Biomedical subjects

Toshihisa Murofushi

Publications and source records attributed to Toshihisa Murofushi.

At least 19 recordsLinked to original sources

PubMed2006

The effectiveness of wedge shoes in patients with insufficient vestibular compensation.

OBJECTIVES: Patients who fail to achieve sufficient vestibular compensation after acute vestibular deafferentation show a tendency to deviate toward the affected side. This study evaluated the effectiveness of wedge shoes specially manufactured with a 4mm inclination on the affected side to patients with chronic vestibular insufficiency. METHODS: Subjects comprised 13 patients with chronic vestibular insufficiency for >6 months after acute unilateral vestibular dysfunction and 9 healthy volunteers. Subjects underwent vestibular tests wearing wedge shoes and regular shoes. Differences in results were compared. RESULTS: Patients showed significant improvements in the straight gait test (p<0.01), Unterberger-Fukuda stepping test (p<0.01) and posturography test (p=0.015) when wearing wedge shoes compared with wearing regular shoes. CONCLUSION: Our results suggested that raising the lateral sole of shoes on the affected side could effectively ameliorate the effects of chronic vestibular insufficiency.

Adult↗

PubMed2006

Intratympanic injection of dexamethasone as an alternative treatment of steroid-dependent sensorineural hearing loss associated with aortitis syndrome.

We report a 44-year-old Japanese woman who presented with fluctuating hearing loss. She suffered from aortitis syndrome (AS) since she was 30-year-old and took daily tablets of prednisolone (10mg). Pure tone audiometry showed bilateral high-tone sensorineural hearing loss. Although her hearing recovered with higher doses of steroids, she was concerned about the systemic side effects of frequent administration of high doses of steroids. Thus, she underwent intratympanic injection of dexamethasone at the time of worsening of hearing. Her hearing has been maintained by intratympanic injection of dexamethasone. Intratympanic injection of steroids may be an alternative treatment for hearing loss associated with AS.

Administration, Oral↗

PubMed2006

A case of severe dyspnea caused by relapsing polychondritis.

Relapsing polychondritis (RP) is a multi-systemic rheumatic disease characterized by widespread and potentially destructive inflammatory lesion of the cartilage. The rarity of the disease and the lack of pathognomonic laboratory findings sometimes cause delay in diagnosis. We report a 72-year-old woman with RP. When she was referred to our hospital 4 weeks after the onset of respiratory symptoms, she was having severe breathing difficulty. Immediate tracheostomy followed by steroid therapy dramatically improved her condition of RP, although the treatment was complicated due to her other condition, depression. While airway involvement of RP can be life threatening, it is curable with steroid therapy. Otolaryngologists should keep in mind that airway obstruction could be caused by RP.

Aged↗

PubMed2006

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.

Adult↗

PubMed2006

Superficial siderosis causing retrolabyrinthine involvement in both cochlear and vestibular branches of the eighth cranial nerve.

Although superficial siderosis (SS) has been clinically characterized as a combination of sensorineural hearing impairment, cerebellar ataxia and pyramidal signs, precise evaluation of the function of the eighth cranial nerve has rarely been reported. The purpose of this study was to evaluate the audiological and vestibular function. We present a patient with complaints of progressive bilateral hearing loss and gait difficulty. We evaluated the audiological and vestibular functions with auditory brainstem responses and vestibular evoked myogenic potentials (VEMPs) by clicks and galvanic stimuli. The patient showed linear hypointensities surrounding the brainstem, cerebellum and the eighth cranial nerve on T2-weighted MRI images, which is characteristic of SS. Auditory brainstem response showed only wave I in the right ear and no response in the left ear. Click VEMPs and galvanic VEMPs showed no response on either side. The results of a neuro-otological examination suggested that both audiological and vestibular dysfunction in the patient with SS is of retrolabyrinthine origin.

Ataxia↗

PubMed2006

Recovery of subjective visual horizontal after unilateral vestibular deafferentation by intratympanic instillation of gentamicin.

The time course of the recovery of subjective visual horizontal (SVH) after unilateral vestibular deafferentation by intratympanic instillation of gentamicin was studied. Six patients who underwent intratympanic gentamicin instillation therapy for Meniere's disease (1 man and 5 women, 32 to 69 years of age) were enrolled in this study. For comparison, SVH in 23 healthy subjects (12 men and 11 woman, 23 to 48 years of age) was also measured. The mean +/- SD of SVH in healthy subjects was 0.0 +/- 1.1 deg. All of the 6 patients showed significantly deviated SVH toward the injected side-down at the early stage after the therapy. Although one patient showed recovery of SVH to the normal range 25 days after the injection, the other patients required more time for recovery. Three patients did not show recovery to the normal range after 1 year. On the other hand, spontaneous nystagmus observed using an infrared CCD camera in total dark disappeared after 35 days (median). Patients who had normal vestibular evoked myogenic potentials before the therapy showed a tendency of delay of recovery of SVH. The reasons why the recovery of SVH took longer than the disappearance of spontaneous nystagmus are discussed in this report.

Adult↗

PubMed2005

Subjective visual horizontal and stabilometer findings in patients with unilateral severe vestibular dysfunction.

The records of both stabilometer and subjective visual horizontal (SVH) testing can be used to evaluate vestibular compensation. When results of SVH testing have a strong significant correlation to those of stabilometer testing, clinicians can omit one of two tests from the test battery. To investigate the correlation, results of these two tests of patients with unilateral severe vestibular dysfunction were studied. Twenty-eight patients, 20 men and 8 women, with unilateral severe vestibular dysfunction were enrolled in this study. The correlation between these two tests was considered not significant according to the results. In conclusion, we cannot omit either stabilometer testing or SVH testing for the evaluation of patients with vestibular dysfunction.

Adolescent↗

PubMed2005

VEMP recording by binaural simultaneous stimulation in subjects with vestibulo-cochlear disorders.

To reduce the testing time of vestibular evoked myogenic potentials (VEMP) and the physical efforts of subjects, we studied if VEMP recording by binaural simultaneous stimulation in patients with vestibulo-cochlear disorders can be applicable as a screening test. Twenty-eight patients with vestibulo-cochlear disorders (12 men and 16 women, 22 to 77 years of age) were enrolled in this study. Patients were presented with binaural or monaural click (95 dBnHL) stimulation to record VEMPs. Their VEMP responses to binaural simultaneous stimulation were compared with those of monaural individual stimulation. Twenty-six of the 28 patients (93%) showed the same results in binaural simultaneous stimulation as in monaural individual stimulation. Amplitudes of p13-n23 to binaural simultaneous stimulation showed significant correlation to those of monaural individual stimulation ( r =0.774, P <0.0001 t -test). Peak latencies of p13 and n23 of binaural simultaneous stimulation also showed significant correlation to those of monaural individual stimulation (p13: r =0.684, P <0.0001 t -test, n23: r =0.657, P <0.0001 t -test). The binaural simultaneous stimulation method for VEMP recording is applicable for patients with vestibulo-cochlear disorders as a screening test in the clinic.

Adult↗

PubMed2005

Extent of lesions in idiopathic sudden hearing loss with vertigo: study using click and galvanic vestibular evoked myogenic potentials.

OBJECTIVE: To clarify the extent of the vestibular lesions in idiopathic sudden hearing loss with vertigo using vestibular evoked myogenic potentials (VEMPs) in response to click (click-VEMP) and galvanic (galvanic-VEMP) stimulation, as well as caloric tests. DESIGN: Retrospective study. SETTING: University hospital. PATIENTS: We enrolled 22 patients with idiopathic sudden hearing loss with vertigo in this study. All patients underwent audiometry and click-VEMP and caloric tests. Eight patients underwent a galvanic-VEMP test. RESULTS: Among the 22 patients, 17 (77%) showed an absence of click-VEMPs on the affected side. In response to caloric testing, 10 patients (45%) showed a decreased response on the affected side. All 8 patients who underwent galvanic-VEMP testing showed normal responses. Most patients with decreased caloric responses (9 [90%] of 10 patients) showed an absence of click-VEMPs, whereas 9 (53%) of the 17 patients who showed abnormal click-VEMPs showed decreased caloric responses. Initial hearing level and hearing outcome significantly correlated with abnormalities on the vestibular test results. CONCLUSIONS: The lesion site of vestibular disorders in idiopathic sudden hearing loss with vertigo appeared to be within the labyrinth on the basis of galvanic-VEMP findings. Results of the click-VEMP and caloric tests suggested that the saccule could be involved more frequently than the semicircular canals. The combined use of click-VEMP and caloric tests is useful for evaluating vestibular functions in idiopathic sudden hearing loss with vertigo because the extent of vestibular abnormalities correlated well with hearing outcome.

Adult↗

PubMed2005

Sound-evoked neurogenic responses with short latency of vestibular origin.

OBJECTIVE: In ABR recording, a large negative deflection with a latency of 3 ms (N3) has been recorded in patients with peripheral profound deafness. It has been suggested that N3 might be of vestibular origin. So far, N3 has been recorded only in patients with peripheral profound deafness. If we can record N3 potentials in subjects with preserved hearing, recording N3 potentials might be a new clinical test of the vestibular system. To record neurogenic potentials (N3) of vestibular origin in healthy volunteers and patients with vestibular disorders. METHODS: Twelve healthy volunteers (10 men and two women, aged 23-37 years) and 12 patients with vestibular disorders (6 men and 6 women, aged 29-71 years) were enrolled in this study. To record responses, surface electrodes were placed on the ipsilateral mastoid and the vertex. An electrode on the nasion served as the ground. Recording was performed using an auditory evoked potential recording system with a mini-mixer and a stereo-amplifier. Signals at the vertex to the ispilateral mastoid were amplified and bandpass filtered (100-3000 Hz). One thousand-hertz short tone bursts (1 kHz STB; rise/fall time=0.5 ms, plateau time=1 ms) were presented to either ear through a headphone with or without white noise (WN) ipsilateral to the stimulated ear. The stimulation rate was 10 Hz, and the analysis time was 10 ms. The responses to 500 stimuli were averaged twice. RESULTS: When 1 kHz STB (95 dBnHL, equivalent to 130 dBSPL) were presented with 100 dBSPL WN (ipsilateral to the stimulated ear), a negative peak with 3-4 ms latency (N3) was observed in 23 of the 24 ears (95.8%) with reproducibility in healthy subjects. Without WN, N3 was observed in 17 of the 24 ears (70.8%). The threshold of N3 was 90.2 dBnHL on the average. The presence of N3 in the patients was in agreement with the presence of the VEMP, which were also recorded. CONCLUSIONS: Using techniques of WN exposure ipsilateral to the stimulated ear, we recorded N3 in healthy subjects and in vestibular disorder patients with preserved hearing. This negative peak is likely to be of vestibular origin. SIGNIFICANCE: N3 may be measured from subjects who cannot contract neck muscles due to their ages, mental states, or consciousness disorders. In other words, N3 may be measured from subjects from whom VEMP cannot be recorded. In combination with VEMP, N3 may be useful for the detection of lesion sites.

Acoustic Stimulation↗

PubMed2005

Independent effects of simultaneous inputs from the saccule and lateral semicircular canal. Evaluation using VEMPs.

OBJECTIVE: To determine the effects of stimulation of bilateral lateral semicircular canals (LSCCs) by accelerated rotation and caloric stimulation of unilateral LSCC on vestibular evoked myogenic potentials (VEMPs) in healthy volunteers. METHODS: In experiment 1, VEMPs were recorded while subjects (n = 11) were seated in a rotational chair and angular acceleration around the earth-vertical axis was provided. Amplitudes of p13-n23 were corrected using background muscle activities. In experiment 2, subjects (n = 8) in the semilateral position kept the LSCC in the vertical position and activated the sternocleidomastoid muscle by twisting the neck. After irrigating the external auditory canal with ice water, VEMPs were recorded on the irrigated side. In experiment 3, the same setting as experiment 2 was applied (n = 6), and hot water of 44 degrees C was used for irrigation. RESULTS: There were no significant differences in latencies of p13 or n23, and in corrected amplitudes by either rotatory or caloric stimulation. CONCLUSIONS: Simultaneous stimulation of LSCCs has little effect on VEMPs. SIGNIFICANCE: No functional interaction between the saccule and LSCC was detected in VEMPs, although convergence of semicircular canal and otolith nerve inputs onto single vestibular nucleus neurons has been demonstrated electrophysiologically in animal experiments.

Adult↗

PubMed2005

Effect of stimulation repetition rate on galvanic-evoked vestibulo-collic reflexes.

CONCLUSION: Taking examination time and patient compliance into consideration, we propose that 5 Hz is the optimal stimulation rate of galvanic vestibular-evoked myogenic potentials for clinical use. OBJECTIVES: To evaluate the influence of stimulation repetition rate on galvanic-evoked vestibulo-collic reflexes and to propose the optimal stimulation rate for clinical use. MATERIAL AND METHODS: Both ears of 30 healthy adults were tested at 5 different galvanic stimulation rates (1, 3, 5, 7 and 9 Hz) in a random order. RESULTS: Responses were evident in all 60 ears only at 5 Hz; some ears showed no response at the other frequencies. The relative amplitudes in individual ears were higher at 1, 3 and 5 Hz than at 7 and 9 Hz. Comparison of the latencies of p13g and n23g showed no significant difference among the five stimulation rates.

Adult↗

PubMed2005

Lesion site in idiopathic bilateral vestibulopathy: a galvanic vestibular-evoked myogenic potential study.

CONCLUSION: The result suggests that patients with idiopathic bilateral vestibulopathy may have nerve lesions when the inferior nerve system is affected, while the inferior vestibular nerve system may be spared. OBJECTIVE: To clarify the lesion site in idiopathic bilateral vestibulopathy, an acquired bilateral vestibulopathy of unknown cause. MATERIAL AND METHODS: Two 75-year-old males diagnosed with idiopathic bilateral vestibulopathy were enrolled. Both showed absent or highly decreased responses on the caloric test on both sides. They underwent vestibular-evoked myogenic potential (VEMP) testing by means of acoustical and electrical stimulation. As acoustic stimulation, 95 dB nHL clicks and short tone bursts (500 Hz) were presented, while 3 mA (1 ms) short-duration galvanic stimuli were presented as electrical stimulation. Responses were recorded on the sternocleidomastoid muscles. RESULTS: Both patients showed unilateral absence of VEMPs with both acoustic and short-duration galvanic stimuli.

Acoustic Stimulation↗

PubMed2005

Neuro-otologic findings in unilateral isolated narrow internal auditory meatus.

OBJECTIVE: To report neuro-otologic findings concerning the four nerves in the internal auditory meatus (IAM) in patients with isolated congenitally narrow IAM and explore the implications regarding ontogeny of the nerves in the IAM. DESIGN: Retrospective case series study. SETTING: University hospital. SUBJECTS: Five consecutive patients between 1997 and 2002 with unilateral isolated narrow IAM demonstrated by high-resolution computed tomography whose chief complaint was hearing loss (1 male and 4 females, 4 right sides and 1 left; age range 5-37 years, mean 20 years; IAM diameter at the porus: 26-33% of that on the normal side). MAIN OUTCOME MEASURES: Functional studies concerning the VIIth cranial nerve and the three branches of the VIIIth cranial nerve. RESULTS: In all ears, auditory brain stem responses were absent, the speech discrimination score was 0%, and otoacoustic emissions were absent or markedly reduced compared with those on the normal side. Caloric responses were absent in two ears, reduced in two ears, and normal in one ear. Galvanic body sway tests showed no responses in the two ears in which caloric responses were absent. Inferior vestibular nerve function was estimated as normal in all ears on the basis of vestibular evoked myogenic potential recordings. Facial nerve functions were normal in all patients. CONCLUSIONS: In isolated congenital stenosis of IAM, dysfunction of each nerve in the IAM can occur independently. In the ontogeny of the VIIIth cranial nerve, the cochlear and superior vestibular nerves tended to be involved together, whereas the cochlear and inferior vestibular nerves appeared independent of each other.

Adolescent↗

PubMed2005

Abnormal vestibular evoked myogenic potentials in the presence of normal caloric responses.

OBJECTIVE: Combined use of vestibular evoked myogenic potential (VEMP) and caloric response testing has enabled us to examine the function of the inferior and superior vestibular nerves separately. Although results of VEMP testing and caloric response testing have been reported for many diseases, a clinical entity showing abnormal VEMP responses but normal caloric test responses has rarely been reported. The aim of the study was to investigate clinical features of diseases showing abnormal VEMP responses with normal caloric test responses. STUDY DESIGN: Retrospective. SETTING: University hospital. PATIENTS: Eight hundred eleven patients with balance problems who had undergone both caloric response and VEMP testing were included in the study. MAIN OUTCOME MEASURES: The amplitudes and latencies of the first positive-negative peak of the VEMP (p13-n23) were measured. RESULTS: Forty of the 811 patients (5%) were found to have abnormal VEMP responses with normal caloric test responses. Clinical diagnoses of these patients were Ménière's disease (n = 12), acoustic neuroma (n = 8), sudden deafness with vertigo (n = 6), and other diseases (n = 6). Eight patients could not be diagnosed as having a disease already recognized. Clinical manifestations of these eight patients were rotatory vertigo in six patients and non-rotatory dizziness in two. None of these patients showed abnormalities other than VEMP responses on neurologic or neurotologic examinations. CONCLUSION: Apart from Ménière's disease, acoustic neuroma, and sudden deafness with vertigo, which are already known as diseases with abnormal VEMP responses but normal caloric test responses, some patients might be diagnosed as having a disease that involves only the inferior vestibular nerve region.

Adult↗

PubMed2004

A case of Cronkhite-Canada syndrome with vestibular disturbances.

A 66-year-old Japanese man with Cronkhite-Canada syndrome (CCS) presented with complaints of long-lasting dysequilibrium. On neuro-otological examination, he showed gaze-evoked nystagmus at the rightward and leftward gaze, and saccadic pursuit. On the caloric test, he showed no response in either side, and on the head-impulse test he showed bilateral loss of vestibule-ocular reflexes around the yaw axis, while he had bilateral normal responses on the vestibular-evoked myogenic potential testing. Neuro-otological findings suggested that he had lesions in the peripheral vestibular system as well as the central nervous system. Neurological disorders such as sensory neuropathy have been reported in patients with CCS. This patient's balance problems could be due to CCS itself.

Aged↗

PubMed2004

Vestibular testing by electrical stimulation in patients with unilateral vestibular deafferentation: galvanic evoked myogenic responses testing versus galvanic body sway testing.

OBJECTIVE: To investigate the agreement of a lesion site as indicated by two different vestibular tests with electrical stimulation, galvanic body sway testing (GBST) and galvanic evoked myogenic responses (galvanic vestibular evoked myogenic potential; galvanic VEMP) testing, in patients with unilateral vestibular deafferentation. METHODS: Nineteen patients with unilateral vestibular deafferentation were studied, and the criteria for patient selection were as follows: (1) absence of a caloric response to ice water on the affected side in a supine position, and (2) absence of VEMP to 95 dBnHL clicks on the affected side. We assessed the postural response of the subjects to long duration galvanic stimulation (1 mA, 5 s) by measuring the lateral displacement at the center of foot pressure with a cathode electrode on the forehead, and an anode electrode on the mastoid (GBST). We also recorded the electromyographic (EMG) activities of the sternocleidomastoid muscle (SCM) to short duration galvanic stimulation (3 mA, 1 ms) (galvanic VEMP) with a cathode electrode on the mastoid, and an anode electrode on the forehead. RESULTS: In 18 of the 19 patients, the lesion site indicated by GBST was identical to that indicated by galvanic VEMP. Fourteen patients had abnormal results in both tests while 4 patients had normal results in both tests. One patient with acoustic neuroma had normal results in GBST but abnormal results in galvanic VEMP. CONCLUSIONS: These results suggest that electrical stimulation in these two tests stimulates the same area of the peripheral vestibular afferent system, although the duration of stimulation was different, and that the estimate of the lesion site indicated by these tests in patients with complete or nearly complete unilateral vestibular damages is reliable. SIGNIFICANCE: These results suggest that short-duration galvanic stimulation as well as long-duration galvanic stimulation stimulates the vestibular system at the same level.

Adult↗

PubMed2004

Vestibular neuritis in a child with otitis media with effusion; clinical application of vestibular evoked myogenic potential by bone-conducted sound.

Vestibular evoked myogenic potential (VEMP) has been applied for patients with vestibulo-cochlear disorders. The impairment of the sound transmission due to middle ear pathology affects VEMP results. In children, otitis media with effusion (OME) is well documented and it is difficult to apply conventional VEMP in such cases. To overcome the attenuation of stimulation due to middle ear pathology, VEMP by bone-conducted sound has been developed. We report a 3-year-old girl with vestibular neuritis and OME as a representative case of clinical application of VEMP by bone-conducted sound. VEMP by bone-conducted sound can be an alternative method to elicit vestibular-dependent potential.

Bone Conduction↗