The interpretation of static positional nystagmus in a balance clinic

Benign paroxysmal positional vertigo without dizziness is common in people presenting to falls clinics

PURPOSE

To determine the prevalence of benign paroxysmal positional vertigo without dizziness, a treatable falls risk factor in people attending outpatient falls clinics.

METHODS

Over 6 years, 618 people at risk of falls attending 2 falls clinics were assessed for benign paroxysmal positional vertigo, whether dizzy or non dizzy. Data regarding demographics, canal location of positive tests and comorbidities were collected from medical records.

RESULTS

Thirty-nine percent (238) of people with falls risk tested positive for benign paroxysmal positional vertigo; 62 (26%) or 1 in 4 of those testing positive were not dizzy. Thirty-nine of 104 (38%) testing positive for single canal benign paroxysmal positional vertigo and twenty-four of 134 (18%) testing positive for multiple canal benign paroxysmal positional vertigo were not dizzy. Comorbidities were common for all with falls risk but did not differentiate for benign paroxysmal positional vertigo on testing.

CONCLUSIONS

Benign paroxysmal positional vertigo is common in people attending falls clinics and contributes to falls risk. Dizziness is common in BPPV though 26% or 1 in 4 people testing positive were not dizzy and would be missed without mandatory testing. Testing should also include all semicircular canals as multiple-canal involvement was high.

Prevalence of benign paroxysmal positional vertigo in a population-based setting among 75-year-olds

BACKGROUND

Benign paroxysmal positional vertigo (BPPV) is one of the most frequently diagnosed cause of dizziness among older adults.

OBJECTIVE

To investigate the prevalence of BPPV and positional symptoms of dizziness and nystagmus among 75-year-olds and to identify factors associated with BPPV and positional dizziness and nystagmus.

METHODS

In this cross-sectional population-based study of 75-78-year-olds in Gothenburg, 887 participants were examined with questions regarding dizziness and health and social factors. A total of 681 participants underwent the Dix-Hallpike test or the side-lying test for BPPV using Video Frenzel goggles.

RESULTS

In total 32% reported problems with dizziness (n = 887). The prevalence of BPPV was 4% in the unweighted and 4.5% in the weighted analyses, compensating for selective attrition of women and participants with previous positional dizziness. Positional dizziness without nystagmus was found in 2% and nystagmus without dizziness was found in 9%. Individuals with BPPV and positional dizziness experienced more dizziness in everyday life compared with those with normal tests, while those with positional nystagmus did not.

CONCLUSIONS

The estimated prevalence of BPPV among 75-year-olds was 4.5%. Despite weighted analyses, the true prevalence may be higher since many participants with dizziness refused testing. Dizziness was associated with fear and discomfort so strong that around 20% of the participants declined testing.

Evaluation of the reliability and validity of the upright head roll test for lateral semicircular canal benign paroxysmal positional vertigo

BACKGROUND

The upright head roll test (UHRT) is a recently introduced diagnostic maneuver for lateral semicircular canal benign paroxysmal positional vertigo (LSC-BPPV).

OBJECTIVE

This study aimed to evaluate the reliability and validity of the UHRT.

METHODS

Two separate studies were conducted. Study 1 analyzed 827 results of videonystagmography (VNG) to assess UHRT reliability, and Study 2 analyzed 130 LSC-BPPV cases to evaluate UHRT validity.

RESULTS

The inter-test reliability between UHRT and the supine head roll test (SHRT) showed substantial agreement (Cohen's kappa = 0.753) in direction-changing positional nystagmus (DCPN) and almost perfect agreement (Cohen's kappa = 0.836) in distinguishing the direction of DCPN. The validity assessment of UHRT showed high accuracy in diagnosing LSC-BPPV (80.0%) and in differentiating the variant types (74.6%). UHRT was highly accurate in diagnosing the canalolithiasis type in LSC-BPPV patients (Cohen's kappa = 0.835); however, it showed only moderate accuracy in diagnosing the cupulolithiasis type (Cohen's kappa = 0.415). The intensity of nystagmus in UHRT was relatively weaker than that in SHRT (P < 0.05).

CONCLUSION

UHRT is a reliable test for diagnosing LSC-BPPV and distinguishing subtypes. However, UHRT has a limitation in discriminating the affected side owing to a weaker intensity of nystagmus than SHRT.

Correlation between nystagmus intensity and vestibular-ocular reflex gain in benign paroxysmal positional vertigo: A prospective, clinical study

BACKGROUND

Video head impulse test (vHIT) and videonystagmography (VNG) provide significant benefits in evaluating benign paroxysmal positional vertigo (BPPV) and determining the semicircular canal localization of the otoconia.

OBJECTIVE

This study aimed to investigate the relationship between vestibular-ocular reflex (VOR) gains measured via vHIT and the slow-phase velocity (SPV) of nystagmus in patients with the posterior semicircular canal (PSCC)-BPPV.

METHODS

Sixty-two patients were included in this study and divided into the study (n = 32, patients with isolated PSCC-BPPV) and control (n = 30, age- and sex-matched healthy individuals) groups. While VOR gains were measured with vHIT in both groups and compared between groups, the SPV values of nystagmus observed during the Dix-Hallpike maneuver in the study group were recorded using VNG and compared with the VOR gains of the study group.

RESULTS

There were significant differences in posterior canal VOR gains between the study and control groups (p < 0.001 and p < 0.01, respectively). Although the affected PSCC had decreased VOR gains versus the control group, it was still within the normal range. However, there was no significant relationship between the VOR gains of the affected PSCC and the SPV of the nystagmus.

CONCLUSIONS

vHIT can help detect semicircular canal dysfunction in patients with PSCC-BPPV. The SPV values of nystagmus on VNG during the Dix-Hallpike maneuver do not correlate with the level of VOR gain.

Central positional nystagmus: an update

Clinically, central positional nystagmus (CPN) is often suspected when atypical forms of its peripheral counterpart, i.e., benign paroxysmal positional vertigo (BPPV), are observed, namely a linear horizontal nystagmus as in horizontal canal BPPV or a downwardly and torsionally beating nystagmus as in anterior canal BPPV. Pathophysiologically, CPN is caused by cerebellar and/or brainstem dysfunction. Recent work has provided further insights into the different clinical phenotypes and the underlying pathomechanisms. We performed a PubMed review focused on the findings on CPN using the key words "Central Positional Nystagmus", "Central Positional Vertigo", "Positional Nystagmus" OR "Positioning Nystagmus" OR "Positional Vertigo" OR "Positioning Vertigo" AND "Central" from January 2015 to August 2021. CPN may account for up to 12% of patients with positional nystagmus. Clinical data on CPN are mostly based on case reports or small retrospective case series. CPN is frequently associated with cerebellar and/or brainstem structural lesions, namely stroke, tumours or demyelination, or diffuse involvement of these structures due to degenerative or autoimmune/paraneoplastic diseases; it is also found in patients with vestibular migraine. CPN can be paroxysmal or persistent. The direction of the nystagmus is often downward in head-hanging or apogeotropic in lateral supine positions; combinations of both forms also occur. Clinically it is important to note that CPN is often associated with other central, often cerebellar ocular motor or other neurological signs; typically, it is not improved by the therapeutic liberatory manoeuvres for BPPV. These additional features are also important for the diagnosis, in particular if no structural lesions are found. Pathophysiologically, CPN is believed to reflect an abnormal integration of semicircular canal-related signals by the cerebellar nodulus, uvula and/or tonsil, ultimately providing an erroneous estimation of the head tilt and/or eye position coordinates. The natural course of CPN remains, so far, largely unknown. Symptomatic treatment of CPN consists of pharmacotherapy, e.g., with 4-aminopyridine, and causative treatment of the underlying disease if known. CPN is an important differential diagnosis to BPPV and a clinically relevant entity with heterogenous clinical presentations and various pathomechanisms and etiologies. In particular, studies on the natural course and treatment of CPN are needed.

Reconstructing animated eye movements from electrooculography data to aid the diagnosis of vestibular disorders

OBJECTIVE

To develop a method of visualising electrooculography data to improve the interpretability of nystagmus eye-movements captured using the Continuous Ambulatory Vestibular Assessment (CAVA^®) device.

DESIGN

We are currently undertaking a clinical investigation to evaluate the capabilities of the CAVA^® device to detect periods of pathological nystagmus. The work presented here was undertaken using unblinded data obtained from the preliminary phase of this investigation.

STUDY SAMPLE

One patient with Ménière's disease and one with Benign Paroxysmal Positional Vertigo.

RESULTS

Using the electrooculography data captured by the CAVA^® device, we reconstructed 2D animations of patients' eye movements during attacks of vertigo. We were able to reanimate nystagmus produced as a consequence of two conditions. Concurrent video footage showed that the animations were visually very similar to the patient's actual eye-movements, excepting torsional eye-movements.

CONCLUSIONS

The reconstructed animations provide an alternative presentation modality, enabling clinicians to largely interpret electrooculography data as if they were present during a vertigo attack. We were able to recreate nystagmus from attacks experienced in the community rather than a clinical setting. This information provides an objective record of a patient's nystagmus and could be used to complement a full neurotologic history when considering diagnosis and treatment options.

Estimated Vestibulogram (EVEST) for Effective Vestibular Assessment

BACKGROUND

The availability and development of methods testing the vestibuloocular reflex (VOR) brought a broader view into the lateral semicircular canal (L-SCC) function. However, the higher number of evaluated parameters makes more difficult the specialist's diagnose-making process.

PURPOSE

To provide medical specialists, a new diagnostic-graphic tool, Estimated Vestibulogram- EVEST, enabling a quick and easy-to-read visualization and comparison of the VOR test results within the L-SCC.

METHODS

The development of EVEST involved 148 participants, including 49 healthy volunteers (28 female and 21 male) and 99 (58 female and 41 male) patients affected by different degrees of peripheral vestibular deficit. The corresponding L-SCC VOR test results, from patients meeting the diagnostic criteria, were used to create the EVEST.

RESULTS

Based on the test results, we depicted and calculated the EVEST vestibular function asymmetry (VFA) in all the groups. To assess a feasibility of EVEST to describe a vestibular function deficit, we calculated sensitivity and specificity of VFA using a receiver operating characteristic curve (ROC) and compared it to single tests. In all the tests, we determined the cutoff value as the point with the highest sensitivity and specificity. For discrimination of any vestibular deficit, the VFA with cutoff 6.5% was more sensitive (91%) and specific (98%) than single tests. Results showed that EVEST is a beneficial graphic tool for quick multifrequency comparison and diagnosis of different types of the peripheral vestibular loss.

CONCLUSIONS

EVEST can help to easily evaluate various types of peripheral vestibular lesion.

Treatment of horizontal canal BPPV-a randomized sham-controlled trial comparing two therapeutic maneuvers of different speeds

OBJECTIVES

To compare the effect of a high-speed barbecue maneuver with the modified Lempert maneuver and sham in patients with benign paroxysmal positional vertigo (BPPV) of the horizontal canal.

METHODS

Randomized sham-controlled, single blinded multicenter clinical trial in two university hospitals investigating consecutive patients with horizontal canal BPPV.Patients were randomly assigned to high-speed barbecue (HSB), modified Lempert maneuver (ML), or sham maneuver (SM). All treatments were performed in a biaxial rotational chair with weekly follow-up to a maximum of three treatment sessions. The final follow-up was 3 months after the last treatment.

RESULTS

Primary outcome: 2-week recovery rate per protocol. Secondary outcome: Cumulative recovery rate and Dizziness Handicap Inventory (DHI) scores after 3 months per protocol (HSB and ML) and intention to treat (all groups).Fifty-four patients were analyzed after 2 weeks (HSB = 17; ML = 20; SM = 17). Two-week recovery rate was 14/17 after HSB, 11/20 after ML, and 4/17 after SM, with significantly better recovery in HSB [OR 15.17, 95% CI (1.85, 124.63), P = .001] using sham as base level. Recovery rate after 3 months was 15/17 after HSB and 15/19 after ML. Cumulative recovery rate showed no significant differences between the two treatment groups [95% CI (0.30, 13.14), P = .46] in cure rate DHI [95% CI (-16.56, 15.02), P = .92]. No unexpected adverse events were observed.

CONCLUSION

Velocity change in horizontal canal BPPV treatment gives a faster initial recovery. Rapid recovery could reduce the disease burden.

TRIAL REGISTRATION

Clinicaltrials.gov. Identifier: NCT01905800.

LEVEL OF EVIDENCE

1b.