Discrepancies of video head impulse test results in patients with idiopathic sudden sensorineural hearing loss with vertigo and vestibular neuritis.

Objective: Sudden sensorineural hearing loss with vertigo (SHLV) and vestibular neuritis (VN) remain frequent causes of acute vestibular syndrome (AVS). The aim of study was to compare the results of video head impulse test (vHIT) in patients with SHLV and VN. The characteristics of high-frequency vestibule-ocular reflex (VOR) and the differences of the pathophysiological mechanisms underlying these two AVS were explored. Methods: Fifty-seven SHLV patients and 31 VN patients were enrolled. vHIT was conducted at the initial presentation. The VOR gains and occurrence of corrective saccades (CSs) of anterior, horizontal, and posterior semicircular canals (SCCs) in two groups were analyzed. Pathological vHIT results refer to impaired VOR gains and presence of CSs. Results: In SHLV group, pathological vHIT results was most prevalent in the posterior SCC on the affected side (30/57, 52.63%), followed by horizontal (12/57, 21.05%) and anterior SCC (3/57, 5.26%). In VN group, pathological vHIT preferentially affected horizontal SCC (24/31, 77.42%), followed by anterior (10/31, 32.26%) and posterior SCC (9/31, 29.03%) on the affected side. As for anterior and horizontal SCC on the affected side, the incidences of pathological vHIT results in VN group were significantly higher than those in SHLV group (ß = 2.905, p < 0.01; ß = 2.183, p < 0.001). There were no significant differences in the incidence of pathological vHIT result in posterior SCC between two groups. Conclusion: Comparison of vHIT results in patients with SHLV and VN revealed discrepancies in the pattern of SCCs impairments, which may be explained by different pathophysiological mechanisms underlying these two vestibular disorders presenting as AVS.

Comparison between audio-vestibular findings and contrast-enhanced MRI of inner ear in patients with unilateral Ménière's disease.

Objective: The diagnosis of Ménière's disease (MD), characterized by idiopathic endolymphatic hydrops (ELH), remains a clinical priority. Many ancillary methods, including the auditory and vestibular assessments, have been developed to identify ELH. The newly emerging delayed magnetic resonance imaging (MRI) of the inner ear after intratympanic gadolinium (Gd) has been used for identifying ELH in vivo. We aimed to investigate the concordance of audio-vestibular and radiological findings in patients with unilateral MD. Methods: In this retrospective study, 70 patients with unilateral definite MD underwent three-dimensional fluid-attenuated inversion recovery (3D-FLAIR) sequences following intratympanic application of Gd. Audio-vestibular evaluations were performed, including pure tone audiometry, electrocochleogram (ECochG), glycerol test, caloric test, cervical and ocular vestibular evoked myogenic potentials (VEMPs), and video head impulse test (vHIT). The relationship between imaging signs of ELH and audio-vestibular results was investigated. Results: The incidence of radiological ELH was higher than that of neurotological results, including the glycerol test, caloric test, VEMPs, and vHIT. Poor or slight agreement was observed between audio-vestibular findings and radiological ELH in cochlear and/or vestibular (kappa values <0.4). However, the pure tone average (PTA) in the affected side significantly correlated with the extent of both cochlear (r = 0.26795, p = 0.0249) and vestibular (r = 0.2728, p = 0.0223) hydrops. Furthermore, the degree of vestibular hydrops was also positively correlated with course duration (r = 0.2592, p = 0.0303) and glycerol test results (r = 0.3944, p = 0.0061) in the affected side. Conclusion: In the diagnosis of MD, contrast-enhanced MRI of the inner ear is advantageous in detecting ELH over the conventional audio-vestibular evaluations, which estimates more than hydropic dilation of endolymphatic space.

Radiological presence of vascular loops in the cerebellopontine angle region in patients with unilateral Ménière's disease.

OBJECTIVE: The relationship between vascular compression of the vestibulocochlear nerve and audio-vestibular symptoms remains controversial. We aimed to examine the radiological features of vascular loops signs in cerebellopontine angle (CPA) and internal auditory canal (IAC) in patients with unilateral Ménière's disease (MD). METHODS: One hundred and thirty-seven patients with unilateral definite MD and 69 control subjects (138 ears) were enrolled. All subjects received magnetic resonance imaging of CPA-IAC. The configuration of vascular loops in CPA-IAC, based on the Kazawa classification system, from MD-affected, non-affected and control ears were compared. The associations between imaging findings and Ménière's stage, electrocochleogram (EcochG) and caloric test were analyzed. RESULTS: (1) Among the MD-affected ears, 6 cases (4.4%) were classified as Kazawa type IA, 27 cases (19.7%) as IB, 60 cases (43.8%) as IIA, and 44 cases (32.1%) as IIB. No significant interaural difference in the distribution of Kazawa's types was found ([Formula: see text] = 4.737, p = 0.578) in unilateral MD patients. (2) The distribution of Kazawa's types were not significantly different between the MD-affected ears and the control subjects ([Formula: see text] = 2.876, p = 0.411). (3) No relationship was found between Kazawa staging of the MD-affected ear and Ménière's stage (H = 2.679, p = 0.444), EcochG ([Formula: see text] = 0.827, p = 0.867) and caloric test ([Formula: see text] = 4.116, p = 0.248). CONCLUSIONS: In patients with unilateral MD, the configuration of vascular loops in CPA-IAC region, measured by Kazawa criteria, did not correlate with the laterality, clinical stage, the results of EcochG and caloric test, suggesting that vascular loops may be natural anatomical variations for patients with MD.

Video Head Impulse Test Findings in Patients With Benign Paroxysmal Positional Vertigo Secondary to Idiopathic Sudden Sensorineural Hearing Loss.

Benign paroxysmal positional vertigo (BPPV) is amongst the most common causes of episodic vestibular syndrome. It can be classified as idiopathic and secondary types according to the causative factors, and the underlying mechanism between idiopathic (i-BPPV) and secondary BPPV (s-BPPV) may differ. Idiopathic sudden sensorineural hearing loss (ISSNHL) has been considered as a common inner ear disease that precipitates s-BPPV. Yet, few studies have addressed the functional impairment of the semicircular canal (SCC) system in patients with s-BPPV associated with ISSNHL. Our purpose was to explore the pathophysiological mechanism and investigate the clinical implications of video head impulse test (vHIT) in these patients. Here, the clinical and laboratory data of patients with BPPV secondary to ISSNHL, including the results of vHIT, were retrospectively reviewed, and compared with those of patients with i-BPPV. Pathological vHIT findings (low vestibulo-ocular reflex gain and re-fixation saccade), which mainly affected the posterior SCC, were more common in the s-BPPV group than in the i-BPPV group (41.9 and 0%, respectively). The incidence of horizontal SCC involvement was also higher in the s-BPPV group (45.16 and 16.67%, respectively). Furthermore, patients with s-BPPV showed lower vHIT gains of the posterior and horizontal SCCs in affected ears than in unaffected ears. Compared to i-BPPV, posterior SCC paresis detected by vHIT is more prevalent in BPPV secondary to ISSNHL. This dysfunction may be associated mainly with vestibular impairments caused by ISSNHL, and not with BPPV per se.

Anatomical variation of inner ear may be a predisposing factor for unilateral Ménière's disease rather than for ipsilateral delayed endolymphatic hydrops.

OBJECTIVE: Radiological anatomical variations, measured by magnetic resonance imaging (MRI), were evaluated in patients with ipsilateral delayed endolymphatic hydrops (DEH) and unilateral Ménière's disease (MD). The role of anatomical variations in different subtypes of hydropic ear disease was investigated. METHODS: Twenty-eight patients with ipsilateral DEH, 76 patients with unilateral MD, and 59 control subjects were enrolled. The radiological indices included the distance between the vertical part of the posterior semicircular canal and the posterior fossa (MRI-PP distance) and the visibility of vestibular aqueduct (MRI-VA). These variations among patients with DEH, MD, and control subjects were compared. The correlation between radiological anatomical variations and clinical features or audio-vestibular findings was also examined. RESULTS: (1) MRI-PP distance in the affected side of unilateral MD was shorter than that in ipsilateral DEH (Z = - 2.481, p = 0.013) and control subjects (Z = - 2.983, p = 0.003), while the difference of MRI-PP distance between the affected side of ipsilateral DEH and control subjects was not statistically significant (Z = - 0.859, p = 0.391). (2) There was no significant interaural difference of MRI-PP distance in patients with unilateral MD (Z = - 0.041, p = 0.968) and ipsilateral DEH (t = - 0.107, p = 0.915) respectively. (3) No significant interaural difference of MRI-VA visibility was observed in patients with unilateral MD (χ2 = 0.742, p = 0.389) and ipsilateral DEH (χ2 = 0.327, p = 0.567) respectively. (4) No correlation was found between these anatomical variables and clinical features or audio-vestibular findings in patients with unilateral MD and ipsilateral DEH respectively (p > 0.05). CONCLUSIONS: Anatomical variations of inner ear may be a predisposing factor in the pathogenesis of unilateral MD rather than ipsilateral DEH. KEY POINTS: • Patients with ipsilateral delayed endolymphatic hydrops showed normal distance between the vertical part of the posterior semicircular canal and the posterior fossa. • Compared to patients with ipsilateral delayed endolymphatic hydrops and control subjects, patients with unilateral Ménière's disease exhibited shorter distance between the vertical part of the posterior semicircular canal and the posterior fossa. • Anatomical variations of inner ear may be a predisposing factor in the pathogenesis of unilateral Ménière's disease rather than ipsilateral delayed endolymphatic hydrops.

[The relationship between vestibular function and gait parameters in vestibular dysfunctional patients with idiopathic sudden sensorineural hearing loss].

Objective:Based on the application of vHIT, cVEMP test and oVEMP test to locate the peripheral vestibular lesions, we aimed to explore the relationship between vestibular function（semicircular canal and otolith function） and gait parameters in vestibular dysfunctional patients with idiopathic sudden sensorineural hearing loss（ISSNHL）. Methods:In this study, 23 ISSNHL patients（including 14 patients with vertigo） were enrolled. All patients underwent audiometry, Walk Across, vHIT, cVEMP test and oVEMP test. Results:Vestibular otolith function was significantly associated with gait parameters. Semicircular canal function was not associated with any gait parameter. Conclusion:Reduced otolith function was associated with slower and wider steps in patients with ISSNHL. These results indicate that vestibular signals may contribute to specific aspects of gait.

Vestibulo-ocular reflex tests may reflect unilateral Ménière disease progression: A cross-sectional study.

ABSTRACT: Vestibular disorders can manifest several patterns of horizontal vestibulo-ocular reflex (VOR) impairment, which can be detected by caloric test and video head impulse test (vHIT). Several studies have examined the patterns of caloric-vHIT response in Ménière disease (MD). The purpose of this study was to investigate the diversity of caloric-vHIT response and its related factors in unilateral MD patients. We also explore the possibility of assessing the progression of unilateral MD by using the horizontal VOR tests.Ninety-eight patients with unilateral MD were enrolled and underwent a battery of audio-vestibular evaluations, including the pure tone audiogram, caloric test, and horizontal vHIT. Some patients received the electrocochleography and glycerol test. The combined results of caloric test and horizontal vHIT were categorized qualitatively into 4 patterns: Pattern I: normal caloric and vHIT responses; Pattern II: abnormal caloric and normal vHIT responses; Pattern III: normal caloric and abnormal vHIT response; and Pattern IV: abnormal caloric and vHIT responses. The abnormal caloric results were semi-quantitatively subdivided into sub-patterns as mild, moderate, and severe abnormality. The associations between these patterns/sub-patterns and related factors were analyzed.Pattern I was found in 35 cases (35.7%), Pattern II in 57 (58.2%), and Pattern IV in 6 (6.1%). No patient had Pattern III. No significant differences were found between the patterns/sub-pattern distribution and age, electrocochleography, and glycerol test results. Disease duration was not associated with the pattern distribution, while remained a relation with sub-pattern distribution. The pattern/sub-pattern distribution varied significantly across MD stages. The proportion of pattern II or pattern IV increased with the stage of unilateral MD.MD can manifest several patterns of horizontal VOR impairment, of which the impaired caloric response with normal vHIT is the most common pattern. With the progression of unilateral MD, the caloric-vHIT pattern tends to shift, which may reflect the deterioration of endolymphatic hydrops and vestibular hair cells impairments.

[Clinical analysis of idiopathic bilateral vestibulopathy].

Objective:To improve the level of clinical diagnosis and treatment of idiopathic bilateral vestibulopathy（IBV） by investigating the clinical characteristics of this disease. Method:Retrospective analysis was performed on patients with IBV diagnosed, excluding patients with clear primary factors, and including IBV patients with unknown causes, to analyze their clinical symptoms and vestibular function examination results. Result:In this group of cases, three cases were in line with the diagnosis of IBV. The clinical manifestations included imbalance, oscillopsia, and normal hearing level, which cannot be explained by other diseases. The vestibular function testing of the patients with IBV showed bilateral reduced response in caloric tests, positive response in video head impulse test, and decreased score in sensory organization test. Vestibular rehabilitation therapy were carried for these patients, and could improve the patients' symptoms. Conclusion:IBV has typical clinical manifestations. Vestibular function testing indicates bilateral vestibular dysfunction. Other diseases with bilateral vestibulopathy should be excluded for diagnoses, and vestibular rehabilitation therapy is one of the appropriate treatments.

[Research on modelling vestibular rehabilitation decision based on machine learning].

Objective:To evaluate the effect of the support vector machine（SVM） and artificial neutral network（ANN） on the treatment choice of vestibular rehabilitation. Method:Total scores COMP and three ratios of sensory analysis: somatosensory（SOM）, visual（VIS）, vestibular（VEST） from the sensory organization test（SOT）, and physical score（DHI-P）, emotional score（DHI-E）, functional score（DHI-F） from the dizziness handicap inventory（DHI） were chosen as input of SVM and ANN, rehabilitation program as output. According to the data source of the literatures, we constructed simulation database used as the sample set to conduct model training, and part of the clinical data was used to train the model accuracy. Result:After trainings, the accuracy rate of ANN model was 52.3%, and that of SVM model was 83.4%. The error mainly comes from the serious overlap of each score data interval under the three diagnostic schemes, which easily leads to the misclassification of boundary sample points, which is also a difficult problem to overcome in clinical diagnosis. Conclusion:Vestibular rehabilitation decision based SVM is more accurate than ANN. The use of machine learning to assist decision-making of vestibular rehabilitation scheme has important prospective reference significance in promoting clinical medical informatization and improving medical quality.

Foam pad of appropriate thickness can improve diagnostic value of foam posturography in detecting postural instability.

OBJECTIVE: The present study investigated the effect of foam thickness on postural stability in patients with unilateral vestibular hypofunction (UVH) during foam posturography. METHODS: Static and foam posturography were performed in 33 patients (UVH group) and 30 healthy subjects (control group) with eyes open (EO) and closed (EC) on firm surface and on 1-5 foam pad(s). Sway velocity (SV) of center of pressure, standing time before falling (STBF) and falls reaction were recorded and analyzed. RESULTS: (1) SVs had an increasing tendency in both groups as the foam pads were added under EO and EC conditions. (2) STBFs, only in UVH group with EC, decreased with foam thickness increasing. (3) Significant differences in SV were found between the control and UVH group with EO (except for standing on firm surface, on 1 and 2 foam pad(s)) and with EC (all surface conditions). (4) Receiver operating characteristic curve analysis showed that the SV could better reflect the difference in postural stability between the two groups while standing on the 4 foam pads with EC. CONCLUSION: Our study showed that diagnostic value of foam posturography in detecting postural instability might be enhanced by using foam pad of right thickness.

Sensory organization test principally reflects utricular function.

CONCLUSION: Our study showed that sensory organization test (SOT) could principally reflect utricular function, and our cut-score of VEST ratio (the indicator of inputs from the vestibular system in balance performance) in SOT could help to screen patients with unilateral peripheral vestibular dysfunction in non-fallers. OBJECTIVES: We aimed to know SOT reflects the function of which vestibular end organs and to assess the possibility of screening patients with peripheral vestibular dysfunction in non-fall population by means of SOT. METHODS: A total of 75 patients with unilateral peripheral vestibular dysfunction underwent SOT, ocular vestibular-evoked myogenic potential (oVEMP), cervical vestibular-evoked myogenic potential (cVEMP) and caloric tests. RESULTS: Regression model indicated that oVEMP, as an independent variable, exerted the greatest influence on VEST ratio, followed by age and cVEMP. There were no significant differences in VEST ratio among groups with different extents of peripheral vestibular involvement (p > .05). VEST ratio in the vestibular impairment groups was significantly lower than in the control group and significantly higher than in fall group (p < .01). VEST ratio in group with normal oVEMP was significantly higher than in group with abnormal oVEMP (p = .013). The cut-score between populations with functional and dysfunctional vestibule was 0.649.

Assessment of balance and vestibular functions in patients with idiopathic sudden sensorineural hearing loss.

This study investigated the relationship among the severity of hearing impairment, vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss (ISSNHL). A total of 35 ISSNHL patients (including 21 patients with vertigo) were enrolled. All of the patients underwent audiometry, sensory organization test (SOT), caloric test, cervical vestibular-evoked myogenic potential (cVEMP) test and ocular vestibular-evoked myogenic potential (oVEMP) test. Significant relationship was found between vertigo and hearing loss grade (P=0.009), and between SOT VEST grade and hearing loss grade (P=0.001). The abnormal rate of oVEMP test was the highest, followed by the abnormal rates of caloric and cVEMP tests, not only in patients with vertigo but also in those without vertigo. The vestibular end organs were more susceptible to damage in patients with vertigo (compared with patients without vertigo). Significant relationship was found between presence of vertigo and SOT VEST grade (P=0.010). We demonstrated that vestibular end organs may be impaired not only in patients with vertigo but also in patients without vertigo. The cochlear and vestibular impairment could be more serious in patients with vertigo than in those without vertigo. Vertigo does not necessarily bear a causal relationship with the impairment of the vestibular end organs. SOT VEST grade could be used to reflect the presence of vertigo state in the ISSNHL patients. Apart from audiometry, the function of peripheral vestibular end organs and balance function should be evaluated to comprehensively understand ISSNHL. Better assessment of the condition will help us in clinical diagnosis, treatment and prognosis evaluation of ISSNHL.

Repeated courses of intratympanic dexamethasone injection are effective for intractable Meniere's disease.

CONCLUSION: Intra-tympanic dexamethasone injection (ITD) could serve as a first-line intra-tympanic (IT) treatment for Meniere's disease (MD), regardless of hearing level. Even if the response to initial ITD course was unsatisfactory, a repeated course may be beneficial with some patients. OBJECTIVES: This study examined the effect of repeated courses of ITD administered on demand and investigated the possibility of ITD as an initial IT treatment for medically intractable MD patients. METHOD: Fifty-one patients who had been diagnosed with definite MD and given course(s) of ITD treatment were included. Vertigo control, pure tone average and functional disability scores were evaluated against the American Academy of Otolaryngology-Head and Neck Surgery guidelines for MD. RESULTS: Vertigo disappeared or was substantially controlled in 58.8% and 23.5% of the patients, respectively, after the first ITD course. A repeated course further raised the complete vertigo control rate by 15.7% and intra-tympanic gentamycin injection could be postponed or avoided in 78.6% of the patients who required repeated IT treatment. Hearing was unchanged after the first course of ITD (p > .05). No significant differences were detected in the clinical profiles or laboratory findings between patients receiving single course of ITD and those on multiple courses (p > .05).

Assessment of Balance and Vestibular Functions in Patients with Idiopathic Sudden Sensorineural Hearing Loss / 华中科技大学学报（医学）（英德文版）

This study investigated the relationship among the severity of hearing impairment,vestibular function and balance function in patients with idiopathic sudden sensorineural hearing loss (ISSNHL).A total of 35 ISSNHL patients (including 21 patients with vertigo) were enrolled.All of the patients underwent audiometry,sensory organization test (SOT),caloric test,cervical vestibular-evoked myogenic potential (cVEMP) test and ocular vestibular-evoked myogenic potential (oVEMP) test.Significant relationship was found between vertigo and hearing loss grade (P=0.009),and between SOT VEST grade and hearing loss grade (P=0.001).The abnormal rate of oVEMP test was the highest,followed by the abnormal rates of caloric and cVEMP tests,not only in patients with vertigo but also in those without vertigo.The vestibular end organs were more susceptible to damage in patients with vertigo (compared with patients without vertigo).Significant relationship was found between presence of vertigo and SOT VEST grade (P=0.010).We demonstrated that vestibular end organs may be impaired not only in patients with vertigo but also in patients without vertigo.The cochlear and vestibular impairment could be more serious in patients with vertigo than in those without vertigo.Vertigo does not necessarily bear a causal relationship with the impairment of the vestibular end organs.SOT VEST grade could be used to reflect the presence of vertigo state in the ISSNHL patients.Apart from audiometry,the function of peripheral vestibular end organs and balance function should be evaluated to comprehensively understand ISSNHL.Better assessment of the condition will help us in clinical diagnosis,treatment and prognosis evaluation of ISSNHL.

Intratympanic steroids injection is effective for the treatment of drop attacks with Ménière's disease and delayed endolymphatic hydrops: A retrospective study.

Drop attack (DA) associated with Ménière's disease (MD) and delayed endolymphatic hydrops (DEH) is not common and may cause life-threatening clinical problems. The intratympanic dexamethasone (ITD) is one of primary treatments for MD or DEH. Our study investigated the effect of ITD on the DA associated with endolymphatic hydrops (EH).We retrospectively reviewed 10 patients with MD- and DEH-associated DA between January 2009 and December 2013 in Outpatient Department of Otolaryngology, Union Hospital, Wuhan, China. Among them, 7 patients (5 cases with MD, 2 cases of DEH) received ITD (4 times, on weekly basis). Further repeated ITD courses or intratympanic gentamicin (ITG) were given if the vertigo was not satisfactorily controlled. The number of DA and status of vertigo control after intratympanic injection were evaluated. After a follow-up study lasting from 19 to 35 months, DA in 5 cases (71.4%) disappeared after initial ITD course. In 2 cases, DA was altogether controlled after an additional intratympanic injection (repeated ITD or/and ITG).This study showed that ITD promises to be a first-line conservative treatment for MD- or DEH-related DA since the steroid possesses no inner-ear toxicity. Furthermore, for MD- or DEH-related DA refractory to ITD, ITG can be an effective alternative.

Modified titration intratympanic gentamicin injection for unilateral intractable Ménière's disease.

This study looked into the efficacy of a modified titration protocol of intratympanic gentamicin injection (ITG) in the patients with unilateral intractable Ménière's disease (MD). Modified titration protocol of ITG at a low dose (20 mg/mL) was administered to 10 patients with definite unilateral intractable MD. After initial first two fixed ITGs on weekly basis, the patients might or might not be given any more injections, depending on the appearance of unilateral vestibular loss (UVL). ITG was terminated if the patients satisfied the criteria of UVL. All patients were followed-up for at least two years. The effects of ITG on the vertigo attack, functional level scores and postural balance were evaluated. Of the 10 cases, 8 showed the sign of UVL after receiving initial two ITGs and were not given any more intratympanic injections, and the other 2 patients were administered three ITGs. A two-year follow-up revealed that complete and substantial vertigo control was achieved in 9 cases, and limited vertigo control in 1 patient. Hearing level was lowered in 2 patients. The posture stability and functional level scores were improved. Our study showed that the modified titration protocol of ITG at a low dose could effectively control vertigo in patients with unilateral intractable MD.

Intratympanic injection in delayed endolymphatic hydrops.

CONCLUSIONS: The present study showed that intratympanic dexamethasone injection (ITD) is a promising approach for the treatment of contralateral and ipsilateral delayed endolymphatic hydrops (DEH). Moreover, intratympanic gentamicin injection (ITG), as a chemical labyrinthectomy, is a simple alternative for controlling vertigo in patients with ipsilateral DEH. OBJECTIVE: This study examined the effect of ITD or ITG on DEH. METHODS: Fourteen patients with DEH completed the clinical and audio-vestibular evaluation. Among them, 10 cases (ipsilateral type: nine cases, contralateral type: one case) were treated with intratympanic injection. Four patients with ipsilateral DEH underwent ITG, five patients with ipsilateral type and one patient with contralateral type received ITD. All 10 cases were followed up for 8-48 months. RESULTS: Complete and substantial vertigo control was achieved in four of nine ipsilateral DEH patients treated with ITG. In the other five ipsilateral cases who received ITD, two accomplished complete vertigo control and two had substantial control. In one case, the vertigo was not effectively controlled. One case of contralateral DEH underwent ITD and this case had complete vertigo control. The vertigo intensity, vertigo frequency, vertigo duration and the functional level scale after intratympanic injection was decreased significantly.

[The balance function of the patients with benign paroxysmal positional vertigo during standing].

OBJECTIVE: The purpose of the study was to investigate the balance function of the patients with benign paroxysmal positional vertigo (BPPV) during standing. METHOD: In this study 41 patients with posterior semicircular canal BPPV (PC BPPV) and 11 patients with horizontal semicircular canal BPPV (HC BPPV) were recruited. Dynamic balance during standing was measured in Sensory Organization Test (SOT). Static balance during standing was measured in modified Clinical Test of Sensory Interaction and Balance (mCTSIB). Data of BPPV patients were compared to that from 44 normal controls. RESULT: Scores of the patients with PC BPPV were lower than that of the normal controls in the last three test conditions of SOT. Patients with PC BPPV demonstrated greater sway velocity in stance on foam with eyes open and eyes closed in mCTSIB. No postural deficit was observed in neither SOT nor mCTSIB when the patients with HC BPPV were compared to the normal controls. CONCLUSION: Disorders of the horizontal semicircular canal do not influence postural control. Both dynamic and static posturography can detect the postural imbalance caused by posterior semicircular canal dysfunction.

The changes in mGluR2 and mGluR7 expression in rat medial vestibular nucleus and flocculus following unilateral labyrinthectomy.

It is known that the medial vestibular nucleus (MVN) and the cerebellar flocculus are the key areas, which contribute to the behavioral recovery ("vestibular compensation") after unilateral labyrinthectomy (UL). In these areas, how the genetic activities of the metabotropic glutamate receptors mGluR2 and mGluR7 performance after UL is unknown. With the means of quantitative real-time PCR, Western blotting, and immunohistochemistry, we analyzed the expression of mGluR2 and mGluR7 in the bilateral MVN and the flocculus of rats in different stages after UL (the 1st, 3rd, and 7th day). Our results show that in the MVN, the mRNA, and protein expressions of mGluR7 were ipsilaterally decreased at the 1st day following UL. However, in the MVN, no change was observed in the mRNA and protein expressions of mGluR2. On the other hand, the mRNA and protein expression of mGluR2 were enhanced in the ipsilateral flocculus at the 1st day following UL, while in the flocculus no change was shown in mGluR7 mRNA and protein expressions. Our results suggest that mGluR2 and mGluR7 may contribute to the early rebalancing of spontaneous resting activity in the MVN.

Changes in Histamine Receptors (H1, H2, and H3) Expression in Rat Medial Vestibular Nucleus and Flocculus after Unilateral Labyrinthectomy: Histamine Receptors in Vestibular Compensation.

Vestibular compensation is the process of behavioral recovery following peripheral vestibular lesion. In clinics, the histaminergic medicine is the most widely prescribed for the treatment of vertigo and motion sickness, however, the molecular mechanisms by which histamine modulates vestibular function remain unclear. During recovery from the lesion, the modulation of histamine receptors in the medial vestibular nucleus (MVN) and the flocculus may play an important role. Here with the means of quantitative real-time PCR, western blotting and immunohistochemistry, we studied the expression of histamine receptors (H1, H2, and H3) in the bilateral MVN and the flocculus of rats on the 1st, 3rd, and 7th day following unilateral labyrinthectomy (UL). Our results have shown that on the ipsi-lesional flocculus the H1, H2 and H3 receptors mRNA and the protein increased significantly on the 1st and 3rd day, with compare of sham controls and as well the contralateral side of UL. However, on the 7th day after UL, this expression returned to basal levels. Furthermore, elevated mRNA and protein levels of H1, H2 and H3 receptors were observed in the ipsi-lesional MVN on the 1st day after UL compared with sham controls and as well the contralateral side of UL. However, this asymmetric expression was absent by the 3rd post-UL. Our findings suggest that the upregulation of histamine receptors in the MVN and the flocculus may contribute to rebalancing the spontaneous discharge in bilateral MVN neurons during vestibular compensation.