Evaluation of Vestibular Function in Diagnosis of Vestibular Schwannomas.

Vestibular schwannomas (VS) are benign tumors of the vestibular nerve. The common first symptoms are hearing loss and tinnitus, followed by imbalance, vertigo, and facial nerve involvement. The subjective symptoms of VS patients are not consistent with the severity of vestibular lesions and the results of vestibular tests, which often interfere with clinicians' diagnoses. Thus, the main screening and diagnostic methods for VS are audiometry and magnetic resonance imaging (MRI), ignoring the evaluation of vestibular function at the source of pathological lesions. With the development and improvement of vestibular evaluation technology and its wide application in the clinic, modern vestibular examination technology can reflect the severity and frequency of vestibular lesions and compensation from multiple perspectives, providing an objective basis for the diagnosis and treatment of vestibular diseases. In this report, we review the results and characteristics of vestibular tests in VS patients and further clarify the clinical value of vestibular function assessment in the diagnosis and treatment of VS.

Protection of Cochlear Ribbon Synapses and Prevention of Hidden Hearing Loss.

In the auditory system, ribbon synapses are vesicle-associated structures located between inner hair cells (IHCs) and spiral ganglion neurons that are implicated in the modulation of trafficking and fusion of synaptic vesicles at the presynaptic terminals. Synapse loss may result in hearing loss and difficulties with understanding speech in a noisy environment. This phenomenon happens without permanent hearing loss; that is, the cochlear synaptopathy is "hidden." Recent studies have reported that synapse loss might be critical in the pathogenesis of hidden hearing loss. A better understanding of the molecular mechanisms of the formation, structure, regeneration, and protection of ribbon synapses will assist in the design of potential therapeutic strategies. In this review, we describe and summarize the following aspects of ribbon synapses: (1) functional and structural features, (2) potential mechanisms of damage, (3) therapeutic research on protecting the synapses, and (4) the role of synaptic regeneration in auditory neuropathy and the current options for synapse rehabilitation.

[Observation of early clinical effect of percutaneous transforaminal endoscopic technology in treating cervical spondylotic radiculopathy].

OBJECTIVE: To explore the early clinical effect and safety of percutaneous transforaminal endoscopic technology for cervical spondylotic radiculopathy. METHODS: From August 2016 to September 2017, 14 patients with cervical spondylotic radiculopathy who responded poorly to non-surgical treatment for at least 6 weeks underwent percutaneous transforaminal endoscopic discectomy via posterior approach. There were 6 males and 8 females, aging from 32 to 68 years old with an average of (40.5±7.6) years. The course of disease ranged from 0.5 to 13.0 months with an average of (6.0±1.33) months. The lesions involved C4,5 in 2 cases, C5,6 in 8 cases, C6,7 in 4 cases. Visual analogue scale (VAS), Japanese Orthopedic Association (JOA), Short Form 36 health survey questionnaire(SF-36) were recorded preoperatively and during the latest follow-up to evaluate the clinical outcome. Horizontal displacement and angular displacement of vertebral body were measured by cervical dynamic X-rays. RESULTS: All operations were successful. No spinal cord injury, nerve root or vascular injuries were found. Operation time was from 60 to 100 min with a median of 75 min;intraoperative bleeding was from 30 to 80 ml with a median of 40 ml. All patients were followed up for 2 to 13 months with a median of 9 months. During the follow-up period, the patients with neck and shoulder pain were significantly relieved without recurrence. No nucleus pulposus protrusion was found in the primary surgical segment, and there was no obvious sign of degeneration in the adjacent vertebral body. At the latest follow-up, VAS, JOA and SF-36 scores were obviously improved(P<0.05). There was no significant difference in horizontal displacement and angular displacement of vertebral body before and after the operation (P>0.05). The cervical curvature at the latest follow-up was higher than preoperative findings (P<0.05). And there was no significant difference in intervertebral disc height preoperatively and postoperatively(P>0.05). CONCLUSIONS: Percutaneous transforaminal endoscopic discectomy in treating cervical spondylotic radiculopathy can effectively and safely relieve neck and shoulder pain, improving nerve function, enhance life quality, maintaining cervical stability. It is worthwhile to generalize and apply in clinical settings.

Stress Writing Textured Graphite Conducting Wires/Patterns in Insulating Amorphous Carbon Matrix as Interconnects.

This study reports a mechanical stress-based technique that involves scratching or imprinting to write textured graphite conducting wires/patterns in an insulating amorphous carbon matrix for potential use as interconnects in future carbonaceous circuits. With low-energy post-annealing below the temperature that is required for the thermal graphitization of amorphous carbon, the amorphous carbon phase only in the mechanically stressed regions transforms into a well aligned crystalline graphite structure with a low electrical resistivity of 420 µΩ-cm, while the surrounding amorphous carbon matrix remains insulating. Micro-Raman spectra with obvious graphitic peaks and high-resolution transmission electron microscopic observations of clear graphitic lattice verified the localized phase transformation of amorphous carbon into textured graphite exactly in the stressed regions. The stress-induced reconstruction of carbon bonds to generate oriented graphitic nuclei is believed to assist in the pseudo-self-formation of textured graphite during low-temperature post annealing.

[Changes of Forest Canopy Spectral Reflectance with Seasons in Lang Ya Mountains].

The physiological mechanism and ecological structure of forest trees can change with the changes of years. In a certain extent, the changes were expressed through the canopy spectral features. The mastery of changing rules about spectral characteristics of trees over the years is benefit to remote sensing interpretation and provide scientific basis for the classification of different trees. The study adopted high-resolution spectrometer to measure the canopy spectral characteristics for seven major deciduous trees and seven evergreen trees to gain the spectrum curve of four different ages and calculate the first derivative curve. The analysis of changing rules about spectral characteristics of different deciduous trees and evergreen trees and the comparison of changes about spectrum of various trees in the visible and infrared band could find the best year and best band for identification of trees. The results showed that the canopy spectral reflectance of deciduous and evergreen trees increases with the increase of age. And the spectral changes of two species were most obvious in the near infrared band.

[Spectrum Variance Analysis of Tree Leaves Under the Condition of Different Leaf water Content].

Leaf water content is an important factor affecting tree spectral characteristics. So Exploring the leaf spectral characteristics change rule of the same tree under the condition of different leaf water content and the spectral differences of different tree leaves under the condition of the same leaf water content are not only the keys of hyperspectral vegetation remote sensing information identification but also the theoretical support of research on vegetation spectrum change as the differences in leaf water content. The spectrometer was used to observe six species of tree leaves, and the reflectivity and first order differential spectrum of different leaf water content were obtained. Then, the spectral characteristics of each tree species leaves under the condition of different leaf water content were analyzed, and the spectral differences of different tree species leaves under the condition of the same leaf water content were compared to explore possible bands of the leaf water content identification by hyperspectral remote sensing. Results show that the spectra of each tree leaf have changed a lot with the change of the leaf water content, but the change laws are different. Leaf spectral of different tree species has lager differences in some wavelength range under the condition of same leaf water content, and it provides some possibility for high precision identification of tree species.

[Objective characteristics of nystagmus in horizontal semicircular canal benign paroxysmal positional vertigo].

OBJECTIVE: To discuss the objective characteristics and mechanism of nystagmus direction, intensity and time in horizontal semicircular canal benign paroxysmal positional vertigo (HSC-BPPV) . METHODS: A total of 233 patients with HSC-BPPV, whereas 179 horizontal semicircular canalithasis (HSC-Can) and 54 horizontal semicircular cupulolithiasis (HSC-Cup) were involved respectively. The induced nystagmus in roll tests recorded by video-nystagmograph(VNG) , whose direction, intensity and time characteristics were compared in various BPPV. RESULTS: Horizontal nystagmus was both induced by turning left or right in HSC-BPPV roll tests. The direction of the induced nystagmus was the same with turning in HSC-Can. The latency, duration time and intensity ([AKx(-)D] ± s) turning to lesion and normal side were (1.922 ± 1.501)s and (1.447 ± 0.855)s, (25.620 ± 10.409)s, and (22.110 ± 10.931)s, (56.441 ± 33.168)°/s and (24.239 ± 13.892) °/s in HSC-Can. The latency, duration time and intensity turning to lesion side were larger than normal side (t = 3.715, 15.219 and 4.070, P < 0.01) , the difference was statistically significant, and the intensity rate was about 2: 1. The direction of the induced nystagmus was opposite to turning in HSC-Cup. The intensity turning to normal side was larger than lesion side obviously. The intensity rate was about 2: 1, the difference was statistically significant (t = -7.634, P < 0.01) . While the latency and intensity of turning to lesion side in HSC-Can were larger than turn to normal side in HSC-Cup, and the difference detected no statistically significant difference (t = 1.554 and 0.305, P > 0.05). CONCLUSIONS: The induced nystagmus intensity of head to two sides in roll tests for HSC-BPPV both follow Ewald's law, and the ratio between stronger and weaker are both 2: 1. These nystagmus parameters of VNG in roll tests are an objective guideline for BPPV diagnosis.

[Frequency characteristics of the semicircular canals lesion in Hunt syndrome with vertigo].

OBJECTIVE: To research the frequency characteristics of the semicircular canals lesion in Hunt syndrome with vertigo and the clinical value of the video head impulse test (vHIT) for vestibular function evaluated in this disease. METHODS: Thirty normal persons (control group) accepted the vHIT, 26 patients with Hunt syndrome with vertigo (study group) accepted low, mid and high frequency vestibular function tests, including caloric test (CT), head shaking test (HST) and vHIT. The parameters of the unilateral weakness (UW), head shaking nystagmus (HSN) and video head impulse test gain (vHIT-G) were observed. The correlations and characteristics of the results of the three tests in Hunt syndrome with vertigo deal were analyzed with SPSS 16.0 software. RESULTS: The values of vHIT-G of the six groups semicircular canal in the control group were normal distribution without statistical significance (F = 0.005, P < 0.01), two sides anterior, horizontal and posterior semicircular canals vHIT-G average (x ± s) were (16.80 ± 9.80)%, (16.57 ± 10.30)%, (16.52 ± 11.12)% respectively; in the study group the separately vHIT-G of the three canals of the affected side were (46.96 ± 34.54)%, (75.35 ± 35.29)% and (41.65 ± 32.87)%, in which statistical significance comparing with the control group was detected (all P < 0.01); the positive one of the three tests vHIT, HSN and CT were 23 cases (88.46%), 22 cases (84.61%) and 24 cases (92.31%), bilateral exact probability χ² test all the P > 0.05;there were Positive correlation between UW and the vHIT-G of lateral semicircular canal (r = 0.692, P < 0.01). CONCLUSIONS: The vestibular lesion of Hunt syndrome with vertigo is almost complete or multiple-frequency, which is characterized by the reduced or even aborted nerve conduction. Therefore, vHIT can be ultimately used for the screening test evaluating due to the vestibular function in Hunt syndrome with vertigo.

[Analysis of the dysfunction frequency and characteristics of semicircular canal in benign paroxysmal positional vertigo].

OBJECTIVE: To assess the characteristics of the dysfunction of semicircular canal in benign paroxysmal positional vertigo and the relationship with the ectopic otoconia. METHODS: There were 214 patients with benign paroxysmal positional vertigo (BPPV), including 107 cases of posterior semicircular canal canalithiasis (PSC-Can) 80 cases of horizontal semicircular canal canalithiasis (HSC-Can), 27 cases of horizontal semicircular canal cupulolithiasis (HSC-Cup). One hundred and ninety (88.8%) patients were accompany with relevant diseases while 24 (11.2%) cases were not. They accepted low, middle and high frequency vestibular function tests, including caloric test (CT), head shaking test (HST) and video head impulse test (vHIT) respectively. The parameters of the unilateral weakness (UW), head shaking nystagmus (HSN) and video head impulse test gain (vHIT-G) were observed. Patients classified into three groups (PSC-Can, HSC-Can, HSC-Cup) according to the involvement semicircular canal. The results of the three tests were analyzed with SPSS16.0 software. RESULTS: The positive cases of the three tests were vHIT: 15 (7.0%), HST: 52 (24.3%), CT: 152 (71.0%), a statistically significant difference (P < 0.05) was found between the three tests. When compared the Caloric Test, HST and vHIT between the BPPV patients with and without relevant diseases, there were no significant differences (P > 0.05). The variance without statistical significance (P > 0.05) was showed between three tests' results in each groups, it was also showed that the variance between the three groups in each tests reached no statistical significance (P > 0.05). The test of affected side UW between PSC-Can, HSC-Can and HSC-Cup showed the variance without statistical significance (F = 0.970, P = 0.383). CONCLUSIONS: The lesion of semicircular canals has the same etiological factors with the utricle pathological change in benign paroxysmal positional vertigo, and the dysfunction mostly happens in low frequency range of semicircular canal frequency band. The ectopic otoconia is not the main etiological factors for that. HST and vHIT of middle and high frequency can not be ultimately used for the screening test evaluating due to the semicircular canal function in BPPV.

[Subjective visual horizontal in peripheral unilateral vestibular dysfunction].

OBJECTIVE: To analyze the characteristics of subjective visual horizontal (SVH) and evaluate its clinical value for vestibular function in peripheral unilateral vestibular hypofunction (UVH). METHODS: Eighty-five patients with UVH (study group) and 39 normal persons (control group) accepted vestibular function tests, including SVH, subjective visual vertical (SVV) and caloric test by video-nystagmography. The parameters of the angle of SVH and SVV, directional preponderance (DP) and unilateral weakness (UW) of caloric test were observed. The correlation between SVH/SVV, DP, UW and the course of disease were investigated respectively. SPSS 16.0 software was used to analyze the data. RESULTS: Reference range of SVH and SVV was from -2° to 2° in the control group. Among the 85 patients, 46 cases (54.1%) and 43 cases (50.6%) had the abnormal values of SVH and SVV respectively, with no statistical significance (χ(2) = 12.5, P = 0.481) by chi square test. Fifty-five cases (64.7%) with abnormal DP had no statistical significance when compared with SVH and SVV respectively (χ(2) values were 0.19 and 2.86, respectively, P value were 0.164, 0.067, respectively). In UVH, there were positive correlation between SVH, SVV and DP (r value was 0.939, 0.648, 0.658, all P < 0.05) respectively, but no correlation between UW and SVH or SVV (r value was 0.048, 0.085, all P > 0.05). According to the permutation and combination of the four parameters, positive or negative, three main groups could be defined [SVH(+)DP(+)UW(+), SVH(-)DP(+)UW(+), SVH(-)DP(-)UW(+); SVV(+)DP(+)UW(+), SVV(-)DP(+)UW(+), SVV(-)DP(-)UW(+)]. The course of disease in the three main groups was positively skewed distribution, with median of 5.0, 10.0, 15.0 d and 5.0, 9.5, 14.5 d respectively. By Kruskal-Wallis Test, χ(2) value were 8.80 and 6.26, respectively(P value were 0.012, 0.040, respectively), with statistical significance between the above three main groups. CONCLUSIONS: The SVH value can evaluate the function of the otolithic. The angle of SVH and SVV are changing in the course of disease, SVH and SVV can be used as a guidance of the vestibular compensation evaluation.

[Analysis of directional preponderance of caloric test in evaluation of vestibular dynamic compensation].

OBJECTIVE: To analyze the value of directional preponderance (DP) in vestibular dynamic compensation evaluation. METHODS: One hundred fifty-five patients with sudden deafness accompanied vertigo were asked to accept routine vestibular tests including the spontaneous nystagmus (SN) and caloric test with video-nystagmography. DP, SN and unilateral weakness (UW) were selected as the observation parameters. Then the correlation analysis between DP, SN, UW and course of disease were investigated respectively. The change characteristic of the three parameters was also analyzed in the course of vestibular compensation. RESULTS: Of the 155 patients, there were negative correlations between SN, DP and course of disease (r(s) = -0.386, r(s) = -0.424, P < 0.05), positive correlation between SN and DP (r(s) = 0.543, P < 0.05), but no correlation between UW and course of disease (r(s) = 0.004, P > 0.05), and also positive correlation (r(s) = 0.274, P < 0.05) between DP and UW. According to three parameters were positive or negative, three main groups (DP+UW+SN+, DP+UW+SN- and DP-UW+SN-) in DP, UW, SN. The course of disease in three main groups was positively skewed distribution. Median was 6 days, 10 days and 20 days respectively. Through Kruskal-Wallis Test, chi(2) = 24.63, P < 0.05, there was statistical significance among the above three main groups. CONCLUSIONS: DP keeps on changing in the acute stage, static and dynamic compensation stage of peripheral vestibular disease. This indicates that DP can be considered as an objective evaluation index of vestibular dynamic compensation and as a guidance of the vestibular rehabilitation evaluation.

[Clinical research of vestibular autorotation test for patients with vertebrobasilar insufficiency].

OBJECTIVE: To explore the diagnostic values of vestibular autorotation test (VAT) for patients with vertebrobasilar insufficiency (VBI). METHODS: VAT and videonystagmography ( VNG) were performed on 73 patients with VBI and 48 patients with peripheral vestibular lesions (contrast group). Parameters analyzed included Gain, phase and asymmetry of VAT, as well as the canal paresis (CP) of caloric test and results of optokinetic-pursuit tests in VNG. Positive result of the test could be defined if anyone of the parameters was abnormal. RESULTS: For VAT test, Gain was enhanced in VBI group and was reduced in contrast group. In VBI group and contrast group, Gain enhanced showed in 47 (64.4%) cases and 5 (10.4%) cases, respectively (chi2 = 31.19, P < 0.01). Simultaneity, Gain reduced in 11 cases (15.5%) and 22 cases (45.8%), respectively (chi2 = 13.82, P < 0.01). But there was no statistics significant for results of the parameters of phase, asymmetry and integration between two groups. For VNG test, results with optokinetic-pursuit tests were more abnormal in VBI group than that in contrast group, which showed central lesions characteristics. Forty-four cases (60.3%) in VBI group and 10 cases (20.8%) in control group showed central lesions results with optokinetic-pursuit tests and visual fixation test (chi2 = 15.89, P < 0.01). Unilateral or bilateral CP showed in 33 cases (68.6%) in control group and 51 cases (69.9%) in VBI group with caloric test. CONCLUSIONS: Gain of VAT is mostly enhanced in VBI group, and Gain as a main characteristic is reduced in patients with peripheral vestibular lesions. The Gain parameter is availability for assessing characteristics of vestibular lesions. Phase and asymmetry can be used to assess the vestibular function but can not indicate the characteristics of vestibular lesions.