The impact of disease duration in persistent postural-perceptual dizziness (PPPD) on the quality of life, dizziness handicap and mental health

1Introduction

In 2017, the Barany’s Society Classification Committee amalgamated the main elements of postural phobic vertigo, space motion discomfort, visual vertigo and chronic subjective dizziness to form persistent postural-perceptual dizziness (PPPD) [21]. It is essentially a chronic functional disorder plaguing the sufferers with persistent dizziness or unsteadiness for at least 3 months which is exacerbated by upright position, being in motion and or exposure to busy visual stimuli [21]. While the disorder is largely precipitated by an acute vestibular event such as BPPV, there has since been reports of primary PPPD where no acute event is reported [9].

As physical examination, clinical laboratory testing and vestibular evaluation may be normal in PPPD [21, 22], advances in neuroimaging have provided new insights in patients with PPPD illustrating the delicate changes in functional activity and inter-network connectivity involving the vestibular, visual and emotion processing centers [10, 12, 13, 24, 26]. However, the functional MRI is not easily available and diagnosis relies heavily on clinical history [21].

Studies have since shown that PPPD is more often seen in females and middle aged [1, 4, 26, 27], interferes with the way individuals experience their personal, social and work life [20] and treatment is patient centric that begins with communication and education regarding the disorder [16]. However, there has not been studies that investigated the impact of disease duration in an already chronic ailment. Hence, the aim of this study is to understand the impact of disease duration in PPPD on the quality of life, dizziness handicap and mental health on the patients.

2Methodology

This was a prospective observational study registered with the National Medical Research Ethics Committee (NMRR-19-35-45775). Consenting patients diagnosed with PPPD aged 18 and above, attending the Otorhinolaryngology (ORL) Clinic between 2019 and 2021 were recruited. Demographic data such as age, gender, co-morbidity illnesses were documented. Patients were examined and had hearing and vestibular assessment performed including pure-tone audiometry, tympanometry, video nystagmography, video head impulse test, rotatory chair and VEMP to confirm the diagnosis of PPPD. The PPPD patients were treated based on their complaints with vestibular rehabilitation therapy (VRT) with or without cognitive behavioral therapy (CBT) and medications such as Selective Serotonin Reuptake Inhibitor (SSRI) under the counsel of a psychiatrist. The control arm consisted of age and gender-matched patients attending the ORL Clinic who had dizziness but resolved within three months and was not on any psychotropic or vestibular drugs. Sample size was calculated with a significance level (α) of 5%, power (1-β) of 80% and using continuous means of DHI as an endpoint from the study conducted by Ertugrul 2019 [7] with mean of 51.81 and standard deviation of outcome of 17.04 (control mean 38), total sample size required was 48 (24 in each group).

3Results

3.2Relationship between EQ5D, DHI and DASS-21

There was a significant negative linear relationship between the QOL using the EQ-5D VAS and the degree of dizziness handicap (DHI) (R² = 0.3163, p = 0.0023) and total scores for DASS-21 (R² = 0.183, p = 0.026) indicating reduction in QOL with worsening of dizziness handicap and mental well-being (Fig. 1).

Fig. 1

A significant negative linear relationship between the severity of Dizziness Handicap Index (DHI) and the health-related quality of life measured by EQ-5D VAS indicating poorer perception of health with increased dizziness handicap (R² = 0.3163, p = 0.0023). There is also a significant negative linear relationship between DASS-21 and the health-related quality of life measured by EQ-5D VAS indicating poorer perception of health with worsening mental health (R² = 0.183, p = 0.026).

There was also significant positive linear relationship between the degree of dizziness handicap (DHI) and the level of depression (R² = 0.2608, p = 0.0065), level of anxiety (R² = 0.2555, p = 0.0072), level of stress (R² = 0.3552, p = 0.001) and overall DASS-21 scores (R² = 0.3277, p 0.0018). (Fig. 2)

Fig. 2

A positive linear relationship is seen between the DHI and overall mental health (R² = 0.3277, p = 0.0018)as well as independently on depression (R² = 0.2608, p = 0.0065)), anxiety (R² = 0.2555, p = 0.0072)and stress levels (R² = 0.3552, p = 0.001).

4Discussion

This study recruited consecutive PPPD patients who visited the ORL Clinics and all consented to the study as they were keen to learn more about this condition. Our local PPPD patients were no different from the published demographic data of being predominantly females (66.7%) and middle aged [1, 4, 7, 27]. The DHI in PPPD had a mean of 48.3±25.7. This fell within the documented range of 44.5±18.9 to 59.8±19.3 in the recent literature [4, 9]. The DHI was significantly higher (p = 0.00002) than in the controls which had a mean of 19.1±22.2 and this further supports the findings of those in literature [7, 9, 25].

The raised dizziness handicap was accompanied with a reduction in QOL in PPPD patients by 20 points where PPPD patients scored the EQ-5D VAS at 67.9±17.3 as compared to 88.3±12 in those who recovered from the vestibular event (p = 0.00001). Habs et al also found a 20 point drop in the EQ-5D VAS scores from 78 points which was the country-related population norm to 58±20 reported by their PPPD patients [9]. It was interesting to note that while most of the dimensions in the QOL in our PPPD patients was affected, self-care was spared. However, when looking back on data studying non-specific dizziness and its impact on QOL, it has been established that dizziness leads to poorer QOL especially in physical and social functioning [8]. Cheng et al had found that more severe dizziness tended to have poorer quality of health which was not seen in mild and moderate dizziness handicap levels. Bodily pain, general health, role limitation due to emotional problems and mental health were the main domains affecting the QOL [5] which were similar to the domains our population had problems with such as mobility, performing usual activities, pain and mental health.

We also noted a linear positive relationship where higher levels of DHI also had higher overall DASS-21 scores (p = 0.0018) as well as individual aspects such as depression (p = 0.0065), anxiety (p = 0.0072) and stress (p = 0.001). Correlation between mood disorders and dizziness has been established and impairment is increased with comorbid anxiety [5]. Dizzy patients with anxiety and depressive moods also had greater emotional distress and handicaps [6]. Thus it is not surprising that PPPD is predisposed in subjects with anxiety or depression [7, 18, 25] and this was seen in our study population with significantly higher scores in depression (p = 0.015), anxiety (p = 0.002) and stress (p = 0.009) when compared to the control group. The mean value for depression was 6 which placed it as mild, anxiety was 8 (moderate) at and stress at 7.5 (mild). These values do not characterise them as having depression or an anxiety disorder as the values are borderline. However, they certainly demonstrate traits of anxiety and with greater tendencies for depressed mood. The anxiety trait affects the assessment of postural challenges resulting hypervigilance and adopting the high-risk control strategies during movement [4]. The functional MRI (fMRI) studies have shown significant functional alterations in the amygdala, insula, anterior cingulate, prefrontal cortex, superior frontal gyrus, para-cingulate and inferior frontal gyrus which are responsible for emotion processing and anxiety but also have connections to the central vestibular system [11, 12, 17, 24, 26]. Other fMRI studies also demonstrated the increase in activity and connectivity to the visual centres which explains the visual dependence in PPPD and this was particularly increased in neuroticism [15, 19, 24, 26].

Addressing the matter of chronicity, Best et al showed that there was no correlation between acute or chronic vestibular dysfunction on psychometric testing. Instead, a more important factor is how one reacts to the dysfunction [3]. Co-morbid psychiatric disorders are known to emerge in a vestibular event leading to psychological reactions such as anxiety, phobias, avoidance and depressive symptoms and this relationship is bidirectional as the anticipatory anxiety about future spells can sustain both physical and functional impairments [3, 23]. Our study went one step ahead to look at the effects of disease duration in a chronic condition in a population who already have anticipatory anxiety. We found a further increase in anxiety levels among those who had PPPD for more than a year (p = 0.008). This was accompanied by significant increase in physical handicap (p = 0.041). While it is now established that anxiety mood is not a core PPPD symptom but predisposes one to it [21], our findings support the notion that chronicity of PPPD symptoms worsens the mental health especially anxiety. This may lock the PPPD patient in a vicious never-ending cycle where being anxious predisposes one to PPPD and PPPD worsens the anxiety. Interestingly, the PPPD patients did not note any significant drop in overall health quality nor overall DHI scores with increased disease duration. There was also no significant effect on the depression or stress levels.

Grimby et al found that QOL decrease was most pronounced in those having experienced dizziness for less than 6 months and speculates that after 6 months, coping process begins and that reduces the negative effects of dizziness. However, they too found that physical mobility scores continued to worsen with the duration of dizziness as was seen in our study population [8]. Another aspect should be highlighted is the possible reason for the chronicity is the delay of diagnosis. Sezier et al reported their PPPD patients had lost confidence or trust in their health professionals with some being aloof or unable to provide them with answers or cure. While the patients did not necessarily expect the health care professionals to have all the answers, they wanted validation for an invisible and unidentifiable condition. This is where it is important for health care providers to build and sustain a stable therapeutic relationship tailored to the individual PPPD patient while providing validation to prevent self-stigmatisation [20]. Of the 27 PPPD patients in the study, 25 underwent vestibular rehabilitation, 4 were started on SSRI with CBT and 2 defaulted follow-up. After 3 months of treatment, 4(16%) patients reported complete resolution of symptoms of which 1 had less than a year of symptoms and 3 had more than a year of symptoms. 20 (80%) reported improvement of symptoms with 1 reporting no change in symptoms. More details on PPPD treatment outcome in this study group is being prepared for publication (CS Teh et al).

5Conclusion

Persistent postural-perceptual dizziness is a chronic functional disorder predominantly seen in females and middle-aged which significantly reduces the quality of life, increases dizziness handicap and increases depression, anxiety and stress levels. The increase in duration of illness further increases the anxiety levels and physical handicap. As anxiety predisposes and likely to perpetuate PPPD, the increased anxiety levels in an untreated patient may worsen the PPPD patient’s symptoms and quality of life. Hence, it is important to diagnose and begin therapy early to break the cycle.