Vestibular Neuritis: Three-dimensional Videonystagmography and Vestibular Evoked Myogenic Potential Results

Eight patients diagnosed with vestibular neuritis received the newly developed three-dimensional videonystagmography (3D VNG) and vestibular evoked myogenic potential (VEMP) examination in order to localize the lesion site. Two (25%) of the 8 patients exhibited spontaneous nystagmus with 3 components, indicating that both the horizontal semicircular canal (HSCC) and anterior semicircular canal (ASCC) were affected. The remaining 6 patients (75%) displayed only horizontal nystagmus, meaning that only the HSCC was involved. Seven (88%) of the 8 patients had bilateral normal VEMPs, revealing sparing of the posterior semicircular canal (PSCC). In a comparative study, another seven patients with vestibular neuritis 1 year post-treatment also received the caloric test, 3D VNG and VEMP examination. Only one patient exhibited spontaneous nystagmus. An absent caloric response of the lesioned side persisted in 5 (71%) of the 7 patients. However, all patients showed normal VEMPs bilaterally. 3D VNG and VEMP examination indicates that vestibular neuritis mainly affects the superior division of the vestibular nerve, which innervates the HSCC and ASCC. Meanwhile, the function of the PSCC and saccule, innervated by the inferior vestibular nerve, is preserved.     

Changes in vestibular evoked myogenic potentials after Meniere attacks

OBJECTIVES: The aim of this study was to apply videonystagmography (VNG) and vestibular evoked myogenic potential (VEMP) tests to patients with Meniere attacks, to explore the mechanics of where saccular disorders may affect the semicircular canals. METHODS: From January 2001 to December 2003, 12 consecutive patients with unilateral definite Meniere's disease with vertiginous attacks underwent VNG for recording spontaneous nystagmus, as well as VEMP tests. RESULTS: At the very beginning of the Meniere attack, the spontaneous nystagmus beat toward the lesion side in 5 patients (42%) and toward the healthy side in 7 patients (58%). Twenty-four hours later, only 6 patients (50%) showed spontaneous nystagmus beating toward the healthy side. Nevertheless, spontaneous nystagmus subsided in all patients within 48 hours. The VEMP test was performed within 24 hours of a Meniere attack; the VEMPs were normal in 4 patients and abnormal in 8 patients (67%). After 48 hours, 4 patients with initially abnormal VEMPs had resolution and return to normal VEMPs, and the other 4 patients still had absent VEMPs. CONCLUSIONS: Most patients (67%) with Meniere attacks revealed abnormal VEMPs, indicating that the saccule participates in a Meniere attack. This is an important idea that stimulates consideration of the mechanism of Meniere attacks.     

Vertigo From Herpes Zoster Oticus: Superior or Inferior Vestibular Nerve Origin?

OBJECTIVE/HYPOTHESIS: This study aims to analyze which division of vestibular nerve in the internal auditory canal is responsible for inducing vertigo in patients with herpes zoster oticus (HZO). METHODS: Eight patients (three men and five women) suffered from auricular vesicles, otalgia, and facial palsy, and five of them also had vertigo. Each patient received a battery of tests, including neurological examination, blood examination, audiometry, caloric test, electronystagmography, and vestibular evoked myogenic potential (VEMP) test. RESULTS: All five HZO patients with vertigo had facial palsy on the lesioned side and spontaneous nystagmus beating toward the healthy side. Absent VEMPs were noted in five patients, absent caloric response was noted in four, and sensorineural HL was noted in three. Compared to another three HZO patients without vertigo, all revealed normal responses in both the caloric test and the VEMP test. On MRI scan, two out of four had abnormal gadolinium enhancement along the nerve segments within the internal auditory canal. Six months after treatment, a follow-up caloric test and VEMP test in these eight patients did not alter the results compared with before treatment. CONCLUSION: The nerve trunks within the internal auditory canal are widely affected in HZO patients with vertigo. Both superior division and inferior division of the vestibular nerve attribute to the vertiginous attack. Further, large numbers of HZO patients undergoing caloric testing and VEMP testing are required to support this tentative conclusion.     

Correlation between bithermal caloric test results and vestibular evoked myogenic potentials (VEMPs) in normal subjects

Bithermal caloric testing and vestibular evoked myogenic potentials (VEMPs) are both diagnostic tools for the study of the vestibular system. The first tests the horizontal semicircular canal and the second evaluates the saccule and lower vestibular nerve. The results of these two tests can therefore be expected to be correlated. The aim of this study was to compare bithermal caloric test results with VEMP records in normal subjects to verify whether they are correlated. Material and method: A prospective study was conducted in 60 healthy subjects (30 men and 30 women) who underwent otoscopy, pure tone audiometry, bithermal caloric testing and VEMPs. From the caloric test, we assessed the presence of possible vestibular hypofunction, whether there was directional preponderance and reflectivity of each ear (all based on both slow phase velocity and nystagmus frequency). The analysed VEMPs variables were: p1 and n1 latency, corrected amplitude, interaural p1 latency difference and p1 interaural amplitude asymmetry. We compared the reflectivity, hypofunction and directional preponderance of the caloric tests with the corrected amplitudes and amplitude asymmetries of the VEMPs. No correlations were found in the different comparisons between bithermal caloric testing results and VEMPs except for a weak correlation (p = 0.039) when comparing preponderance based on the number of nystagmus in the caloric test and amplitude asymmetry with 99 dB tone burst in the VEMPs test. The results indicate that the two diagnostic tests are not comparable, so one of them cannot replace the other, but the use of both increases diagnostic success in some conditions.     

Benign paroxysmal positional vertigo due to a simultaneous involvement of both horizontal and posterior semicircular canals

From April 2001 to November 2003, we investigated 8 patients with benign paroxysmal positional vertigo (BPPV) that was suspected to simultaneously affect both the horizontal and posterior semicircular canals (HSCC and PSCC). These cases showed typical vertical-torsional nystagmus induced by the Dix-Hallpike maneuver, followed by a horizontal nystagmus. They also showed a direction-changing geotropic or apogeotropic positional nystagmus triggered by lateral head rotations in the supine position. Using the three-dimensional analysis of the positional nystagmus, the rotation axis of the positional nystagmus had a component perpendicular to the plane of PSCC and another component perpendicular to the plane of HSCC. All these findings suggest that BPPV in these patients was a combination of posterior and horizontal canal BPPV. The observation of a vertical-torsional positional nystagmus should prompt the specialist to perform not only the canalith repositioning procedure, but also to execute lateral head turns in the supine position.     

迟发性膜迷路积水的诊断

目的：探讨迟发性膜迷路积水（DEH）的诊断手段及意义。方法：15例DEH患者,分别行纯音听阈及耳蜗电图检查、前庭双温试验和前庭诱发的肌源性电位检查（VEMP）,用以诊断及判断DEH的侧别和病变累及范围。结果：15例患者均为中～重度以上感音神经性聋。积水与听力下降同侧10例,对侧4例,双侧1例。水平半规管和球囊均有积水5例,水平半规管积水6例,球囊积水2例。VEMP异常者7例,其中1例患侧p13-n23振幅消失,2例p13潜伏期延长,4例患侧p13-n23低振幅。结论：DEH的诊断除了纯音测听外,耳蜗电图检查、前庭双温试验和VEMP检查是重要的实验室检查,应列为诊断常规。     

Assessment of vestibular function of infants and children with congenital and acquired deafness using the ice-water caloric test, rotational chair test and vestibular-evoked myogenic potential recording

CONCLUSIONS: The vestibular function can be assessed by ice-water caloric test, rotational chair test and VEMP recording in severely hearing impaired infants and young children, and 85% of these patients showed abnormal responses in these tests. OBJECTIVES: To evaluate the vestibular function of infants and young children with congenital and acquired deafness, we examined the semicircular canal and otolith function in their early childhood. MATERIALS AND METHODS: Our subjects were 20 children (11 boys, 9 girls; age range 31-97 months, mean age 54.2 months) with severe hearing impairment. Their vestibular functions were assessed by the ice-water caloric test, rotational chair test and vestibular-evoked myogenic potential (VEMP) recording. RESULTS: Among these 20 severely hearing impaired children, only 3 (15%) showed normal responses in the caloric test, rotational chair test and VEMP recording bilaterally. Seven (35%) showed responses asymmetrically in the caloric test despite normal responses in the rotational chair test and VEMP recording bilaterally. Five (25%) showed hyporeflexia or areflexia in the caloric test bilaterally, but showed normal responses in the rotational chair test and normal reproducible or decreased VEMPs. Five (25%) showed no responses at all in the caloric test, rotational chair test and VEMP recording.     

3D analysis of spontaneous nystagmus in early stage of vestibular neuritis

Objective

The pathological localization of vestibular neuritis is still controversial. Analyses of the spontaneous nystagmus support the temporal bone studies, which indicated the location of the pathology to be in the superior vestibular nerve. However, based on the data from the head impulse testing the pathology is in the vestibular nerve including the inferior branch.

Methods

Twenty-three patients with vestibular neuritis participated in this study. The spontaneous nystagmus was recorded within 1 week after the onset of the disease. Three-dimensional analysis of the nystagmus was performed using video image analysis system. The rotation axis was calculated and compared to the anatomical axes of the semicircular canals.

Results

The axes of the spontaneous nystagmus in all patients were scattered around the axes of horizontal and anterior canals, especially between the compound axis of anterior and horizontal canals and the axis of horizontal canal. The statistical analysis revealed that in the quite early stage of the disease (day 0–2 of the attack), the spontaneous nystagmus tended to have more torsional eye movements as compared to the less early stage (day 3–6).

Conclusion

The present study strongly suggests that the pathology of vestibular neuritis is in the superior vestibular nerve branch. Also it can be speculated that at the early stage of this disease, the pathology is in the whole branch of the nerve. Subsequently, the anterior canal branch recovers faster than the horizontal canal branch.     

Horizontal vestibulo-ocular reflex dynamics in acute vestibular neuritis and viral labyrinthitis: evidence of otolith-canal interaction

OBJECTIVE: To evaluate the dynamic properties of the horizontal vestibulo-ocular reflex (h-VOR) in the acute stage of two common labyrinthine diseases that provoke severe attacks of vertigo with spontaneous nystagmus: vestibular neuritis (vestibular loss alone) and viral labyrinthitis (cochleovestibular loss). MATERIAL AND METHODS: Sixty-three patients were investigated: 42 were diagnosed with vestibular neuritis and 21 with viral labyrinthitis. The h-VOR function was evaluated by conventional caloric and impulsive testing. A simplified model of vestibular function was used to analyze the vestibulo-ocular response to rotational stimulation. RESULTS: The results showed a significant difference in h-VOR characteristics between the two pathologies. Patients with vestibular neuritis exhibited a strong horizontal semicircular canal deficit, but no h-VOR asymmetry between the two rotational directions. In contrast, patients with viral labyrinthitis demonstrated moderate canal paresis and a marked h-VOR deficit in rotation toward the affected ear. CONCLUSION: These findings support the hypothesis that the h-VOR dynamic asymmetry that occurs after an acute unilateral inner ear lesion is not due to canal dysfunction alone, but involves complex adaptive changes in the central VOR that may implicate the otolith system. Based on histopathologic and clinical differences in the two pathologies reported in the literature, we postulate that this otolith-canal interaction is mainly linked to the loss of saccular function.     

Does unilateral utricular dysfunction cause horizontal spontaneous nystagmus?

The presence of spontaneous nystagmus in darkness with a strong horizontal component has been taken to indicate that there is asymmetrical function of the horizontal semicircular canals. If this horizontal spontaneous nystagmus can be suppressed by vision, then it is regarded as due to peripheral horizontal canal dysfunction. However, we report evidence from one patient (61-year-old male), who visited the MSA ENT Clinic, Cassino (FR) Italy, reporting acute, severe vertigo, postural unsteadiness, nausea and vomiting associated with right sudden hearing loss. The patient received instrumental audiovestibular testing to obtain objective measurements of his inner-ear receptors. At the time of the attack, the patient showed spontaneous nystagmus, mainly with horizontal and vertical components (3D infrared video-oculography). Video head-impulse tests of dynamic horizontal canal function showed that the functional status of both horizontal canals was within the normal range. Cervical VEMPs to 500 Hz bone-conducted vibration at Fz showed normal results; ocular VEMPs to the same stimulus showed a reduced n10 amplitude beneath the left eye, corresponding to the right ear. For this reason, the patient was diagnosed as having right unilateral selective utricular macula lesion due to labyrinthitis. There is considerable evidence of convergence of neural input from the otoliths onto horizontal canal neurons in the vestibular nuclei. The firing of such neurons could reflect either asymmetrical horizontal canal function or asymmetrical utricular function. The problem with this patient was not due to asymmetrical horizontal canal function, but only to asymmetrical utricular function, demonstrated by the results of the oVEMP test.     

Vestibular evoked myogenic potentials in brainstem stroke

OBJECTIVES/HYPOTHESIS: Despite its widespread application in the posterior fossa tumor, the study of vestibular evoked myogenic potential (VEMP) in cases of posterior fossa stroke remains scarce. The purpose of the study was to establish the role of VEMP in patients with brainstem stroke. STUDY DESIGN: Retrospective study. METHODS: Patients with acute vertigo were admitted and underwent a battery of auditory vestibular tests including caloric and VEMP tests; then they were surveyed by magnetic resonance imaging scan. Seven patients (two men and five women) were demonstrated as having brainstem stroke, including infarction in five patients and hemorrhage in two. RESULTS: Clinical manifestations consisted of dizziness/vertigo in all patients, spontaneous nystagmus in five (71%), and ataxia in three. No patients had experienced conscious change or conventional neurological deficits (eg, long tract signs). Electronystagmography revealed abnormal findings on eye tracking test in 100% of patients, on optokinetic nystagmus test in 71% of the patients, and on caloric testing in 10 ears (71%), including absent ice-water caloric test response in 7 ears and canal paresis in 3 ears. Vestibular evoked myogenic potential testing displayed normal response in 3 ears and abnormal response in 11 ears (79%), including absent vestibular evoked myogenic potentials in 8 ears and delayed vestibular evoked myogenic potentials in 3 ears. When results of both caloric testing and VEMP test were combined, the abnormal rate increased to 93% (13 of 14 patients). CONCLUSIONS: Caloric testing assesses the vestibulo-ocular reflex, which passes upward through the upper brainstem, whereas VEMP testing evaluates the sacculocollic reflex, which travels downward through the lower brainstem. Hence, in evaluating the extension of brainstem stroke, both caloric and VEMP testing should be performed.     

Recovery of vestibular evoked myogenic potentials after a vertigo attack due to vestibular neuritis

CONCLUSIONS: Inferior vestibular nerve functions could recover in patients with vestibular neuritis (VN). OBJECTIVES: Although the recovery of superior vestibular nerve functions has been reported, there is little information about the recovery of inferior vestibular nerve functions in patients with VN. This study was done to clarify if inferior vestibular nerve functions recover after an attack of VN. METHODS: Neuro-otological tests including vestibular evoked myogenic potential (VEMP) testing and caloric testing were sequentially performed in 13 patients with VN, who showed absence of VEMP on the affected side at the initial examination (7 men and 6 women, 28-82 years of age). VEMPs to click stimulation (95 dBnHL) were recorded with surface electrodes over each sternocleidomastoid muscle. RESULTS: Among the 13 patients, 5 patients (4 men and 1 woman) showed recovery of VEMP responses. Four of the five patients (three men and one woman) showed recovery of VEMP to the normal range. It takes 6 months to 2 years to recover within the normal range. On the other hand, caloric responses recovered to the normal range only in one patient.     

Vestibular evoked myogenic potentials in patients with idiopathic bilateral vestibulopathy. Report of three cases.

Idiopathic bilateral vestibulopathy (IBV) is an acquired bilateral peripheral vestibular disorder of unknown cause. Three patients diagnosed as IBV by neuro-otological examination were reported. They underwent vestibular evoked myogenic potential (VEMP) testing which reflects the functionality of the sacculo-collic pathway. As a result, 2 of the 3 patients showed bilateral absence of VEMPs and one showed unilateral absence. The VEMPs of the 3 patients revealed that IBV affects not only the superior but also the inferior vestibular nerve systems. As previously reported in the cases of vestibular neuritis, VEMP could be useful for classifying IBV according to the function of the inferior vestibular nerve.     

Changes in the Tullio phenomenon and the fistula sign in the course of endolymphatic hydrops

We performed electronystagmography with caloric stimulation and studied vestibular evoked myogenic potentials (VEMPs) associated with changes in the Tullio phenomenon and the fistula sign during the clinical course of a patient with endolymphatic hydrops. The Tullio phenomenon and the fistula sign disappeared in association with a reduction in the caloric response, which implicates the ampullary function of the lateral semicircular canal. Even when no VEMP could be detected for the affected ear, the Tullio phenomenon and fistula signs were observed; thus, either these phenomena had a lower response threshold than the VEMPs, or saccular receptors were not involved in the Tullio phenomenon.     

Horizontal vestibulo-ocular reflex dynamics in acute vestibular neuritis and viral labyrinthitis: evidence of otolith-canal interaction

Objective To evaluate the dynamic properties of the horizontal vestibulo-ocular reflex (h-VOR) in the acute stage of two common labyrinthine diseases that provoke severe attacks of vertigo with spontaneous nystagmus: vestibular neuritis (vestibular loss alone) and viral labyrinthitis (cochleovestibular loss).

Material and Methods Sixty-three patients were investigated: 42 were diagnosed with vestibular neuritis and 21 with viral labyrinthitis. The h-VOR function was evaluated by conventional caloric and impulsive testing. A simplified model of vestibular function was used to analyze the vestibulo-ocular response to rotational stimulation.

Results The results showed a significant difference in h-VOR characteristics between the two pathologies. Patients with vestibular neuritis exhibited a strong horizontal semicircular canal deficit, but no h-VOR asymmetry between the two rotational directions. In contrast, patients with viral labyrinthitis demonstrated moderate canal paresis and a marked h-VOR deficit in rotation toward the affected ear.

Conclusions These findings support the hypothesis that the h-VOR dynamic asymmetry that occurs after an acute unilateral inner ear lesion is not due to canal dysfunction alone, but involves complex adaptive changes in the central VOR that may implicate the otolith system. Based on histopathologic and clinical differences in the two pathologies reported in the literature, we postulate that this otolith-canal interaction is mainly linked to the loss of saccular function.     

Clinical presentation of posterior fossa epidermoid cysts

The aim of this study was to investigate the audiovestibular deficits in those with posterior fossa epidermoid cyst including cerebellopontine angle in two patients and cerebellum in one patient. Prior to operation, all three patients showed bilateral gaze nystagmus. Audiometry revealed mild hearing loss in two patients, and caloric test displayed canal paresis in two patients. After operation, subsidence of gaze nystagmus and recovery of caloric responses were disclosed in all patients. Two patients had both hearing and vestibular evoked myogenic potential (VEMP) results recovered to normal. In contrast, the only one who underwent craniotomy twice displayed bilateral mild hearing loss and delayed VEMPs, possibly due to operation sequela. Hence, bilateral gaze nystagmus may present as an initial sign for posterior fossa epidermoid cyst. Audiovestibular deficits in cases of epidermoid cyst are attributable to compression neuropathy, which may resolve and return to normal responses after surgery.     

Treatment of Ménière's disease by low-dosage intratympanic gentamicin application: effect on otolith function

OBJECTIVES: The intratympanic application of a low dosage of gentamicin is increasingly favored as treatment for Ménière's disease. While posttreatment observations have confirmed a long-term success of the therapy of vertigo attacks, clear differences in the posttreatment recovery interval can be observed. In addition to differences in central-vestibular compensation, the degree of peripheral vestibular damage, i.e., to the saccule, utricle, and semicircular canal ampullae, varies among patients. This study provides comprehensive pre- and posttreatment results from unilateral functional tests of the individual vestibular receptors and of the cochlea in patients with Ménière's disease. STUDY DESIGN: Prospective clinical study. METHODS: Nineteen patients with unilateral Ménière's disease were treated by intratympanic application of gentamicin by injection of 0.3 mL (12 mg) through the tympanic membrane under local anesthesia. Tests were performed immediately previous to treatment and subsequently in the periods 4 to 8 weeks and 12 to 16 weeks after treatment. Unilateral saccular function was tested by means of acoustic-click, vestibular-evoked myogenic potentials (VEMP), and unilateral utricular function by subjective visual vertical (SVV) during unilateral centrifugation. Bithermal caloric testing was performed to assess unilateral semicircular canal function. RESULTS: Prior to gentamicin treatment, the caloric response from the diseased ear was normal in 3 patients, below normal in 14 patients, and in 2 cases almost completely absent. VEMP responses could be recorded bilaterally in 13 patients; while in 6, no VEMPs could be measured from the diseased ear. Utricular function measured by SVV estimation was found to be normal in 11 patients and marginally abnormal in 2 patients. In six cases, the SVV was clearly underestimated during centrifugation of the diseased side. The posttreatment findings demonstrate that VEMPs were absent in all treated patients, and the caloric response was abnormally low in all but one case. In contrast, only 12 of 19 patients produced abnormal SVV responses. CONCLUSION: The results demonstrate that incremental, intratympanic application of gentamicin effectively eliminates semicircular canal and saccular function. In contrast, utricular function appears to be maintained in 30 to 40% of cases.     

Caloric vertical nystagmus: the vertical semicircular canal in caloric testing

Vertical nystagmus elicited by caloric testing does not necessarily mean there is central pathology. In a patient with confirmed peripheral vestibular disease, caloric stimulation produced an intense vertical nystagmus, which showed all the features of a caloric nystagmus. The patient had bilateral mastoid cavities, allowing easy stimulation of the posterior semicircular canal, using air. At the same time, a unilateral horizontal semicircular canal functional loss was observed, raising the possibility of dissociated canal dysfunction.     

Topographical correlations of lateral medullary infarction with caloric- and vestibular-evoked myogenic potential results

This study investigated the correlation of caloric- and vestibular-evoked myogenic potential (VEMP) results with topographical lesions of lateral medullary infarction. Five patients with lateral medullary infarction were enrolled in this study. Each patient underwent a battery of tests, including audiometry, caloric test, VEMP test, and magnetic resonance imaging (MRI) study. Gaze nystagmus was observed in four patients (80%), while abnormal pursuit, saccade, and optokinetic nystagmus tests were noted in all patients (100%). MRI demonstrated infarction at the ponto-medullary junction in one patient and upper medulla in one patient. Both patients revealed caloric areflexia and normal VEMPs. In contrast, another three patients with infarction at the middle inferior olive level, all displayed abnormal (including absent or delayed) VEMPs, and one patient showed caloric areflexia. Topographical correlations of lateral medullary infarction with caloric and VEMP tests reveal that caloric areflexia is possibly linked with rostrally located infarction, while absent or delayed VEMPs relate to caudally located infarction.     

Vestibular evoked myogenic potentials in acoustic tumor patients with normal auditory brainstem responses

In order to clarify the utility of the vestibular evoked myogenic potential (VEMP) in detecting acoustic tumors, we report two patients who were found to have normal auditory brainstem responses (ABRs) and abnormal VEMPs. To record VEMPs, electromyographic responses to brief loud clicks (0.1 ms at 95 dBnHL) were amplified and averaged on the sternocleidomastoid muscle ipsilateral to the stimulated side. The stimulation rate was 5 Hz and the analysis time 50 ms. The first case was a 54-year-old woman in whom VEMPs were absent on the affected side while caloric tests and ABRs were normal. The second case was a 58-year-old woman whose VEMPs were absent on the affected side while caloric tests revealed a 22% canal paresis and normal ABRs. These results and previous studies suggested that the VEMP could reflect a function different from those evaluated by the ABR or the caloric test. We concluded that the VEMP can provide useful information in diagnosing acoustic tumors. Received: 17 March 1998 / Accepted: 29 July 1998