Long-term prognosis of preserved useful hearing after surgery in patients with vestibular schwannoma: a study of 91 cases.

BACKGROUND: In patients with a vestibular schwannoma, some studies have reported that useful hearing preserved initially after surgery deteriorates gradually in the long term. Studies with more patients are needed to clarify the maintenance rate of postoperative hearing function and to identify prognostic of hearing function. METHOD: Ninety-one patients (mean age, 39.5 years; mean tumor size, 18.9 mm) with preserved useful hearing immediately after surgery were retrospectively analyzed. The useful hearing was defined as the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) classes A and B. Hearing tests, including auditory brainstem responses (ABR) and distortion product otoacoustic emissions (DPOAE), were evaluated preoperatively, immediately after surgery, and at outpatient follow-up. RESULTS: At the final follow-up (mean, 63.0 months), the useful hearing was maintained in 79 patients (87%), and the hearing class remained unchanged during the follow-up period in 40 patients (44%). Significant predictors of useful hearing maintenance were AAO-HNS class A immediately after surgery, improvement of ABR, and the absence of postoperative DPOAE deterioration. Postoperative DPOAE deterioration correlated with hearing class deterioration. CONCLUSIONS: Despite hearing being preserved in vestibular schwannoma patients immediately after surgery, Thirteen percent lost their useful hearing during the long follow-up period, and hearing class worsened in 55% of the patients. This study, which analyzed one of the largest series of vestibular schwannoma patients, demonstrated that retrocochlear condition is a key factor for useful hearing maintenance. In patients with vestibular schwannoma who have preserved hearing function, regular postoperative monitoring of hearing function is as important as regular MRI.

Role of follow-up gallium scintigraphy in the evaluation of malignant external otitis (skull base osteomyelitis): A case report.

Malignant otitis externa (skull base osteomyelitis) can be fatal and long-term antibiotic therapy is recommended. Despite being potentially fatal, this infection causes minor changes in inflammatory biomarkers (white blood cell count and C-reactive protein levels) upon blood testing. Computed tomography and magnetic resonance imaging changes persist over a long period. Therefore, it is difficult to determine the optimal time for the discontinuation of antibiotics. We present a 77-year-old male whose medical history included type 2 diabetes mellitus who suffered from chronic otitis media with Pseudomonas aeruginosa infection. His condition did not improve with proper treatment, and imaging revealed malignant otitis media. Intravenous cefepime treatment was administered. Antibiotic treatment was de-escalated to oral levofloxacin treatment after Gallium-67 scintigraphy showed less accumulation after 6 weeks of Cefepime administration; accumulation almost disappeared after 1 year. In this report, we describe the usefulness of gallium scintigraphy in the evaluation of malignant otitis externa.

The clinical outcome of the patients with horizontal semicircular canal variants of benign paroxysmal positional vertigo.

BACKGROUND: Gufoni maneuver is known to be effective for horizontal canal benign positional vertigo (HC-BPPV), but there are some intractable patients that the treatment procedure does not work. OBJECTIVE: The clinical outcomes of patients with HC-BPPV were investigated. We also investigated the characteristics of intractable patients which needed long time to the remission. METHODS: Sixty-six patients with HC-BPPV receiving Gufoni maneuver at Tokyo Medical University Hachioji Medical Center were investigated. The patients were classified into geotropic DCPN group and apogeotropic DCPN group. The clinical outcomes in 2 groups were examined. RESULTS: There were 48 patients with geotropic DCPN and 18 patients with apogeotropic DCPN. There were significant differences between the geotropic HC-BPPV and apogeotropic HC BPPV in the period to remission. There were 7 intractable patients and the average ages of these intractable patients were higher than other patients. CONCLUSION: The patients with geotropic DCPN and the patients with the nystagmus conversion from apogeotropic to geotropic DCPN have tendency to easy to resolve, but in patients with apogeotropic type without nystagmus transformation have long time to resolve. The elderly patients whose nystagmus remains apogeotropic without nystagmus conversion have tendencies to become intractable.

Electronystagmography in 166 patients with acoustic neuroma before and after surgery.

OBJECTIVE: To analyze the preoperative patterns of caloric test, eye tracking test (ETT), and optokinetic pattern (OKP) in patients with acoustic neuroma (AN) and compare them with the postoperative patterns of ETT and OKP results METHODS: A total of 166 patients with AN (102 women; mean age: 41 years, range: 11-79 years) who were being treated at our hospital between 2013 and 2016 were enrolled. Preoperatively, a detailed history was taken regarding the presence of subjective symptoms of equilibrium dysfunction, and the patients underwent caloric test, ETT, and OKP. They were classified into three groups based on the preoperative ETT and OKP results as follows: Group A, normal ETT and OKP; Group B, either ETT or OKP was abnormal; and Group C, both ETT and OKP were abnormal. All patients were evaluated for subjective symptoms of vestibular dysfunction and were also grouped based on the tumor size on imaging. All surgeries were performed by a neurosurgeon using the lateral suboccipital retrosigmoid approach. About one month later after surgery, postoperatively ETT was performed on 150 patients and OKP was performed on 148 patients. The preoperative and postoperative ETT and OKP results were compared. The same two specialists analyzed the postoperative ETT and OKP findings as improved, unchanged, or worse. Student t-test was used for statistical analysis and a P-value of <0.05 was considered to indicate a statistically significant difference. RESULTS: The average canal paresis(CP) % was 65.8%. No correlation was found between tumor size and CP%. The other side, the average tumor size in each group was 26.6 mm, 28.7 mm, and 37.8 mm in the Group A, B, and C, respectively. The average tumor size in Group C was significantly greater than those of Group A and B (P<0.01). The presence of gait disturbance in Group C was significantly higher than the other groups (P<0.01). The other side, abnormal ETT and OKP were seen in 32.5% and 31.9% of all patients, respectively. ETT and OKP results improved postoperatively in 67.4% and 68.9% of these patients. CONCLUSIONS: Abnormal ETT and OKP results showed positive correlations with the tumor size and presence of subjective symptoms. Further, dysfunction of cerebellum and brain stem owing to tumor compression was observed to recover in many cases after surgery.

Pathologic correlations of otologic symptoms in acute lymphocytic leukemia.

OBJECTIVES: To assess the clinicopathologic correlations of otologic complaints in patients with acute lymphocytic leukemia. DESIGN: Otologic complaints and histologic findings were evaluated in 25 temporal bones of 13 acute lymphocytic leukemia patients. RESULTS: Nine patients had a history of otologic complaints, including hearing loss, otalgia, otorrhea, and vertigo in 5, 3, 3, and 2 patients, respectively. Hemorrhage was most commonly observed in the middle ear (6 patients, 9 temporal bones) and was also observed in cochlea (4 patients, 4 temporal bones), and vestibule (6 patients, 6 temporal bones). Leukemic infiltration was observed in the petrous apex (13 patients, 24 temporal bones), middle ear (7 patients, 14 temporal bones), cochlea (3 patients, 4 temporal bones), vestibule (3 patients, 4 temporal bones), and internal auditory canal (5 patients, 8 temporal bones). Inflammatory changes were observed in the cochlea (5 patients, 8 temporal bones) and vestibule (5 patients, 8 temporal bones). Middle ear effusion containing floating tumor cells was observed in 4 temporal bones of 3 patients. Irreversible histopathologic changes of the middle ear, such as the destruction of the ossicles, perforation of the tympanic membrane, and granulation tissues were observed in 5 temporal bones of 4 patients. CONCLUSIONS: Ear involvement is common in acute lymphocytic leukemia patients. With prolonged survival due to the progress of treatment, the diagnosis and treatment of nonhematopoietic system symptoms, such as ear problems due to acute lymphocytic leukemia, have become more important.

Transplantation of autologous oral mucosal epithelial cell sheets inhibits the development of acquired external auditory canal atresia in a rabbit model.

Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, hearing loss and chronic otorrhea. Although the disease can be treated surgically, the recurrence rate is high. This study explored whether autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. We succeeded in generating a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Endoscopic and histological findings in this model indicated that atresia developed over a 4-week period and was not inhibited by the placement of polyglycolic acid sheets immediately after skin dissection. By contrast, transplantation of autologous oral mucosal epithelial cell sheets, which had been fabricated by culture on temperature-responsive inserts without a feeder layer, prevented the development of atresia during the 4-week period after skin dissection. Transplantation of autologous epithelial cell sheets after surgical treatment of acquired external auditory canal atresia could be a promising new method to reduce the risk of disease recurrence. STATEMENT OF SIGNIFICANCE: Acquired external auditory canal atresia is characterized by fibrous tissue formation in the ear canal, which leads to hearing loss and chronic otorrhea. Although surgical treatments are available, the recurrence rate is high. In this study, we successfully generated a rabbit model of acquired external auditory canal atresia by dissecting the skin of the ear canal. Furthermore, we utilized this new animal model to investigate whether the transplantation of autologous oral mucosal epithelial cell sheets could be used as a novel therapy for ear canal atresia. Our results raise the possibility that the transplantation of autologous epithelial cell sheets after surgical treatment of ear canal atresia could be a promising new method to reduce the risk of disease recurrence.

Lessons learned from conventional animals: Encouragement to use specific-pathogen-free animals.

Experimental rabbits provide evidence for translational research regarding the pathogenies or treatment of human diseases. We developed a novel method for regenerating the middle ear mucosa using autologous cultured nasal mucosal epithelial cell sheets, and evaluated the wound healing process in the middle ear mucosa of experimental rabbits. Nonetheless, vigilant microbiological monitoring of experimental animals is essential to effectively prevent a decline in their health conditions, which may affect the research results. We experimented with contamination of Pasteurella multocida in non-specific-pathogen-free (SPF) rabbits (without microbiological monitoring). Most non-SPF rabbits had otitis media, whereas SPF rabbits did not, which affected their results during the mucosal regeneration study. The contamination was resolved by changing the experimental design from using non-SPF rabbits to that using SPF rabbits. It is crucial to use the SPF animals for any surgical intervention studies.

Extradural Transjugular Transsigmoid Approach with High Cervical Exposure for Glomus Jugulare Tumor.

Surgical removal of glomus jugulare tumors is challenging owing to the complex anatomy of the temporal bone and craniocervical region, aggressive tumor invasion into the nearby structures, and their hypervascularity. However, recent advances in skull base techniques, intraoperative neuromonitoring, and radiological interventions have enabled their relatively safe resection, while giving priority to functional preservation. This video demonstrates a case of a glomus jugulare tumor treated by the extradural transjugular transsigmoid approach with high-cervical exposure and tympamoplasty, after preoperative embolization. A 47-year-old woman presented with progressive hearing disturbance, pulsatile tinnitus, and hemifacial spasm. Neuroimaging displayed a hypervascular tumor occupying the temporal bone, extending to the cervical region through the jugular foramen, and to the external auditory canal. Preoperative feeder occlusion was successfully performed without any additional symptoms, while carefully evaluating the provocative test. Near-total resection of the tumor was achieved through the transjugular transsigmoid approach with high-cervical exposure under detailed neuromonitoring, including continuous facial nerve monitoring and auditory brainstem response. In this patient, in whom the tumor did not invade intradurally and the sigmoid sinus was already occluded preoperatively, the sinus was managed only by coagulation, to avoid unnecessary dural opening and the risk of cerebrospinal fluid leakage. Anterior facial nerve rerouting was not required since the tumor removal was accomplished through the corridor above and below the fallopian bridge. The patient had no new neurological deficits, and her pulsatile tinnitus and hemifacial spasm disappeared after the surgery. Her hearing disturbance improved postoperatively. The link to the video can be found at: https://youtu.be/gqf3dxHlv_0 .

A case of acute disseminated encephalomyelitis presenting with vertigo.

We report a 37-year-old woman with acute disseminated encephalomyelitis (ADEM) who presented with progressive vertigo. A central nervous system disorder was initially suspected because gaze-evoked torsional nystagmus was observed and electrical nystagmography (ENG) revealed abnormal eye movements with saccadic ocular pursuit and pathological optokinetic nystagmus. Finally ADEM was diagnosed by the clinical symptoms and the characteristic patterns of brain MRI. It is rare for otolaryngologists to examine patients with ADEM. ADEM takes an acute course and can present a grave state and therefore needs early diagnosis, early treatment. We have to keep ADEM in mind in the diagnosis of vertigo.

Comparison of cervical vestibular evoked potentials evoked by air-conducted sound and bone-conducted vibration in vestibular Schwannoma patients.

OBJECTIVE: The vestibular evoked myogenic potential (VEMP) is associated with otolithic afferents and can be used to evaluate the function of the saccule and utricle. In this study, we compared cervical VEMP evoked by stimulation with Air-conducted sound (ACS) and bone-conducted vibration (BCV) to the forehead and investigated whether BCV can be used as a substitute for ACS. METHODS: Data were obtained from 33 patients with vestibular schwannoma. Vestibular examinations were performed preoperatively. VEMP was obtained upon stimulation with ACS (ACS cVEMP) and BCV to the forehead using a minishaker (BCV cVEMP). Vestibular function was also analyzed using the caloric test and ocular VEMP (oVEMP) testing. oVEMP was measured using bone-conductive vibration to the forehead. The results of BCV cVEMP, ACS cVEMP, and oVEMP were compared by the caloric test. RESULTS: Rates of patients with abnormal ACS cVEMP, BCV cVEMP, oVEMP, and caloric test results were 78.8%, 75.8%, 78.8%, and 69.7%, respectively. BCV cVEMP did not correlate with ACS cVEMP, but correlated with oVEMP and caloric test results. CONCLUSION: BCV cVEMP did not correlate with ACS cVEMP. Therefore, BCV cVEMP cannot be used as a substitute for ACS cVEMP.

Experimental model of benign paroxysmal positional vertigo with biphasic nystagmus using isolated semicircular canals.

CONCLUSIONS: The co-existence of cupulolithiasis and canalolithiasis might be a possible mechanism for the spontaneous inversion of positional nystagmus. OBJECTIVE: To investigate the mechanism of spontaneous inversion of nystagmus direction without a positional change in experimental models of co-existing cupulolithiasis and canalolithiasis. METHODS: Co-existing canalolithiasis and cupulolithiasis models were prepared using the bullfrog posterior semicircular canal (PSC). Ten bullfrogs were used. The ampullary nerve discharges were recorded as compound action potentials (CAPs). First, an otoconial mass was placed on the cupula to produce cupulolithiasis. Subsequently, another otoconial mass was introduced into the canal lumen to produce canalolithiasis. Decremental time constants for cupulolithiasis and incremental time constants for canalolithiasis were determined. RESULTS: At first the CAPs increased and continued for a long time when the cupulolithiasis was generated. Subsequently the CAPs were suppressed by creating canalolithiasis. Finally, the CAPs increased again after the motion of otoconia inside the canal lumen stopped. The decremental time constant for cupulolithiasis was significantly longer than the incremental time constant for canalolithiasis.

Model experiments of BPPV using isolated utricle and posterior semicircular canal.

OBJECTIVES: This study was aimed to experimentally investigate the effect of returned otoconia on the utricular using isolated utricles. The effect of interposed otoconia in models of canalolithiasis and cupulolithiasis were also investigated using isolated posterior semicircular canal (PSC). METHODS: Bullfrogs were used. The utricles (Experiment I) and PSC (Experiment II) were removed in Ringer solution. Experiment I-a: The otoconia were carefully removed from the utricular macula with gentle flush of Ringer solution. Before and after the otoconial removal, sinusoidal rotatory stimulation (0.1 Hz, 135 degrees ) was given to record utricular compound action potentials (CAPs). Experiment I-b: (1) Instantaneous changes in the utricular potentials when the otoconial mass was positioned on the macula were recorded. (2) Utricular CAP changes in response to sinusoidal rotation immediately and 10 min after the otoconial positioning were recorded. Experiment II: PSC CAPs due to sinusoidal rotatory stimulation in normal specimen, canalolithiasis and cupulolithiasis models were recorded. RESULTS: Experiment I-a: The utricular CAPs in response to sinusoidal rotation showed sinusoidal oscillation. However, this oscillation disappeared after the otoconial removal. Experiment I-b: (1) The utricular potentials transiently increased for 3-4 s after positioning the otoconial mass. (2) The utricular CAPs increased in seven specimens and decreased in four. Ten minutes after the CAPs were almost the same as immediately after otoconial positioning. Experiment II: In cupulolithiasis model, the PSC CAPs decreased in all specimens. CONCLUSIONS: The otoconia played an essential role as a transducer of acceleration to the utricular macula. Otoconia returned to the utricular macula change utricular reactivity and hence are the possible cause of dizziness after physical therapy. PSC responses to sinusoidal rotation were suppressed in cupulolithiasis model.

Spontaneous inversion of nystagmus without a positional change in the horizontal canal variant of benign paroxysmal positional vertigo.

OBJECTIVE: We investigated the neuro-otological findings, including nystagmus, and the clinical course of patients with the horizontal canal variant of benign paroxysmal positional vertigo (HC-BPPV), who showed spontaneous inversion of nystagmus without a positional change. Furthermore, we speculated on the possible mechanism of spontaneous inversion of nystagmus without a positional change. PATIENTS AND METHODS: The characteristics of spontaneous inversion of positional nystagmus without a positional change were analyzed in 7 patients with HC-BPPV. RESULTS: All patients were diagnosed as having HC-BPPV. During the positional test, the spontaneous inversion of nystagmus was observed in the same head position in all patients. Spontaneous inversion was observed on both sides in 5 patients, and only on 1 side in 2 patients. All patients presented with geotropic nystagmus in the first phase, and ageotropic nystagmus in the second phase. CONCLUSIONS: The coexistence of cupulolithiasis and canalolithiasis appears to be a possible mechanism of the spontaneous inversion of positional nystagmus.

Stapes fixation accompanied with abnormal facial nerve pathway.

The patient was a 52-year-old woman. She had been aware of her bilateral hearing loss since she was 20 years old. The hearing in her left ear started to deteriorate at the age of 49. Pure-tone audiometry showed a bilateral mixed hearing loss. The hearing levels for the right ear and the left ear were 52 dB and 68 dB, respectively. There were no remarkable findings in a computed tomography (CT) scan of the temporal bone. We suspected that she had otosclerosis, and an operation was performed on her left ear. When the incudostapedial joint (I-S joint) was exposed to investigate the movement of the stapes, a soft white band that ran under the superstructure of the stapes was noted. By using a nerve monitoring system, we confirmed that the white band was the bare facial nerve. The ossicular chain was normal, except for a malformed stape due to the facial nerve, and the footplate of the stapes was fixed. Therefore, she was diagnosed as having otosclerosis with an abnormal facial nerve pathway. The malformed superstructure of the stapes was removed carefully. When the ectopic facial nerve was shifted to anteroinferior side, the oval window could be seen. Stapedotomy using a Teflon piston prosthesis was performed with no complications.

Ocular vestibular evoked myogenic potentials induced by bone-conducted vibration in patients with unilateral inner ear disease.

CONCLUSION: Patients with vestibular neuritis (VN) with complete canal paresis (CP) showed a higher rate of abnormal ocular vestibular evoked myogenic potential (oVEMP) than those with partial CP. From these results, it is speculated that the superior vestibular nerve function mainly affects oVEMP. Significant correlation was found between the grades of the hearing outcome and oVEMP in sudden sensorineural hearing loss (SSHL). OBJECTIVE: We attempted to correlate the results of oVEMP with the results of cervical VEMP (cVEMP), results of subjective visual vertical (SVV), and clinical course in patients with various vestibular disorders. METHODS: Twenty-two patients with VN, 65 with SSHL, and 22 with Meniere's disease (MD), were enrolled in this study. We compared the results of oVEMP with those of cVEMP, SVV, and the caloric test. Furthermore, the oVEMP results were compared with the initial hearing threshold, presence of vertigo, and hearing recovery in the patients with SSHL. RESULTS: The patients with VN with complete CP showed a higher rate of abnormal oVEMP than those with partial CP. In the patients with SSHL, the hearing recovery rate was lower in the patients with abnormal oVEMP than in those with normal oVEMP.

Intermittent positional downbeat nystagmus of cervical origin.

Intermittent positional down beat nystagmus (p-DBN) is rare. We describe an unusual case of intermittent p-DBN which was induced by rotation, anteflexion, and lateral flexion of the neck. A 59-year-old man complained of loss of consciousness and lightheadedness. Positional testing revealed the p-DBN. The evoked p-DBN had latency and the patient had a feeling of passing out while the p-DBN was present. There were no abnormal findings in the vestibular functional examinations. Findings of the MRI were negative. MRA revealed no stenosis of the vertebral artery bilaterally, but there was an anatomical difference. The p-DBN characteristics were documented by electronystagmography during the positional test. The p-DBN lasted intermittently while maintaining the provoking position. It was found that p-DBN occurred with not only the rotation of the neck, but also in the anteflexion and lateral flexion of the neck. There was no stenosis of the vertebral artery (VA) on angiography, but we speculated that the cause of the p-DBN was the VA occlusion due to rotation, anteflexion, and lateral flexion of the neck.

Auditory-pupillary responses in patients with vestibular neuritis.

Pupillary dilation in response to sound stimuli is well established and generally represents a startle reflex to sound. We previously reported that auditory-pupillary responses (APRs) persist with bilateral deafness, and that the pathways mediating APRs involve not only the cochlea but also otolith organs, especially the saccule. Here, we evaluated the vestibulo-autonomic responses in vestibular neuritis (VN) by assessing APRs. Twelve young healthy volunteers without a history of hearing and equilibrium problems and 10 VN patients participated. To clarify the relationship between APRs and vestibular function, especially otolith function, we performed caloric and vestibular-evoked myogenic response testing on VN patients. In normal subjects, we examined APRs when delivering sound stimuli to both sides. In VN patients, we examined APRs when delivering stimuli simultaneously to both sides, to the affected side alone, and then to the unaffected side alone. With binaural stimulation, the pupillary index (PI) - the rate of dilation - of VN patients significantly differed from those of normal subjects. Moreover, in VN patients, PIs of the affected sides were significantly larger than those of the unaffected sides. Our study provides evidence that examining APRs may be useful for evaluating vestibulo-autonomic reflexes, especially otolith-autonomic reflexes.

Subjective visual vertical perception in patients with vestibular neuritis and sudden sensorineural hearing loss.

OBJECTIVE: To determine the subjective visual vertical (SVV) perception in patients with vestibular neuritis (VN) and sudden sensorineural hearing loss (SSHL) using the SVV test and other neuro-otological examinations, namely, the vestibular evoked myogenic potential (VEMP) and caloric tests, and to clarify which vestibular nerve function is associated with an SVV shift. PATIENTS AND METHODS: We performed the SVV test in 36 VN patients and 80 SSHL patients. Thereafter, we investigated directional changes in the SVV in the VN and SSHL patients, and compared the results of the SVV test with those of the VEMP and caloric tests. RESULTS: Abnormal SVV (> 2° was found at a rate of 69.4% in the VN patients and 26.3% in the SSHL patients. In all except 1 VN patient, the SVV tilted to the lesion side. The rate of abnormal SVV was significantly higher in patients with complete canal paresis (CP) than in patients with partial CP. There was no significant relationship between the rates of abnormal SVV and VEMP. In the SSHL patients, neither the SVV nor the VEMP affected the hearing outcome and patients with abnormal VEMP tended to show abnormal SVV. CONCLUSION: VN patients showed a higher rate of abnormal SVV than SSHL patients. From the results, it is speculated that the superior vestibular nerve function mainly affects the SVV tilt, although the inferior vestibular nerve function may also have an effect.

Changes in the cupula after disruption of the membranous labyrinth.

CONCLUSION: Various changes were observed in the cupula, including shrinkage and enlarged volume, following the disruption of the membranous labyrinth. Cupular change after membranous labyrinth disruption may be a pathology of vestibular disorders. OBJECTIVES: To observe the morphological changes of the cupula after disruption of the membranous labyrinth and to compare the cupular changes with changes in the compound action potential (CAP) of the ampullary nerve. METHODS: A labyrinthine injury model was created by puncturing the membranous labyrinth of bullfrogs. The cupula was observed from 3 to 17 days after the membrane puncture. The CAP in response to mechanical endolymphatic flow was recorded from the ampullary nerve. The correlation between cupular change and CAP positivity was evaluated using the authors' scale. RESULTS: Various kinds of cupular changes including shrinkage were observed. Cupular change was more severe after a longer survival period. Large or elongated volume of the cupula was also observed, which was not observed in our previous study using gentamicin. The CAP could be recorded even when the cupular change was severe.

Vestibular system changes in sudden deafness with and without vertigo: a human temporal bone study.

OBJECTIVE: To investigate the vestibular system changes in sudden deafness with vertigo (SDwV) and sudden deafness without vertigo (SDwoV) and the cause of persistent canal paresis (CP) in SDwV patients. STUDY DESIGN: Retrospective study. MATERIALS AND METHODS: Four temporal bones from the affected ear in 4 patients with unilateral sudden deafness (SD), 2 SDwV and 2 SDwoV, were selected. Four contralateral temporal bones with normal-hearing ears were defined as the control. Morphologic findings of the labyrinth, the number of Scarpa's ganglion cells, and the density of vestibular hair cells were investigated in all temporal bones. Clinical data and the results of vestibular tests of 11 patients with unilateral SD, as a separate group, also were investigated. RESULTS: Atrophic change of the organ of Corti, tectorial membrane, and stria vascularis in cochlea, and deposits and atrophic otoconial membrane in vestibular sense organs were seen on affected ears more than control ears. The density of Type I hair cells seemed to decrease on the saccular macula and the posterior semicircular canal crista on affected ears, and there was no remarkable difference between SDwV and SDwoV. In 1 patient with SDwoV who died 10 months after the onset of SD, there were large amount of deposits on the cupula, the atrophied otoconial membrane was peeling off from the saccular macula, and the saccular membrane collapsed to the saccular macula in the affected ear. In the clinical data, all SDwV who were examined within 2 years from the onset had CP, and all SDwV had profound hearing loss. CONCLUSION: There is no remarkable difference between SDwV and SDwoV in the number of Scarpa's ganglion cells and the density of vestibular hair cells. The damage of the extracellular superstructure is seen in SD with or without vertigo. The damage of extracellular superstructure is potentially one of the causes of persistent CP in patients with SD.