Volume ratio and distribution rate in patients with orthostatic vertigo/dizziness using MR imaging: a comparison with vertiginous diseases.

BACKGROUND: Orthostatic dizziness/vertigo (ODV) is characterized by lightheadedness owing to postural changes. AIMS/OBJECTIVES: To measure the endolymphatic space (ELS)/total fluid space (TFS) volume ratio and the distribution rate of endolymphatic fluid (ELF) of patients with ODV and compare them with those of control subjects (CS). MATERIALS AND METHODS: This study included 22 patients (44 ears) with ODV and 52 controls (104 ears, CS). The ELS/TFS volume ratio (%) and distribution rate (%) of the inner ear components were measured using 3-dimensional magnetic resonance imaging. RESULTS: In the ODV group, the mean ELS/TFS volume ratios of the cochlea, vestibule, and semi-circular canals (SCCs) were 12.1%, 18.6%, and 18.1%, respectively; the mean ELS distribution rates for the cochlea, vestibule, and SCCs were 27.3%, 26.2%, and 46.6%, respectively. The ELS distribution rate of the vestibule was significantly lower (p < .01) and the ELS distribution rate of the SCCs was significantly higher in the ODV than in the CS group (p < .01). CONCLUSIONS AND SIGNIFICANCE: The ELS distribution rate in the vestibule + SCCs among patients with ODV did not differ from that in the CS; ELF in the vestibule moved to the SCCs, and a large amount of ELF was distributed only in the SCCs.

Effects of endolymphatic space volume on discrepancy of results between caloric test and video head impulse test.

OBJECTIVE: The caloric test (C-test) and video head impulse test (vHIT) are known to occasionally show contradictory results in patients with Meniere's disease (MD). The reasons underlying this discrepancy between the two tests are currently unclear. We aimed to reveal the mechanisms responsible for this discrepancy by performing volumetric evaluation of the endolymphatic space (ELS) by using endoluminal contrast-enhanced inner ear MRI (ieMRI). METHODS: We enrolled 136 patients (174 ears) who visited the vertigo/dizziness center of our university and underwent the C-test and vHIT between February 2018 and February 2020. Inner ear MRI was also performed to determine the presence of endolymphatic hydrops (EH). The percentage of patients diagnosed with each vestibular disease was as follows: MD, 23.0%; benign paroxysmal positional vertigo (BPPV), 17.8%; bilateral vestibular disorder (BVD), 9.2%; sudden deafness with vertigo (SD), 8.0%; peripheral dizziness (PD), 7.5%; unilateral vestibular disorder (UVD), 6.9%; vestibular neuritis (VN), 6.3%; delayed endolymphatic hydrops (DEH), 3.4%; central dizziness (CD), 2.9%; Hunt syndrome (Hunt), 1.2%; and other disorders (OD), 13.8%. RESULTS: Among the ears in the present study, 46.0% (80/174) showed a discrepancy in the results of the C-test and vHIT, and the disease-related distribution of patients showing this discrepancy was as follows; MD, 38.8% (27/80; p = 0.0019); BVD, 13.8% (11/80); UVD, 12.5% (10/80); SD, 7.5% (6/80); BPPV, 6.3% (5/80); PD, 6.3% (5/80); VN, 3.8% (3/80); DEH, 3.8% (3/80); CD, 2.5% (2/80); Hunt, 0.0% (0/80); and OD, 10.0% (8/80). In all cases, the discrepancy presented as a positive C-test result and negative vHIT result. The ELS ratio was measured for the whole inner ear, cochlea, vestibule, and semicircular canal, and the relationships between the rates and the presence of discrepancy was examined. Inner ear ELS ratio was 17.9% ± 10.8% in patients with the discrepancy and 15.2% ± 8.8% in those without the discrepancy (p = 0.036). Cochlear ELS ratio was 14.9% ± 11.3% in patients with the discrepancy and 11.9% ± 10.3% in those without the discrepancy (p = 0.0012). Vestibular ELS ratio was 22.3% ± 16.2% in patients with the discrepancy and 17.2% ± 12.7% in those without the discrepancy (p = 0.032). Semicircular canal ELS ratio was 18.0% ± 11.0% in patients with the discrepancy and 16.5% ± 9.6% in those without the discrepancy (p = 0.442). CONCLUSION: The volume of the ELS may affect the discrepancy of results between the C-test and vHIT.

Magnetic resonance imaging of the endolymphatic space in patients with benign paroxysmal positional vertigo: volume ratio and distribution rate of the endolymphatic space.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is the most common peripheral vestibular disease. It is characterised by sudden onset short lived vertigo triggered by sudden changes in head position relative to gravity. AIMS/OBJECTIVES: We aimed to perform a quantitative volumetric analysis of the inner ear endolymphatic space in patients with BPPV. MATERIAL AND METHODS: This study included 67 patients with BPPV and 50 control subjects (CS). The endolymphatic space/total fluid space volume ratio (%) and the distribution rate of the inner ear components in the endolymphatic space (%) were measured using three-dimensional magnetic resonance imaging. RESULTS: Differences in the endolymphatic space/total fluid space volume ratio of the inner ear, cochlea, vestibule, and semi-circular canals (SCCs) between the CS and BPPV groups were not significant. The endolymphatic space distribution rate of the vestibule in the BPPV group was significantly lower than that in the CS group, and the endolymphatic space distribution rate of SCCs in the BPPV group was significantly higher than that in the CS group. CONCLUSIONS AND SIGNIFICANCE: Extended endolymphatic space in patients with BPPV did not exist. The otoconia released from the damaged utricles were considered to move with the endolymphatic flow toward SCCs.

Investigation of endolymphatic hydrops positivity rates in patients with recurrent audiovestibular symptoms using inner ear magnetic resonance imaging.

OBJECTIVES: This study aimed to investigate the endolymphatic hydrops (EH)-positivity rates among patients with recurrent audiovestibular symptoms using intravenous injection of gadolinium-enhanced inner ear magnetic resonance imaging (ieMRI). METHODS: We reviewed 710 successive patients with recurrent audiovestibular symptoms at the Vertigo/Dizziness Center of Nara Medical University and other related hospitals, between May 2014 and April 2020. We performed ieMRI on 153 patients with unilateral recurrent cochleovestibular symptoms (rCV), 51 with recurrent vertigo symptoms (rVO), and 84 with unilateral recurrent cochlear symptoms (rCO). RESULTS: EH was observed in 69.4% of the participants: 81.7% in the rCV group, 19.6% in the rVO group, and 77.4% in the rCO group. The participants were divided into two groups according to the disease duration: short-duration and long-duration groups. In the short-duration group (less than 4 years), EH was observed in 82.3%, 42.9%, and 71.4% of the patients in rCV, rVO, and rCO groups, respectively; in the long-duration group (more than 5 years), EH was observed in 81.1%, 10.8%, and 81.6% of the patients in rCV, rVO, and rCO groups, respectively. CONCLUSIONS: The longer the duration of the disease, the larger the EH-positivity rates in patients with rCO, smaller in those with rVO, and unchanged in those with rCV. Although ieMRI could not detect EH with 100% accuracy in Ménière's disease, the present pathological statistics of patients with recurrent audiovestibular symptoms might be helpful in considering the pathology-based treatment strategy.

Left parietal involvement in motion sickness susceptibility revealed by multimodal magnetic resonance imaging.

Susceptibility to motion sickness varies greatly across individuals. However, the neural mechanisms underlying this susceptibility remain largely unclear. To address this gap, the current study aimed to identify the neural correlates of motion sickness susceptibility using multimodal MRI. First, we compared resting-state functional connectivity between healthy individuals who were highly susceptible to motion sickness (N = 36) and age/sex-matched controls who showed low susceptibility (N = 36). Seed-based analysis revealed between-group differences in functional connectivity of core vestibular regions in the left posterior Sylvian fissure. A data-driven approach using intrinsic connectivity contrast found greater network centrality of the left intraparietal sulcus in high- rather than in low-susceptible individuals. Moreover, exploratory structural connectivity analysis uncovered an association between motion sickness susceptibility and white matter integrity in the left inferior fronto-occipital fasciculus. Taken together, our data indicate left parietal involvement in motion sickness susceptibility.

Bilateral Asymmetry in Ocular Counter-Rolling Reflex Is Associated With Individual Motion Sickness Susceptibility.

Accumulating evidence suggests that individual variations in vestibular functions are associated with motion sickness (MS) susceptibility. We investigated whether vestibular functions in the reflex and cortical pathways could predict the susceptibility of individuals to MS. MS-susceptible and control adults were recruited according to the Motion Sickness Susceptibility Questionnaire (MSSQ) score. Otolith reflex and cortical functions were assessed using the ocular counter rolling test and the head-tilt subjective visual vertical (HT-SVV) test, respectively. The bilateral asymmetry of each function was compared between the MS-susceptible and the control groups. Although the two tests for otolith functions were conducted using the same stimulation (lateral head tilt), bilateral asymmetry of otolith reflex rather than cortical function was significantly associated with MS susceptibility. Our data suggests that bilateral asymmetry in the otolith reflex pathway is capable of predicting susceptibility to MS to some extent. Our data also suggest that the association between vestibular function and MS susceptibility can vary based on the vehicle types. Future vehicles, such as self-driving cars, will make us aware of other vestibular functions associated with MS susceptibility.

Posturographic Findings in Patients With Psychological Dizziness.

BACKGROUND: The diagnosis and treatment of patients with psychogenic vertigo (PSY) is difficult because of the lack of reliable objective findings for this condition. We examined the characteristics of foam posturography in patients with peripheral vestibular disorders (PVD) and those with PSY. In particular, we focused on the objective findings of foam posturography in PSY. METHODS: Between January 2010 and December 2011, 2-legged stance tasks were conducted in patients with vertigo/dizziness under 4 conditions: eyes opened with/without foam rubber and eyes closed with/without foam rubber. In terms of the velocity of movement of the center of pressure, we examined Romberg ratios, that is, the ratios of changes in visual conditions under the fixed foam rubber conditions, and foam rubber ratios, that is, the ratios of changes in foam rubber conditions under fixed visual conditions. These ratios were compared among 3 groups: healthy controls (CONT) (n=195), PVD (n=178), and PSY (n=32). RESULTS: Romberg ratios using foam rubber in the PVD group were significantly higher than those in the CONT group. Those in the PSY group were significantly lower. Likewise, the foam rubber ratios in the PVD group were significantly higher than those in the CONT group when the eyes were closed. Those in the PSY group were significantly lower. CONCLUSION: Judging from scores in Romberg ratios using foam rubber and foam rubber ratios when eyes were closed, foam posturography might have the potential to differentiate PSY from PVD.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: volume ratio and distribution rate of the endolymphatic space.

BACKGROUND: Endolymphatic hydrops (ELH), which is a pathological feature of Meniere's disease (MD), is characterized by an extended endolymphatic space (ELS). AIMS/OBJECTIVES: We aimed to perform a quantitative volumetric analysis of inner-ear ELH in patients with unilateral MD (uMD). MATERIAL AND METHODS: This study included 97 patients with definite uMD and 49 control subjects (CS). The ELS/total fluid space (TFS) volume ratio (%) and the distribution rate of the inner-ear components in the ELS (%) were measured using 3D magnetic resonance imaging and compared between patients with uMD and CS. RESULTS: Compared to CS, patients with uMD had significantly higher mean ELS/TFS volume ratios for inner-ear components. The mean distribution rate of the inner-ear components in the ELS was not significantly different between the two groups. CONCLUSIONS AND SIGNIFICANCE: In patients with uMD, ELH was noted to be spread throughout the entire inner ear and the endolymph was evenly distributed in the total ELS. These findings should be useful as a standard reference for further research.

Vestibular Morphological Asymmetry Associated With Motion Sickness Susceptibility.

Sensory conflicts leading to motion sickness can occur not only between but also within sensory modalities. The vestibular organs are located in both left and right inner ears, and their misalignment can be a source of self-motion related sensory conflicts. In the current study, using inner ear magnetic resonance imaging, we examined whether morphological asymmetry of the bilateral vestibular organs was associated with motion sickness susceptibility. The results showed a larger position asymmetry of bilateral vestibular organs in individuals with high rather than low susceptibility. In addition, vestibular position asymmetry was associated with reciprocal interaction (negative resting state functional connectivity) between vestibular and visuocortical regions in lowly, but not highly, susceptible individuals. In conclusion, these findings suggest that vestibular morphological asymmetry can be a source of sensory conflicts in individuals with dysfunctional reciprocal visuo-vestibular interactions, a putative neural mechanism for resolving sensory conflicts.

Endolymphatic Sac Drainage Surgery and Plasma Stress Hormone Vasopressin Levels in Meniere's Disease.

Meniere's disease is a common inner ear disorder accompanied by vertigo attacks and fluctuating hearing loss that some believe is due to a stressful lifestyle. To elucidate the scientific relationship in neuro-endocrinology between Meniere's disease and stress, we examined the surgical results of endolymphatic sac drainage surgery and changes in stress-induced plasma arginine-vasopressin levels. We enrolled 100 intractable Meniere's patients and examined surgical results and plasma vasopressin levels. Fifty-four chronic otitis media patients who underwent tympano-mastoidectomy formed a control group. We assessed surgical results during a 2-year follow-up period, including vertigo and hearing loss. We examined plasma vasopressin levels just before surgery and 1 week, 1 year, and 2 years after surgery. In patients with intractable Meniere's disease, plasma vasopressin levels were significantly reduced 1 week after surgery compared to the decrease observed in chronic otitis media patients after tympano-mastoidectomy. In intractable Meniere's disease, long-lasting low plasma vasopressin levels after surgery were associated with significantly good surgical results. In recurrent Meniere's disease, a gradual plasma vasopressin level elevation was observed after surgery, followed by recurrent vertigo attacks and sensorineural hearing loss. It is suggested that long-lasting high levels of plasma vasopressin could have adverse effects on inner ear water metabolism and the subsequent Meniere's disease symptoms. Effective treatments for Meniere's disease might be best based on the maintenance of low plasma vasopressin levels.

Novel Magnetic Resonance Imaging-Based Method for Accurate Diagnosis of Meniere's Disease.

Background: Pathologically, Meniere's disease symptoms are considered to be associated with endolymphatic hydrops. Examinations revealing endolymphatic hydrops can be useful for accurate Meniere's disease diagnosis. We previously reported a quantitative method for evaluating endolymphatic hydrops, i.e., by measuring the volume of the endolymphatic space using three-dimensional magnetic resonance imaging (MRI) of the inner ear. This study aimed to confirm the usefulness of our methods for diagnosing Meniere's disease. Here, we extracted new explanatory factors for diagnosing Meniere's disease by comparing the volume of the endolymphatic space between healthy volunteers and patients with Meniere's disease. Additionally, we validated our method by comparing its diagnostic accuracy with that of the conventional method. Methods and Findings: This is a prospective diagnostic accuracy study performed at vertigo/dizziness centre of our university hospital, a tertiary hospital. Eighty-six patients with definite unilateral Meniere's disease and 47 healthy volunteers (25 and 33 males, and 22 and 53 females in the control and patient groups, respectively) were enrolled. All participants underwent 3-Tesla MRI 4 h after intravenous injection of gadolinium to reveal the endolymphatic space. The volume of the endolymphatic space was measured and a model for Meniere's disease diagnosis was constructed and compared with models using conventional criteria to confirm the effectiveness of the methods used. The area under the receiver operating characteristic curve of the method proposed in this study was excellent (0.924), and significantly higher than that derived using the conventional criteria (0.877). The four indices, sensitivity, specificity, positive predictive value, and negative predictive value, were given at the threshold; all of these indices achieved higher scores for the 3D model compared to the 2D model. Cross-validation of the models revealed that the improvement was due to the incorporation of the semi-circular canals. Conclusions: Our method showed high diagnostic accuracy for Meniere's disease. Additionally, we revealed the importance of observing the semi-circular canals for Meniere's disease diagnosis. The proposed method can contribute toward providing effective symptomatic relief in Meniere's disease.

Essential roles of plexin-B3+ oligodendrocyte precursor cells in the pathogenesis of Alzheimer's disease.

The role of oligodendrocyte lineage cells, the largest glial population in the adult central nervous system (CNS), in the pathogenesis of Alzheimer's disease (AD) remains elusive. Here, we developed a culture method for adult oligodendrocyte progenitor cells (aOPCs). Fibroblast growth factor 2 (FGF2) promotes survival and proliferation of NG2+ aOPCs in a serum-free defined medium; a subpopulation (~5%) of plexin-B3+ aOPCs was also found. FGF2 withdrawal decreased NG2+, but increased plexin-B3+ aOPCs and Aß1-42 secretion. Plexin-B3+ aOPCs were distributed throughout the adult rat brain, although less densely than NG2+ aOPCs. Spreading depolarization induced delayed cortical plexin-B3+ aOPC gliosis in the ipsilateral remote cortex. Furthermore, extracellular Aß1-42 accumulation was occasionally found around plexin-B3+ aOPCs near the lesions. In AD brains, virtually all cortical SPs were immunostained for plexin-B3, and plexin-B3 levels increased significantly in the Sarkosyl-soluble fractions. These findings suggest that plexin-B3+ aOPCs may play essential roles in AD pathogenesis, as natural Aß-secreting cells.

Magnetic resonance imaging of endolymphatic hydrops in patients with unilateral Meniere's disease: a comparison between with and without herniation into the posterior and lateral semi-circular canals.

BACKGROUND: The presence of endolymphatic hydrops (ELH) in patients with Meniere's disease (MD) is considered a pathological hallmark. AIMS/OBJECTIVES: We aimed to conduct a quantitative volumetric measurement of inner ear ELH in patients with unilateral MD (uMD). The values of uMD with and without herniation into the posterior semi-circular canal (h-PSC) and the lateral semi-circular canal (h-LSC) were compared using 3 D magnetic resonance imaging. MATERIAL AND METHODS: This study included 130 individuals (47 controls and 83 patients with uMD). We measured the total fluid space (TFS) and endolymphatic space (ELS) volumes. We also evaluated the ELS/TFS volume ratios (%). RESULTS: The ELS/TFS volume ratios in the inner ear, cochlea, and vestibule were significantly different between the affected and contralateral sides in patients with h-PSC. Moreover, the ELS/TFS volume ratios of the inner ear, vestibule, and semi-circular canals in the affected ear were significantly higher in patients with h-PSC than in those without h-PSC. The vestibular ELS/TFS volume ratio in the affected ear was significantly higher in patients with h-LSC than in those without h-LSC. CONCLUSIONS AND SIGNIFICANCE: H-LSC is present in extended vestibular ELH. However, this is a result of ELH progression in the inner ear.

Effects of Vestibular Rehabilitation on Physical Activity and Subjective Dizziness in Patients With Chronic Peripheral Vestibular Disorders: A Six-Month Randomized Trial.

Introduction: The present study aimed to determine whether supervised vestibular rehabilitation therapy (VRT) by physical therapists (PTs) affects subjective dizziness in patients with chronic vestibular disorders, and whether supervised VRT-induced changes in subjective dizziness are related to the changes in physical activity levels in daily life. Methods: Patients (n = 47) with chronic peripheral vestibular disorders were randomly divided into the VRT group (n = 25) and control group (n = 22). Patients in the VRT group received weekly supervised visits from PTs for a period of 6 months. Every other month, both groups were advised by neuro-otologists to increase the amount of activity in their daily life. All patients wore an accelerometer device, which recorded their physical activity for seven successive days before the end of the intervention. Patients also completed the dizziness and unsteadiness questionnaires before and after the intervention. Results: Subjective dizziness decreased significantly regardless of whether supervised VRT was administered; however, dizziness evoked by social activity and head and body movements improved more significantly in the VRT group than in the control group. In the VRT group, there was a significant negative correlation between the increase in sedentary behavior and improvement in subjective dizziness, and a significant positive correlation between the increase in light physical activity and improvement in subjective dizziness at the second month of intervention. The VRT group showed a significantly higher rate of increase in light physical activity than the control group, after 6 months of intervention. Conclusion: Supervised VRT could be highly effective in treating subjective dizziness in patients with chronic peripheral vestibular disorders. We believe frequent (weekly) and medium-term (6 months) PT-guided interventions may be highly effective in enhancing physical activity in daily life, and may subsequently improve subjective dizziness in these patients. Trial registration: This clinical study was registered with University hospital Medical Information Network (identification number: 000028832). https://www.umin.ac.jp/.

Changes in the Results of the Subjective Visual Vertical Test After Endolymphatic Sac Drainage for Intractable Meniere's Disease.

OBJECTIVE: To investigate otolithic function before and after endolymphatic sac drainage (ELSD) for Meniere's disease (MD) by using the subjective visual vertical test (SVV) in the upright and tilted positions. METHODS: Eighteen patients with definite unilateral MD diagnosed in accordance with the American Academy of Otolaryngology Head and Neck Surgery criteria in 1995 and Barany Society criteria in 2015 were included. SVV in the upright position and the head-tilt position was performed preoperatively and on postoperative days 1, 5, 8, 28, and 112. Changes in the results of SVV in the upright position (UP-SVV) and head-tilt perception gain (HTPG) after surgery were measured. RESULTS: The average UP-SVV values significantly changed from 0.05° by the affected side before surgery to 2.5° by the unaffected side on the fifth postoperative day, followed by recovery to the normal range by the eighth postoperative day. The HTPG values for the unaffected side showed the maximum increase on postoperative day 5 during the present study period, although the values in the affected side did not alter significantly. CONCLUSION: ELSD for MD is a surgical treatment that involves less risk of otolith function damage and abnormalities in gravitational cognition. SVV in the head-tilt position could be one of the neuro-otologic examinations used to easily understand the vestibular compensatory process.

Magnetic Resonance 3D Measurement of the Endolymphatic Space in 100 Control Human Subjects.

Three Dimensional-magnetic resonance imaging of the inner ear endolymphatic space was performed in 100 control human subjects. Ear endolymphatic space was visualized using contrast-enhanced magnetic resonance imaging with intravenous gadolinium injection. The images were acquired on a 3-tesla magnetic resonance scanner using a 32-channel array head coil for all patients. The ear endolymphatic space and total fluid space volumes of the inner ear, cochlea, and vestibule were measured, and the ear endolymphatic space in the cochlea and vestibule was classified into four categories. The cochlea categories were: c-1, no ear endolymphatic space; c-2, ear endolymphatic space visualized only until the upper turn; c-3, ear endolymphatic space visualized from the upper turn to the second turn; and c-4, ear endolymphatic space visualized up to the basal turn. The vestibule categories were: v-1, no ear endolymphatic space; v-2, ear endolymphatic space visualized only in the utriculus; v-3, ear endolymphatic space visualized in the utriculus and sacculus separately; and v-4, ear endolymphatic space visualized in the utriculus and sacculus together. The mean TFS volumes of the inner ear, cochlea, and vestibule were 282.1 ± 33.2 µL, 112.9 ± 15.9 µL, and 69.1 ± 9.9 µL, respectively, and that of the ampulla of the posterior semicircular canal was 7.8 ± 1.7 µL. The mean ear endolymphatic space/total fluid space volume ratio in the cochlea was 10.3 ± 6.7% and that in the vestibule was 17.3 ± 12.2%. This ratio in the cochlea was between the results of categories c-1 and c-2 and that in the vestibule between those of categories v-2 and v-3. Two subjects had ear endolymphatic space extending from the vestibule to the posterior non-ampullated crus of the lateral semicircular canal. These findings can be applied as standard reference values for further research.

Patients with vertigo/dizziness of unknown origin during follow-ups by general otolaryngologists at outpatient town clinic.

OBJECTIVES: The purpose of this study was to access the contribution of vertigo/dizziness-related patients' interview and examinations during short-term hospitalization in determining the accurate final diagnosis of vertigo/dizziness of unknown origin. METHODS: We reviewed 1905 successive vertigo/dizziness patients at the Vertigo/Dizziness Center of Nara Medical University, who were introduced from general otolaryngologists at outpatient town clinic from May 2014 to April 2020. However, 244 patients were diagnosed with vertigo/dizziness of unknown origin (244/1905; 12.8%). Of these patients, 240 were hospitalized and underwent various examinations, including caloric test (C-test), video head impulse test (vHIT), vestibular evoked cervical myogenic potentials (cVEMP), subjective visual vertical (SVV), inner ear magnetic resonance imaging (ieMRI), Schellong test (S-test), and self-rating questionnaires of depression score (SDS). RESULTS: According to the examination data, together with interviewed vertigo/dizziness characteristics and daily changeable nystagmus findings, the final diagnoses were as follows: benign paroxysmal positional vertigo (BPPV: 107/240; 44.6%), orthostatic dysregulation (OD: 56/240; 23.3%), vestibular peripheral disease (VPD: 25/240; 10.4%), vestibular migraine (VM: 14/240; 5.8%), Meniere's disease (MD: 12/240; 5.0%), gravity perception disturbance (GPD: 10/240; 4.2%), psychogenic vertigo (Psycho: 10/240; 4.2%), and unknown (Unknown: 6/240; 2.5%). Supporting factors of final diagnosis was seen in gender, evoked dizziness, and positional nystagmus as BPPV; in evoked dizziness, S-test, and hypertension as OD; in evoked dizziness, head shaking after nystagmus, C-test, and vHIT as VPD; in gender, headache, and S-test as VM; in ear fullness and ieMRI as MD; in gender, evoked dizziness, and SVV as GPD; and in SDS as Psycho. To sum up, the ratios of Unknown were significantly reduced by this short-term hospitalization (244/1905→6/240). CONCLUSIONS: The answer lists for vertigo/dizziness of unknown origin obtained in the present study may be helpful for future general otolaryngologists at outpatient town clinic to better attain an accurate final diagnosis.

What diagnosis should we make for long-lasting vertiginous sensation after acute peripheral vertigo?

BACKGROUND: Differential diagnosis of persistent vertigo/dizziness in patients with a past history of vestibular neuritis (VN) and sudden deafness with vertigo (SDV) could sometimes be difficult for physicians due to variable vertiginous symptoms from rotatory to floating sensation. OBJECTIVES: The main purpose of the present study was to examine the associations between the findings of otology/neurotology examinations in patients at the chronic stage after VN and SDV. MATERIAL AND METHODS: We encountered 1789 successive vertigo/dizziness patients at the Vertigo/Dizziness Center in Nara Medical University between 2014 and 2018. Eighty-five patients were diagnosed as showing VN and 60 showed SDV according to the diagnostic guideline . The VN and SDV patients included 75 and 45 patients with chronic-stage of persistent vertigo/dizziness, of which 55 and 40 were enrolled into the present study. RESULTS: Persistent vertigo/dizziness after VN was attributable to delayed vestibular compensation (dVC: 33/55; 60.0%), secondary benign paroxysmal positional vertigo (sBPPV: 20/55; 36.4%), and secondary endolymphatic hydrops (sEH: 2/55; 3.6%), while that after SDV was attributable to sBPPV (20/40; 50.0%), sEH (16/40; 40.0%), and dVC (4/40; 10.0%). CONCLUSION AND SIGNIFICANCE: The present results could allow to simplify differential diagnosis of persistent vertigo/dizziness after VN and SDV such diseases as dVC, sBPPV, or sEH.

Comparison of the video head impulse test results with caloric test in patients with Meniere's disease and other vestibular disorders.

Background: The caloric test has been used to evaluate the semi-circular canal function for decades. In 2009, the video head impulse test (vHIT) was introduced, which can be used to evaluate the semi-circular canal function within a short time. Although both tests examine the semi-circular canal, the stimulation methods differ and it is unclear whether the vHIT is equivocal to the caloric test.Aims/objectives: This study aimed to discern the differences between the vHIT and caloric test.Material and methods: This study comprised 112 patients with vertigo who visited the vertigo/dizziness centre at our university hospital. Each of these patients underwent a caloric test and vHIT within the same day, and their results were compared. Additionally, an electrocochleography (EcoG) examination, glycerol test (G test), and MRI (performed 4 h after an intravenous gadolinium injection) were conducted to evaluate the influence of endolymphatic hydrops (EH) on the caloric test and vHIT results.Results: Differences in the caloric test and vHIT results, among those with and without EH, were observed in 66.7 and 35.3% of patients, respectively.Conclusions and significance: EH resulted in a difference in results between the caloric test and vHIT. Activated hair cell type may also be implicated.