrical stimulation (GVS) combined with rotary chair stimulation to simulate ocean conditions, inducing neurophysiological learning processes and promoting habituation to seasickness. After a 3-month intervention, motion sickness patients exhibited reduced clinic visits and decreased consumption of anti-motion sickness medications, with a significant reduction in Tc. This approach not only lowered the prevalence of severe seasickness but also mitigated the severity of motion sickness in chronically susceptible individuals. Consequently, it may serve as a non-pharmacological method for treating motion sickness-prone individuals.
5.3 Precision vestibular rehabilitation based on quantitative parameters from rotating chair tests
The objective of vestibular rehabilitation is to restore vestibular system homeostasis through neuroplasticity, a field increasingly shifting toward the paradigm of precision medicine. Rotating chair tests provide multi-frequency, high-precision quantitative parameters that can be utilized clinically to formulate precision vestibular rehabilitation strategies.
First, gain values are used to determine the rehabilitation training load and establish frequency-graded training protocols. If a patient exhibits low gain (< 0.15), it typically suggests vestibular hypofunction. In this scenario, rehabilitation should prioritize visual-somatosensory substitution, utilizing gaze stabilization exercises and augmented proprioceptive feedback (e.g., practicing on foam pads) to compensate for the vestibular deficit. For patients with moderate gain (0.15–0.35), indicating partially preserved function, training should focus on vestibular adaptation. This involves gradually increasing head oscillation velocity or utilizing the rotating chair as a training tool to provide repetitive stimulation at the specific frequencies where gain impairment is most pronounced, thereby enhancing VOR adaptation.
Second, asymmetry can be leveraged for unilateral reinforcement. For instance, in a completely dark environment, one may perform five high-angular-velocity constant-acceleration rotations toward the "weaker side" (the side with lower gain), followed by an extremely slow deceleration to avoid inducing reciprocal stimulation. This enhanced unilateral stimulation can augment vestibular nuclear function on the weaker side while utilizing commissural pathways to suppress compensatory activity on the stronger side, thereby facilitating the regulation of vestibular functional balance.
Furthermore, the time constant (Tc) can be used to evaluate the depth of compensation. The recovery of the time constant often lags behind symptom alleviation, serving as a critical indicator for distinguishing between “true physiological compensation” and “behavioral substitution.” During the early stages of rehabilitation, a short Tc (< 7 s) suggests poor velocity storage function; rehabilitation plans at this stage should be conservative, focusing on mitigating motion sickness. In the intermediate stage, the Tc begins to increase but is accompanied by a significant phase lead. Rehabilitation should then incorporate habituation training to reduce reliance on visual cues. If the Tc recovers to above 15 s and becomes symmetric between sides (even if vHIT shows low high-frequency gain), it indicates that the patient’s balance in low-frequency daily activities has largely been restored, allowing for progression to the consolidation phase of rehabilitation.
6 Advantages and Limitations of the Rotational Chair Test
Due to its minimal stimulation and high patient tolerance, the rotational chair test is particularly suitable for children and adolescents who cannot tolerate caloric testing, have inner ear malformations, consume small amounts of alcohol, or are unable to cooperate with other vestibular function tests. It is also appropriate for those with external auditory canal atresia, obstruction, stenosis, or foreign bodies. Furthermore, the rotational chair test has been proven reliable for assessing vestibular function in children. The caloric test remains an indispensable clinical tool for identifying the affected side of vestibular dysfunction due to its ability to stimulate both semicircular canals separately. However, it cannot fully detect functional changes in the semicircular canals across different frequency bands. The rotational chair test not only indicates vestibular impairment but also identifies whether the vestibular center is compensating. It is superior to the caloric test for detecting vestibular dysfunction caused by ototoxic drugs and exhibits higher sensitivity than the caloric test.
It is important to note that in clinical practice, these two methods cannot replace each other. They should be used in combination based on actual circumstances to better assess vestibular function status. Furthermore, the results of the rotational chair test lack age-related standard data and are susceptible to interference from factors such as fatigue, alertness, stress, and habituation. Therefore, in clinical application, one should not blindly rely on data provided by equipment manufacturers; instead, establish laboratory-specific standard reference data. Moreover, operational errors and subjective interpretation of results are inherent challenges in all ancillary examinations. In practice, comprehensive judgment must fully integrate the patient’s medical history and clinical progression, while utilizing ancillary tests as supplementary references to provide holistic and scientifically grounded guidance for disease diagnosis and treatment.
7 Summary
In summary, as a tool for evaluating mid-to-low frequency vestibular function, the rotational chair test is not only a core method for diagnosing bilateral vestibulopathy and presbyvestibulopathy but also offers unique advantages in specific scenarios, such as pediatric dizziness, the early stages of acute vestibular injury, and cases where patients are unable to cooperate with other vestibular tests. It is also uniquely valuable for monitoring central compensation status. In clinical practice, a comprehensive and dynamic assessment integrated with other patient data is necessary to achieve better diagnostic and therapeutic outcomes. However, there is currently no unified evaluation standard, and standardized data remain insufficient. More high-quality research is still required in the future to further explore the application value of the rotational chair test in the diagnosis and treatment of vestibular diseases. Furthermore, deep learning models can be integrated for AI-assisted interpretation of test results, alongside the implementation of cloud-based collaborative diagnostic and treatment systems. These advancements aim to overcome the bottlenecks currently hindering clinical application at the primary care level, facilitating a strategic transition from traditional auxiliary equipment to integrated digital diagnostic and therapeutic platforms.
The Author(s). This article is published by Higher Education Press at journal.hep.com.cn.
This is an open access article distributed under the Creative Commons Attribution License 4.0 (CC BY), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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