Preliminary exploration of Gd-DTPA enhanced inner ear image of guinea pig using magnetic resonance scan / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To observe the distribution of Gd-DTPA in the inner ear of guinea pig by MRI at different time points after intratympanic administration, explore the optical time for observing the whole inner ear. To study the pharmacokinetic feature of Gd-DTPA in the inner ear, and find out whether discrimination of endolymph and perilymph can be obtained under current conditions.</p><p><b>METHODS</b>Sixty-five guinea pigs were randomly divided into 13 groups, after diluted Gd-DTPA intratympanic injection, each group of guinea pigs were scanned through MRI (3D-T1 FSE sequence) at different time points (0 h, 0.5 h, 1 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 24 h, 48 h, 72 h, 96 h). Pixel intensity values of some locations in the inner ear were analyzed using e-Film software, then pixel intensity was converted into concentration using the results of previous in-vitro study. ABR thresholds of bilateral ears before, 1 d and 7 d after intratympanic injection were compared.</p><p><b>RESULTS</b>Six hours after transtympanic Gd-DTPA injection was the time point when contrast agent was distributed all over the inner ear, and reached a high concentration: 589.29, 552.54, 570.17, 255.08, 107.09 and 139.18 µmol/L in the vestibule, scala vestibuli and scala tympani of basal turn, the 2(nd), the 3(rd) and the apical turn individually, that was also the optimal time for observing the whole inner ear by MRI. Perilymph appeared to be preferentially enhanced relative to the endolymph, resulting in a distinction between the scales of the inner ear. There was no significant difference between the experimental ear (diluted GD-DTPA injected ear) and contrast ear (physiological saline injected ear) on 1 d and 7 d.</p><p><b>CONCLUSIONS</b>The best time getting MRI imaging after intratympanic diluted GD-DTPA injection is 6 h. After diluted agent injection perilymph can be enhanced so as to be differentiated with endolymph by MRI, diluted agent have no obvious effect on the ABR threshold. The pharmacokinetic feature of Gd-DTPA in the inner can be studied using MRI.</p>

Non-invasive visualization of endolymphatic hydrops in patients with Meniere's disease / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To visualize the endolymph in Meniere's disease by applying for non-invasive intratympanic gadolinium through eustachian tube and three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI).</p><p><b>METHODS</b>With a 3 Tesla magnetic resonance imaging (MRI) unit, 3D-FLAIR imaging was performed 24 h after intratympanic gadolinium through eustachian tube in seven patients with Meniere's disease. Pure tone test was performed 24 h before and after administered gadolinium. Tympanometry was performed 24 h before, 24 h and 3 months after administered gadolinium.</p><p><b>RESULTS</b>In five patients, the gadolinium could appear in parts of the perilymph inside the inner ear but not in the middle ear and mastoid, moreover, the border between the perilymph and endolymph was visible so that endolymphatic space was clearly shown on 3D-FLAIR imaging. In two patients with endolymphatic hydrops, the perilymphatic space surrounding endolymph was small or disappeared. In two patients, the gadolinium could appear in parts of the middle ear and mastoid but not in the inner ear. No significant changes in pure tone test and tympanometry were noted.</p><p><b>CONCLUSIONS</b>3D-FLAIR MRI with intratympanic gadolinium through eustachian tube could clearly reveal the visualization of endolymphatic space in Meniere's disease.</p>

Clinical features of multiple canal involvement in benign paroxysmal positional vertigo / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To describe a series of patients with multiple canal involvement in benign paroxysmal positional vertigo (BPPV), with respect to diagnosis and management.</p><p><b>METHODS</b>Ninety-five individuals with symptoms of BPPV and positional nystagmus were included in this study. The diagnosis was based on a history of brief episodes of vertigo and the presence of multiple positional nystagmus as confirmed by video-oculographic examination. Patients were treated by means of different particle repositioning manoeuvres according to the affected canal.</p><p><b>RESULTS</b>Ninety-five patients showed multiple positional nystagmus during the examination corresponding to simultaneous multi-canal BPPV. Fourteen patients (14.7%) had bilateral canal BPPV. Six patients had bilateral posterior canal. Six patients had bilateral horizontal canal, and two patients had bilateral anterior canal. Fifty-three patients (55.8%) had torsional, up-beating nystagmus with down-beating nystagmus, which suggested possible affected both of posterior and anterior canals. Twenty patients (21.1%) had torsional up-beating nystagmus and horizontal direction nystagmus, which suggested possible affected both of posterior and horizontal canals. Five patients had down-beating nystagmus with horizontal nystagmus, which suggested affected both of anterior and horizontal canals. Three patients had torsional up-beating with down-beating and horizontal nystagmus, which suggested possible affected multiple canals. Treatment given to the patients varied according to the canal affected, started with the canal that elicited a strong positional nystagmus and vertigo, and 93.7% (89/95) of patients were symptom free or improved.</p><p><b>CONCLUSIONS</b>It has been found that multi-canal BPPV is not a rate observation in clinic, and most of them affected posterior and anterior canals. Treatment of multi-canal BPPV can be effective using repositioning maneuver.</p>

Vestibular pathology associated with noise-induced inner ear impairment / 中国医学科学院学报

<p><b>OBJECTIVE</b>To evaluate the pathological status of the vestibular system associated with noise-induced inner ear impairment.</p><p><b>METHODS</b>Totally 68 patients with noise-induced hearing loss (NIHL) who presented with vestibular symptoms including vertigo, dizziness, and chronic disequilibrium were screened. All patients underwent a series of conventional vestibular function tests and vestibular autorotation test and the results were retrospectively reviewed and evaluated.</p><p><b>RESULTS</b>Sixty-eight (14.5%) patients with NIHL were identified among 469 patients with vertigo, dizziness, or imbalance. A pure tone hearing threshold of patients with vertigo and NIHL at 4000 Hz were between 30 dB HL and 80 dB HL with an average threshold of (46.7 +/- 17.6) dB HL in left ear and (37.3 +/- 16.7) dB HL in right ear. Patients with symmetrical hearing loss at 4000 Hz accounted for 41.7% and those with asymmetrical loss accounted for 58.3%. Vestibular pathologies included benign positional paroxysmal vertigo (45.7%), unilateral decreased caloric responses (20.0%), bilateral decreased caloric responses (26.7%), abnormal vestibulo-spinal reflex function (28.6%), vestibular function response hyperactivity (3.0%), and abnormal vestibulo-ocular reflex presentation at high frequencies (97.0%).</p><p><b>CONCLUSIONS</b>Loud acoustic stimulation not only damages the cochlea but also causes clear functional impairment to the vestibular end organs. Although the vestibular pathology is not correlated with the severity of the hearing loss, it correlates with the subjective symptoms of the vestibular system.</p>

Endolymphatic visualization in patients with Meniere's disease / 中国医学科学院学报

<p><b>OBJECTIVE</b>To attempt to visualize the endolymph in patients with Meniere's disease by applying non-invasive intratympanic gadolinium through eustachian tube and three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI).</p><p><b>METHODS</b>With a 3 Tesla magnetic resonance imaging (MRI) unit, 3D-FLAIR imaging was performed 24 hours after intratympanic gadolinium through eustachian tube in two patients with medically active and intractable Meniere's disease. Pure tone test and tympanometry were performed 24 hours before and after the administration of gadolinium.</p><p><b>RESULTS</b>The gadolinium appeared in almost all parts of the perilymph inside the inner ear; moreover, the border between the perilymph and the endolymph was visible so endolymphatic space was clearly shown on 3D-FLAIR. No change in pure tone test and tympanometry was noted.</p><p><b>CONCLUSIONS</b>3D-FLAIR MRI with intratympanic gadolinium through eustachian tube can clearly reveal the visualization of endolymph in patients with Meniere's disease. Intratympanic gadolinium therapy through eustachian tube is a safe and effective.</p>

Normal values of vestibular autorotation test in young people / 中国医学科学院学报

<p><b>OBJECTIVE</b>To explore the normal values of vestibular autorotation test (VAT) in young people.</p><p><b>METHODS</b>VAT was performed in 31 young people aged 20-30 years. The measured value were analyzed and compared with the reference normal value.</p><p><b>RESULTS</b>The measured values of VAT in healthy young people are almost within the normal range of the general population. Compared with the reference normal values, the horizontal gains at 2.0, 2.3, 2.7, 5.5, and 5.9 Hz, the vertical gains at 2.0 and 5.9 Hz, and the vertical phases at 2.0, 2.3, 2.7, 3.1, 3.5, and 3.9 Hz were significantly different (P < 0. 05). No significant difference was shown in the horizontal phases and asymmetry.</p><p><b>CONCLUSIONS</b>The normal values of VAT in young people is within the reference normal range of the general population. The vestibular function of young people may be more sensitive in lower frequency range (2-3Hz).</p>

Clinical short-term effect of Meniett pulse generator for Meniere disease / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the short-term efficacy and safety of transtympanic pressure treatment in the management of recalcitrant vertigo in Meniere disease in order to lead to the further long-term treatment.</p><p><b>METHODS</b>Using cross-sectional case study, eighteen patients with medically intractable and active Meniere disease were opted to manage with Meniett pulse generator. A standard ventilation tube was inserted in the affected ear and the treatment period with Meniett pulse generator was 8 weeks. Patients indicated on the symptom report card and six-point functional scale the maximum level of vertigo, activity and stress. Hearing was assessed by pure tone average thresholds (PTA), moreover, electrocochleogram and vestibular caloric were performed.</p><p><b>RESULTS</b>Of eighteen patients, the changes of vertigo severity, vertigo frequency, sick day and six-point functional scale between after and before treatment with Meniett were statistically significant (P < 0.05), moreover, the changes of--SP/AP between after and before treatment with Meniett were statistically significant (P < 0.05). No change in vestibular function was noted. Two of 18 patients showed a significant PTA increase of 10dB or more and hearing was stable in the remainder of patients 4 weeks after treatment with Meniett. Twelve of 18 patients showed a significant PTA increase of 10dB or more and hearing was stable in the remainder of patients 8 weeks after treatment with Meniett. There were no complications during 6-month follow-up with Meniett.</p><p><b>CONCLUSIONS</b>Meniett seemed to be a safe, effective and non-destructive level of therapy, which could reduce vertiginous symptoms and functional handicap and showed an improvement of hearing in patients with medically intractable Meniere disease. This method was recommended before attempting any surgical or chemical vestibular ablation procedure.</p>

Diagnosis and therapy for benign paroxysmal positional vertigo of the anterior semicircular canal / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To analyse the video-oculographic findings of positional tests and evaluate the efficacy of canalith repositioning procedure (CRP) in patients with paroxysmal positional vertigo ( BPPV) of the anterior semicircular canal (ASC).</p><p><b>METHODS</b>A retrospective study of 31 patients with ASC BPPV. Then the CRP was performed.</p><p><b>RESULTS</b>Twenty-two individuals (70.97%) presented a unilateral positional nystagmus during the Dix-Hallpike test, in 17 individuals had torsional nystagmus component, 5 individuals only had pure positional down beat nystagmus. Nine patients presented bilateral positional nystagmus, 7 individuals had torsional component positional nystagmus, in 2 patients the direction of the torsional component were the same during right and left Dix-Hallpike test, in 4 patients the torsional component were concurrent with positional down beat nystagmus but the direction could not be ascertained clinically, in 2 patients had pure positional down beat nystagmus. Nineteen patients (61.29%) had unilateral lesion, 11 patients had the left ASC BPPV, 8 patients had right ASC BPPV. Eleven patients had with both ASC and PSC BPPV in the ipsilateral. Twenty-one patients (67.74%) were cured, 29 patients (93.55%) were improved, 2 (6.45%) patients were inefficacy. CRP effectively resolved the nystagmus and vertigo in 14 patients (45.16%) when applied only once, The average number of CRP was 1.7 times, there were 5 patients recurrence during the follow-up.</p><p><b>CONCLUSIONS</b>ASC BPPV was not a common condition. The torsional nystagmus component of ASC BPPV might be weak during the Dix-Hallpike test. The positional nystagmus of ASC BPPV was triggered bilaterally. Based on these findings, CRP could be one of the most effective treatment methods for ASC BPPV.</p>

Functional localization of vestibular cerebral representations in human using functional magnetic resonance imaging / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To study human vestibular cerebral representations by combining right-sided ice-water stimulation at 0 degree C with blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) and to evaluate the value of this method in the functional localization of human vestibular cortex.</p><p><b>METHODS</b>Twenty right-handed volunteers (12 men and 8 women) received unilateral irrigation of the right external auditory meatu for 15 s with 15 ml of water at 0 degrees C during fMRI in complete darkness. The functional imaging of brain cortex was acquired with a 1.5-T MRI scanner (Signa Infinity Twin + Excite; General Electric Co., USA). The successive functional images from each subject were analyzed as a group with statistical parametric mapping software (SPM 99).</p><p><b>RESULTS</b>Ultimately, data obtained from 17 subjects were analyzed (3 subjects were eliminated from data because of head movement exceeding 2 mm). The group analysis showed bilateral (particularly left-sided) cortical activation, associated with caloric stimulus involving in temporoparietal junction extending into the posterior insula, supramarginal gyrus in the inferior parietal lobe, precuneus, supplementary motor area (SMA), the ventrolateral portion of the occipital lobe, cuneus and lingual gyrus, superior temporal gyrus and cingular cortex.</p><p><b>CONCLUSIONS</b>Ice-water stimulation at 0 degree C in fMRI reveals a widespread cortical network involved in vestibular signal processing in human. As the functional localization of vestibular cortex could be determined precisely, ice-water stimulation at 0 degree C in fMRI would hold great promise as a sensitive and reproducible tool for the research in human vestibular cortex.</p>

Study on the causes and risk factors on vertigo and balance disorders in 118 elderly patients / 中华流行病学杂志

<p><b>OBJECTIVE</b>To understand the various factors causing vertigo and balance disorders in the elderly.</p><p><b>METHODS</b>118 elderly patients (aged equal or older than 60 years of age) with vertigo or balance disorders were retrospectively analyzed through clinical symptoms, audio-vestibular function tests, X-ray, CT scan or MRI in cervical vertebras, brain and inner ears, ultrasonography, transcranial doppler (TCD) or magnetic resonance angiography (MRA) in blood vessels on head and neck.</p><p><b>RESULTS</b>Of 118 patients, 70 (23%) of them suffered perip heral vestibular disorders while 29 (58%) having cerebral vertigo or dizzness, leaving 19 cases (16%) as unclassified.</p><p><b>CONCLUSION</b>For elderly patients, vertigo and balance disorders were commonly caused by many kinds of peripheral and cerebral vestibular pathological disfunctions while the functional weakness of vestibular organs and systems affected by the physiological process of ageing and different concommitant diseases as well as environmental, psychogenic factors should also be considered.</p>