Neurological update: dizziness

Fractional Amplitude of Low-Frequency Fluctuation and Voxel-Mirrored Homotopic Connectivity in Patients with Persistent Postural-Perceptual Dizziness: Resting-State Functional Magnetic Resonance Imaging Study

Purpose: Persistent postural-perception dizziness (PPPD) is a chronic subjective form of dizziness characterized by the exacerbation of dizziness with active or passive movement, complex visual stimuli, and upright posture. Therefore, we aimed to analyze the resting-state functional magnetic resonance imaging (fMRI) in patients with PPPD using fractional amplitude of low-frequency fluctuation (fALFF) and voxel-mirrored homotopic connectivity (VMHC) and evaluate the correlation between abnormal regions in the brain and clinical features to investigate the pathogenesis of PPPD. Methods: Thirty patients with PPPD (19 females and 11 males) and 30 healthy controls (HCs; 18 females and 12 males) were closely matched for age and sex. The fALFF and VMHC methods were used to investigate differences in fMRI (BOLD sequences) between the PPPD and HC groups and to explore the associations between areas of functional abnormality and clinical characteristics (dizziness, anxiety, depression, and duration). Result: Compared to the HC group, patients with PPPD displayed different functional change patterns, with increased fALFF in the right precuneus and decreased VMHC in the bilateral precuneus. In addition, patients with PPPD had a positive correlation between precuneus fALFF values and dizziness handicap inventory (DHI) scores, and a negative correlation between VMHC values and the disease duration. Conclusions: Precuneus dysfunction was observed in patients with PPPD. The fALFF values correlated with the degree of dizziness in PPPD, and changes in VMHC values were associated with the duration of dizziness, suggesting that fMRI changes in the precuneus of patients could be used as a potential imaging marker for PPPD.

Exploring the role of attention towards balance in chronic dizziness: Development of the Balance Vigilance Questionnaire

BACKGROUND AND PURPOSE

Vigilance towards balance has been proposed to underpin various chronic dizziness disorders, including persistent postural-perceptual dizziness (PPPD). The objective of this study was to develop (through patient input) a validated balance-specific measure of vigilance that comprehensively assesses the varied ways in which this construct may manifest.

METHODS

We developed the Balance Vigilance Questionnaire (Balance-VQ) through patient and clinician feedback, designed to assess vigilance towards balance. We then validated the questionnaire in 497 participants consisting of patients diagnosed with chronic dizziness disorders (including 97 individuals diagnosed with PPPD) and healthy controls.

RESULTS

The final six-item Balance-VQ was shown to be a valid and reliable way to assess vigilance towards balance. Scores were significantly higher in individuals diagnosed with PPPD compared to controls. Although scores were also higher in the PPPD group compared to individuals with diagnosed vestibular disorders other than PPPD, Balance-VQ scores did not discriminate between the two groups when confounding factors (including dizziness severity) were controlled for. Scores did, however, independently discriminate between the PPPD group and individuals who experience dizziness in daily life, but who have not been diagnosed with a neuro-otological disorder.

CONCLUSIONS

Our findings confirm that the Balance-VQ is a valid and reliable instrument for assessing vigilance towards balance. As symptom vigilance has been identified as a key risk factor for developing chronic dizziness following acute vestibular symptoms or balance disruption, we recommend using the Balance-VQ as a screening tool in people presenting with such symptoms.

Psychosocial Factors Associated with dizziness and chronic dizziness: a nationwide cross-sectional study

BACKGROUND

Dizziness is a common symptom in adults, and chronic dizziness, such as persistent postural-perceptual dizziness, is also frequently reported and affects the quality of life of patients. This study aimed to identify psychosocial factors related to dizziness and chronic dizziness in a large-scale nationwide cohort.

METHODS

This population-based cross-sectional study used the database of the Eighth Korea National Health and Nutrition Examination Survey in 2020. Data from 4,147 adults over 40 years old were analyzed, and 1,102 adults who experienced dizziness were included in the dizziness cohort. Demographic data, medical conditions, comorbidities, functional status variables, nutritional variables and psychological variables were collected. The pattern of depressive symptoms according to the severity of dizziness was analyzed by network analysis.

RESULTS

The prevalence rate of dizziness was 24.6% in the general population, and chronic dizziness (≥ 3 months) developed in 210 of 1,102 (17.1%) individuals who experienced dizziness. Multiple logistic regression analysis revealed that female sex, stress, and depression were associated with dizziness. Chronic dizziness was related to tympanic abnormalities, diabetes, short sleep duration, and higher levels of stress and depression. Psychomotor retardation/agitation was a central symptom of depression in patients with chronic dizziness.

CONCLUSIONS

This study found sex differences in factors associated with dizziness and identified psychosocial factors linked to chronic dizziness. Focusing on somatic factors rather than depressive symptoms may benefit patients with chronic dizziness.

Treating Psychiatric Symptoms in Persistent Postural Perceptual Dizziness

Persistent postural perceptual dizziness (PPPD) is a functional neurological disorder characterized by troublesome feelings of dizziness and might be precipitated by vestibular events, postural changes, psychopathologies, and/or a person's perceptual experiences. The diagnosis is confirmed by assessing a patient's history. A variety of psychiatric symptoms are associated with PPPD; anxiety and depression are the most common. Psychotherapy and pharmacotherapy can be clinically helpful in reducing psychiatric symptoms and dizziness. Early intervention improves prognosis.

Comprehensive Normative Data for Objective Vestibular Tests

INTRODUCTION

 Vestibular dysfunction is a debilitating disorder frequently encountered in neurological and otological settings. The vestibular system is a complex network between peripheral and central mechanisms. This innate complexity of the vestibular system necessitates objective test procedures for evidence-based diagnostic formulations and intervention. Objective tests aid in the evaluation of both peripheral and central vestibular pathologies. Establishing and availability of comprehensive normative data for these objective tests is crucial for clinicians and researchers alike.

MATERIALS AND METHODS

This is a prospective study involving 120 participants (both males and females) aged between 18 and 55 years. All participants were right-handed individuals and had no significant medical history. On pre-set protocols, cVEMP (cervical vestibular evoked myogenic potential), oVEMP (ocular vestibular evoked myogenic potential), vHIT (video head impulse test), and VNG (videonystagmography) were done.

RESULTS

While all participants (n=120) underwent cVEMP, oVEMP, vHIT, saccade, smooth pursuit, and optokinetic tests, only 109 participants consented to the caloric test. Each test's mean, standard deviation, median, quartile, and third quartiles have been recorded. A right-left comparison yielded no significant difference on cVEMP, oVEMP, caloric test, smooth pursuit, and optokinetic test. However, few vHIT and saccade parameters did reveal significant differences.

DISCUSSION

This study presents comprehensive normative data for cVEMP, oVEMP, vHIT, caloric test on VNG, and oculomotor tests (smooth pursuit, saccade, optokinetic) on VNG. The test results were in concordance with previously published data. The significant difference between the right and left sides in vHIT may be because of the monocular goggles used for the testing.

CONCLUSION

This study brings out the normative data for various vestibular tests on individuals aged between 18-55 years. This information could aid both clinicians and researchers working in the field of vestibular science.

Subcutaneous stretching enlarges adjacent vertebral artery instantly in patients with cervicogenic dizziness: Two case reports

RATIONALE

Fu's subcutaneous needling (FSN) is effective for cervicogenic dizziness (CGD), which is often a result of vascular problems. Here, we attribute the positive treatment effect of FSN for CGD to improvements in vascular problems.

PATIENT CONCERN

Two patients were experiencing low quality of life due to reproducible dizziness.

DIAGNOSIS

Two patients with cervical spine disorder, presented with neck pain and reproducible dizziness. Other causes of dizziness were excluded.

INTERVENTIONS

Case 1 received 1 session of FSN treatment, while case 2 received 3 sessions of FSN treatment in a month.

OUTCOMES

The dizziness and neck pain experienced by both patients instantly improved significantly after FSN treatment, and the luminal diameter of the vertebral artery (VA) measured by carotid and VA ultrasound enlarged simultaneously up to 1.29-fold and 1.09-fold for both cases. According to the Hagen-Poiseuille equation, the blood flow volume increased 2.77-fold and 1.43-fold, respectively. Case 2 recovered from CGD with 1.19-fold VA luminal diameter increment and about 2.01-fold increase of blood flow volume in a month.

LESSONS

Subcutaneous stretching provides a safe, convenient and immediate solution to CGD, and supports the diagnosis and treatment of CGD under carotid and VA ultrasound. This study suggests that stretching subcutaneously can influence adjacent VA, which may also help improve some cerebrovascular diseases.

Effect of Interventional Therapy Unexplained Dizziness and Relationship Between Dizziness Handicap Inventory and Right-to-Left Shunt Grading

Objective

Unexplained dizziness remains a clinical challenge. Our previous studies have shown that unexplained dizziness may be related to patent foramen ovale (PFO). This study aims to explore whether the degree of shunt is correlated with the degree of unexplained dizziness and looking for the possible clinical intervention for patients with unexplained dizziness.

Methods

This study was a large single-center, prospective, controlled study. From March 2019 to March 2022, patients with unexplained dizziness and explained dizziness and healthy controls were recruited. Contrast-enhanced transcranial Doppler sonography (c-TCD) was performed to detect the existence of right-to-left shunt (RLS) and shunt grading. The dizziness handicap inventory (DHI) was completed to evaluate the dizziness. Unexplained dizziness patients with large amount of PFO were volunteered to receive medication treatment and transcatheter PFO closure and followed up six months.

Results

A total of 387 patients (132 unexplained, 123 explained and 132 controls) were enrolled. There was a statistical difference in the RLS grading with three groups (p < 0.001). The Spearman correlation coefficient of RLS grading and DHI scores in unexplained dizziness patients (r=0.122, p=0.163) and explained dizziness patients (r=0.067, p=0.460). In the unexplained group, there were 49 cases with massive grading RLS. Of which 25 patients received percutaneous PFO closure treatment and 24 cases received medication treatment. Followed up six months after treatment, the amount of DHI scores change in patients who received the percutaneous PFO closure was significantly higher than that in the medication treatment group (p < 0.001).

Conclusion

RLS may play an important role in unexplained dizziness. For unexplained dizziness patients, PFO closure may contribute to better outcomes. In the future, large-scale randomized controlled studies are still needed.

A comparison of placebo and nocebo effects on objective and subjective postural stability: a double-edged sword?

Background: Positive expectations (i.e., placebo effect) can improve postural control during quiet standing. This raises an important question: if postural control is susceptible to positive expectations, is it possible to elicit the opposite, a decline in postural stability, simply by suggesting a performance impairment (i.e., nocebo) will take place? Yet no studies have examined the nocebo effect on balance performance. To better understand both phenomena, comparative studies, which include both placebo and nocebo conditions, are needed.

Method: Forty-two healthy adults were initially assessed for objective (center of pressure movement) and subjective (perceived) postural stability and performance expectations. Participants were then randomly assigned in equal numbers to a placebo (positive expectation), nocebo (negative expectation) or control (no suggestion) group. Participants in the placebo/nocebo groups were deceptively administered an inert capsule described as a potent supplement which would either positively or negatively influence their balance performance. Objective and subjective postural stability, and performance expectations were reassessed 20 min later.

Results: The nocebo procedure evoked an increase in COP sway movements and reduced perceived stability compared to a control group. The placebo group presented with reductions COP sway movements and increased perceived stability following expectation manipulation. Compared to the control group, the placebo group showed a significantly higher performance expectation whilst the nocebo group showed a significantly lower performance expectation. Regression analyses also revealed that performance expectations following the placebo/nocebo procedure significantly predicted perceptions of postural instability (i.e., perceived performance), accounting for around 50% of the variance. These results remained even when controlling for actual performance (i.e., objective postural stability).

Conclusion: Our findings indicate that positive and negative performance expectations evoked by instructional manipulation can profoundly influence both objective and subjective postural stability. Postural control—and perceptions regarding such—are clearly susceptible to expectation manipulation, which could have important practical implications and repercussions on testing, training interventions and rehabilitation programs. Positive and negative expectancies are a double-edged sword for postural control.

Relevance of Cognition and Emotion for Patient-Reported Quality of Life After Stroke in Working Age: An Observational Cohort Study

Background

Patient-reported quality of life (QoL) may help to capture sequela of stroke more comprehensively. We aimed to investigate QoL in working age persons with ischemic stroke regarding impaired domains and identify factors associated with better QoL.

Methods

We invited persons with stroke aged 18–55 years to participate in this prospective observational study. We assessed QoL and self-rated health using the EuroQol 5 Dimension questionnaire (EQ-5D) during hospital stay (baseline) and at 3-months follow-up (FU). Additionally, the National Institute of Health Stroke Scale (NIHSS), modified Rankin Scale (mRS), cognition (Montreal Cognitive assessment, MOCA), emotion (Hospital Anxiety and Depression Scale), and return to work were evaluated. We used hierarchical regression to identify predictors of QoL (self-rated health and QoL Index score) at FU.

Results

We included 138 persons with stroke (mean age = 43.6 ± 10 years; 41% female; median admission NIHSS = 2), of whom 99 participated at FU. QoL Index and self-rated health were correlated with NIHSS, mRS, anxiety, and depression at both timepoints. Although 80% had favorable functional outcome at FU (mRS < 2), high proportions of these persons reported problems in the “Pain and/or Discomfort” (25.3%) and “Anxiety/Depression” (22.8%) dimensions. Only discharge NIHSS and baseline MOCA independently predicted self-rated health at FU. Female sex, higher discharge NIHSS, and higher baseline depression scores predicted worse QoL Index scores at FU.

Conclusions

Three months post-stroke, working age persons with stroke frequently reported problems in dimensions not assessed by the routinely used mRS. Despite correlations between clinical scales and QoL, patient-reported outcomes and screening for cognition and emotion ensure a more comprehensive assessment of post-stroke consequences relevant for QoL.

Vestibular migraine

Vestibular migraine is an under-diagnosed but increasingly recognised neurological condition that causes episodic vertigo, associated with migrainous features. Making a diagnosis of VM relies on a clinical history, including the presence of recurrent episodes of vertigo or dizziness, on a background of migraine headaches, and associated migraine features that accompany the vestibular symptoms. It is the most common cause of spontaneous (non-positional) episodic vertigo, affecting up to 1% of the population, but remains under-diagnosed outside specialist centres, partly due to an absence of diagnostic biomarkers. Its pathophysiology remains poorly understood, and there is a paucity of high-quality treatment trials. Here we review the clinical features of vestibular migraine, highlight current theories that account for vestibular symptoms, and outline treatment guidelines.

Can Type of Dizziness Influence the Vestibular Caloric Test Result?

Background:

The broad range of vestibular tests used to diagnose labyrinth diseases allows for a functional assessment of the vestibular system. Among the many tests performed, the caloric test is considered the gold standard by providing an objective measurement of the vestibular function for each labyrinth.

Objective:

to correlate the different types of dizziness with the caloric test result.

Methods:

a descriptive study was performed based on the previous records of vestibular tests performed on patients with body balance disorders evaluated at Audiology Service between 2000 and 2020. The variables evaluated were sex, age, hearing loss, tinnitus, and caloric test result.

Results:

the sample was composed of 892 patients, 654 (73.4%) women, and 238 (26.6%) men. Normal results were obtained for 57.4% (N = 514) of the individuals, while peripheral disease 40.1% (N = 357), and central disease 2.5% (N = 21) accounted for the remaining. Complaint of vertigo was not common in central disorders (P = .02; OR = 0.17) and instability was associated with bilateral vestibular weakness (P = 0.02; OR = 5.92). Vertigo associated with tinnitus and/or hearing loss was more frequent in the caloric test with peripheral abnormality (P = 0.008).

Conclusion:

complaints of vertigo associated with tinnitus and/or hearing loss must be directed for clinical observation of unilateral peripheral lesion and instability to central disease or bilateral peripheral lesion.

Predicting value of fibrinogen in identifying cerebrovascular ischemic events in patients with dizziness/vertigo

PURPOSE

Dizziness and vertigo are caused by multiple etiologies, including cerebrovascular ischemic events. However, identifying cerebrovascular ischemic events as a cause of dizziness and vertigo remains a challenge. We tried to assess the value of fibrinogen (FIB) in identifying of cerebral ischemic event in patients with dizziness/vertigo.

METHODS

The study enrolled patients with dizziness/vertigo presented within 72 h in a tertiary hospital. The plasma FIB levels were measured in all participants. According to the final diagnosis, participants were divided into cerebral ischemic events group and non-cerebrovascular diseases group. Multivariate logistic regression was performed to explore the association between FIB and cerebral ischemic events. The receiver operating characteristic curve was performed, and the nomogram was constructed to evaluate the overall prediction ability of FIB in cerebral ischemic event.

RESULTS

A total of 298 participants were enrolled in our study, of 126 cerebral ischemic events patients. Multivariate logistic regression analysis showed that FIB was independently associated with cerebral ischemic event in patients with dizziness (OR = 1.84, 95%CI [1.15, 2.92], p = 0.010). The cut-off value of FIB in predicting cerebral ischemic event was 2.43 g/L (AUC = 0.658). The nomogram showed that higher FIB level was associated with a greater risk of cerebral ischemic event (C-index = 0.800).

CONCLUSIONS

Our study suggested that FIB may be a useful biochemical parameter for identifying cerebral ischemic event in patients with dizziness/vertigo.

Consciously processing balance leads to distorted perceptions of instability in older adults

Background

Persistent dizziness without a clear cause is common in older adults. We explored whether an anxiety-driven preoccupation with consciously processing balance may underpin the distorted perceptions of unsteadiness that characterises ‘unexplained’ dizziness in older adults.

Methods

We experimentally induced anxiety about losing one’s balance (through a postural threat manipulation) in a cohort of asymptomatic older adults and evaluated associated changes in perceived stability, conscious movement processing and postural control. These outcomes were also assessed when performing a distracting cognitive task designed to prevent anxiety-related conscious movement processing, in addition to during baseline conditions (ground level).

Results

Despite a lack of increase in postural sway amplitude (p = 0.316), participants reported reductions in perceived stability during postural threat compared to baseline (p < 0.001). A multiple linear regression revealed that anxiety-related conscious movement processing independently predicted perceptions of instability during this condition (p = 0.006). These changes were accompanied by alterations in postural control previously associated with functional dizziness, namely high-frequency postural sway and disrupted interaction between open- and closed-loop postural control (ps < 0.014). While the distraction task successfully reduced conscious processing (p = 0.012), leading to greater perceived stability (p = 0.010), further increases in both postural sway frequency (p = 0.002) and dominance of closed-loop control (p = 0.029) were observed.

Conclusion

These findings implicate the role of conscious movement processing in the formation of distorted perceptions of unsteadiness, suggesting that such perceptions may be modifiable by reducing an over-reliance on conscious processes to regulate balance.