The three faces of vestibular ganglionitis

We present temporal bone and clinical evidence that common syndromes of recurrent vertigo are caused by a viral infection of the vestibular ganglion. In the present series, histopathologic and radiologic changes in the vestibular ganglion and meatal ganglion were consistent with a viral inflammation of ganglion cells in cases of Meniere's disease, benign paroxysmal positional vertigo, and vestibular neuronitis. Clinical observations of multiple neuropathies involving cranial nerves V, VII, and VIII on the same side in patients with recurrent vertigo are best explained by a cranial polyganglionitis caused by a neurotrophic virus, which is reactivated by a stressful event later in life. The reactivation of the latent virus may manifest as one of the above vertigo syndromes, depending on the part of the vestibular ganglion that is inflamed, the type and strain of the virus, and host resistance.     

Efferent system degeneration in the human temporal bone

Sense organ deposits have been described in temporal bones from patients with vestibular neuronitis, Meniere's disease, and benign paroxysmal positional vertigo that are not found in a comparable series of temporal bones without vestibulopathy. Because the recurrent vestibulopathies are caused by vestibular ganglionitis and the vestibulocochlear anastomosis was degenerated in these temporal bones, the deposits may represent the end buds of regenerating efferent axons injured in passage through the vestibular ganglion. Such neural buds have been described with transmission electron microscopy in animals after vestibular nerve transection and in a human temporal bone with endolymphatic hydrops. The buds may be visible by light microscopy, because their size is comparable to that of hair cell nuclei and they stain blue with hematoxylin because of their nucleic acid content. The variable location and size of these deposits (buds) in the labyrinthine sense organs is described to aid in the recognition of efferent system injury in human temporal bones.     

Retrolabyrinthine vestibular nerve section: efficacy in disorders other than Menière's disease

The retrolabyrinthine vestibular nerve section has evolved as an effective treatment for intractable vertigo of peripheral vestibular origin when hearing preservation is desired. This report studies the efficacy of retrolabyrinthine vestibular nerve section for control of vertigo due to causes other than Meniere's disease. This report details our experience with 42 patients with a wide variety of diagnoses. The reduced success rate of retrolabyrinthine vestibular nerve section in these patients is difficult to evaluate, as very few patients have been analyzed with respect to their specific diagnoses. Of patients who underwent retrolabyrinthine vestibular nerve section for control of vertigo, 23 patients had uncompensated vestibular neuritis and 19 others had a wide range of other diagnoses. For patients with uncompensated vestibular neuritis (n = 23), the physician record noted that 39% of patients were cured and 30% improved. This compares to our series of patients with Meniere's disease (n = 48), where 94% were cured and 2% improved. The true vestibular abnormality may be less reliably identified in patients with uncompensated vestibular neuritis, contributing to the less effective results. Since the development of a vestibular rehabilitation program, retrolabyrinthine vestibular nerve section for uncompensated vestibular neuritis has been all but abandoned. Retrolabyrinthine vestibular nerve section appears to achieve a high cure rate in patients with sensorineural hearing loss associated with their vestibular abnormalities. While retrolabyrinthine vestibular nerve section is helpful for control of vertigo in some diagnoses, a substantial incidence of persistent postoperative dysequilibrium was noted.     

Diagnosis and initiating treatment for peripheral system disorders: imbalance and dizziness with normal hearing

Disorders affecting the peripheral vestibular system commonly involve the peripheral auditory system causing hearing loss. There are a number of disorders, however, that selectively involve the peripheral vestibular system causing dizziness without hearing loss. These disorders include benign paroxysmal positional vertigo, vestibular neuritis, recurrent vestibulopathy, familial vestibulopathy, and bilateral idiopathic vestibulopathy. This article reviews these disorders and their diagnosis and management.     

Evaluation of acute vertigo: unusual lesions imitating vestibular neuritis

The acute onset of vertigo is a common clinical problem presenting to primary care physicians or otologists for evaluation. Usually the underlying disease process is benign and self-limited in nature. In the absence of hearing loss or additional neurologic findings, a common initial diagnosis is vestibular neuritis. The patient is treated symptomatically and observed for spontaneous resolution. However, other more serious disease processes may mimic the presentation of vestibular neuritis and be misdiagnosed. Five cases of serious central nervous system disorders that were similar to vestibular neuritis in their initial presentation are reviewed to illustrate this point. Each patient presented with the acute onset of continuous vertigo without associated hearing loss. The correct diagnosis was established only after further evaluation was pursued. Recommendations for the initial and subsequent evaluation of these patients are discussed.     

Vestibular neuritis: etiopathogenesis

Vestibular neuritis presents as sudden unilateral vertigo in the absence of hearing loss or neurologic involvement and is thought to be due to neurotropic viruses. Its morbidity is unknown and it affects both sexes equally, with the highest incidence at 40-50 years of age. The etiology of this condition has been ascribed to viral, bacterial and protozoan infections, as well as allergic and auto-immune causes. Inflammation of the vestibular nerve is followed by demyelination and loss of function, which is not always reversible. Higher plasma fibrinogen and CRP levels in the acute phase, longer BERA latency and I-III interval and increased gadolinium uptake in the vestibular nerve and Scarpa's ganglion on enhanced MRI confirm the inflammatory nature of the process. An animal model of vestibular neuritis using retroauricular inoculation of herpes simplex virus in mice, histologic findings in the temporal bone of individuals who had vestibular neuritis, and influenza A virus infection in cultured Schwann's cells suggest viral infection as the main aetiologic cause.     

Migraine-associated vertigo

CONCLUSIONS: It is probably not wise to demand a temporal relationship between migraine symptoms and vertigo for the definition of migrainous vertigo. When recurrent vertigo attacks begin at an early age in a patient with normal hearing and migraine, there are few diagnoses other than migraine that need to be considered. OBJECTIVE: The clinical association between migraine and vestibular symptoms, such as dizziness, motion intolerance and spontaneous attacks of vertigo, is well documented. Recently, investigators have attempted to develop diagnostic criteria for this association. We hypothesized that there are multiple migraine-associated vestibular syndromes and studied a more homogenous subset of them (benign recurrent vertigo). MATERIAL AND METHODS: A structured interview was conducted over the telephone with 40 patients who presented to our neurotology clinic with benign recurrent vertigo and met the International Headache Society criteria for migraine. The structured interview was also conducted with 40 relatives of the patients who reported the same symptoms. RESULTS: A marked female predominance was found. Most of the patients had vertigo attacks lasting minutes or hours and most were completely free of dizziness between attacks. Imbalance and nausea typically accompanied the vertigo. However, in half of the cases, vertigo occurred without an association with headache.     

Various causes and clinical characteristics in vertigo in children with normal eardrums

OBJECTIVE: The differential diagnosis of vertigo in children is extensive. Otitis media and middle ear effusion could be the most common causes of vertigo in children, but there are some problems in detecting the other causes for vertigo because they are one of most frequent diseases of childhood. The purpose of this study is to review the clinical characteristics and both the audiological and vestibular findings of vertigo in children with normal eardrums, who do not show otitis media or middle ear effusion, and to assist in making a differential diagnosis of vertigo. METHODS: The fifty five children (< 16 years old) with vertigo, who visited the Department of Otolaryngology, Ajou University Hospital, Suwon, South Korea between January 1995 and December 2001 were selected for this study. These excluded the patients with abnormal eardrums/tympanograms or those that did not perform questionnaires, audiological, or vestibular evaluations. They were retrospectively analyzed for clinical symptoms, vestibular functions, and differential diagnosis. RESULTS: The most common causes for vertigo in children were migraine in 17 (30.9%) and benign paroxysmal vertigo of childhood (BPVC) in 14 (25.5%). Other less frequent causes included four cases of trauma, two cases each of Meniere's disease, delayed endolymphatic hydrops, benign positional vertigo, and one case only for cerebellopontine angle tumor, seizure, acute vestibular neuritis, juvenile rheumatoid arthritis, leaving ten cases (18.2%) as unclassified. Abnormal findings were noted in 13 (23.6%) in pure tone audiogram, 3 (5.5%) in positioning test, 6 (10.9%) in bithermal caloric test, and 36 (65.5%) in rotation chair test. CONCLUSIONS: The vertigo in children with normal eardrums, who did not show otitis media or middle ear effusion, was most commonly caused by migraine and BPVC. These findings have shown to be very different from those with adult vertigo. The evaluation of vertigo in children requires a questionnaire for extensive and complete history taking, audiograms and vestibular function tests. And in selected cases, electroencephalography, hematological evaluation, imaging of the brain or temporal bone should be performed.     

前庭下神经炎的临床分析

目的探讨前庭下神经炎的临床特点。方法回顾性分析我科眩晕门诊就诊的8例前庭下神经炎患者资料,综合病史、查体、听力学、影像学、冷热试验及前庭诱发的肌源性电位（vestibular evoked myogenic potential,VEMP）检查结果 ,给予明确诊断。结果 8例患者眩晕发作特点均符合前庭神经炎表现,纯音听力测试及冷热试验结果 均正常,颅脑CT或MRI检查正常,排除中枢病变。VEMP8例均异常,其中6例一侧不能引出,2例一侧振幅低下。结论前庭下神经炎属于前庭神经炎的一个亚型,临床特征为病变单纯累及前庭下神经,VEMP检查可辅助诊断。对临床怀疑前庭神经炎患者应常规行VEMP检查,以利于明确诊断及评估病变范围。     

The results of vestibular evoked myogenic potentials, with consideration of age-related changes, in vestibular neuritis, benign paroxysmal positional vertigo, and Meniere's disease

CONCLUSION: We interpreted VEMP findings in patients with the three major peripheral vertigo diseases, taking age-related changes into consideration. We found different abnormal VEMP rates among the three diseases, as well as differences in the proportion of parameters that were abnormal, according to the type of disease. OBJECTIVES: Vestibular neuritis, benign paroxysmal positional vertigo (BPPV), and Meniere's disease, common diseases that cause peripheral vertigo, often affect the saccule or inferior vestibular nerve, which are pathways of vestibular evoked myogenic potential (VEMP). Also, aging could have a primary effect on diminished VEMP responses. Our study investigated VEMP the findings in patients with the diseases in relation to their age. PATIENTS AND METHODS: A total of 134 patients with vestibular neuritis, 62 with BPPV, and 29 with Meniere's disease were enrolled in this study. The VEMP findings in patients within the three disease groups were interpreted using our own normative ranges according to age. RESULTS: Abnormal VEMP rates in the vestibular neuritis, BPPV, and Meniere's disease groups were 36.6%, 25.8%, and 69%, respectively. The proportion of prolonged p13 latency in BPPV patients with abnormal VEMP responses was relatively high compared with the other two diseases. VEMP asymmetry in the patients with Meniere's disease was relatively high.     

Anatomic differences in the lateral vestibular nerve channels and their implications in vestibular neuritis.

HYPOTHESIS: Anatomic differences may render the superior division of the vestibular nerve more susceptible to injury during vestibular neuritis. BACKGROUND: Neural degeneration has been identified in temporal bone studies of vestibular neuritis. Previous anatomic and physiologic studies of vestibular neuritis have demonstrated that the superior division of the vestibular nerve is preferentially affected, with sparing of the inferior division. A preliminary temporal bone study has implicated neural entrapment as a possible cause for this preferential injury. METHODS: Two independent unbiased observers performed histologic analysis of 184 temporal bones from our temporal bone library. Measurements of the medial, midpoint, and lateral portions of the superior vestibular, inferior vestibular, and the singular nerves and their bony channels lateral to the internal auditory canal were made. These measurements included the length and width of each bony channel and an estimated percent of each channel occupied by bony spicules at each location. RESULTS: The lengths of the bony channels of the singular nerve (0.598 mm) and the inferior vestibular nerve (0.277 mm) were significantly shorter than the average length of the superior vestibular channel (1.944 mm; p < 0.0001). The total percent of the channel occupied by bone at the midpoint was significantly greater for the superior vestibular (28%) compared with either the singular (0%) or the inferior vestibular channel (18%) (p < 0.0001). CONCLUSION: The lateral bony channel of the superior vestibular nerve is seven times longer than the inferior vestibular and more than three times longer than the singular channel. There are a larger percentage of bony spicules occupying the superior vestibular compared with the inferior vestibular or singular channels. In addition, the superior nerve passes through a longer area of severe narrowing compared with the inferior or singular nerves. This anatomic arrangement of a longer bony channel with more interspersed bony spicules could make the superior vestibular nerve more susceptible to entrapment and ischemia.     

Hydropische Ohrerkrankung vom vestibulären Typ

We report the case of a patient with episodic rotational vertigo for years. Ear symptoms were negated. The clinical diagnosis was not clear – Menière’s disease, vestibular migraine and recurrent vertigo after vestibular neuritis all qualified for differential diagnoses. A locally enhanced inner-ear MRI established clarity by showing an endolymphatic hydrops in the vestibulum. Besides the classical triad of Menière’s disease there are other clinical appearances of endolymphatic hydrops, which can be visualized with inner-ear MRI.     

Study on 242 inpatients reporting vertigo and dizziness

We studied 242 inpatients--men (34%) and women (66%) reporting vertigo and dizziness while hospitalized at Hakodate Municipal Hospital from July 1999 to June 2002. Adults over 65 years old accounted for 47.3% of all subjects. Reports of symptoms tended to increase in March, August, and December. Cases were classified into 4 groups: 1) peripheral disorders (35.7%), 2) central disorders (7.9%), 3) disorders of other origins (8.3%), and 4) disorders of unknown origin (47.1%). Group 1) involved vestibular neuritis (10.1% of all cases), Meniere diseases (12.4%), benign paroxysmal positional vertigo (BPPV) (5.8%), and sudden deafness with vertigo (5.8%). Patients with vestibular neuritis--25 subjects including men (68%) and women (32%)--tended to be admitted mainly in July. Vestibular compensation in 15 patients with vestibular neuritis was studied using the platform stabilometry. The total length of a locus and the area of surroundings with open eyes decreased significantly (p < 0.05) as the condition of patients improved. In conclusion, many subjects reporting vertigo and dizziness had vestibular neuritis and few had BPPV. We found platform stabilometry to be useful in estimation of improvement in patients with vestibular neuritis.     

Vestibular evoked myogenic potentials

Vestibular Evoked Myogenic Potentials (VEMP) are commonly recorded in patients experiencing vertigo or chronic instability. This test evaluates the patient's otolith function and is often combined with both Videonystagmography and Video Head Impulse Test. VEMP is a simple, reproducible test, in the absence of any pre-existing conductive hearing loss. Cervical VEMP explore both saccular function and the inferior vestibular nerve, whereas ocular VEMP assess utricular function and the superior vestibular nerve. In combination with previously described tests, VEMP allows characterization of vertigo and provides support for the diagnosis of superior semicircular canal dehiscence syndrome, Menière's disease, vestibular neuritis, vestibular schwannoma or idiopathic bilateral vestibulopathy. A good knowledge of these electrophysiological tests is essential in order to precisely assess the presence or absence of vestibular function impairment. We describe the test recording technique and the most common pitfalls in interpretation of the results. We then outline the results observed in various diseases impacting vestibular function.     

Isolated vestibular areflexia after blunt head trauma.

The sudden unilateral loss of vestibular function is a frequent cause of vertigo. This condition is called vestibular neuronitis or vestibular neuritis. Its cause remains unknown, but many authors consider it to be a sequel of vestibular viral infection. We report the history and clinical findings of 5 patients in whom a unilateral vestibular loss occurred after head trauma. None of these patients complained of hearing loss. In all cases, the vertigo gradually subsided over days or weeks. The follow-up showed the partial recovery of vestibular function in 2 cases, while vestibular areflexia persisted in 3. The clinical course and findings were similar in every respect to those in patients with classic idiopathic vestibular neuronitis.     

Benign recurrent vertigo in Japanese

Twenty-one cases of Japanese patients exhibiting recurrent attacks of vertigo are reported. Fifteen of the cases are females. The mean age of onset of the vertigo is 30.8 years. In 11 patients, the duration of attacks is less than 10 min. Caloric responses are normal in all patients. Although two patients demonstrate hearing loss, the rest of the patients exhibit no hearing loss. Headaches have been reported in all patients. Eighteen of the patients experience headaches associated with the vertiginous attacks. The clinical features observed in our cases are consistent with a diagnosis of benign recurrent vertigo. Four patients exhibit cranial nerve symptoms which are features of basilar artery migraine. Basilar artery migraine is attributed to a migrainous disturbance of the basilar artery. Benign recurrent vertigo is also ascribed to a migrainous disorder affecting the vestibular system, thus it is a localized clinical manifestation of basilar artery migraine.     

Vestibular Neuritis: a Follow-up Study

Seven to eight years after a disease period of vestibular neuritis 19 patients previously examined at our department were given a questionnaire about whether they had experienced any audiovestibular symptoms since they first fell ill. All 19 patients responded and 18 consented to participate in the long-term follow-up study. The patients were subjected to a clinical evaluation, a bithermal caloric test and audiological examinations with stapedius reflex measurements with use of the same technique as at the first examinations. Ten of the 18 patients had experienced recurrent vestibular symptoms with sensation of dysequilibrium and vertigo. Six of these 10 patients also had periods of positional vertigo. The remaining nine patients were free of symptoms. None of the patients had noticed any change in their hearing ability. The mean caloric side difference at the 7- or 8-year follow-up was not significantly higher in the group of patients with symptoms than in the group without symptoms. Neither did the group of patients with pathologically elevated stapedius reflex thresholds at onset display a larger mean caloric side difference than the group of patients with normal thresholds. However, a small caloric side difference at onset of the disease served as a predictor for residual vestibular symptoms. It is speculated whether the group of patients with residual symptoms had a different pathophysiological localization of their disease within the vestibular system than the group of patients with no symptoms at follow-up.     

Vestibular neuritis: a follow-up study

Seven to eight years after a disease period of vestibular neuritis 19 patients previously examined at our department were given a questionnaire about whether they had experienced any audiovestibular symptoms since they first fell ill. All 19 patients responded and 18 consented to participate in the long-term follow-up study. The patients were subjected to a clinical evaluation, a bithermal caloric test and audiological examinations with stapedius reflex measurements with use of the same technique as at the first examinations. Ten of the 18 patients had experienced recurrent vestibular symptoms with sensation of dysequilibrium and vertigo. Six of these 10 patients also had periods of positional vertigo. The remaining nine patients were free of symptoms. None of the patients had noticed any change in their hearing ability. The mean caloric side difference at the 7- or 8-year follow-up was not significantly higher in the group of patients with symptoms than in the group without symptoms. Neither did the group of patients with pathologically elevated stapedius reflex thresholds at onset display a larger mean caloric side difference than the group of patients with normal thresholds. However, a small caloric side difference at onset of the disease served as a predictor for residual vestibular symptoms. It is speculated whether the group of patients with residual symptoms had a different pathophysiological localization of their disease within the vestibular system than the group of patients with no symptoms at follow-up.     

Galvanic-Induced Postural Movements As a Test of Vestibular Function in Humans

Galvanic stimulation produces postural sway and eye movements in humans. Since galvanic currents are thought to exert their effect at the trigger zone of the vestibular nerve, an intact vestibular nerve should be necessary to produce a response. We have used galvanic stimulation in humans to test the hypothesis that intact vestibular nerve fibers are required to obtain a postural sway response. Experimental subjects included normal subjects, patients who had undergone resection of an acoustic neuroma, and patients who had undergone vestibular neurectomy and surgical labyrinthectomy. Our results support the hypothesis that an intact vestibular nerve is necessary to produce a response. Moreover, two patients with recurrent vertigo following vestibular neurectomy and labyrinthectomy, who had absent ice-water caloric test responses in the operated ears, were found to have a positive galvanic response. This result suggested that their recurrent vertigo was based on intact residual vestibular nerve fibers. Although previous research has not yielded a routine clinical use for galvanic stimulation, our results suggest that galvanic stimulation of the vestibular system can provide unique and valuable diagnostic information.     

Evidence for a viral neuropathy in recurrent vertigo

The concept that reactivation of latent neurotropic viruses (i.e. Herpesviridae group) in the vestibular ganglion is responsible for recurrent vestibulopathies is presented. A similar histopathologic degeneration of vestibular ganglion cells in vestibular neuronitis (VN), Ménière's disease and benign paroxysmal positional vertigo is presented to support this concept. The clinical response (relief of vertigo) to the administration of antiviral medication in these syndromes provides practical evidence of a viral neuropathy in patients with recurrent vertigo. Relief of vertigo after this treatment was 90% in VN, Ménière's disease and VN. The relief of positional vertigo (benign paroxysmal positional vertigo) was 66%.