Analyses of the Relation between BPPV and Thyroid Diseases: A Nested Case-Control Study

Vestibular function is associated with immune inflammatory response

Association between vestibular function and immune inflammatory response has garnered increasing interest. Immune responses can lead to anatomical or functional alterations of the vestibular system, and inflammatory reactions may impair hearing and balance. Vestibular disorders comprise a variety of conditions, such as vestibular neuritis, benign paroxysmal positional vertigo, Meniere's disease, vestibular migraine, posterior circulation ischemia, and bilateral vestibular disease. Moreover, some patients with autoimmune diseases develop vestibulocochlear symptom. This paper offers an overview of prevalent vestibular diseases and discusses associations between vestibular dysfunction and immune diseases.

Statistical Associations between Vestibular Pathologies and Hypothyroidism: A Retrospective Study

The association between vestibular pathologies and thyroid hormone disorders has been known for several decades. However, very little information is available on the types of vestibular symptoms that may be affected by altered thyroid hormone levels. The aim of this study was to provide patient data in order to identify statistical associations between vestibular pathologies and thyroid hormone disorders. A retrospective review of the records of 422 patients seen for physiotherapy treatment of vertigo was carried out. Statistical analysis of the data was performed using logistic regression, providing Chi2 and Odds Ratio statistics. Our results show that hypothyroidism statistically significantly increases the expression of certain symptoms, such as vestibular instability and gait disorders, in vestibular pathologies such as Menière's disease or central vertigo. By analyzing patient data, our study provides new evidence of dependence between altered thyroid status and the expression of vestibular pathologies.

Recurring benign paroxysmal positional vertigo after successful canalith repositioning manoeuvers

Benign baroxysmal positional vertigo (BPPV) represents the most common peripheral vestibular dysfunction encountered in clinical practice. Although canalith repositioning procedures (CRPs) are a relatively successful treatment for BPPV, many patients suffer from recurrences. Several studies have demonstrated that various pathological conditions (diabetes, hypertension, endolymphatic hydrops, low vitamin D levels) as well as delayed BPPV treatment using CRP, multiple canal involvement may be associated with recurrence of BPPV. We evaluated the history of 1,428 patients (558 males and 870 females, age range 10-92 years) suffering from BPPV. Of 1,428 cases, 820 (77%) did not relapse in the following 20 years. Mean age and gender did not differ significantly between groups with and without recurrence. Regarding risk factors for BPPV recurrence, age, female gender, migraine, hypertension, diabetes mellitus, hyperlipidaemia, osteoporosis, vascular diseases, and vitamin D deficiency may be associated with recurrent BPPV and should be kept in mind. Osteoporosis, vitamin D deficiency as well as thyroid dysfunction should be evaluated in postmenopausal women. Treatment of these comorbidities may help to reduce the risk of BPPV recurrence.

Vestibular Disorders and Hormonal Dysregulations: State of the Art and Clinical Perspectives

The interaction between endocrine and vestibular systems remains poorly documented so far, despite numerous observations in humans and animals revealing direct links between the two systems. For example, dizziness or vestibular instabilities often accompany the menstrual cycle and are highly associated with the pre-menopause period, while sex hormones, together with their specific receptors, are expressed at key places of the vestibular sensory network. Similarly, other hormones may be associated with vestibular disorders either as causal/inductive factors or as correlates of the pathology. This review was carried out according to the PRISMA method, covering the last two decades and using the MEDLINE and COCHRANE databases in order to identify studies associating the terms vestibular system and/or vestibular pathologies and hormones. Our literature search identified 646 articles, 67 of which referred directly to vestibular dysfunction associated with hormonal variations. While we noted specific hormonal profiles depending on the pathology considered, very few clinical studies attempted to establish a direct link between the expression of the vestibular syndrome and the level of circulating hormones. This review also proposes different approaches to shed new light on the link between hormones and vestibular disorders, and to improve both the diagnosis and the therapeutic management of dizzy patients.

Does Thyroid Hormone Metabolism Correlate with the Objective Assessment of the Vestibular Organ in Patients with Vertigo?

The aim of this study was to assess the relationship between the results of the objective assessment of the vestibular organ in patients with peripheral vertigo with Hashimoto's thyroiditis and thyroid hormone metabolism. Twenty eight women with Hashimoto's thyroiditis and chronic vertigo were enrolled in the study. Patients underwent audiological assessment of hearing, Dix-Hallpike test, videonystagmography with caloric test, head impulse test (HIT) and cervical vestibular-evoked myogenic potentials (cVEMPs). Levels of thyroid hormones and anti-thyroid antibodies were determined. Relationships between age, weight, height, BMI and the results of the objective assessment of the vestibular organ were calculated. The mean age in the study group was 48 years, while the mean BMI was 26.425. The causes of peripheral vertigo in the study group were benign paroxysmal positional vertigo (BPPV) (n = 19), Meniere's disease (n = 7) and vestibular neuronitis (n = 2). No correlation was found between age, weight, height, BMI and the results of thyroid function tests or the objective assessment of the vestibular organ. The study did not confirm the influence of thyroid metabolism (i.e., thyroid hormone levels or the increase in antithyroid antibodies) on the results of cVEMP or the directional preponderance in the caloric test.

Benign paroxysmal positional vertigo: is hypothyroidism a risk factor for recurrence?

OBJECTIVE

To investigate the relationship between risk of Benign Paroxysmal Positional Vertigo (BPPV) recurrence and hypothyroidism treated with hormone replacement therapy (HRT).

METHODS

797 patients with idiopathic BPPV were divided into two groups: 250 patients with recurrence of BPPV (R-BPPV) and 547 patients without recurrence (NR-BPPV). Regarding patients with thyroid disease on HRT, we collected serum test results of thyroid-stimulating hormone (TSH), free triiodothyronine f-T3, free thyroxine f-T4, thyroglobulin antibodies (TG-Ab) and thyroid peroxidase antibodies (TPO-Ab).

RESULTS

Hypothyroidism in long-term HRT was found in 61/250 (24.4%) patients of the R-BPPV group vs 79/547 (14.4%) of the NR-BPPV-group (p = 0.0006). Hashimoto thyroiditis (HT) was associated with recurrence (p < 0.0001). A significant correlation was found between recurrence and level of serum TPO-Ab (p = 0.0117) and TG-Ab (p = 0.0025), but not with mean serum TSH, f-T3 and f-T4.

CONCLUSIONS

We assume that patients with hypothyroidism in HRT have an increased risk of BPPV recurrence, which is particularly strong for patients with HT and positive thyroid antibodies, suggesting an association between autoimmunity and recurrent vertigo.

Hormones and Vestibular Disorders: The Quest for Biomarkers

The vestibular system exerts control over various functions through neural pathways that are not yet fully mapped. Functional dysregulations or tissue lesions at different levels of the peripheral and the central vestibular networks can alter these different functions, causing a wide variety of symptoms, ranging from posturo-locomotor alterations to psychiatric syndromes such as PPPD, including the deregulation of the main biological functions. These different symptoms differ by their expression kinetics (they each appear and regress with their own kinetics) by the targets affected (muscles, organs, and brain areas) and by the sensitivity specific to each individual. Vestibular pathologies thus cover a mosaic of distinct effects, and they involve various effectors—which constitute the many markers of their different types and stages. It is therefore crucial, to predict the onset of a vertigo syndrome, to follow its temporal course, or to monitor the impact of therapeutic approaches, and to have specific and reliable biomarkers. Hormonal variations are among the possible sources of biomarkers for neurotology. We know that specific hormonal profiles can promote the appearance of vestibular disorders. We also know that the expression of vertigo syndrome is accompanied by measurable hormonal variations. The link between endocrine deregulation and vestibular alterations therefore no longer needs to be proven. However, there are still few data on their precise correlations with the vertigo syndrome. This study was undertaken with the aim to deliver an extensive review of the hormonal alterations linked to vestibular disorders. A review of the literature covering the last two decades was carried out using the MEDLINE and COCHRANE databases in order to identify studies associating the terms vestibular system or vestibular pathologies and hormones. Bibliographic data provides several outcomes in terms of therapeutic innovation in the diagnosis and therapeutic follow-up of vestibular pathologies.

Recurrence of benign paroxysmal positional vertigo: experience in 3042 patients

OBJECTIVES

Benign paroxysmal positional vertigo (BPPV) is a disorder of the inner ear with a high rate of recurrence. Vascular disorders, migraine and autoimmune disorders have been considered facilitating factors for relapsing episodes. Our aim was to assess the role of vascular disorders, migraine and anti-thyroid antibodies in patients with recurrences.

METHODS

We retrospectively analysed records of 3042 patients treated for BPPV without other lifetime vertigo. Clinical data included previous vascular disorders of the central nervous system, heart disorders, migraine and recent head trauma. The presence of anti-thyroid autoantibodies was assessed in all patients.

RESULTS

Mean age of the first BPPV was 52.8 ± 14.5 years; there were 2339 females (76.9%), while 2048 (67.3%) of patients presented recurrences within two years of follow-up. Previous disorders of the central nervous system, presence of anti-thyroid antibodies, head trauma and migraine showed an association with recurrences. Above all, in subjects having the first BPPV while aged between 40 and 60 years, anti-thyroid antibodies were predictive for recurrences.

CONCLUSIONS

Our data are consistent with the hypothesis that anti-thyroid autoantibodies may play a role in recurrences in subjects with initial manifestations between 40 and 60 years.