Cortical Projection of Peripheral Vestibular Signaling

2003 ◽  
Vol 89 (5) ◽  
pp. 2639-2646 ◽  
Author(s):  
Miklós Emri ◽  
Mihály Kisely ◽  
Zsolt Lengyel ◽  
László Balkay ◽  
Teréz Márián ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Vestibular Function ◽  
Vestibular Stimulation ◽  
Induced Response ◽  
Cortical Region ◽  
Cortical Projection ◽  
Vestibular Cortex ◽  
Caloric Vestibular Stimulation ◽  
Significant Difference ◽  
Two Populations

The cerebral projection of vestibular signaling was studied by using PET with a special differential experimental protocol. Caloric vestibular stimulation (CVS)-induced regional cerebral blood flow (rCBF) changes were investigated in two populations. Butanol perfusion scans were carried out on six healthy volunteers and on six patients following the removal of tumors from the right cerebello pontine angle. The complete loss of the vestibular function postoperatively allowed a comparison of the rCBF changes in the populations with or without this input and offered a promising functional approach whereby to delineate the cortical region most responsive to pure vestibular input. The activations by left-sided and right-sided CVS were determined for both the healthy volunteers and the patient population. Statistical analysis of the data obtained following left-sided CVS did not reveal any cerebral region for which there was a significant difference in CVS-induced response by these two populations. In the case of right-sided CVS, however, the statistical comparison of the CVS-related responses demonstrated a single contralateral area characterized by a significantly different degree of response. This cortical area corresponds to part of the cortical region described recently which can be activated by both CVS and neck vibration. It appears to be anatomically identical to the aggregate of the somatosensory area SII and the retroinsular cortex described in primates, a region identified by other investigators as an analog of the parietoinsular vestibular cortex.

Assessing head acceleration to identify a motor threshold to galvanic vestibular stimulation

2021 ◽  
Author(s):  
Youstina Mikhail ◽  
Jonathan Charron ◽  
Jean-Marc Mac Thiong ◽  
Dorothy Barthélemy
Keyword(s):  
Center Of Pressure ◽  
Vestibular Function ◽  
Vestibular Stimulation ◽  
Galvanic Vestibular Stimulation ◽  
Head Acceleration ◽  
Motor Threshold ◽  
Recruitment Curve ◽  
Eyes Closed ◽  
Postural Responses ◽  
Significant Difference

Galvanic vestibular stimulation (GVS) is used to assess vestibular function, but vestibular responses can exhibit variability depending on protocols or intensities used. We measured head acceleration in healthy subjects to identify an objective motor threshold on which to base GVS intensity when assessing postural responses. Thirteen healthy right-handed subjects stood on a force platform, eyes closed, head facing forward. An accelerometer was placed on the vertex to detect head acceleration, and electromyography activity of the right soleus was recorded. GVS (200 ms; current steps 0.5;1-4mA) was applied in a binaural and bipolar configuration. 1) GVS induced a biphasic accelerometer response at a latency of 15 ms. Based on response amplitude, we constructed a recruitment curve for all participants and determined the motor threshold. In parallel, the method of limits was used to devise a more rapid approach to determine motor threshold. 2) We observed significant differences between motor threshold based on therecruitment curve and perceptual thresholds (sensation/perception of movement). No significant difference was observed between the motor threshold based on the method of limits and perceptual thresholds . 3) Using orthogonal polynomial contrasts, we observed a linear progression between multiples of the objective motor threshold (0.5, 0.75, 1, 1.5x motor threshold) and the 95% confidence ellipse area, the first peak of center of pressure velocity, and the short and medium latency responses in the soleus. Hence, an objective motor threshold and a recruitment curve for GVS were determined based on head acceleration, which could increase understanding of the vestibular system.

scholarly journals Reduction in Posterior Cerebral Artery Blood Flow Velocity during Caloric Vestibular Stimulation

1996 ◽  
Vol 16 (6) ◽  
pp. 1379-1382 ◽  
Author(s):  
F. P. Tiecks ◽  
J. Planck ◽  
R. L. Haberl ◽  
T. Brandt
Keyword(s):  
Blood Flow ◽  
Cerebral Artery ◽  
Posterior Cerebral Artery ◽  
Vestibular Stimulation ◽  
Artery Blood Flow ◽  
Multisensory Interaction ◽  
Vestibular Cortex ◽  
Caloric Irrigation ◽  
Eyes Closed ◽  
Caloric Vestibular Stimulation

Transcranial Doppler (TCD) sonography was performed to assess the differential effects of caloric vestibular stimulation on cerebral blood flow (CBF) to the vestibular [middle cerebral artery (MCA)] and the visual [posterior cerebral artery (PCA)] cortices in 15 healthy volunteers with eyes closed. Caloric irrigation caused a sensation of rotation and nystagmus and not only increased velocity in the MCA (2.7 ± 3.3%) but also, simultaneously, decreased velocity in the PCA (4.2 ± 6.2%, p < 0.001 vs. MCA). CBF changes indicated by changes in velocity through the MCA and PCA may reflect functional deactivation of the visual cortex together with activation of the vestibular cortex: this beneficial multisensory interaction suppresses distressing oscillopsia.

scholarly journals Visual-vestibular processing in the human Sylvian fissure

2016 ◽  
Vol 116 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Sebastian M. Frank ◽  
Anna Maria Wirth ◽  
Mark W. Greenlee
Keyword(s):  
Insular Cortex ◽  
Vestibular Stimulation ◽  
Object Motion ◽  
Sylvian Fissure ◽  
Visual Object ◽  
Vestibular Cortex ◽  
Cortical Organization ◽  
Caloric Vestibular Stimulation ◽  
Cortex Area ◽  
And Function

Unlike other sensory systems, the cortical organization of the human vestibular system is not well established. A central role is assumed for the region of the posterior Sylvian fissure, close to the posterior insula. At this site, activation during vestibular stimulation has been observed in previous imaging studies and labeled as the parieto-insular vestibular cortex area (PIVC). However, vestibular responses are found in other parts of the Sylvian fissure as well, including a region that is referred to as the posterior insular cortex (PIC). The anatomical and functional relationship between PIC and PIVC is still poorly understood, because both areas have never been compared in the same participants. Therefore, to better understand the apparently more complex organization of vestibular cortex in the Sylvian fissure, we employed caloric and visual object motion stimuli during functional magnetic resonance imaging and compared location and function of PIVC and PIC in the same participants. Both regions responded to caloric vestibular stimulation, but only the activation pattern in right PIVC reliably represented the direction of the caloric stimulus. Conversely, activity in PIVC was suppressed during stimulation with visual object motion, whereas PIC showed activation. Area PIC is located at a more posterior site in the Sylvian fissure than PIVC. Our results suggest that PIVC and PIC should be considered separate areas in the vestibular Sylvian network, both in terms of location and function.

scholarly journals Caloric vestibular stimulation in aphasic syndrome

2013 ◽  
Vol 7 ◽  
Author(s):  
David Wilkinson ◽  
Rachael Morris ◽  
William Milberg ◽  
Mohamed Sakel
Keyword(s):  
Vestibular Stimulation ◽  
Caloric Vestibular Stimulation

scholarly journals Impact of Face Masks on 6-Minute Walk Test in Healthy Volunteers

2021 ◽  
Vol 11 (1) ◽  
pp. 204589402098843
Author(s):  
Kevin M. Swiatek ◽  
Charnetta Lester ◽  
Nicole Ng ◽  
Saahil Golia ◽  
Janet Pinson ◽  
...  
Keyword(s):  
Healthy Volunteers ◽  
Face Mask ◽  
Walk Test ◽  
Six Minute Walk Test ◽  
Significant Difference ◽  
6 Minute Walk Test ◽  
The Impact ◽  
Minute Walk

Our objective was to establish the impact of wearing a face mask on the outcome of six-minute walk test in healthy volunteers. In a study of 20 healthy volunteers who each completed two 6MWTs, one with a mask and one without, there was no difference in distance walked. However, there was a significant difference in perception of dyspnea between the two groups.

Safety evaluation of an antimalarial herbal product from Andrographis paniculata (AS201-01) in healthy volunteers

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Aty Widyawaruyanti ◽  
Arijanto Jonosewojo ◽  
Hilkatul Ilmi ◽  
Lidya Tumewu ◽  
Ario Imandiri ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Healthy Volunteers ◽  
Day Treatment ◽  
Phase 1 ◽  
Andrographis Paniculata ◽  
Control Group ◽  
Healthy Human ◽  
Double Blind ◽  
Random Blood Glucose ◽  
Significant Difference

Abstract Objectives Andrographis paniculata tablets (AS201-01) have previously been shown to have potent bioactivity as an antimalarial and to produce no unwanted side effects in animal models. Here, we present the phase 1 clinical trial conducted to evaluate the safety of AS201-01 tablets in healthy volunteers. Methods The study was a randomized, double-blind controlled cross-over, a placebo-controlled design consisting of a 4-day treatment of AS201-01 tablets. A total of 30 healthy human volunteers (16 males and 14 females) were divided into two groups, and each group was given 4 tablets, twice daily for 4 days. Group 1 received AS201-01, while group 2 received placebo tablets. Volunteers were given a physical examination before the treatment. The effects of AS201-01 on random blood glucose, biochemical, and hematological as well as urine profiles were investigated. Results There were no changes in observed parameters as a result of AS201-01 being administered. Statistical analysis showed no significant difference (p>0.05) between the test and control group regarding hematology profile, biochemical profile, and random blood glucose. Increased appetite and better sleep, which categorized as grade 1 adverse event was reported after treatment with AS201-01 tablet Conclusions The outcome supports our previous observation that the AS201-01 tablet, given twice a day for 4 days, is safe and nontoxic.

scholarly journals Effects of caloric vestibular stimulation on serotoninergic system in the media vestibular nuclei of guinea pigs

2007 ◽  
Vol 120 (2) ◽  
pp. 120-124 ◽  
Author(s):  
Fu-rong MA ◽  
Jun-xiu LIU ◽  
Xue-pei LI ◽  
Jian-jun MAO ◽  
Qun-dan ZHANG ◽  
...  
Keyword(s):  
Guinea Pigs ◽  
Vestibular Nuclei ◽  
Vestibular Stimulation ◽  
Serotoninergic System ◽  
Caloric Vestibular Stimulation ◽  
The Media

scholarly journals Assessment of cervical and ocular vestibular evoked myogenic potentials in migraine patients

2020 ◽  
Vol 36 (1) ◽  
Author(s):  
Doaa Elmoazen ◽  
Hesham Kozou ◽  
Jaidaa Mekky ◽  
Dalia Ghanem
Keyword(s):  
Vestibular Function ◽  
Vestibular Dysfunction ◽  
Peak Amplitude ◽  
Vestibular Evoked Myogenic Potentials ◽  
Healthy Controls ◽  
Latency Difference ◽  
Significant Difference ◽  
Cervical Vemp ◽  
Vestibular Symptoms ◽  
Function Assessment

Abstract Background Patients suffering from vestibular migraine (VM) are known to have various vestibular test abnormalities interictally and ictally. Recently, vestibular evoked myogenic potentials (VEMPs) have become accepted as a valid method for otolith function assessment. Many studies have identified various vestibular symptoms and laboratory abnormalities in migraineurs. Since migraineurs with no accompanying vestibular symptoms might exhibit subclinical vestibular dysfunction, we investigated vestibular function using ocular and cervical VEMPs in migraine patients. The aim was to study cervical VEMP and occular VEMP in migraineurs with and without vestibular symptoms interictally. Results Migraine and VM patients showed significantly longer P13 latency of cVEMP compared to controls. A statistically significant cVEMP interaural P13 latency difference was found in VM compared to healthy controls. Cervical VEMP N23 latency, peak-to-peak amplitude, interaural N23 latency, and amplitude asymmetric ratio did not show any significant difference in migraine and VM patients compared to healthy controls as well as no significant difference across the three groups regarding oVEMP parameters. Conclusions Abnormal interictal cVEMP results in migraineurs might indicate subclinical vestibulo-collic pathway dysfunction.

Abstract 51: Peripheral Regulatory T cells and Th17 Cells Is Associated With Pathogenesis of Moyamoya Disease

Stroke ◽  
2016 ◽  
Vol 47 (suppl_1) ◽  
Author(s):  
Leihua Weng ◽  
Xiang Chen ◽  
Yun Xu
Keyword(s):  
Healthy Volunteers ◽  
Moyamoya Disease ◽  
Peripheral Blood ◽  
Th17 Cells ◽  
Treg Cells ◽  
Peripheral Blood Lymphocytes ◽  
Pathological Process ◽  
Medium Term ◽  
Significant Difference ◽  
And Gender

Background: Despite unclear pathogenesis, previous studies have suggested immune responses may play a pivotal role in the process of Moyamoya disease (MMD), a rare cerebrovascular occlusive disorder. The objective of this study is aimed to explore the change of peripheral Treg/Th17 in MMDpatients and whether the change is associated with pathogenesis of MMD. Methods: In the present study, we collected 26 MMD patients diagnosed by angiography according to the diagnostic criteria of definitive MMD and recruited 32 healthy volunteers. To explore the balance of peripheral Treg/Th17 in MMD patients, lymphocytes in peripheral blood were harvested and flow cytometry was used to measure the percentage of Treg and Th17in CD4+ Tcells, respectively. Meanwhile, relevant cytokines in serum were measured to evaluate the function of Treg and Th17 cells. Results: According to Suzuki’s angiographic staging of moyamoya disease, patients were divided into subgroups of the preliminary-term, medium-term and late-term. Cerebral hemorrhage is thefirstsymptom of onset occuringin half of patients, followed bycerebral ischemia.Our data revealed that both the percentage of Treg and Th17 cells in peripheral blood lymphocytes was increased in MMD patients compared with volunteer group. Meanwhile, the levels of IL-6, IL-10,IL-12, IL-17, TNF-α, VEGF and TGF-β in serum were significantly increased in MMD patients. In this study, the level of HMGB-1, a middle-late period inflammation biomarker, in serum of MMD patients is obviously elevated compared with volunteers. However, the ratio of Treg/Th17 had no significant difference in MMD patients compared to healthy volunteers. Intriguingly, our data revealed that ratio of Treg/Th17 was significantly increased in late-term MMD patients compared with medium-term patients as evidenced by elevated percentage of Treg cells.. In addition, TGF-β level in later-term MMD patients was significantly higher than this in medium-term MMD patients. No difference was observed in the way of onset and gender between two groups. Conclusion: Enhanced peripheral Treg and Th17 in MMD patients suggested that there may be an immunological component in the pathogenesis of MMD. Peripheral Treg may be associated with pathological process of MMD.

scholarly journals HbA1c levels in individuals heterozygous for hemoglobin variants

2017 ◽  
Vol 63 (4) ◽  
pp. 341-346
Author(s):  
Ricardo Silva Tavares ◽  
Fábio Oliveira de Souza ◽  
Isabel Cristina Carvalho Medeiros Francescantonio ◽  
Weslley Carvalho Soares ◽  
Mauro Meira Mesquita
Keyword(s):  
Test Group ◽  
Exchange Chromatography ◽  
Group Method ◽  
Control Group ◽  
Significant Difference ◽  
Hemoglobin Variants ◽  
Different Populations ◽  
And Control ◽  
Two Populations ◽  
Hba1c Levels

Summary Objective: To evaluate the levels of glycated hemoglobin (HbA1c) in patients heterozygous for hemoglobin variants and compare the results of this test with those of a control group. Method: This was an experimental study based on the comparison of HbA1c tests in two different populations, with a test group represented by individuals heterozygous for hemoglobin variants (AS and AC) and a control group consisting of people with electrophoretic profile AA. The two populations were required to meet the following inclusion criteria: Normal levels of fasting glucose, hemoglobin, urea and triglycerides, bilirubin > 20 mg/dL and non-use of acetylsalicylic acid. 50 heterozygous subjects and 50 controls were evaluated between August 2013 and May 2014. The comparison of HbA1c levels between heterozygous individuals and control subjects was performed based on standard deviation, mean and G-Test. Results: The study assessed a test group and a control group, both with 39 adults and 11 children. The mean among heterozygous adults for HbA1c was 5.0%, while the control group showed a rate of 5.74%. Heterozygous children presented mean HbA1c at 5.11%, while the controls were at 5.78%. G-Test yielded p=0.93 for children and p=0.89 for adults. Conclusion: Our study evaluated HbA1c using ion exchange chromatography resins, and the patients heterozygous for hemoglobin variants showed no significant difference from the control group.

Sign in / Sign up

Export Citation Format

Share Document