Reflex Function Research Articles

Short-Term and Long-Term Stability of Medial Olivocochlear Reflex in Adults with Typical Hearing.

This study aimed to assess the stability of Medial Olivocochlear Reflex (MOCR) function in typical hearing adults with the use of Contralateral Suppression (CS) of Distortion Product Otoacoustic Emissions (DPOAEs). This study included fifty-three (90ears) participants between the ages of 18-30. Participants were divided into 3 groups (Group A-daily stability, Group B-short-term stability, and Group C- long-term stability). For each group, 4 measurements (30 × 4 = 120sessions) were taken. Group A measurements were taken daily, Group B measurements were taken weekly and Group C measurements were taken monthly. DPOAEs and Contralateral Suppression of DPOAEs were measured for each group. Analyses indicated that Medial Olivocochlear Reflex (MOCR) measured through contralateral suppression of DPOAE was unstable. This result indicates a DPOAE-based measure of the MOCR was not repeated across time. A great deal has been learned using CS of DPOAEs to study medial efferent activation, but several unresolved methodological issues that could impact the data to produce poor stability across time. Those methodological issues need to be explored and researched in the future.

Oral administration of baicalein-enriched fraction during pre- and post-ischemic stroke alleviated cognitive impairments in rat models

<abstract> <p>In recent years, numerous studies have discovered the potential of natural compounds extracted from medicinal plants as a promising alternative treatment for ischemic stroke (IS). <italic>Oroxylum indicum</italic> is among the plants that has been widely proven to contain a beneficial flavonoid compound known as baicalein. However, the therapeutic potential of this compound for IS disease has yet to be demonstrated. In this study, a baicalein-enriched fraction (BEF) was harvested from the leaves of <italic>O. indicum</italic> and tested on neural stem cells (NSCs) to determine its effects on the cell viability and gene expression prior to an in vivo animal study. NSCs were chosen because they are the primitive brain cells that play important roles in neurogenesis after IS injury. It was found that NSCs treated with BEF at concentration of 3.125 µg/mL for 48 hours showed a significant higher cell proliferation rate. Moreover, these cells expressed high NSC markers (Nestin and SOX2) and genes responsible for antioxidant (SOD2) and angiogenesis (ANGPT1) mechanisms, indicating that the BEF treatment could enhance the progenitor brain cells viability and the expression of cytokines that are beneficial to reduce oxidative stress and reinstate blood flow in an ischemic brain. Subsequently, the in vivo therapeutic effects of BEF for IS disease was tested by administering 50 mg/kg b.wt of BEF to male Sprague Dawley (SD) rats via oral gavage before and after induction of IS. Assessments of neurological impairments were performed using a modified neurological severity score (mNSS) and the quantification of the total infarct volume was evaluated as the endpoint of this study. Results showed that an oral administration of BEF improved the behavioral scoring for motor functions (forelimb flexion and forelimb twisting), contralateral sensory functions (paw-whiskers test), motor coordination, balance functions (beam balance test) and reflex functions (pinna, corneal, startle and tail reflex) within 24–72 h; alternatively, the non-treated rats showed continuously lower scores for all the tests throughout the study, indicating that the BEF-treated rats exhibited a faster recovery rate as compared to the non-treated rats. Such improvements were observed up to two weeks. In addition, histological assessment also revealed a reduction of infarct volume in the BEF-treated rats as compared to the control rats. In summary, the present study demonstrated the potential of BEF extracted from the <italic>O. indicum</italic> as a supplement to improve preclinical IS models.</p> </abstract>

A Multicentre Randomized Controlled Clinical Study of Cross Electro-Nape-Acupuncture (CENA) for the Treatment of Pseudobulbar Palsy in Patients with Tracheotomy Intubation for Severe Cerebral Haemorrhage.

The objective is to evaluate the clinical efficacy of cross electro-nape-acupuncture (CENA) in the treatment of pseudobulbar palsy in patients with tracheotomy intubation for severe cerebral haemorrhage and to provide an innovative acupuncture method for the treatment of such patients. A total of 126 patients from six trial centres who met the inclusion criteria were randomly divided into three groups according to the random number table method in the ratio of 1 : 1 : 1, with 42 patients in each group, and the three groups were divided into CENA group, electro-acupuncture group, and acupuncture group. Each group's acupuncture treatment lasted for 30 minutes, and the needles were removed at the end of the treatment. Acupuncture was performed once a week on Sunday only and twice a day from Monday to Saturday, a total of 4 weeks of treatment. The SWT, FDA, ChSWAL-QOL, and TCRGS scores of the three groups of patients before and after treatment were compared to evaluate the effect of CENA on remodelling the function of swallowing reflex and cough reflex and promoting the recovery of dysarthria and swallowing quality of life in pseudobulbar palsy in patients with tracheotomy intubation for severe cerebral haemorrhage. After treatment, the WST and TCRGS grade scores decreased and the FDA and ChSWAL-QOL scores increased significantly in all three groups compared with the pretreatment scores and were statistically significant. There was a significant difference between the three groups for these four indicators after treatment; the comparison between groups showed significant differences in the CENA group compared to the electro-acupuncture and acupuncture groups. The efficiency of the CENA group was significantly better than that of the electro-acupuncture and acupuncture groups. Compared with the acupuncture and electro-acupuncture groups, the CENA could better promote the remodelling of swallowing function and cough reflex function, promote the recovery of dysarthria, and better improve the quality of life of patients with pseudobulbar palsy from tracheotomy intubation in severe cerebral haemorrhage.

Vestibular loss disrupts visual reactivity in the alpha EEG rhythm

The alpha rhythm is a dominant electroencephalographic oscillation relevant to sensory-motor and cognitive function. Alpha oscillations are reactive, being for example enhanced by eye closure, and suppressed following eye opening. The determinants of inter-individual variability in reactivity in the alpha rhythm (e.g. changes with amplitude following eye closure) are not fully understood despite the physiological and clinical applicability of this phenomenon, as indicated by the fact that ageing and neurodegeneration reduce reactivity. Strong interactions between visual and vestibular systems raise the theoretical possibility that the vestibular system plays a role in alpha reactivity. To test this hypothesis, we applied electroencephalography in sitting and standing postures in 15 participants with reduced vestibular function (bilateral vestibulopathy, median age = 70 years, interquartile range = 51–77 years) and 15 age-matched controls. We found participants with reduced vestibular function showed less enhancement of alpha electroencephalography power on eye closure in frontoparietal areas, compared to controls. In participants with reduced vestibular function, video head impulse test gain – as a measure of residual vestibulo-ocular reflex function – correlated with reactivity in alpha power across most of the head. Greater reliance on visual input for spatial orientation (‘visual dependence’, measured with the rod-and-disc test) correlated with less alpha enhancement on eye closure only in participants with reduced vestibular function, and this was partially moderated by video head impulse test gain. Our results demonstrate for the first time that vestibular function influences alpha reactivity. The results are partly explained by the lack of ascending peripheral vestibular input but also by central reorganisation of processing relevant to visuo-vestibular judgements.

Gaze stability in youth athletes: A normative observational study.

The Gaze Stabilization Test (GST) assesses vestibulo-ocular reflex (VOR) function by determining the maximum head velocity at which an individual can accurately perceive a fixed-size visual target. There is limited information about gaze stability performance in youth athletes. The purpose of this study is to describe baseline performance of athletes ages 17 years and under on a computerized GST and explore the influence of demographic characteristics on performance. Baseline GST and demographic data were acquired via retrospective chart review. The sample included 106 athletes aged 8 to 17 years (mean 13.9 years±1.79; 78% male). The median values for baseline GST function were 180 (IQR: 150-210) degrees per second (d/sec) in the leftward direction, and 190 d/sec (IQR: 160-220) in the rightward direction. There were no significant effects of sex/gender or concussion history on GST performance. The GST is one of many tools available for clinicians to use in a multi-modal approach to concussion management. Understanding how healthy young athletes perform can assist clinicians in determining vestibular impairment, formulating the exercise prescription, and estimating physiologic recovery.

Effects of contact lens wearing on corneal sensitivity and reflex functions

AbstractPurpose: To study the effects of contact lens (CL) use on corneal sensory nerve activity, exploring corneal sensitivity and ocular functions regulated by sensory input in asymptomatic (CL‐A) and symptomatic (CL‐S) CL wearers.Methods: CL wearers (23.8 ± 1.0 years; n = 31) participating in the study were classified as CL‐S when OSDI ≥13. Sex and age eye glasses (EG) users (24.5 ± 0.8 years, n = 29) participated as control group. Corneal mechanical, chemical and cold sensitivity was explored using a gas esthesiometer and 4°C‐saline drops; intensity, irritation and cold components of the evoked sensation were measured with Visual Analogue Scales (VASs). Tear volume (with phenol red threads), tear stability (TBUT), basal blinking frequency (BF), ocular surface temperature (OST; by IR thermography) were also assessed.Results: CL wearers scored higher irritation VAS values than EG wearers for mechanical (2.5 ± 0.5 vs. 1.4 ± 0.4 for 160 ml/min air flow, CL vs EG, p = 0.09) and chemical stimuli (1.8 ± 0.5 vs. 0.7 ± 0.3 for 40% CO2, p < 0.05), and lower intensity values for cold stimulation (2.2 ± 0.4 vs. 4.5 ± 0.7, p < 0.05); tear volume was similar (27.0 ± 2.2 vs. 27.2 ± 1.6 mm), TBUT lower (8.3 ± 0.5 vs. 11.7 ± 0.5 s, p < 0.001), BF was higher (25.1 ± 2.4 vs. 14.3 ± 1.9 blinks/min, p < 0.001), and OST was lower (34.4 ± 0.2 vs. 35.2 ± 0.2°C, p < 0.01). VAS values for cold stimulation was slightly lower in CL‐S than in CL‐A (2.0 ± 0.4 vs. 4.0 ± 0.8, p = 0.06), while OST was higher (35.0 ± 0.2 vs. 33.9 ± 0.3°C, p < 0.01).Conclusions: CL wearing affects corneal sensory nerve functions, changing corneal sensitivity, blinking rate, tearing stability, and OST. The changes found in corneal sensitivity fully agree with those described in neural activity of corneal sensory nerves after injury or inflammation using animal models: sensitization of corneal nociceptors and inhibition of cold thermoreceptors. The differences between CL‐S and CL‐A wearers could be due to the presence of subclinical ocular surface inflammation in symptomatic subjects.

Intermittent exposure to chlorpyrifos results in cardiac hypertrophy and oxidative stress in rats

Forbidden in some countries due to its proven toxicity to humans, chlorpyrifos (CPF) still stands as an organophosphate pesticide (OP) highly used worldwide. Cardiotoxicity assessment is an unmet need in pesticide regulation and should be deeply studied through different approaches to better inform and generate an appropriate regulatory response to OP use. In the present study, we used our 4-week intermittent OP exposure model in rats to address the CPF effects on cardiac morphology allied with cardiovascular functional and biomolecular evaluation. Rats were intermittently treated with CPF at doses of 7 mg/kg and 10 mg/kg or saline (i.p.) and assessed for cardiac morphology (cardiomyocyte diameter and collagen content), cardiopulmonary Bezold-Jarisch reflex (BJR) function, cardiac autonomic tone, left ventricle (LV) contractility, cardiac expression of NADPH oxidase (Nox2), catalase (CAT), superoxide dismutase 1 (SOD1), superoxide dismutase 2 (SOD2) and cardiac levels of advanced oxidation protein products (AOPP) and thiobarbituric acid reactive substances (TBARS). Plasma butyrylcholinesterase (BuChE) and brainstem acetylcholinesterase (AChE) were also measured. Intermittent exposure to CPF induced cardiac hypertrophy, increasing cardiomyocyte diameter and collagen content. An impairment of cardioinhibitory BJR responses and an increase in cardiac vagal tone were also observed in CPF-treated animals without changes in LV contractility. CPF exposure increased cardiac Nox-2, CAT, SOD1, and TBARS levels and inhibited plasma BuChE and brainstem AChE activities. Our data showed that intermittent exposure to CPF induces cardiac hypertrophy together with cardiovascular reflex impairment, imbalance of autonomic tone and oxidative stress, which may bring significant cardiovascular risk to individuals exposed to OP compounds seasonally.

The Underlying Mechanisms of Handwriting of Individuals with Autism Spectrum Disorder: A Scoping Review

ABSTRACT Integration of cognitive, sensory, and motoric processes is essential for the production of handwriting, however, challenging for children and youth with Autism Spectrum Disorder (ASD). The objective of this scoping review is to identify potential underlying mechanisms of handwriting of children and youth with ASD by reviewing cognitive, sensory, and motoric body functions as predictors of their handwriting. The International Classification of Functioning, Disability, and Health – Children and Youth version was used to structure the analysis. Eleven studies (0.9%) met inclusion criteria. Results show that linguistic functions, psychomotor functions, motor control functions, and motor reflex functions predict handwriting of children and youth with ASD. This suggests these body functions are underlying mechanisms of handwriting of children and youth with ASD, encouraging future research to test these body functions as potential pathways to handwriting intervention for children and youth with ASD. Findings suggest a bottom-up approach to the development of handwriting interventions for children and youth with ASD.

Therapeutic efficacy of matrix metalloproteinase-12 suppression on neurological recovery after ischemic stroke: Optimal treatment timing and duration.

We recently showed that the post-ischemic induction of matrix metalloproteinase-12 (MMP-12) in the brain degrades tight junction proteins, increases MMP-9 and TNFα expression, and contributes to the blood-brain barrier (BBB) disruption, apoptosis, demyelination, and infarct volume development. The objectives of this study were to (1) determine the effect of MMP-12 suppression by shRNA-mediated gene silencing on neurological/functional recovery, (2) establish the optimal timing of MMP-12shRNA treatment that provides maximum therapeutic benefit, (3) compare the effectiveness of acute versus chronic MMP-12 suppression, and (4) evaluate potential sex-related differences in treatment outcomes. Young male and female Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion and reperfusion. Cohorts of rats were administered either MMP-12shRNA or scrambled shRNA sequence (control) expressing plasmids (1 mg/kg; i.v.) formulated as nanoparticles. At designated time points after reperfusion, rats from various groups were subjected to a battery of neurological tests to assess their reflex, balance, sensory, and motor functions. Suppression of MMP-12 promoted the neurological recovery of stroke-induced male and female rats, although the effect was less apparent in females. Immediate treatment after reperfusion resulted in a better recovery of sensory and motor function than delayed treatments. Chronic MMP-12 suppression neither enhanced nor diminished the therapeutic effects of acute MMP-12 suppression, indicating that a single dose of plasmid may be sufficient. We conclude that suppressing MMP-12 after an ischemic stroke is a promising therapeutic strategy for promoting the recovery of neurological function.

Analysis of control strategies for VIVA OpenHBM with active reflexive neck muscles

Modeling muscle activity in the neck muscles of a finite element (FE) human body model can be based on two biological reflex systems. One approach is to approximate the Vestibulocollic reflex (VCR) function, which maintains the head orientation relative to a fixed reference in space. The second system tries to maintain the head posture relative to the torso, similar to the Cervicocolic reflex (CCR). Strategies to combine these two neck muscle controller approaches in a single head-neck FE model were tested, optimized, and compared to rear-impact volunteer data. The first approach, Combined-Control, assumed that both controllers simultaneously controlled all neck muscle activations. In the second approach, Distributed-Control, one controller was used to regulate activation of the superficial muscles while a different controller acted on deep neck muscles. The results showed that any muscle controller that combined the two approaches was less effective than only using one of VCR- or CCR-based systems on its own. A passive model had the best objective rating for cervical spine kinematics, but the addition of a single active controller provided the best response for both head and cervical spine kinematics. The present study demonstrates the difficulty in completely capturing representative head and cervical spine responses to rear-impact loading and identified a controller capturing the VCR reflex as the best candidate to investigate whiplash injury mechanisms through FE modeling.

Determining the Agreement Between Common Measures Related to Vestibulo-ocular Reflex Function After a Mild Traumatic Brain Injury in Children and Adolescents

ObjectiveTo (1) determine the level of agreement between symptom provocation and performance-based tests of vestibulo-ocular reflex (VOR) function after pediatric mild traumatic brain injury (mTBI) and (2) describe the level of symptom provocation induced by a VOR task in individuals with and without cervical findings. DesignCross-sectional. SettingThis study was conducted at a tertiary care pediatric hospital. ParticipantsA total of 101 participants (N=101) aged 6-18 years within 3 weeks of mTBI diagnosis were included (54.5% female; mean age, 13.92±2.63 years; mean time since injury at assessment, 18.26±6.16 days). InterventionsNone. Main Outcome MeasuresSymptom provocation (Vestibular/Ocular Motor Screening tool), performance (clinician-observed VOR performance, head thrust test [HTT], computerized dynamic visual acuity test, video head impulse test), and cervical impairment (cervical flexion-rotation test, range of motion test, self-reported neck pain). Agreement was evaluated using Cohen's κ statistic. ResultsNo outcomes demonstrated agreement with symptom provocation (κ=−0.15 to 0.14). Fair agreement demonstrated between clinician-observed VOR performance and HTT (κ=0.32), with little to no agreement demonstrated between other measures. Proportions reporting test-induced dizziness and headache were greater among individuals with cervical findings (29.1%-41.8%) than without (2.3%-6.8%). ConclusionsFindings support that symptom provocation and performance-based tests measure different constructs and thus have distinct roles when assessing VOR function. Findings suggest results from measures of symptom provocation may be influenced by coexisting cervical impairments, underlining the value of assessing for cervical injury after pediatric mTBI.

Report of oscillopsia in ataxia patients correlates with activity, not vestibular ocular reflex gain

Patients with cerebellar ataxia report oscillopsia, "bouncy vision" during activity, yet little is known how this impacts daily function. The purpose of this study was to quantify the magnitude of oscillopsia and investigate its relation to vestibulo-ocular reflex (VOR) function and daily activity in cerebellar ataxia. 19 patients diagnosed with cerebellar ataxia and reports of oscillopsia with activity were examined using the video head impulse test (vHIT), Oscillopsia Functional Index (OFI), and clinical gait measures. Video head impulse data was compared against 40 healthy controls. OFI scores in ataxia patients were severe and inversely correlated with gait velocity (r = -0.55, p < 0.05), but did not correlate with VOR gains. The mean VOR gain in the ataxic patients was significantly reduced and more varied compared with healthy controls. All patients had abnormal VOR gains and eye/head movement patterns in at least one semicircular canal during VHIT with passive head rotation. Patients with cerebellar ataxia and oscillopsia have impaired VOR gains, yet severity of oscillopsia and VOR gains are not correlated. Patients with cerebellar ataxia have abnormal oculomotor behavior during passive head rotation that is correlated with gait velocity, but not magnitude of oscillopsia.

Characterizing the evolution of oculomotor and vestibulo-ocular function over time in children and adolescents after a mild traumatic brain injury.

BackgroundImpairments to oculomotor (OM) and vestibulo-ocular reflex (VOR) function following pediatric mTBI have been demonstrated but are poorly understood. Such impairments can be associated with more negative prognosis, affecting physical and mental wellbeing, emphasizing the need to more fully understand how these evolve.Objectivesto determine i) the extent to which performance on clinical and computerized tests of OM and VOR function varies over time in children and adolescents at 21 days, 3-, and 6-months post-mTBI; ii) the proportion of children and adolescents with mTBI presenting with abnormal scores on these tests at each timepoint.DesignProspective longitudinal design.SettingTertiary care pediatric hospital.Participants36 participants with mTBI aged 6 to18.ProceduresParticipants were assessed on a battery of OM and VOR tests within 21 days, at 3- and 6-months post injury.Outcome measuresClinical measures: Vestibular/ocular motor screening tool (VOMS) (symptom provocation and performance); Computerized measures: reflexive saccade test (response latency), video head impulse test (VOR gain), and dynamic visual acuity test (LogMAR change).AnalysisGeneralized estimating equations (parameter estimates and odd ratios) estimated the effect of time. Proportions above and below normal cut-off values were determined.ResultsOur sample consisted of 52.8% females [mean age 13.98 (2.4) years, assessed on average 19.07 (8–33) days post-injury]. Older children performed better on visual motion sensitivity (OR 1.43, p = 0.03) and female participants worse on near point of convergence (OR 0.19, p = 0.03). Change over time (toward recovery) was demonstrated by VOMS overall symptom provocation (OR 9.90, p = 0.012), vertical smooth pursuit (OR 4.04, p = 0.03), voluntary saccade performance (OR 6.06, p = 0.005) and right VOR gain (0.068, p = 0.013). Version performance and VOR symptom provocation showed high abnormal proportions at initial assessment.DiscussionResults indicate impairments to the VOR pathway may be present and driving symptom provocation. Vertical smooth pursuit and saccade findings underline the need to include these tasks in test batteries to comprehensively assess the integrity of OM and vestibular systems post-mTBI.ImplicationsFindings demonstrate 1) added value in including symptom and performance-based measures in when OM and VOR assessments; 2) the relative stability of constructs measured beyond 3 months post mTBI.

태권도 선수의 운동기능 향상을 위한 트레이닝 방법 분석

Purpose: To suggest the development and application of the training program and the direction of follow-up research by systematically reviewing the previous literatures that include the training program for Taekwondo athletes. Method: From 2010 to December 2020, search databases (RISS, KISS) were used, the risk of bias in randomized studies was evaluated using the RoB (Risk of Bias) tool, and the effect size estimation was performed using Rev Man Manager (Version 5.4.1). was used. Results: A total of 1097 studies were searched and eight studies were finally included after all review process. The results are as follows: 1) Flexibility: Effect Size (ES) of core stabilization training is 1.76, 2) Strength: ES of core stabilization training on strength is 2.39, 3) Muscle endurance: ES of core stabilization training is 1.60, 4) Reflex: ESs of plyometric training and weight training are 1.23~1.26 and 1.46, repectively, and 5) Isokinetic muscle strength: ESs of weight training and plyometric training are 1.21 and 1.60~2.46, respectively. Conclusion: 1) Plyometric training was effective in improving flexibility, muscle strength, muscular endurance, agility, isokinetic muscle function, and maximal oxygen intake. 2) Core stabilization training was effective in improving flexibility, strength, and muscular endurance. 3) Underwater training was effective in improving isokinetic muscle function. 4) Weight training was effective in improving reflex and isokinetic muscle function.

The exercise pressor reflex: An update.

The exercise pressor reflex is a feedback mechanism engaged upon stimulation of mechano- and metabosensitive skeletal muscle afferents. Activation of these afferents elicits a reflex increase in heart rate, blood pressure, and ventilation in an intensity-dependent manner. Consequently, the exercise pressor reflex has been postulated to be one of the principal mediators of the cardiorespiratory responses to exercise. In this updated review, we will discuss classical and recent advancements in our understating of the exercise pressor reflex function in both human and animal models. Particular attention will be paid to the afferent mechanisms and pathways involved during its activation, its effects on different target organs, its potential role in the abnormal cardiovascular response to exercise in diseased states, and the impact of age and biological sex on these responses. Finally, we will highlight some unanswered questions in the literature that may inspire future investigations in the field.

Debating News Media: Politics, Identities, and Alternatives in the Greek Mediascape

ABSTRACT Against the backdrop of intertwined crises, this study explores discursive interplays between news media, journalists, and the audience. Analyzing media texts, it sets as its epicentre something that rarely concerns the academic community, i.e., the way in which Media talk about themselves, exploring their reflexive function and the ways they configure their relation to state and party politics, as well as professional identities. Employing focus groups, our study sheds light on the dialogue between journalists and the audience, delving into their argumentative strategies and psycho-discursive practices. Furthermore, the combination of critical approaches to discourse analysis with the use of lexicometric techniques allows us to bring to the fore “unmapped” territories of the media landscape, enhancing our findings with higher levels of reliability. This interdisciplinary research design throws into sharp relief the antagonistic discourses as well as the contingency of meanings that are crucial to democracy, carving out the space to challenge normative perceptions of freedom of speech, pluralism, accountability and citizens’ participation in the public debate. Therefore, the gap between the rules governing the Media and their operation in practice emerges, pointing to alternative ways of collectively reinventing the entire mediatic ecosystem.

Binocular Function in Different Gaze Positions.

PurposeTo evaluate varied aspects of binocular function in multiple gaze positions.MethodsIn 2018, this cross-sectional study was conducted on 21 participants (male = 11) with an age range of 19–25 years. Having emmetropia and 10/10 visual acuity in both eyes were conditions of the inclusion criteria for the cross-sectional study. The following aspects of binocular function including amplitude of accommodation (AA), near point of convergence, near phoria, and monocular accommodative facility were evaluated in five gazes (primary, upward, downward, left, and right) for all subjects.ResultsNear point of convergence values showed significant differences in all gaze positions (P 0.001). The lowest near point of convergence value was seen in the primary gaze (2.69 cm) and the downward gaze (3.47 cm) and the highest near point of convergence value was seen in the left gaze (7.5 cm). There was also a significant difference in the amplitude of accommodation among the upward, downward, and the primary gaze (P 0.001) positions but no difference was observed among the temporal, nasal, and the primary gaze positions. There was a significant difference in near phoria between the upward gaze and the primary gaze (P = 0.008) while no significant differences were observed among the other gazes. There was no significant variance in the monocular accommodative facility among the different gaze positions (P = 0.175).ConclusionThe results of this study indicated variations that exist in the convergence and accommodation reflex functions in multiple gaze positions, which proved to be more prominent in the convergence system. Although the accommodative sufficiency evaluation was inconsistent among the multiple gaze positions, the accommodative facility evaluation was consistent in all gazes.

Beneficial effects of kebar grass (Biophytum petersianum klotzsch) ethanol extract to increase motor reflex and spatial memory in mice offspring (Mus musculus) from lactating mothers exposed to carbofuran.

Background and purpose:This study aimed to determine the potency of kebar grass ethanol extract to overcome an increase in cerebellar neuronal cell necrosis, which has an impact on decreasing motor reflex function and spatial memory of mice from lactating mothers exposed to carbofuran.Experimental approach:Forty lactating mice were divided into four groups, 10 each; including control, T1 (carbofuran 0.0125 mg/day), T2 (vitamin C 5 mg + carbofuran 0.0125 mg/day), T3 (kebar grass extract 3.375 mg + carbofuran 0.0125 mg/day). The mice were orally administered with carbofuran, vitamin C, and kebar grass extract on days 0 to 14 postnatal. On the 15th day, brains of the mice were necropsied to measure the levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH), H&E staining; motor reflex tests were performed on 10-day-old mice, and the mice aged 30 days were tested on their swimming and spatial memory.Findings / Results:Carbofuran caused an increase in MDA, GSH, neuronal cell necrosis, surface righting reflex, a decrease in SOD, swimming ability, and spatial memory. Kebar grass extract and vitamin C administration decreased MDA, GSH, neuron necrosis, surface righting reflex, and increased SOD, swimming ability, and spatial memory.Conclusion and implications:Exposing to carbofuran in lactating mice caused brain oxidative stress, impaired motor reflexes, and spatial memory in mice offspring. Kebar grass extract and vitamin C administration prevented brain oxidative stress and inhibited disorders in motor reflexes, and spatial memory in mice offspring. Kebar grass extract administration was more effective than vitamin C.

Discordant vestibulo-ocular reflex function according to the frequency and mode of stimulation.

This study aimed to determine the incidence, pattern, and etiology of dissociated vestibulo-ocular reflex (VOR) function according to the stimulus frequency in dizzy patients. We retrospectively evaluated the results of bithermal caloric tests and video-head impulse tests (vHITs) in 1022 patients with dizziness or vertigo between July 2016 and April 2021. Patients were classified into concordant group (normal or abnormal results on both tests) and discordant group (dissociated results between two tests). Of 1022 patients, discordant group had 159 (16%), comprising abnormal horizontal vHITs with normal caloric responses (n = 36, 23%) and abnormal caloric tests with normal horizontal vHITs (n = 123, 77%). The former group showed similar frequency of peripheral (44%) and central (42%) causes, and more common involvement of bilateral horizontal semicircular canals in central than peripheral causes (86.7 vs 37.5%, p = 0.005). The most common peripheral causes were Meniere's disease and chronic vestibular neuritis, while central causes were variable, but mainly affecting the cerebellum. In the latter group, peripheral causes were common (67%), with the main etiologies being Meniere's disease and vestibular neuritis, whereas central causes were found in only 5%. The degree of canal paresis did not differ significantly between patients with central and peripheral causes. Discordant VOR function according to the stimulus frequency was not uncommon in dizzy patients. Specific patterns of VOR dissociation according to the disease etiologies may offer insight into underlying pathophysiology.

Effect of manual acupuncture on expression of BDNF/TrkB/ERK/CREB signaling in infarcted tissue of cerebral ischemia rats

To observe the effect of acupuncture on the expression of cortical brain-derived neurothrophic factor (BDNF) and tyrosine kinase receptor B (TrkB) mRNAs, and phosphorylated extracellular regulated protein kinases (p-ERK) 1/2 and phosphorylated cAMP response element binding protein (p-CREB) proteins in cerebral ischemia (CI) rats, so as to explore its neuroprotective mechanism on ischemic brain tissue. Thirty male SD rats were randomly divided into sham-operation (control), model and acupuncture groups, with 10 rats in each group. The CI model was established by occlusion of the left middle cerebral artery (MCAO) using thread embolization method. Manual acupuncture was applied to"Baihui"(GV20),"Quchi"(LI11),"Neiguan"(PC6),"Hegu"(LI4),"Zusanli"(ST36),"Sanyinjiao"(SP6) and"Shenmai"(BL62) once daily, 6 days a week for 2 weeks. The modified neurological severity score (mNSS) including motor, sensation, balance, and neural reflex functions (0 point, normal; 18 points, maximal deficit) was used to assess the neurological impairment state. The expression levels of p-ERK 1/2 and p-CREB proteins, and BDNF and TrkB mRNAs in the ischemic cerebral cortex were measured by Western blot and real-time fluorescence quantitative PCR, respectively. The mNSS was significantly increased on day 1, 7 and 14 in the model group compared with the control group (P<0.01), and evidently decreased on day 14 in the acupuncture group in contrast to the model group (P<0.05). The expression levels of BDNF and TrkB mRNAs, and p-ERK1, p-ERK2 and p-CREB proteins on day 7 and 14 were significantly lower in the model group than in the control group (P<0.001). Following acupuncture treatment, the down-regulated expression levels of the two genes and the three proteins on day 14 were reversed (P<0.001, P<0.05, P<0.01). Acupuncture may promote neurological recovery in rats with cerebral ischemia, which may be related to its function in up-regulating the activities of BDNF/TrkB-ERK-CREB signaling in the cerebral cortex on the ischemic side.