Posturographic Assessment of Sway Misperception Accurately Identifies Persistent Postural–Perceptual Dizziness in Neurotologic Patients

ABSTRACT

Objective

To assess whether a posturographic assessment of sway misperception (PASM) discriminates persistent postural–perceptual dizziness (PPPD) from peripheral balance disorders.

Methods

We retrospectively reviewed adults (≥ 18 years) evaluated at Saitama Medical University Hospital between September 2024 and April 2025 with PPPD (Bárány Society diagnostic criteria) or peripheral balance disorders who underwent PASM; central/psychogenic disorders were excluded. On a stabilometer, postural sway area (PSA) and velocity of path length (VPL) were recorded during eyes‐closed standing. Then, with eyes open, patients completed a “reproduction” trial: they were asked to intentionally recreate the instability they had just perceived by deliberately swaying to match the subjective magnitude, rather than standing still. Reproduction rates (RRs) were calculated as eyes‐open reproduced/eyes‐closed recorded values for PSA and VPL. Groups were compared with Mann–Whitney U tests, and ROC analyses estimated AUCs and cutoffs.

Results

Nineteen PPPD patients (11 women; 50.2 (16.4) years, mean (SD)) and 20 peripheral cases (10 women; 53.8 (13.3) years) were analyzed. Eyes‐closed PSA and VPL were similar (p > 0.05), but PSA RR (4.0 (1.5) vs. 1.7 (0.7)) and VPL RR (1.6 (0.5) vs. 1.1 (0.4)) were higher in PPPD (p < 0.001 and p = 0.001, respectively). PSA RR discriminated PPPD with an AUC of 0.94 (95% CI, 0.87–1.00); cutoff ≥ 1.89 yielded sensitivity 1.00 and specificity 0.75. VPL RR showed an AUC of 0.81 (95% CI, 0.67–0.95); cutoff ≥ 1.55 yielded sensitivity 0.63 and specificity 0.90.

Conclusions

PASM quantifies exaggerated perceived sway in PPPD. An intentional sway‐reproduction task, particularly PSA RR, may provide a practical objective biomarker for diagnosis of PPPD.

Level of Evidence

4.

1. Introduction

Persistent postural–perceptual dizziness (PPPD) is a functional disorder characterized by dizziness, unsteadiness, or nonspinning vertigo present on most days for at least 3 months. Symptoms are exacerbated by upright posture, active or passive movement, and exposure to moving or complex visual stimuli. PPPD typically develops following an inciting balance‐related event, such as an episode of vestibular vertigo. The diagnostic concept of PPPD was developed by Bárány Society's expert consensus from an exhaustive review of clinical and empirical findings on phobic postural vertigo (PPV), space‐motion discomfort, visual vertigo, and chronic subjective dizziness [1]. PPV is often comorbid with anxiety and depression, particularly in patients with obsessive–compulsive personality traits. In such patients, it has also been hypothesized that PPV may arise from a discrepancy between the conscious perception of body motion and actual postural sway [2].

PPPD is common in clinical practice. In a cohort of 90 patients with chronic vestibular syndrome who presented to a vertigo clinic within a neurology department in China, PPPD accounted for 35.6% of cases, making it the most common diagnosis within this disease category [3]. Similarly, a large referral‐based dizziness clinic study from South Korea comprising 21,166 patients found that the combined diagnostic category of psychiatric dizziness or PPPD was the second most common category after benign paroxysmal positional vertigo (BPPV), accounting for 20.8% of diagnoses among all patients, although PPPD itself was not analyzed separately [4]. Consequently, PPPD can cause substantial distress and functional impairment, with a negative impact on patients' quality of life [5].

Although PPPD is included in the World Health Organization's International Classification of Diseases, 11th Revision (ICD‐11), the diagnostic process remains largely clinical and relies on patient history and symptom‐based criteria. At present, objective physical findings, biomarkers, or validated instrumental measures that can aid in the assessment of PPPD are limited. Accordingly, ancillary tests capable of providing objective findings may be useful for supporting clinical judgment and improving diagnostic confidence in patients suspected of having PPPD. Against this background, San Pedro Murillo and colleagues proposed a posturography‐based method for investigating misperception of motion in patients with PPPD [6]. In this approach, patients stand on a force platform and are asked to reproduce the body sway they perceive subjectively. Using this method, they objectively quantified sway misperception and showed that patients with PPPD overestimated the magnitude of their body sway to a greater extent than patients with bilateral vestibulopathy.

In the present study, we evaluated the diagnostic accuracy of this posturographic assessment for identifying PPPD among patients presenting to a neurotology clinic. We hypothesized that patients with PPPD overestimate their body sway relative to objectively measured sway, and that quantitative assessment of this sway misperception using posturography could differentiate PPPD from other peripheral balance disorders.

2. Materials and Methods

2.1. Study Subjects

This study was a retrospective chart review of patients who visited the otolaryngology outpatient clinic at Saitama Medical University Hospital between September 2024 and April 2025.

Patients were included if they (1) were ≥ 18 years of age (women or men), (2) presented with dizziness or vertigo as the chief complaint and were diagnosed with PPPD or a peripheral balance disorder, and (3) underwent the posturographic assessment of sway misperception (PASM). PPPD was diagnosed according to the Bárány Society diagnostic criteria (2017) [1]. The clinical diagnoses among patients with peripheral balance disorders were as follows: BPPV (n = 4), vestibular neuritis (n = 4), Ménière's disease (n = 3), perilymphatic fistula (n = 2), Ramsay Hunt syndrome (n = 1), an episode of rotational vertigo associated with idiopathic sudden sensorineural hearing loss (n = 1), bilateral vestibulopathy (n = 1), and unclassified peripheral vestibular disorders (n = 4) (Table 1). One patient with a central balance disorder and four patients with a psychogenic balance disorder were excluded. None of the patients included in this study had a history of polyneuropathy or substance use disorder.

TABLE 1.

Diagnoses of patients with peripheral balance disorders included in this study.

Diagnoses of the patients with peripheral balance disorders (n = 20)
Benign paroxysmal positional vertigo	4
Vestibular neuritis	4
Ménière's disease	3
Perilymphatic fistula	2
Ramsey Hunt syndrome	1
An episode of rotational vertigo associated with idiopathic sudden sensorineural hearing loss	1
Bilateral vestibulopathy	1
Unclassified peripheral vestibular disorders	4

The study protocol was approved by the Institutional Review Board of Saitama Medical University Hospital (protocol no. 2025–115; principal investigator, T.I.) and was conducted in accordance with the Declaration of Helsinki. The patients were given an opportunity to decline use of their medical records for research purposes through an opt out approach by posting an explanatory document on Saitama Medical University website.

2.2. Questionnaires for Dizziness, Anxiety, and Depression

Subjective dizziness‐related disability was assessed using the Dizziness Handicap Inventory (DHI) [7, 8]. The DHI consists of 25 items with a total score ranging from 0 to 100, with higher scores indicating greater perceived dizziness‐related handicap.

Whether dizziness was exacerbated by upright posture, active or passive movement, and exposure to moving or complex visual stimuli was assessed using the Niigata PPPD Questionnaire (NPQ) [9]. The NPQ consists of 12 items with a total score ranging from 0 to 72; higher scores indicate greater symptom exacerbation. The NPQ includes three subscores—upright posture/walking, movement, and visual stimulation—each ranging from 0 to 24.

Anxiety and depressive symptoms were evaluated using the Hospital Anxiety and Depression Scale (HADS) [10, 11]. The HADS‐Anxiety and HADS‐Depression subscales each consist of seven items with scores ranging from 0 to 21; higher scores indicate more severe anxiety or depressive symptoms.

2.3. Vestibular Function Tests

Patients underwent vestibular function testing, including assessment of vestibular nystagmus, conventional stabilometry, video head impulse testing (vHIT), and cervical and ocular vestibular evoked myogenic potentials (cVEMP and oVEMP). vHIT was performed using the ICS Impulse system (Natus, Pleasanton, CA, USA) according to the standardized protocol published by the Japan Society for Equilibrium Research (JSER) [12]. cVEMP and oVEMP were recorded using the Eclipse system (Interacoustics, Middelfart, Denmark) according to the standardized JSER protocol [12].

2.3.1. Assessment of Vestibular Nystagmus

Patients wore charge‐coupled device (CCD) camera–equipped nystagmus goggles, and eye movements were evaluated in the sitting position while facing forward, during the head‐shaking nystagmus test, and during positional and positioning tests (either the Stenger maneuver or the Dix–Hallpike maneuver). Vestibular nystagmus was considered present when horizontal‐torsional nystagmus was observed in any of these conditions. For the diagnosis of BPPV, mixed vertical‐torsional nystagmus was also regarded as vestibular nystagmus. The patients were assessed for gaze‐evoked nystagmus, but no patient included in this study exhibited this finding.

2.4. PASM

In the present study, patients presenting with balance disorders underwent standard stabilometric testing under eyes‐open and eyes‐closed conditions as part of routine clinical assessment of balance function covered by Japan's public health insurance system. Because PPPD is an important differential diagnosis in patients with chronic dizziness, a PASM session was routinely added for these patients, based on the report by San Pedro Murillo et al., as an adjunctive assessment to support clinical diagnosis.

JSER has published standardized procedures for static posturography (stabilometry), although PASM‐specific procedures are not separately addressed in these recommendations [12]. In accordance with recommendations of the JSER, participants stood on a stabilometer (GW‐5000; Anima Co. Ltd., Tokyo, Japan) with their feet together and arms resting alongside the trunk. Body sway during eyes‐closed standing was recorded once for either 30 s or 1 min, and the postural sway area (PSA) and the velocity of path length (VPL) were measured.

Next, participants stood on the stabilometer with their eyes open and were instructed to intentionally reproduce the subjective instability that they had perceived during eyes‐closed standing. The PSA and the VPL were measured again during this reproduction condition once for either 30 s or 1 min.

For both the PSA and the VPL, the ratio of the reproduced sway during eyes‐open standing to the recorded sway during eyes‐closed standing was calculated and defined as the reproduction rate (RR).

The duration of PASM was matched to that of the eyes‐closed standing body‐sway recording: PASM was performed for 60 s when eyes‐closed body sway was recorded for 60 s and for 30 s when eyes‐closed body sway was recorded for 30 s. During the initial implementation period at our institution (September 2024–November 2024), measurements were obtained for 60 s. Thereafter (November 2024–April 2025), the test duration was reduced to 30 s.

2.5. Statistical Analysis

PSA and VPL were compared between patients with PPPD and those with peripheral balance disorders using the nonparametric Mann–Whitney U test. RR for PSA and VPL was compared between groups in the same manner. Receiver operating characteristic (ROC) curve analyses were performed to assess whether RR exceeding specific cutoff values could discriminate PPPD from peripheral balance disorders. Diagnostic performance was evaluated using the area under the ROC curve (area under the curve—AUC), and optimal cutoff values along with sensitivity and specificity for PPPD diagnosis were calculated. Statistical analyses were performed using SPSS version 31 (IBM Corp., Armonk, NY), with a two‐sided significance level set at 0.05. Data were presented as the mean ± standard deviation (SD).

3. Results

During the study period, PASM was performed in 19 patients with PPPD (11 women; mean age, 50.2 (16.4) years, mean (SD)) and 20 patients with peripheral balance disorders (10 women; 53.8 (13.3) years). A total of 44 patients underwent PASM, with the excluded patients with central balance disorders (n = 1) and those with psychogenic balance disorders (n = 4). There were no significant between‐group differences in the sex distribution (p = 0.62, chi‐square test) or age (p = 0.63, Mann–Whitney U test). Among patients with PPPD, the interval from symptom onset to the last clinical assessment confirming persistent symptoms ranged from 3.1 to 188.2 months (median, 23.8 months; mean, 35.7 months). Among patients with peripheral balance disorders, the corresponding interval ranged from 0.6 to 39.8 months (median, 9.8 months; mean, 11.8 months). A preceding inciting balance‐related event was identified in all patients with PPPD, whereas only two patients had additional peripheral vestibular abnormalities concurrent with PPPD symptoms. The inciting events included episodic dizziness/vertigo of unknown etiology in eight patients, including episodic rotational vertigo in five; BPPV in five; Ménière's disease in two; an episode of rotational vertigo associated with sudden sensorineural hearing loss in one; dizziness attributed to anemia in one; dizziness after COVID‐19 infection in one; and unsteadiness after sudden braking on a train in one.

The total DHI score tended to be higher in the PPPD group than in the peripheral balance disorder group (53.1 (12.9) vs. 42.9 (23.1), respectively; p = 0.091, Mann–Whitney U test). Mean scores for the total NPQ (39.1 (12.9) vs. 30.9 (17.4)), the NPQ upright posture/walking subscore (12.2 (5.0) vs. 9.6 (6.1)), NPQ movement subscore (12.9 (4.7) vs. 11.1 (5.5)), and the NPQ visual stimulation subscore (13.9 (5.0) vs. 10.1 (6.7)) did not statistically differ between the PPPD group and the peripheral balance disorder group. The HADS anxiety score (8.8 (5.0) vs. 7.3 (3.4)) and HADS depression score (8.6 (4.3) vs. 7.1 (4.0)) did not differ significantly between the PPPD and peripheral balance disorder groups. Vestibular nystagmus was observed in nine of the 19 patients in the peripheral balance disorder group, whereas none of the 17 patients in the PPPD group showed vestibular nystagmus (p = 0.001, chi‐square test) (Table 2).

TABLE 2.

Baseline characteristics and posturography data in patients with persistent postural–perceptual dizziness (PPPD) and peripheral balance disorders included in this study (* indicates statistical significance (p < 0.05)).

	PPPD (n = 19, mean (SD))	Peripheral balance disorders (n = 20, mean (SD))	Difference (p)
Female sex	11 out of 19 patients	10 out of 20 patients	0.62
Age	50.2 (16.4)	53.8 (13.3)	0.63
DHI	53.1 (12.9) (n = 19)	42.9 (23.1) (n = 14)	0.091
NPQ total score	39.1 (12.9) (n = 19)	30.9 (17.4) (n = 14)	0.24
NPQ upright posture/walking subscore	12.2 (5.0)	9.6 (6.1)	0.27
NPQ movement subscore	12.9 (4.7)	11.1 (5.5)	0.60
NPQ visual stimulation subscore	13.9 (5.0)	10.1 (6.7)	0.163
HADS anxiety score	8.8 (5.0) (n = 18)	7.3 (3.4) (n = 14)	0.36
HADS depression score	8.6 (4.3)	7.1 (4.0)	0.36
Vestibular nystagmus	0 out of 17 patients (two missing values)	Nine out of 19 patients (one missing value)	*0.001
Postural sway area (cm2)	5.0 (2.7)	6.6 (4.5)	0.48
Velocity of path length (cm/s)	2.6 (1.3)	3.1 (1.7)	0.41
Reproduction rate of postural sway area	4.0 (1.5)	1.7 (0.7)	*< 0.001
Reproduction rate of velocity of path length	1.6 (0.5)	1.1 (0.4)	*0.001

All patients with peripheral balance disorders were evaluated using a combination of vestibular tests, including vestibular nystagmus assessment (n = 19), vHIT (n = 14), cVEMP (n = 8), and oVEMP (n = 8). Vestibular dysfunction was identified in 11 patients with peripheral balance disorders on at least one of these tests. In one patient who did not undergo vestibular nystagmus assessment, vHIT revealed bilaterally reduced vestibulo‐ocular reflex gains and catch‐up saccades, leading to a diagnosis of bilateral vestibulopathy. For these patients, a physician first obtained a detailed clinical history and then selected the vestibular function tests considered appropriate for the suspected disorder or underlying pathophysiology. In nine of the 20 patients, vestibular function testing did not provide objective evidence of vestibular dysfunction, and the diagnosis was based on the patients' symptoms and clinical histories. This subgroup included patients with episodic vertigo, in whom abnormalities may not have been detectable because testing was performed during an interictal period. Of the four patients with unclassified peripheral vestibular disorders, two experienced episodes of spinning vertigo, although brain MRI findings were unremarkable. Of the remaining two patients, one exhibited vestibular nystagmus during examination with CCD camera‐equipped nystagmus goggles, whereas the other showed a reduced right cVEMP amplitude (cVEMP asymmetry), in association with right‐sided sensorineural hearing loss.

The 19 patients with PPPD were similarly evaluated using vestibular nystagmus assessment (n = 17), vHIT (n = 13), cVEMP (n = 9), and oVEMP (n = 9). Abnormal vestibular test findings were identified in only two patients with PPPD: cVEMP asymmetry in one patient and oVEMP asymmetry in the other.

Data related to PASM are summarized in Figure 1. There were no significant differences between the PPPD and peripheral balance disorder groups in PSA (5.0 (2.7) vs. 6.6 (4.5) cm²) or VPL (2.6 (1.3) vs. 3.1 (1.7) cm/s) (p = 0.48 and 0.41, respectively, Mann–Whitney U test) (Figure 1A). In contrast, the RR of PSA (4.0 (1.5) vs. 1.7 (0.7)) and the RR of VPL (1.6 (0.5) vs. 1.1 (0.4)) were both significantly higher in the PPPD group than in the peripheral balance disorder group (p < 0.001 and p = 0.001 respectively, Mann–Whitney U test) (Figure 1B).

FIGURE 1.

Summary of posturographic findings related to sway misperception. (A) There were no significant differences in postural sway area (PSA) or velocity of path length (VPL) between patients with persistent postural–perceptual dizziness (PPPD) and those with peripheral balance disorders. (B) The reproduction rate (RR) of both PSA and VPL was higher in patients with PPPD than in patients with peripheral balance disorders. (C) Receiver operating characteristic curve analysis showed that PSA and VPL RR values at or above the cutoff value could accurately identify PPPD (area under the curve [AUC] = 0.94 and 0.81, respectively). Between‐group comparisons in (A) and (B) were performed using the Mann–Whitney U test.

In ROC analysis, the AUC for diagnosing PPPD using the RR of PSA was 0.94 (95% confidence interval [CI], 0.87–1.00), and the optimal cut‐off value was 1.89 (Youden index, 0.75). At this cut‐off value, sensitivity was 1.00 and specificity was 0.75. The AUC for diagnosing PPPD using the RR of VPL was 0.81 (95% CI, 0.67–0.95), and the optimal cut‐off value was 1.55 (Youden index, 0.53). At this cut‐off value, sensitivity was 0.63 and specificity was 0.90 (Figure 1C).

4. Discussion

The definition of PPPD in the World Health Organization's International Classification of Diseases, 11th Revision (ICD‐11), which was formally adopted after the Bárány Society's 2017 International Classification of Vestibular Disorders criteria, is largely consistent with the earlier Bárány Society criteria. At present, PPPD is diagnosed solely on the basis of subjective symptoms and clinical history. Although adjunctive diagnostic approaches have been reported to quantify subjective symptoms using a questionnaire (NPQ) [9], the development of adjunctive diagnostic methods based on objective test findings remains a key challenge toward a more evidence‐based diagnostic strategy for PPPD. In the present study, we used the symptom‐ and history‐only diagnostic criteria established by the Bárány Society as the gold standard for diagnosing PPPD. We then sought to develop a quantitative tool that could improve diagnostic accuracy when evaluated against this established reference standard.

In the present study, mean NPQ scores did not differ significantly between the PPPD group and the peripheral balance disorder group. NPQ facilitates efficient clinical assessment of PPPD by evaluating its exacerbating factors, namely upright posture/walking, movement, and visual stimulation. However, it has also been noted that worsening of dizziness in response to these factors can be observed in vestibular disorders other than PPPD. In a recent Japanese‐language report, among 473 patients, primarily with non‐PPPD vestibular disorders—including Ménière's disease, BPPV, vestibular migraine, and vestibular neuritis—who had experienced dizziness for 3 months or longer, 53.7% had NPQ scores at or above the cutoff value (27 points) [13]. Therefore, the NPQ should be regarded as an adjunctive tool for the screening of PPPD.

With regard to posturographic (stabilometric) findings in patients with PPPD, increased postural sway on posturography compared with healthy controls has been reported [14, 15]. In our analysis, sway measures in patients with PPPD, including PSA and VPL, were comparable to those observed in patients with peripheral balance disorders. However, we did not compare the foam ratio or Romberg ratio between patients with PPPD and those with peripheral balance disorders. In a previous study of 53 patients with PPPD, the foam ratio was decreased, whereas the Romberg ratio was increased, compared with healthy controls [16]. The findings reported by Ichijo et al. suggest that, during upright stance, patients with PPPD may rely more heavily on visual input and less on somatosensory feedback for postural control, consistent with findings from another study involving visual stimuli [17]. In addition, Kobel and colleagues investigated whether PPPD could be diagnosed by applying recurrence quantification analysis to posturography data [18]. In Kobel's study, posturography revealed that patients with PPPD exhibited unique alterations in the temporal dynamics of center‐of‐pressure motion.

In the present study, we demonstrated that the RR of posturographic sway measures (PSA and VPL) was higher in patients with PPPD than in those with peripheral balance disorders. San Pedro Murillo et al. also reported that such an increase in RR is not observed in healthy individuals [6]. These findings suggest that patients with PPPD substantially misperceive (i.e., overestimate) the magnitude of their own body sway, and that an RR above a certain threshold may aid in the diagnosis of PPPD. In our study, a PSA RR cutoff of ≥ 1.89 yielded an AUC of 0.94 on ROC analysis, with a sensitivity of 1.00 and a specificity of 0.75, enabling accurate discrimination of PPPD. A similar pattern was observed for VPL RR (AUC = 0.81), further supporting our hypothesis that patients with PPPD misperceive their own postural sway. When PSA RR was considered as a diagnostic aid, the rate at which individuals without PPPD were incorrectly classified as having PPPD was one in four, corresponding to a specificity of 0.75. This false‐positive rate was lower for VPL RR, which had a specificity of 0.90. However, when the importance of sensitivity for PPPD screening was also taken into account, PSA RR was judged to have superior overall discriminative ability than VPL RR, as reflected by its higher AUC.

The hypothesis that patients with PPPD overestimate their own bodily sway has also been examined in experimental studies. With respect to the perception of vestibular stimulation, Woll et al. applied galvanic vestibular stimulation (GVS) in patients with PPPD and evaluated how its effects on postural sway differed from those observed in healthy controls [19]. They reported that patients with PPPD had a lower current threshold for detecting GVS. Regarding visual processing, attempts have likewise been made to determine whether visual motion perception differs between patients with PPPD and healthy individuals [20].

In a related line of work based on the similar hypothesis, Yagi et al. applied the subjective visual vertical (SVV) paradigm and showed that patients with PPPD overestimate the tilt angle of the head relative to the gravity axis (Head Roll‐Tilt SVV) [21]. They also examined the diagnostic performance of Head Roll‐Tilt SVV for PPPD; the area under the ROC curve (AUC) was 0.764, which is generally interpreted as indicating moderate diagnostic accuracy. In the present study, we report a posturography‐based approach for diagnosing PPPD, and its diagnostic performance in a neurotology clinic was excellent (AUC = 0.94). Moreover, posturography is already widely used in routine clinical practice, suggesting that this simple diagnostic method may be of practical value in everyday clinical care.

5. Limitations

This study was limited by its retrospective, single‐center design. Future prospective multicenter validation is warranted to further establish the utility of PASM for the diagnosis of PPPD.

6. Conclusion

Among neurotologic outpatients, PASM accurately differentiated PPPD from peripheral vestibular disorders. During the intentional “reproduction” trial, PPPD patients substantially over‐recreated perceived instability, producing higher RRs, most prominently for PSA despite similar eyes‐closed PSA magnitude between the groups. PSA RR showed excellent discrimination (AUC 0.94); a cutoff ≥ 1.89 achieved 100% sensitivity and 75% specificity, whereas VPL RR was less accurate (AUC 0.81). PASM appears to be a practical objective adjunct for PPPD diagnosis.

Funding

This work was supported by the Ministry of Health, Labour, and Welfare of Japan (JPMH25FC1002) (http://www.mhlw.go.jp). The funding organization played no roles in the study design; in the collection, analysis, or interpretation of data; in the writing of the report; or in the decision to submit the article for publication.

Conflicts of Interest

The authors declare no conflicts of interest.

Maeda Y., Kudo H., Yamaguchi T., et al., “Posturographic Assessment of Sway Misperception Accurately Identifies Persistent Postural–Perceptual Dizziness in Neurotologic Patients,” Laryngoscope Investigative Otolaryngology 11, no. 5 (2026): e70591, 10.1002/lio2.70591.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.