Caloric tests in clinical practice in benign paroxysmal positional vertigo

The role of electrocochleography and the caloric test in predicting short-term recurrence of benign paroxysmal positional vertigo

Objective

The study aimed to assess the value of physiological tests for evaluating inner ear function in predicting the short-term recurrence of benign paroxysmal positional vertigo (BPPV).

Materials and methods

The clinical information of all idiopathic BPPV patients who were treated in our clinic between February 2021 and December 2022 were reviewed. All patients included in the study had completed audiology examinations including pure tone audiometry, electrocochleography (EcochG), auditory brainstem response, and vestibular function examination such as the vestibular caloric test. The relationships between the results of the above tests and short-term recurrent BPPV were analyzed.

Results

A total of 96 patients with unilateral idiopathic BPPV were included for analysis. The numbers of non-recurrent patients and recurrent patients were 57 (59.4%) and 39 (40.6%), respectively. Only the results of EcochG and the caloric test showed significant differences between non-recurrent and recurrent patients (both P < 0.05). The results of these two tests were also found to be independently predictive of short-term recurrence (both P < 0.05). The non-recurrence rate for patients with normal results in both tests reached up to 78.3%, which was significantly higher than that for patients with abnormal results in both tests, 28.6% (P < 0.05).

Conclusion

Endolymphatic hydrops and canal paresis were independent risk factors for short-term recurrent BPPV. Additional treatments should be considered to reduce the recurrence rate, including dehydration treatment and vestibular rehabilitation.

The horizontal and vertical components of nystagmus evoked by the supine roll test in horizontal semicircular canal canalolithiasis

Objective

The characteristics of horizontal and vertical components of nystagmus evoked by the supine roll test in patients with horizontal semicircular canal canalolithiasis (HSC-Can) were analyzed, according to Ewald’s first law. It provided a basis for the study of human horizontal semicircular canal function and structure, objective diagnosis, and treatment of benign paroxysmal positional vertigo (BPPV).

Materials and methods

The records of patients that had been tested with 2-dimensional videonystagmography (2D-VNG) were reviewed between June 2019 and June 2021. The intensity and direction of horizontal and vertical nystagmus elicited by the supine roll test were analyzed in 189 patients with idiopathic HSC-Can.

Results

All the 189 patients with HSC-Can were induced horizontal nystagmus with the same direction as head-turning (geotropic) in the supine roll test, of which 119 patients (63.96%) had a weak vertical upward component of nystagmus on the affected and unaffected sides, 57 patients (30.16%) had a vertical downward component of nystagmus on the affected side and/or the unaffected side, and 13 patients (6.88%) had no vertical component of nystagmus on both the sides. The intensity values of the horizontal component on the affected and unaffected sides were 42.14 ± 24.78 (range: 6.26–138.00°/s) and 17.48 ± 10.91°/s (range: 2.40–53.83°/s), with a ratio of 2.96 ± 2.17:1, representing a significant difference (p < 0.001). We analyzed the characteristics of horizontal and vertical components in 119 patients with HSC-Can (57 L-HSC-Can and 62 R-HSC-Can) on the supine roll test. The intensity values of the horizontal component on the affected and unaffected sides were 43.17 ± 23.76 (range: 8.60–124.51°/s) and 17.98 ± 10.99°/s (range: 2.40–53.83°/s), and the intensity values of the vertical component on the affected and unaffected sides were 10.65 ± 8.46 (range: 1.90–50.83°/s) and 4.81 ± 3.45°/s (range: 0.30–20.43°/s), representing a significant difference between groups (p < 0.001). Among 119 patients with HSC-Can who had a vertical upward component on both the affected and unaffected sides in the supine roll test, unilateral weakness (UW) was normal in 53 cases and abnormal in 51 cases, and 15 cases did not undergo the caloric test. We compared the horizontal and vertical components of nystagmus induced on the affected and unaffected sides in the supine roll test in 53 patients with normal UW and 51 patients with abnormal UW, and the difference was not statistically significant.

Conclusion

There is mostly a vertical upward component based on the horizontal component in HSC-Can, and the direction and intensity characteristics of nystagmus accord with Ewald’s first law, which can provide a basis for the study of human HSC function and structure, objective diagnosis, and treatment of BPPV.

Clinical Application of Different Vertical Position Tests for Posterior Canal-Benign Paroxysmal Positional Vertigo-Cupulolithiasis

Background

Posterior canal-benign paroxysmal positional vertigo-cupulolithiasis (PC-BPPV-cu) is a new and controversial type of benign paroxysmal positional vertigo (BPPV). At present, there are few relevant clinical studies as to whether the Half Dix-Hallpike test (Half D-HT) induces more obvious nystagmus than the Dix Hallpike test (D-HT) and straight head hanging test (SHH) in patients with PC-BPPV-cu.

Objectives

To investigate the clinical characteristics of PC-BPPV-cu, and analyze the diagnostic significance of the Dix-Hallpike test (D-HT), Half D-HT, and straight head hanging (SHH) test in these patients.

Methods

A total of 46 patients with PC-BPPV-cu were enrolled, and divided into two groups (N = 23): a group A (induction order: D-HT, Half D-HT, SHH) and a group B (induction order: Half D-HT, D-HT, SHH).

Results

Among 46 patients with PC-BPPV-cu, the bilateral and unilateral abnormality rates of the disease side were 5 cases and 41 cases, respectively. There were significant differences in the proportion of torsional-upbeating nystagmus and upbeating nystagmus among the three headhanging positions in 46 patients with PC-BPPV-cu (P &lt; 0.001). The slow phase velocity (SPV) of induced nystagmus at half D-HT supine position was slower than D-HT supine position (P &lt; 0.05) and SHH supine position (P &lt; 0.05). The nystagmus latency of D-HT supine position was significantly shorter than half D-HT (P &lt; 0.05) and SHH (P &lt; 0.05). PC-BPPV-cu patients were accompanied by 53.5% semicircular canal paresis, 69.6% audiological abnormalities, 76% cervical vestibular evoked myogenic potential (cVEMP), and 75% video head impulse test (vHIT) abnormalities, the concordance rates of the four detection methods were similar (χ2 = 0.243, P = 0.970).

Conclusions

The Half D-HT is simple and feasible, but might have a risk of false-negative diagnoses of the torsional-upbeating nystagmus and upbeating nystagmus. The D-HT is still a classic induction method for PC-BPPV-cu. The two complement each other and may aid in the diagnosis of PC-BPPV-cu patients. Future clinical applications of Half D-HT require extensive research to determine its diagnostic efficacy.

A possible objective test to detect benign paroxysmal positional vertigo. The role of the caloric and video-head impulse tests in the diagnosis

Background

Objectives

Methods

Results

Conclusion

Clinical Characteristics of Patients with Persistent Apogeotropic and Persistent Geotropic Direction-Changing Positional Nystagmus

Background and Purpose

This study aimed to determine the clinical features, diagnosis, and treatment of patients with persistent geotropic (pG) and persistent apogeotropic (pAG) direction-changing positional nystagmus (DCPN).

Methods

This retrospective study included 30 patients with pG-DCPN and 44 patients with pAG-DCPN. All patients underwent neurological and neurotological examinations, including an evaluation of gaze-evoked nystagmus, eye-movement tests, and assessments of limb ataxia and balance, as well as magnetic resonance imaging to exclude central causes. The characteristics of positional nystagmus were detected using the supine roll test (SRT) and bow-and-lean test (BLT). The null point (NP) at which the nystagmus disappeared was determined. All patients were treated with the barbecue maneuver, and treatment efficacy was evaluated immediately, 1 week, and 1 month after treatment.

Results

The history of diseases associated with atherosclerosis, peripheral vestibular disorders, otological disease, and migraine differed significantly between patients with pG-DCPN and pAG-DCPN. The affected sides of persistent horizontal DCPN can be determined using the SRT and the BLT, while determining the second NP and vestibular function as well as performing an audiological evaluation can be used to assist in identifying the affected side. The efficacy rates immediately and 1 week after treatment with the barbecue maneuver were higher in patients with pAG-DCPN than in patients with pG-DCPN.

Conclusions

pAG-DCPN was more compatible with the characteristics of cupulolithiasis, and pG-DCPN was more likely to be associated with a light cupula rather than canalolithiasis. pAG-DCPN was more likely to be accompanied by a disease associated with atherosclerosis, while pG-DCPN was often accompanied by autoimmune-related diseases and a history of migraine. The associations between pAG-DCPN, pG-DCPN, and the above-mentioned diseases need to be clarified further. The canalith-repositioning maneuver was effective in patients with pAG-DCPN and ineffective in patients with pG-DCPN, but most cases of pG-DCPN are self-limiting.

Clinical characteristics of patients with multi-canal benign paroxysmal positional vertigo

Introduction

Multi-canal benign paroxysmal positional vertigo is considered to be a rare and controversial type in the new diagnostic guidelines of Bárány because the nystagmus is more complicated or atypical, which is worthy of further study.

Objective

Based on the diagnostic criteria for multi-canal benign paroxysmal positional vertigo proposed by International Bárány Society, the study aimed to investigate the clinical characteristics, diagnosis and treatment of multi-canal benign paroxysmal positional vertigo.

Methods

A total of 41 patients with multi-canal benign paroxysmal positional vertigo were included and diagnosed by Roll, Dix-Hallpike and straight head hanging tests. Manual reduction was performed according to the involvement of semicircular canals.

Results

Among the 41 cases, 19 (46.3%) patients showed vertical up-beating nystagmus with or without torsional component and geotropic, apogeotropic horizontal nystagmus, and were diagnosed with posterior-horizontal canal. 11 (26.8%) patients showed vertical up-beating nystagmus with torsional component on one side and vertical down-beating nystagmus with or without torsional component on the other side during Dix-Hallpike test or straight head hanging test and were diagnosed with posterior-anterior canal benign paroxysmal positional vertigo 9 (26.8%) patients showed vertical down-beating nystagmus with or without torsional component and geotropic, apogeotropic horizontal nystagmus, and were diagnosed with anterior-horizontal canal 2 (4.9%) patients showed vertical geotropic torsional up-beating nystagmus on both sides and were diagnosed with bilateral posterior canal benign paroxysmal positional vertigo. High correlation between the sides with reduced vestibular function or hearing loss and the side affected by Multi-canal benign paroxysmal positional vertigo was revealed (contingency coefficient = 0.602, p = 0.010). During one-week follow up, nystagmus/vertigo has been significantly alleviated or disappeared in 87.8% (36/41) patients.

Conclusion

Posterior-horizontal canal benign paroxysmal positional vertigo was the most common type. Multi-canal benign paroxysmal positional vertigo involving anterior canal was also not uncommon. Caloric tests and pure tone audiometry may help in the determination of the affected side. Manual reduction was effective in most of Multi-canal benign paroxysmal positional vertigo patients.