Assessment of residual dizziness after successful canalith repositioning maneuvre in benign paroxysmal positional vertigo patients: a questionnaire-based study.

OBJECTIVE: The purpose of this study was to assess residual dizziness (RD) after successful canalith repositioning maneuvre (CRM) treatment in patients with benign paroxysmal positional vertigo (BPPV) using Dizziness Handicap Inventory (DHI) questionnaire and Visual Analog Scale (VAS). METHODS: One hundred sixty BPPV patients after successful CRM treatment were recruited. All patients were divided into the residual dizziness (RD) group and without RD group. The DHI questionnaire and VAS before CRM and follow-up were asked to complete. For analysis of the improvement in symptom, we defined ∆DHI and ∆VAS as the difference between the baseline score and the follow-up score. RESULTS: High incidence of RD was observed in the older patients (p < 0.001). The incidence of hypertension in the RD group was also significantly higher than that of the without RD group (p = 0.022). The ∆DHI-P, ∆DHI-E, ∆DHI-F, ∆DHI-T, and ∆VAS scores in the without RD group were significantly higher than that of the RD group (p < 0.001). When the cutoff point of the ∆DHI total scores was 17, the sensitivity was 64.86% and the specificity was 73.26% for diagnosing RD. When the cutoff point of the ∆VAS scores was 2.5, the sensitivity was 77.03% and the specificity was 81.40% for diagnosing RD. CONCLUSIONS: RD is prone to occur in the older patients and ∆VAS exhibits higher sensitivity and specificity in assessing RD.

Vestibular and oculomotor function in patients with vestibular migraine.

AIM: The purpose of this study was to assess the vestibular and oculomotor function in patients with vestibular migraine (VM). And we also investigate the relationship between testing results and effectiveness of preventive medications in VM. MATERIAL AND METHOD: 41 patients with VM were recruited in this study and examined with cervical and ocular vestibular evoked myogenic potential(cVEMP, oVEMP), video head impulse test(vHIT), caloric test and videonystagmography. All patients were treated with preventive medications. We calculated symptomatic improvement and record episodes frequency in patients with VM. Six months later, the effectiveness of preventive medications were evaluated and the relationship between vestibular testing and effectiveness of preventive medications were analyzed further. RESULTS: In vestibular function testing, 73% of patients with VM showed abnormal results. Abnormal cVEMP, oVEMP, vHIT, and caloric test were found in 20%, 44%, 32% and 56% respectively. The abnormal rate of oVEMP was significantly higher than that of cVEMP(p < 0.05). And the proportion of abnormal caloric test was obviously higher than that of vHIT (p < 0.05). In oculomotor function testing, 42% of the patients with VM showed pathological results which was significantly lower than that of vestibular function testing(p < 0.05). After 6 months follow-up, the proportion of prophylactic medication effectiveness was significantly higher in normal vestibular function testing group compared with the abnormal group (p < 0.05). CONCLUSION: Abnormal vestibular and oculomotor functions are commonly observed in patients with VM. And these patients with abnormal vestibular function possess a weak effectiveness of preventive medications.

Treatment of Rivaroxaban versus Aspirin for Non-disabling Cerebrovascular Events (TRACE): study protocol for a randomized controlled trial.

BACKGROUND: Transient ischemic attack (TIA) or minor ischemic stroke represents the largest group of cerebrovascular disease, and those patients have a high risk of early recurrent stroke. Over decades, anticoagulation therapy has been used prudently in them for likely increasing the risk of intra-/extra-cranial hemorrhagic complications. However, recently rivaroxaban, a new oral anticoagulant, is proved to be as effective as traditional anticoagulants, while carrying significantly less risk of intracranial hemorrhage. Therefore, we assumed that patients may benefit from rivaroxaban if treated soon after TIA or minor stroke, and designed this adequately powered randomized study, TRACE. METHODS AND DESIGN: The Treatment of Rivaroxaban versus Aspirin in Non-disabling Cerebrovascular Events (TRACE) study is a randomized, double-blind clinical trial with a target enrollment of 4400 patients. A 14-days regimen of rivaroxaban 10 mg daily or a 14-days regimen of aspirin 100 mg daily will be administrated to randomized participants with acute TIA or minor stroke, defined as National Institute of Health Stroke Scale scores ≤ 3. The primary efficacy end point is percentage of patients with any stroke (ischemic or hemorrhage) at 14 days. Study visits will be performed at the day of randomization, day 14 and day 90. DISCUSSION: Even though the new oral anticoagulants seem to be both safe and effective, few clinical trials have been carried out to test their effect on non-disabling cerebrovascular events. Treatment with rivaroxaban may prevent more cerebrovascular events with an acceptable risk profile after TIA or minor stroke, compared with aspirin, thus helping to improve the outcome of the disease. TRIAL REGISTRATION: No. NCT01923818.

Ginsenoside Rd attenuates tau protein phosphorylation via the PI3K/AKT/GSK-3ß pathway after transient forebrain ischemia.

Phosphorylated tau was found to be regulated after cerebral ischemia and linked to high risk for the development of post-stroke dementia. Our previous study showed that ginsenoside Rd (Rd), one of the main active ingredients in Panax ginseng, decreased tau phosphorylation in Alzheimer model. As an extending study, here we investigated whether Rd could reduce tau phosphorylation and sequential cognition impairment after ischemic stroke. Sprague-Dawley rats were subjected to focal cerebral ischemia. The tau phosphorylation of rat brains were analyzed following ischemia by Western blot and animal cognitive functions were examined by Morris water maze and Novel object recognition task. Ischemic insults increased the levels of phosphorylated tau protein at Ser199/202 and PHF-1 sites and caused animal memory deficits. Rd treatment attenuated ischemia-induced enhancement of tau phosphorylation and ameliorated behavior impairment. Furthermore, we revealed that Rd inhibited the activity of Glycogen synthase kinase-3ß (GSK-3ß), the most important kinase involving tau phosphorylation, but enhanced the activity of protein kinase B (PKB/AKT), a key kinase suppressing GSK-3ß activity. Moreover, we found that LY294002, an antagonist for phosphatidylinositol 3-kinase (PI3K)/AKT signaling pathway, abolished the inhibitory effect of Rd on GSK-3ß activity and tau phosphorylation. Taken together, our findings provide the first evidence that Rd may reduce cerebral ischemia-induced tau phosphorylation via the PI3K/AKT/GSK-3ß pathway.

[Application of vestibular function examination in the analysis of damaged site in patients with acute vestibular neuritis].

Objective:To analyze the site of vestibular nerve damaged in patients with acute vestibular neuritis. Methods:Fifty-seven patients with acute vestibular neuritis were recruited, and each patient underwent caloric irrigation test, video head impulse test（vHIT） and vestibular evoked myogenic potentials（VEMPs）. The results were further analyzed. Results:Analysis of abnormal rates of different vestibular function tests: the abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and posterior semicircular canal vHIT were 92.98%, 92.98%, 92.98%, and 52.63%, respectively. The abnormal rate of cervical vestibular evoked myogenic potentials（cVEMP） and ocular vestibular evoked myogenic potentials（oVEMP） were 52.63% and 89.47%. The abnormal rate of caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP were significantly higher than posterior semicircular canal vHIT and cVEMP（P<0.01）. Combination analysis of different vestibular function tests: there are twenty-six patients（45.61%, superior and inferior vestibular nerve） with abnormal caloric irrigation test, video head impulse test, and VEMPs. There are twenty-five patients（43.86%, superior vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, anterior semicircular canal vHIT, and oVEMP. There are 4 patients（7.02%, inferior vestibular nerve） with abnormal posterior semicircular canal vHIT and cVEMP. There are two patients（3.51%, ampullary vestibular nerve） with abnormal caloric irrigation test, horizontal semicircular canal vHIT, and anterior semicircular canal vHIT. The rate of superior and inferior vestibular neuritis and superior vestibular neuritis were significantly higher than inferior vestibular neuritis and ampullary vestibular neuritis（P<0.01）. Conclusion:Acute vestibular neuritis subtypes can be divided into four categories: superior and inferior vestibular neuritis, superior vestibular neuritis, inferior vestibular neuritis, and ampullary vestibular neuritis. Video head impulse test can accurately assess the site of vestibular nerve damage in patients with acute vestibular neuritis. In addition, vHIT combined with VEMPs can provide objective evidence for the diagnosis of ampullary vestibular neuritis.

Sevoflurane preconditioning improves mitochondrial function and long-term neurologic sequelae after transient cerebral ischemia: role of mitochondrial permeability transition.

OBJECTIVE: Anesthetic preconditioning appears to be a viable strategy to treat ischemic cerebral injury. Here we investigated 1) whether the protection conferred by sevoflurane preconditioning sustains in time; 2) whether sevoflurane preconditioning diminishes mitochondrial dysfunction following cerebral ischemia; and 3) whether mitochondrial permeability transition pore plays a crucial role in the sevoflurane preconditioning. DESIGN: Laboratory investigation. SETTING: University research laboratory. SUBJECTS: : Sprague-Dawley rats. INTERVENTIONS: Rats underwent 2 hrs of focal cerebral ischemia induced by middle cerebral artery occlusion. Preconditioning was elicited with sevoflurane (2.3%) for 60 mins at 24 hrs before ischemia. The involvement of mitochondrial permeability transition pore was determined with a mitochondrial permeability transition pore opener atractyloside and a specific mitochondrial permeability transition pore inhibitor cyclosporin A. In vitro study was performed on acutely isolated mitochondria subjected to calcium overload. MEASUREMENTS AND MAIN RESULTS: Sevoflurane preconditioning significantly decreased the infarct size by 35.9% (95% confidence interval 6.5-28.4, p < .001). This reduction of injury volume was associated with a long-term improvement of neurological function according to modified neurological severity score (F = 13.6, p = .001) and sticky-tape test (F = 29.1, p < .001) for 42 days after ischemia. Furthermore, sevoflurane preconditioning markedly protected mitochondria, as indicated by preserved respiratory chain complex activities and membrane potential, lowered mitochondrial hydrogen-peroxide production, and attenuated mitochondrial permeability transition pore opening. Isolated mitochondria also demonstrated a reduced sensitivity to Ca-induced mitochondrial permeability transition pore opening after pre-exposure to sevoflurane in vitro (95% confidence interval 24.2-196.5,p = .006). Inhibiting mitochondrial permeability transition pore using cyclosporin A resulted in protective effects similar to those seen with sevoflurane preconditioning, whereas pharmacologically opening the mitochondrial permeability transition pore with atractyloside abrogated all the positive effects of sevoflurane preconditioning and cyclosporin A, including suppression of mitochondrial permeability transition pore opening, counteraction of mitochondria-dependent apoptotic pathway, and subsequent histological and behavioral improvements. CONCLUSIONS: Sevoflurane preconditioning protects mitochondria from cerebral ischemia/reperfusion injury and ameliorates long-term neurological deficits. Inhibition of mitochondrial permeability transition pore opening is a crucial step in mediating the neuroprotection of sevoflurane preconditioning.

Ginsenoside Rd protects neurons against glutamate-induced excitotoxicity by inhibiting ca(2+) influx.

Our previous studies have demonstrated that ginsenoside Rd (GSRd), one of the principal ingredients of Pana notoginseng, has neuroprotective effects against ischemic stroke. However, the possible mechanism(s) underlying the neuroprotection of GSRd is/are still largely unknown. In this study, we treated glutamate-injured cultured rat hippocampal neurons with different concentrations of GSRd, and then examined the changes in neuronal apoptosis and intracellular free Ca(2+) concentration. Our MTT assay showed that GSRd significantly increased the survival of neurons injured by glutamate in a dose-dependent manner. Consistently, TUNEL and Caspase-3 staining showed that GSRd attenuated glutamate-induced cell death. Furthermore, calcium imaging assay revealed that GSRd significantly attenuated the glutamate-induced increase of intracellular free Ca(2+) and also inhibited NMDA-triggered Ca(2+) influx. Thus, the present study demonstrates that GSRd protects the cultured hippocampal neurons against glutamate-induced excitotoxicity, and that this neuroprotective effect may result from the inhibitory effects of GSRd on Ca(2+) influx.

Hydroxyethyl starch 130/0.4 and sodium chloride injection as adjunctive therapy in patients with cerebral hypoperfusion.

BACKGROUND: Both severe stenosis and completed occlusion in internal carotid artery or its distal branches have been considered the main reasons of cerebral hypoperfusion, which contributes to the washout disturbances of embolism in low perfusion territories distal to stenosis. An aggravated hypoperfusion state in certain brain region may induce ischemic stroke and further cognitive decline. However, the effective medication for cerebral hypoperfusion is largely unsettled. METHODS/DESIGN: By using computed tomography perfusion (CTP) imaging, the trial will evaluate the effectiveness, safety and tolerability of hydroxyethyl starch (HES) 130/0.4 for patients with extra-/intra-cranial artery stenosis and cerebral hypoperfusion. From 5 neurological inpatient wards, 300 patients will be randomly recruited for administered routine medications plus intravascular volume therapies using the equal volume of HES 130/0.4 or 0.9% sodium chloride solution. Cerebral hypoperfusion state after 7-day intervention is the primary outcome measure. The secondary outcome measures includes, impaired renal function, abnormal heart function, hematological changes, neurological dysfunctions and cerebrovascular events in peri-intervention period and/or 3-month follow-up. The sample size will allow the detection of a two-sided 5% significance level between groups in the endpoint with a power of 80%. DISCUSSION: The trial would provide important efficacy and safety data on the intravascular administration of HES 130/0.4 in patients with unilateral cerebral hypoperfusion. The effects on kidney function, heart function, coagulation, neurological function and cerebralvascular events will be assessed. TRIAL REGISTRATION: ClinicalTrials.gov (Identifier: NCT01192581).

Risk Factors of Residual Dizziness After Successful Treatment for Benign Paroxysmal Positional Vertigo in Middle-Aged and Older Adults.

Objective: The purpose of this study was to analyze risk factors of residual dizziness (RD) after successful treatment for benign paroxysmal positional vertigo (BPPV) in middle-aged and older adults. Methods: 181 patients with BPPV, after successful canalith repositioning maneuver (CRM) treatment, were recruited. All patients were divided into the middle-aged group (aged 45-59 years, n = 101) and the older group (over 60 years, n = 80). The clinical characteristics were recorded, including age, gender, numbers of maneuvers, involved canal, affected side, RD, comorbidities, dizziness handicap inventory score, and generalized anxiety disorder's 7-item scale score. Results: The incidence of RD in the older group was significantly higher than that of the middle-aged group (p = 0.033). Multivariate logistic regression analysis shows that age (odds ratio = 1.042, p = 0.006), moderate to severe dizziness (odds ratio = 2.017, p = 0.034), and moderate to severe anxiety (odds ratio = 2.228, p = 0.017) were independently associated with RD in middle-aged and older adults. Conclusion: Older adults exhibited higher incidence of RD after successful treatment for BPPV. Age, moderate to severe dizziness, and moderate to severe anxiety were independent risk factors of RD in middle-aged and older adults.

The Association Between Precuneus Function and Residual Dizziness in Patients With Benign Paroxysmal Positional Vertigo.

Objectives: The purpose of this study was to apply the amplitude of the low-frequency fluctuation (ALFF) method to investigate the spontaneous brain activity alterations in patients with residual dizziness (RD) after successful canalith repositioning manoeuvre for benign paroxysmal positional vertigo (BPPV). Methods: All BPPV patients underwent visual vertigo analog scale (VVAS) evaluations and functional magnetic resonance imaging (fMRI). The ALFF method was used to assess the spontaneous brain activity. Screening of brain regions with significant changes in ALFF values was based on analysis of the whole brain. We further analyze the relationship between ALFF values of the altered regions and VVAS scores in BPPV patients with RD. Results: Fifteen BPPV patients with RD and fifteen without RD were recruited in this study. In contrast to without RD, RD patients exhibited increased scores in VVAS tests (p < 0.001) and RD patients also showed significant ALFF decrease in the bilateral precuneus (left: 251 voxels; x = -10, y = -69, z = 51; peak t-value = -3.25; right: 170 voxels; x = 4, y = -59, z = 42; peak t-value = -3.43). Correlation analysis revealed that the mean ALFF z-values in the left precuneus displayed significant negative correlations with the VVAS scores(r = -0.44, p = 0.01). Conclusions: This study shows that RD is associated with left precuneus function as revealed by fMRI. It might provide useful information for explaining neural mechanisms in BPPV patients with RD.

[Review of persistent postural-perceptual dizziness and experience of diagnosis and treatment].

The concept and diagnostic standard of persistent postural-perceptual dizziness（PPPD） improve the ability of clinical workers to recognize these diseases to some extent. However, the diagnosis of PPPD mainly depends on the identification of postural symptoms and the elimination of structural vestibular diseases, so the subjectivity is relatively strong. Moreover, the lack of objective criteria and a slight carelessness will lead to generalized diagnosis or omission diagnosis and misdiagnosis. At present, there is a lack of domestic large sample epidemiological investigation and other related studies, therefore it is a problem for diagnosing generalization of persistent posture perception dizziness and needed to be alert and corrected. Only those items meeting the criteria of the diagnostic standards can be carried out for diagnosis. The treatment needs to ensure sufficient dose and full therapy course. Generally, the medication should not be less than half a year.

Self-Treatment of Posterior Canal Benign Paroxysmal Positional Vertigo: A Preliminary Study.

Objectives: The purpose of this study is to investigate a modified Epley maneuver for self-treatment of posterior canal benign paroxysmal positional vertigo (PC-BPPV). Methods: The study recruited 155 patients with PC-BPPV. All patients were randomized into the Epley maneuver group (n = 77) and modified Epley maneuver group (n = 78). We analyzed the resolution rate (1 day and 1 week), residual symptoms after the maneuver, and adverse effects. Results: It was found that the modified Epley maneuver group had a higher resolution rate than that of the Epley maneuver group in the treatment of PC-BPPV after 1 day of the initial maneuver (p < 0.05). However, there was no difference in resolution rate between the Epley maneuver group and the modified Epley maneuver group in resolution rate after 1 week of the initial maneuver (p > 0.05). The modified Epley maneuver group had fewer residual symptoms than that of the Epley maneuver group 1 week after treatment of PC-BPPV (p < 0.05). Significant improvements were also observed in average DHI scores in patients who underwent the modified Epley maneuver compared to the Epley maneuver (p < 0.05). There was no significant difference in adverse effects between the two groups (p > 0.05). Conclusions: The modified Epley maneuver has a satisfactory therapeutic efficacy with less residual symptoms and could be recommended as a self-treatment for patients with PC-BPPV.

Effect of Stimulus Frequency on Air-Conducted Vestibular Evoked Myogenic Potentials.

OBJECTIVE: The aim of this study is to explore the effect of stimulus frequency on air-conducted cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) in healthy subjects. METHODS: The study included 45 healthy subjects who underwent the VEMP tests. Different stimulus frequencies (250-1500 Hz) were used for air-conducted cVEMP and oVEMP. RESULTS: In cVEMP, P1 and N1 latencies were significantly affected by different frequencies (P < .01). The amplitude at 500 Hz was significantly larger than those at other frequencies (P < .01).There was no significant main effect of frequency on asymmetry ratio (AR) (P > .05). In oVEMP, there was a tendency for the N1 and P1 latencies to decrease from 250 Hz to 1500 Hz (P < .01). The amplitudes at 500 Hz and 1000 Hz were significantly larger than the amplitudes at 250 Hz and 1500 Hz (P < .01).There was no significant main effect of frequency on AR (P > .05). CONCLUSION: The optimal stimulus frequency of the cVEMP is 500 Hz and for the oVEMP is 500Hz or 1000Hz. Due to the absence of impact of stimulus frequency, AR is the best parameter of VEMP for clinical use.

Immediate efficacy of Gufoni maneuver for horizontal canal benign paroxysmal positional vertigo (HC-BPPV): a meta-analysis.

OBJECTIVE: This meta-analysis aims to systematically measure the immediate efficacy of the Gufoni maneuver for horizontal canal benign paroxysmal positional vertigo (HC-BPPV). METHODS: A extensive search electronic databases, including PubMed, Embase, Web of Science and Cochrane library, were searched until to September 1, 2018 for relevant articles. We selected only randomized clinical trials studying with treatment of HC-BPPV employ by the Gufoni maneuver. RESULTS: Five randomized clinical trials were included in the current meta-analysis with a total of 714 HC-BPPV patients. The meta-analysis revealed that Gufoni maneuver had a higher immediate recovery rate than sham maneuver in treatment of HC-BPPV (risk ratio = 2.68, 95% CI, 1.54-4.65, p < 0.01). No difference was observed in immediate recovery rate between Gufoni maneuver and other maneuvers (risk ratio = 1.18, 95% CI, 0.99-1.41, p = 0.06). And Gufoni maneuver had a similar otolith switch rate with other maneuvers (risk ratio = 2.13, 95% CI, 0.56-8.07, p = 0.27). CONCLUSION: Gufoni maneuver has a satisfactory immediate efficacy for HC-BPPV and does not increase otolith switch rate.

Recovery Pattern of High-Frequency Acceleration Vestibulo-Ocular Reflex in Unilateral Vestibular Neuritis: A Preliminary Study.

Objective: To explore the recovery pattern of the high-frequency acceleration vestibulo-ocular reflex (VOR) function in unilateral vestibular neuritis (UVN). Methods: Forty-seven consecutive patients with UVN were recruited within 10 days of symptom onset for this study. The high-frequency acceleration horizontal VOR function was assessed using the video head impulse test (vHIT). Patients returned for follow-up evaluation at ~6 months after the onset of symptoms. According to the dizziness handicap inventory questionnaire (DHI), the patients were classified into the normal to mild dizziness group (DHI score ≤30) and moderate to severe dizziness group (DHI score >30) at the follow-up. All the obtained horizontal vHIT gains and corrective saccades parameters were analyzed. Results: vHIT results showed a significantly horizontal VOR gain recovery in UVN patients at the follow-up on the lesion side (p < 0.01). A significantly reduction in the occurrence of corrective saccades (overt and covert) and velocity of corrective saccades (overt and covert) were observed at the follow-up (p < 0.05). At the follow-up, the normal to mild dizziness group (DHI score ≤30) had a significantly higher normal rate of VOR gain, the mean vHIT gains and occurrence of isolated covert saccades (P < 0.05). Furthermore, the occurrence of mixed saccades and the mean velocity of covert saccades were significantly lower in normal to mild dizziness group (P < 0.05). Conclusion: Apart from the recovery of the VOR gain, recovery pattern of corrective saccades can play a key role in vestibular compensate.

Different effects of mild and severe seizures on hippocampal neurogenesis in adult rats.

Recent evidence shows that functional neurogenesis exists in the adult hippocampus and that epileptic seizures can increase neurogenesis in the dentate gyrus (DG). However, it is unknown whether different seizure severity has different effects on neurogenesis in the DG of adult rats. In this study, we examined hippocampal neurogenesis in the rat mild and severe seizure preparations characterized with frequent wet dog shakes and severe status epilepticus, respectively. Both mild and severe seizures promoted the mitotic activity in the DG, but severe seizures caused a stronger cell proliferative response than mild seizures. Less than 20% of newborn cells in the DG differentiated into neurons in rats suffering severe seizures, whereas more than 60% of newborn dentate cells differentiated into neurons in control and mild seizure groups. Most newborn neurons migrated into the granular cell layer in control and mild seizure groups, but severe seizures were associated with an aberrant migration of newborn neurons into the dentate hilus. Severe seizures induced astrocyte activation and the expression of nestin and the migration directional molecules netrin 1 and Sema-3A in the hilus, which were not present in the hilus of control and mild seizure-attacked rats, suggesting that these molecules are involved in the aberrant migration of newborn neurons.

Inhibited glutamate release by granulocyte-colony stimulating factor after experimental stroke.

We investigated the ability of granulocyte-colony stimulating factor (G-CSF) on inhibiting glutamate release by microdialysis in a rat stroke model. Male Wistar rats (n=15) were treated with either intravenous saline or G-CSF (60 microg/kg) 30 min after temporary middle cerebral artery occlusion (MCAO). G-CSF significantly attenuated the release of glutamate in the infarcted striatum from 30 minutes to 180 minutes after tMCAO compared with control (p<0.05). Infarct volume in G-CSF treated group (135+/-13 mm(3)) reduced significantly compared to control (181+/-10mm(3)) at 24 hours after tMCAO. The result of present study show that G-CSF possess an ability to inhibit excitotoxicity after ischemic stroke.

Study of inflammatory factors' effect on the endothelial barrier using piezoelectric biosensor.

This paper used piezoelectric sensor to study the dysfunction of endothelial cell monolayer barrier caused by inflammatory factors. The biocompatible conductive polymer membrane of pPy[pGlu]-pLys was prepared on the surface of the ITO work electrode to improve the interface between the endothelial cell and the electrode. Both the impedance analysis data and the stable plateau stage of sensor's frequency shift indicated that endothelial cells formed a good monolayer barrier on this polymer surface. The response frequency shifts of lipopolysaccharide (LPS)- and histamine-induced endothelial barrier dysfunction were different, which distinguished their different stimulation mechanism. It provided a valuable analysis method for detecting the endothelial barrier function affected by inflammatory factor, and could further promote the application of piezoelectric sensor in cell biology and toxicology research.

Effects of Hand Positions During Video Head-Impulse Test (vHIT) in Patients With Unilateral Vestibular Neuritis.

Background: The aim of this study is to identify the effects of hand positions (head and jaw) on the video head-impulse test (vHIT). Methods: Eighty-six healthy volunteers and sixty-seven patients with unilateral vestibular neuritis (UVN) were recruited for this study. Different hand positions (head and jaw) were used in the vHIT of horizontal semicircular canals in healthy volunteers and UVN patients. All the obtained horizontal vHIT gains were analyzed. Results: It was observed that when horizontal vHIT was performed with the head hand position, the number of head impulses that produced overhigh vestibulo-ocular reflex (VOR) gains was more than that with the jaw hand position (p < 0.01), irrespective of whether the test was performed in healthy volunteers or UVN patients. The gains obtained were lower when the jaw hand position was used than that obtained when the head hand position was used (p < 0.05). However, no significant difference existed in the mean head velocity between the two hand positions (p > 0.05). Using the head hand position has greater a chance to elicit in UVN patients normal horizontal vHIT gains with refixation saccades than using the jaw hand position (p = 0.04). Conclusion: The jaw hand position can increase the accuracy of vHIT in determining the lesion side.

Different degrees of hypothermia after experimental stroke: short- and long-term outcome.

BACKGROUND AND PURPOSE: The neuroprotective role of mild therapeutic hypothermia was established in animal models of cerebral ischemia. Still, several issues, including optimal target temperature, remain unclear. The optimal depth of hypothermia in a rat model of focal cerebral ischemia was investigated. METHODS: Eighty-four male Wistar rats (n=84) were subjected to filament occlusion of the middle cerebral artery for 90 minutes. Sixty animals were equally split into 6 groups kept at core temperatures of 37 degrees C, 36 degrees C, 35 degrees C, 34 degrees C, 33 degrees C, and 32 degrees C over a period of 4 hours starting 90 minutes after middle cerebral artery occlusion. Twenty-four hours later, after performing a neuroscore, animals were killed and brains examined for infarct size, edema, and invasion of leukocytes. In the second part, 24 animals (8 per group) were kept at 33 degrees C, 34 degrees C, and 37 degrees C for 4 hours, allowed to survive for 5 days, and underwent additional investigation of transferase dUTP nick-end labeling. RESULTS: In the first part, one animal in each treatment group and 2 animals in group 37 degrees C died. The infarct size and edema were smaller for 34 degrees C and 33 degrees C compared with all other groups (P<0.05) over 24 hours. These animals also had better functional outcome (P<0.05) with an advantage for 34 degrees C versus 33 degrees C (P<0.05). Leukocyte count was lower for 34 degrees C and 33 degrees C as compared with the 37 degrees C group. Similar results were obtained in the second part of the study with an advantage for 34 degrees C versus 33 degrees C. CONCLUSIONS: Our results suggest that the optimal depth of therapeutic hypothermia in temporary middle cerebral artery occlusion is 34 degrees C.