Biomedical subjects

Yi-Ho Young

Publications and source records attributed to Yi-Ho Young.

At least 37 records · Page 2Linked to original sources

PubMed2005

Click-evoked myogenic potentials recorded on alert guinea pigs.

The aim of this study was to establish an animal model of acoustically evoked vestibulo-collic reflex using guinea pigs. A special clamp was applied to restrain the head and body of the guinea pigs, but leaving its four legs free. Each animal underwent vestibular evoked myogenic potential (VEMP) and caloric tests using clip electrode method without general anesthesia or decerebrate surgery. The response rates for the myogenic potentials on the neck of guinea pigs using 100, 90, 80 and 70 dB monaural acoustic stimulation with unilateral recording were 100%, 62%, 50% and 0%, respectively. The mean latencies of the positive and negative peaks for the myogenic potentials were 7.24+/-0.49 and 9.15+/-0.47 ms, 7.09+/-0.43 and 9.28+/-0.42 ms, as well as 7.03+/-0.59 and 9.14+/-0.56 ms, when elicited by 100, 90 and 80 dB acoustic stimulation, respectively. The median (minimum-maximum) peak-to-peak amplitudes were 11.93 (6.14-16.86), 10.99 (5.28-19.40), and 11.17 (5.02-20.72) microV, when elicited by 100, 90 and 80 dB acoustic stimulation, respectively. We found no significant relationship between the stimulus intensity and the mean latencies or peak-to-peak amplitude of the myogenic potentials in guinea pigs. For those treated with gentamicin unilaterally, all guinea pigs showed absent caloric responses on the lesion side, and absent myogenic potentials on the neck when using ipsi-lesional acoustic stimulation, while the hearing was preserved. Hence, the use of gentamicin-treated animals, along with normal controls and auditory brainstem responses, results in convincing results that the recorded myogenic potentials are in fact of vestibular origin.

Acoustic Stimulation↗

PubMed2005

Vestibular evoked myogenic potentials in neurofibromatosis 2.

Neurofibromatosis 2 (NF2) is characterized by bilateral vestibular neurofibromas. Although the facial nerve, the cochlear nerve, and the superior division of the vestibular nerve can be evaluated before surgery, whether the inferior division of the vestibular nerve is affected remains undetermined without an operation. A total of 7 patients with NF2 (2 men and 5 women) underwent pure tone audiometry, caloric testing, vestibular evoked myogenic potential (VEMP) testing, and magnetic resonance imaging. Audiometry revealed mean hearing levels of less than 26 dB for 1 ear, 26 to 70 dB for 8 ears, 71 to 90 dB for 3 ears, and more than 90 dB for 2 ears. Caloric testing revealed an absent response in 71% of the 14 ears. Seven ears underwent VEMP testing, and only 1 ear (14%) displayed absent VEMPs. Magnetic resonance imaging depicted space-occupying lesions in all 14 auditory canals: small tumors in 3 ears, medium tumors in 7 ears, and large tumors in 4 ears. The tumor size of NF2 is related to the caloric response, but is unrelated to the mean hearing level or VEMPs. In conclusion, NF2 originates from the superior vestibular nerve more often than the inferior vestibular nerve. It more often infiltrates the cochlear nerve than the inferior vestibular nerve.

Adolescent↗

PubMed2005

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.

Adolescent↗

PubMed2004

Vertigo with rebound nystagmus as an initial manifestation in a patient with basilar artery occlusion.

Basilar artery occlusion (BAO) is generally associated with a high mortality rate and a poor functional outcome in survivors. Recently, we encountered a patient with BAO, initially manifesting as vertigo and rebound nystagmus, subsequently followed by bilateral sudden deafness and dysarthria and terminating in a coma state within an interval of 6 h. A review of his history showed he had had two episodes of transient vertigo 2 weeks before the major stroke, and the neurological decline of BAO was heralded by the vertiginous symptoms. Restated, patients with BAO often have transient vertiginous attacks preceding fatal stroke. Therefore, those with vertigo and nystagmus may be signaling a forthcoming stroke event, something that should be considered for clinicians seeing vertiginous patients.

Humans↗

PubMed2004

Investigating the causes of vertigo in breast cancer survivors.

The vertigo symptom in breast cancer survivors has rarely been mentioned. The aim of this study was to investigate the causes of vertigo in breast cancer survivors with vertigo. From May 1997 to April 2003, 36 consecutive female breast cancer survivors with vertigo underwent a battery of tests including physical examination, neurological examination, serum lipid profile, plain chest radiograph, whole body bone scan, liver sonography, audiometry, electronystagmography (ENG) and MRI scan. Based on these tests, the causes of vertigo were attributed to peripheral labyrinthine origin in 14 patients (39%) and central origin in 22 patients (61%) consisting of 11 cases of vascular insufficiency, eight of hyperlipidemia and three of posterior fossa metastases (8%). The latter included one case of cerebellopontine angle and two of cerebellum, accompanied by extracranial systemic metastases, e.g., of the lung, bone or liver. In conclusion, vertigo in breast cancer survivors warrants concern, especially in those with extra-cranial systemic metastasis accompanied by headache. In addition to 8% occurrence of posterior fossa metastasis, other possible causes for vertigo in breast cancer survivors consist of vascular insufficiency, hyperlipidemia and labyrinthine lesion.

Adult↗

PubMed2004

Radiation-induced otitis media--study of a new test, vestibular-evoked myogenic potential.

PURPOSE: Excluding the radiation history, current physical examination and audiovestibular function tests fail to differentiate radiation-induced otitis media (ROM) from chronic otitis media (COM). This study applied the newly developed vestibular-evoked myogenic potential (VEMP) test to investigate whether the VEMP test can be of help in differentiating between them. METHODS AND MATERIALS: Fourteen irradiated nasopharyngeal carcinoma (NPC) patients with ROM (18 ears) and 14 age-matched, and gender-matched patients with COM (18 ears) were enrolled. Each patient underwent stimulation with a short tone burst initially, and then by tapping the forehead using a tendon hammer. To define the effect of the neck soft tissue on the VEMP response further, an additional two groups (10 non-NPC patients with ROM but no neck fibrosis/edema and 10 non-NPC patients without ROM but with neck fibrosis/edema) were included for comparison. RESULTS: The occurrence of normal VEMPs in the ROM ears (33%) did not differ significantly from that in the COM ears (56%) by tone-burst stimulation. However, using tapping evocation, most (89%) COM ears revealed normal VEMPs, and most (61%) ROM ears demonstrated delayed VEMPs. Furthermore, most (90%) non-NPC patients with ROM but no neck fibrosis/edema revealed delayed or absent VEMPs. In contrast, all non-NPC patients with neck fibrosis/edema but no ROM demonstrated normal VEMPs bilaterally, implying that the effect of neck soft tissue on the VEMP response is less. CONCLUSION: Through tapping evocation, most COM ears revealed normal VEMPs, and most ROM ears demonstrated delayed VEMPs, indicating that ROM is different from COM because of the larger affected areas such as retrolabyrinthine or brainstem involvement. This result can explain why grommet insertion or tympanoplasty is not beneficial to postirradiated ears, possibly because both operations spare the inflammation outside the middle ear cavity.

Adolescent↗

PubMed2004

Earlier and later components of tone burst evoked myogenic potentials.

The aim of this study was to further investigate the response rates, thresholds, latencies and amplitudes of the earlier and later components of tone burst evoked myogenic potentials (TEMPs) in conditions of binaural and monaural stimulation and recordings in a group of normal subjects in response to a 500-Hz tone burst. Each subject underwent simultaneous binaural acoustic stimulation with bilateral recording (B-TEMP) initially, then monaural acoustic stimulation with ipsilateral recording (M-TEMP) on another day. The results showed 100%, 100%, 54%, and 23% response rates for the earlier components of B-TEMPs, when using 105, 95, 85, and 75 dB acoustic stimulation, respectively. It exhibited a significant decrease in the response rate when the stimulus intensity was attenuated from 95 to 75 dB. In addition, no significant difference in the response rate of the earlier components existed between B-TEMPs and M-TEMPs. For the later components of B-TEMPs obtained from 105, 95, 85, and 75 dB acoustic stimulation, the response rates were 85%, 85%, 62%, and 42%, respectively, higher than those of M-TEMPs significantly. Nevertheless, there were no statistical differences in the mean latencies of each peak (p13, n23, n34, and p44) between B-TEMPs and M-TEMPs under similar stimulus intensity. Meanwhile, no significant relationship existed between the stimulus intensity and the latency, regardless of B-TEMPs or M-TEMPs. Comparing the relative amplitudes between B-TEMPs and M-TEMPs, the former displayed significant smaller p13-n23 amplitude, but larger n34-p44 amplitude. However, the mean thresholds for the earlier and later components between B-TEMPs and M-TEMPs did not differ significantly. In conclusion, monaural acoustic stimulation with ipsilateral recording may elicit larger amplitude of the earlier components, whereas binaural acoustic stimulation with bilateral recording evokes higher response rate and larger amplitude of the later components. Although the nerve pathways for both components are different, the thresholds for these potentials do not differ significantly, indicating that both components may, at least in part, share a common origin, but different pathways.

Acoustic Stimulation↗

PubMed2004

Side-difference of vestibular evoked myogenic potentials in healthy subjects.

The aim of this study was to investigate the side-difference of vestibular evoked myogenic potentials (VEMPs) in relation to the provocation rates, latencies and amplitudes using binaural acoustic stimulation with bilateral recording. Fourteen healthy volunteers underwent a serial VEMP testings elicited binaurally by a sequence of alternating stimulus intensities, that is, 95-95 (right-left), 85-95, 95-85, and 85-85 dBHL tone burst, respectively. The provocation rates as well as the mean latencies of p13 and n23 for the VEMPs demonstrated no significant side-difference despite using 95-95, 85-95, 95-85 and 85-85 dBHL binaural acoustic stimulation. In contrast, nine (64%) of the 14 subjects showed side-difference of absolute p13-n23 amplitude, including right side dominant in five subjects, and left side dominant in four subjects. However, there was no significant side-difference in terms of relative amplitude despite using 95-95, 85-95, 95-85 and 85-85 dBHL binaural acoustic stimulation. Furthermore, the relative amplitude or interaural amplitude difference (IAD) ratios between those with and without side-difference of p13-n23 amplitude did not differ significantly. Hence, this study provides a potentially important method for adjusting the side difference of p13-n23 amplitudes by using a relative amplitude or IAD ratio adjustment. It also adds confidence to the successful use of binaural stimulation and recording of VEMPs under conditions of bilateral SCM muscular contractions.

Acoustic Stimulation↗

PubMed2004

Eliciting constant and prominent waves n34-p44 of vestibular-evoked myogenic potentials.

OBJECTIVE: The serial peaks of vestibular-evoked myogenic potentials (VEMPs) have been labeled p13, n23, n34 and p44 according to their latency. Waves p13-n23 have been shown to be of saccular origin, whereas the origin of waves n34-p44 is still unknown. In order to improve the clinical applicability of waves n34-p44, we examine the use of different patterns of acoustic stimuli to evoke constant and prominent VEMPs, especially waves n34-p44. MATERIAL AND METHODS: In this prospective study 27 healthy volunteers (54 ears) underwent VEMP tests. Three kinds of click intensity (85, 95 and 105 dB nHL) were presented in a random order to evoke 85-VEMP, 95-VEMP and 105-VEMP, respectively. The response rate, latency of each peak, peak-to-peak interval and amplitude of waves p13-n23 and n34-p44 were measured and analyzed. RESULTS: The response rates of waves p13-n23 in 85-VEMP, 95-VEMP and 105-VEMP were 26% (14/54), 89% (48/54) and 98% (53/54), respectively. Significant differences in the response rate existed between 85-VEMP and both 95-VEMP and 105-VEMP (p<0.01), whereas there was a non-significant difference between 95-VEMP and 105-VEMP (p>0.05). In contrast, the response rates for eliciting waves n34-p44 were 19% (10/54), 63% (34/54) and 89% (48/54), using 85, 95 and 105 dB acoustic stimuli, respectively. A significantly higher response rate for waves n34-p44 occurred when the intensity of the stimuli increased (p<0.01). Although neither latencies nor interval exhibited a significant difference between 95-VEMP and 105-VEMP, the amplitude of 105-VEMP was significantly greater than that of 95-VEMP for both waves p13-n23 and n34-p44. CONCLUSION: An acoustic stimulus intensity of 105 dB nHL is required to reliably elicit waves n34-p44 in subjects with normal hearing.

Acoustic Stimulation↗

PubMed2004

Vestibular evoked myogenic potentials in basilar artery migraine.

OBJECTIVES/HYPOTHESIS: Because the sacculocollic reflex is a descending pathway passing through the territory of basilar artery, the aim of the study was to investigate whether hypoperfusion affects this pathway by applying vestibular evoked myogenic potential (VEMP) testing in patients with basilar artery migraine. STUDY DESIGN: A prospective study from May 2000 to April 2002. METHODS: Twenty patients were diagnosed as having basilar artery migraine according to the criteria of the International Headache Society and literature. Eight were male and 12 were female patients, and their ages ranged from 9 to 48 years (mean age, 40 y). Each patient underwent a battery of audio-vestibular tests. RESULTS: Electronystagmography disclosed abnormal eye tracking test in six patients (30%), and there were abnormal optokinetic nystagmus test results in nine patients (45%). Caloric test revealed canal paresis in seven patients, directional preponderance in four patients, and normal responses in nine patients (45%). Vestibular evoked myogenic potential testing disclosed absent vestibular evoked myogenic potentials in seven patients and delayed vestibular evoked myogenic potentials in two patients, with one patient showing absent vestibular evoked myogenic potentials on one side and delayed vestibular evoked myogenic potentials on the other side. The remaining 10 patients (50%) had bilateral normal vestibular evoked myogenic potentials. Five patients had preserved both caloric and VEMP test responses, six patients displayed absent caloric and VEMP test responses, and the remaining nine patients had either abnormal caloric test responses or abnormal vestibular evoked myogenic potentials, exhibiting a nonsignificant relationship between caloric test responses and vestibular evoked myogenic potentials. Relief of headache and vertigo was achieved after 3 months of medication. Ten asymptomatic patients with either absent or delayed vestibular evoked myogenic potentials before treatment underwent follow-up VEMP test, and nine patients (90%) displayed normal vestibular evoked myogenic potentials bilaterally. CONCLUSION: Vestibular evoked myogenic potential testing evaluates the sacculocollic reflex, which descends through the lower brainstem. Some patients with basilar artery migraine have absent or delayed vestibular evoked myogenic potentials, presumably because the descending pathway from the saccule through the brainstem to cranial nerve XI is interrupted, which is attributed to hypoperfusion in the territory of the basilar artery. After 3 months of medication, recovery of normal vestibular evoked myogenic potentials in an asymptomatic patient indicates reversible ischemia in the territory of the basilar artery.

Adolescent↗

PubMed2004

Postirradiation vertigo in nasopharyngeal carcinoma survivors.

OBJECTIVE: Vertigo rarely manifested as an initial symptom of nasopharyngeal carcinoma or an early symptom after irradiation; however, increasing numbers of long-term nasopharyngeal carcinoma survivors experienced it. The purpose of this study was to investigate the causes of vertigo in irradiated nasopharyngeal carcinoma survivors. SETTING: University hospital. PATIENTS: From January 1992 to December 2001, a total of 113 nasopharyngeal carcinoma patients (67 men and 46 women) with postirradiation vertigo consecutively visited our vertigo clinic. The mean interval from completion of irradiation to the occurrence of vertigo was 10 years. Each patient underwent otoscopic examination and a battery of audiovestibular function tests. Then, correlation between the vertigo and the radiation effect was explored. RESULTS: Postirradiation vertigo was mainly attributable to peripheral labyrinthine disorder (69%), followed by central vestibular lesions (31%). The vertiginous and associated symptoms including severity, nausea/vomiting, oscillopsia, or imbalance in cases of peripheral labyrinthine disorder were milder than those in central vestibular lesion. Meanwhile, the former had less life impact and better response to therapy compared with the latter. The mean radiation dosage in both groups was 73 +/- 6 Gy and 74 +/- 5 Gy, respectively, without a significant difference. Of these 113 patients, 85 patients (75%) had radiation otitis media in one or both ears, and 28 patients disclosed bilateral intact eardrums. The prevalence of radiation otitis media in patients with postirradiated vertigo was 53% versus 73% for those with radiation dosage less than or more than 71 Gy, respectively, exhibiting a significant difference. However, the prevalence of radiation otitis media is unrelated to radiation interval. In comparison with absent caloric responses in radiation otitis media ears, 32% versus 57% in those of less than or more than 71 Gy, respectively, indicates a significant difference. CONCLUSIONS: Vertigo is a late complication in irradiated nasopharyngeal carcinoma survivors, which is mainly caused by the sequela of radiation otitis media. Because the latter is correlated with the radiation dosage, 70 Gy is recommended as the maximum dosage for nasopharyngeal carcinoma. Eradicating radiation otitis media in nasopharyngeal carcinoma survivors may subsequently prevent the postirradiation vertigo.

Audiometry, Pure-Tone↗

PubMed2004

Aging effect on vestibular evoked myogenic potential.

OBJECTIVE: Vestibular evoked myogenic potential (VEMP) is applied to explore the integrity of sacculocollic reflex. Although tests to evaluate vestibular-ocular reflex pathway have shown that vestibular function is adversely affected by aging, VEMP, in this study, is used as a novel test to define how aging influences sacculocollic reflex pathway. STUDY DESIGN: Prospective study. SETTING: Academic tertiary referral center. SUBJECTS: Eighty normal subjects, equally divided into four groups according to their age, were enrolled to this study. Group I included patients aged <20 years, Group II patient ages ranged from 21 to 40 years, Group III patients were 41 to 60 years, and Group IV included patients older than 60 years. INTERVENTIONS: Recordings of VEMP responses. MAIN OUTCOME MEASURES: The response rate and parameters of VEMP, including p13 latency, n23 latency, amplitude, and interaural difference ratio. RESULTS: The VEMP response rates from Groups I to IV was 98%, 98%, 90%, and 60%, respectively, disclosing a significant difference only between Group IV and other groups (p < 0.05). The amplitude was negatively correlated with age in contrast to the n23 latency, correlating positively with age; both reached a significant difference (p < 0.05). Although the p13 latency had a trend to prolong as age increased, no significant correlation existed (p < 0.06). Moreover, the interaural difference ratio was also not significantly correlated with age. CONCLUSIONS: As age increased over 60 years, the VEMP response rate decreased dramatically. While age increased, the VEMP amplitude decreased in comparison to n23 latency prolonged. These findings might suggest that aging could deteriorate the saccular and corresponding neural functions. When interpreting the VEMP parameters, it should be kept in mind that aging could affect VEMP responses. Based on this study, we suggest establishing different reference values according to different age groups when evaluating VEMP response in patients with vestibular diseases.

Adolescent↗

PubMed2004

Vestibular evoked myogenic potentials in acute low-tone sensorineural hearing loss.

OBJECTIVE/HYPOTHESIS: It was the authors' premise that the vestibular evoked myogenic potential (VEMP) test may be used to differentiate acute low-tone hearing loss (ALHL) from Meniere's disease with low-tone HL. STUDY DESIGN: Prospective study. METHODS: From January 2000 to December 2002, consecutive 12 patients with ALHL and another 12 patients with definite Meniere's disease with low-tone HL were enrolled in this study. All patients underwent audiometry and VEMP test, before and after treatment with isosorbide for 3 consecutive months. RESULTS: Before treatment, 12 patients with ALHL revealed normal VEMPs (11, 92%) and augmented VEMPs (1). After treatment, 11 (92%) patients had resolved to normal hearing within 3 days. One year later, two (17%) patients progressed to Meniere's disease. In comparison with Meniere's disease, 6 (50%) of 12 patients showed normal VEMPs before treatment, and 7 (58%) patients had their hearing improved 3 months after treatment. Comparison of VEMP responses or hearing outcome between both groups exhibited significant differences. CONCLUSION: Most patients with ALHL reveal normal VEMPs throughout the episode, indicating that the saccule is spared. In contrast, 50% of Meniere's disease patients with low-tone HL demonstrate abnormal VEMPs, showing a significant difference. Therefore, the VEMP test can be used to differentiate ALHL from Meniere's disease with low-tone HL.

Adult↗

PubMed2004

Audiovestibular evolution in a patient with multiple sclerosis.

Multiple sclerosis is characterized by the presence of multiple plaques within the central nervous system, manifesting as remission and exacerbation of neurologic dysfunction over variable time courses. We present the case of a 20-year-old woman. Before treatment, her auditory brain stem response (ABR) test revealed bilateral prolongation. A caloric test showed canal paresis of the right ear and a normal response on the left. A vestibular evoked myogenic potential (VEMP) test displayed an absent response in the right ear and a delayed response in the left. A magnetic resonance imaging (MRI) scan demonstrated multiple diffuse high signal lesions in the hemispheres, brain stem, and cerebellum. Six months after treatment, the demyelinating plaques were shown to have resolved spontaneously on MRI. Recovery of caloric responses was anticipated. Bilateral prolongation of ABRs remained, but the VEMP test disclosed a normal response in the right ear and a delayed response in the left. Accordingly, in addition to MRI, caloric tests and ABR and VEMP tests are useful in monitoring the evolution of audiovestibular function in patients with multiple sclerosis.

Adult↗

PubMed2003

Reversible cochleo-vestibular deficits in two cases of jugular foramen tumor after surgery.

Primary jugular foramen (JF) tumor, such as glomus jugular tumor or JF schwannoma, may manifest as a lower cranial nerve deficit; in addition, it can be accompanied by deafness or vertigo if it affects the cranial nerve (CN) VIII. Recently, we encountered JF schwannoma 1 and glomus jugulare tumor 1. Both cases invaded the adjacent cerebellopontine angle, leading to cochleo-vestibular deficits prior to the operation. After surgery, recovery of the audiovestibular function, including hearing, auditory brainstem response and caloric response, was anticipated in both patients. Therefore, cochleo-vestibular deficits in JF tumors can be attributed to compression neuropathy, rather than tumor infiltration.

Adult↗

PubMed2003

Multiple system atrophy manifested as dizziness and imbalance: a report of two cases.

Multiple system atrophy (MSA) is a progressive neurodegenerative disease of undetermined origin that occasionally manifests as dizziness and imbalance. It is not often considered in clinical situations, especially not by neuro-otological consultants. Hence, we report our recent experience with two cases of MSA. One is that of a 62-year-old man with MSA with a predominant cerebellar feature, and the other is that of a 72-year-old man with MSA with a predominant parkinsonian feature. The results of the syncopic study correlated with orthostatic hypotension. The neuro-otological study in both patients revealed an abnormal eye tracking test, abnormal optokinetic nystagmus test and loss of visual suppression in the caloric nystagmus. These indicate that the central vestibular system, e.g., the cerebellum or brain stem, is affected by MSA, contributing to dizziness and imbalance. Therefore, diagnosis of MSA should be kept in mind by neuro-otological consultants when dealing with patients with dizziness and imbalance, especially when this is accompanied by orthostatic hypotension.

Aged↗

PubMed2003

Initial otolaryngological manifestations of severe acute respiratory syndrome in Taiwan.

OBJECTIVE: To provide a clue for screening severe acute respiratory syndrome (SARS), a highly transmissible disease with health care workers at particular risk, in the early stage from an otolaryngological perspective. DESIGN: Prospective study. SETTING: Community hospital. PATIENTS: Between April 17 and April 26, 2003, 32 consecutive patients with SARS were encountered. Investigation consisted of local examination of ear, nose, and throat fields; palpation of the nuchal areas; and plain chest radiography. Analyses of throat swab samples using reverse transcription-polymerase chain reaction were conducted. RESULTS: Clinical manifestations included fever in 31 patients (97%), followed by cough, dyspnea, chill, headache, sore throat, diarrhea, rhinorrhea, and otalgia. Neither the pharyngeal wall nor the tonsillar area demonstrated hyperemia. There was no lymphadenopathy in the neck. Plain chest radiographs revealed consolidation in 25 (78%) of 32 patients. Results of reverse transcription-polymerase chain reaction analysis targeting the novel coronavirus present in throat swab samples were positive in 19 (66%) of 29 patients tested. Twenty-eight patients required supplemental oxygen, and 14 patients were intubated with mechanical ventilation. Twenty-eight patients survived and 4 patients died. CONCLUSIONS: When presented with a patient with flulike symptoms such as fever and/or cough, but no pharyngeal hyperemia or neck lymphadenopathy, physicians should be alerted to the possibility of SARS. In contrast, evidence of inflammatory signs in the otolaryngological field may explain the flulike symptoms, and serve as a differential diagnostic tool between influenza and SARS.

Adolescent↗

PubMed2003

Assessing the stage of Meniere's disease using vestibular evoked myogenic potentials.

BACKGROUND: The staging of Ménière's disease that was proposed by the American Academy of Otolaryngology-Head and Neck Surgery in 1995 was based on the arithmetic mean of the pure-tone thresholds at 0.5, 1.0, 2.0, and 3.0 kHz using the worst audiogram during the 6-month interval before treatment. The stages were classified as follows: stage I, a 4-tone average of less than 26 dB; stage II, 26 to 40 dB; stage III, 41 to 70 dB; and stage IV, more than 70 dB. OBJECTIVE: Because the saccule, next to the cochlea, is the second most frequent site of hydrops formation, we wanted to find out whether vestibular evoked myogenic potential (VEMP) responses can reflect the stage of Ménière's disease. DESIGN: Prospective study. SETTING: Tertiary university hospital. PATIENTS: Forty patients (23 men and 17 women; mean +/- SD age, 43 +/- 12 years) with unilateral definite Ménière's disease were enrolled in the study. MAIN OUTCOME MEASURES: The interaural amplitude difference (IAD) ratio, which was defined as the difference of the amplitudes of peak p13 to peak n23 (p13-n23) in the right (R) and left (L) ears divided by the sum of p13-n23 in both ears (R-L/R + L), was measured, and the stages of the disease were compared with the types of hearing loss, the percentage of unilateral weakness of caloric response, and the IAD ratio, respectively. RESULTS: Six ears were classified as stage I: the VEMPs were normal in 5 and augmented in 1, with a mean +/- SD IAD ratio of -0.02 +/- 0.20. Twelve ears were classified as stage II: the VEMPs were normal in 7, augmented in 2, depressed in 1, and absent in 2, with an IAD ratio of -0.12 +/- 0.39. Seventeen ears were classified as stage III: the VEMPs were normal in 10, depressed in 4, and absent in 3, with an IAD ratio of -0.30 +/- 0.30. Five ears were classified as stage IV: the VEMPs were normal in 2, depressed in 1, and absent in 2, with an IAD ratio of -0.54 +/- 0.43. A comparison of the IAD ratio and the stage of Ménière's disease demonstrated a significant relationship (P<.05, 1-way analysis of variance test), whereas there was no significant relationship noted between the percentage of unilateral weakness of caloric response and the stage of disease. CONCLUSION: The IAD ratio of VEMPs correlates with the stage of Ménière's disease and can be used as another aid to assess the stage of Ménière's disease.

Adult↗