Torsional component of microsaccades during fixation and quick phases during optokinetic stimulation

While many studies have characterized the eye movements during visual fixation, including microsaccades, in most cases only horizontal and vertical components have been recorded and analyzed. Thus, little is known about the torsional component of microsaccades. We took advantage of a newly developed software and hardware to record eye movements around the three axes of rotation during fixation and torsional optokinetic stimulus. We found that the average amplitude of the torsional component of microsaccades during fixation was 0.34 ± 0.07 degrees with velocities following a main sequence with a slope comparable to the horizontal and vertical components. We also found the size of the torsional displacement during microsaccades was correlated with the horizontal but not the vertical component. In the presence of an optokinetic stimulus a nystagmus was induced producing a more frequent and larger torsional quick phases compared to microsaccades produced during fixation with a stationary stimulus. The torsional component and the vertical vergence component of quick phases grew larger with higher velocities. Additionally, our results validate and show the feasibility of recording torsional eye movements using video eye tracking in a desktop mounted setup

Errors of Upright Perception in Patients With Vestibular Migraine

Patients with vestibular migraine (VM) often report dizziness with changes in the head or body position. Such symptoms raise the possibility of dysfunction in neural mechanisms underlying spatial orientation in these patients. Here we addressed this issue by investigating the effect of static head tilts on errors of upright perception in a group of 27 VM patients in comparison with a group of 27 healthy controls. Perception of upright was measured in a dark room using a subjective visual vertical (SVV) paradigm at three head tilt positions (upright, ±20°). VM patients were also surveyed about the quality of their dizziness and spatial symptoms during daily activities. In the upright head position, SVV errors were within the normal range for VM patients and healthy controls (within 2° from true vertical). During the static head tilts of 20° to the right, VM patients showed larger SVV errors consistent with overestimation of the tilt magnitude (i.e., as if they felt further tilted toward the right side) (VM: −3.21° ± 0.93 vs. Control: 0.52° ± 0.70; p = 0.002). During the head tilt to the left, SVV errors in VM patients did not differ significantly from controls (VM: 0.77° ± 1.05 vs. Control: −0.04° ± 0.68; p = 0.52). There was no significant difference in SVV precision between the VM patients and healthy controls at any head tilt position. Consistent with the direction of the SVV errors in VM patients, they largely reported spatial symptoms toward the right side. These findings suggest an abnormal sensory integration for spatial orientation in vestibular migraine, related to daily dizziness in these patients

Abstract Number ‐ 218: Mechanical Thrombectomy in a HIV Patient with Staphylococcus Lugdunensis Bacteremia: A Case Report.

Introduction Occlusion of cerebral arteries account for 40–50% of neurological complications of infective endocarditis with the emboli most commonly lodging in the middle cerebral artery. The management of these occlusions with the use of thrombolytic therapies are associated with intracranial hemorrhage whereas outcomes with endovascular thrombectomy, while still under investigation, appear to be more favorable. In this case report, we present a HIV patient with persistent staphylococcus lugdunenesis bacteremia of unknown origin and acute left middle cerebral artery occlusion, who underwent endovascular thrombectomy. Methods Case Report Results A 66‐year‐old male past medical history of HIV on Elvitegravir/Cobicistat/Emtricitabine/ Tenofovir, pancytopenia and treated hepatitis C who presented for malaise, back pain, and urinary symptoms for 1 week. Initial labs remarkable for pancytopenia, CD4 count 44 and positive urinalysis. Ceftriaxone was started for UTI and Trimethoprim/Sulfamethoxazole for PJP prophylaxis. Urine and multiple blood cultures were positive for staphylococcus lugdunensis. Vancomycin was added to antibiotic therapy. On day two of hospitalization, patient developed new onset aphasia, right facial droop, and right hemiparesis. Upon evaluation, NIHSS was 14. CT head was negative. CTA head and neck showed left M1 occlusion. CT perfusion showed an infarct core of 20cc and 144cc of penumbra. Due to concern for possible infective endocarditis, thrombolytics were not administered but he was taken for thrombectomy. Emboli retrieval was successful with mTICI‐2c reperfusion. During thrombectomy, clot noted to have septic emboli appearance. Post thrombectomy, patient had complete resolution of neurological deficits. MRI brain showed multiple punctate foci of restricted diffusion in the left middle cerebral artery distribution consistent with embolic process. TTE was inconclusive. Intraoperative cultures of the clot resulted positive for staphylococcus lugdunensis and pathology examination detailed clot with bacterial colonization. TEE was performed and negative for valvular vegetations, mass, thrombus, or endocarditis but there was an intrapulmonary shunt. Patient later developed a small acute left parietal lobe parenchymal hematoma and basal ganglia infarct. His neurological status remained unchanged. He completed 6 weeks of IV antibiotic therapy upon discharge. Conclusions This case illustrates the importance of timely endovascular thrombectomy in suspected cerebral septic emboli as outcomes are favorable. It supports prompt recognition of septic emboli bacterial species for targeted antibiotic therapy along with further investigation into staphylococcus lugdunensis and its relation with cerebral septic emboli. This case urges additional exploration into the relationship between HIV patients and cerebrovascular disease including cerebral septic emboli

Bloating in Iran: SEPAHAN systematic review no. 4

Objectives: Bloating is a common and bothersome gastrointestinal symptom. Despite its high prevalence, associated costs, and effects on the quality of life, very few studies have reported the epidemiology of bloating in Iran. Through this systematic review, findings and limitations of the current research will be discussed. Methods: In March 2012, we searched PubMed, Google Scholar, Scientific Information Database, IranMedex, and Magiran to find articles for inclusion in the study. Two of the authors screened the articles on the basis of titles and abstracts. The full manuscripts of these publications were then evaluated according to the predefined criteria. Results: Fifteen articles were included in the study, and data regarding the prevalence of bloating were extracted. The studies depict a prevalence of 1.5% to 8.8% for bloating in the Iranian population. Two studies reported the prevalence of functional bloating to be 1.5% and 10% according to the Rome III and Rome II criteria, respectively. Female to male ratio remains ≥1 for most of the studies criteria. Conclusions: In Iran, data on the prevalence of bloating are limited, and have mostly been gathered from a highly selective population. The results of the present study advocate the necessity to perform further studies on the general population, which may help health policy makers in the allocation of the appropriate resources

Constipation in Iran: SEPAHAN systematic review No. 5

Background: Constipation is physically and mentally troublesome for many patients and has adverse effects on their quality of life. The aim of the present study was to systematically review previous studies on the epidemiology of constipation in Iran. Methods: Bibliographic databases including PubMed, Google Scholar, and Iranian databases including Scientific Information Database, Iran Medex, and Magiran were searched to select studies that reported the prevalence of constipation in Iran. Results: Overall, 10 articles met the inclusion criteria of the current study. The prevalence of constipation in Iran ranged from 1.4-37%, and the prevalence of functional constipation was reported to be 2.4-11.2%. Gender, age, socioeconomic status and educational level seem to have major effects on this condition. Conclusion: The prevalence of constipation is high in Iran. There are very few data available regarding the natural history, quality of life and risk factors of constipation in our country. Conducting population-based studies is necessary to explore different epidemiological aspects of constipation in Iran

Irritable bowel syndrome in Iran: SEPAHAN systematic review no. 1

Objectives: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder. Due to its high prevalence and absence of curative therapy, IBS has the potential to create tremendous burden on the health care system. Herein, we systematically reviewed the published literature to investigate the epidemiology of IBS in Iran. Methods: Studies that were reviewed in this article were primarily identified through four online bibliographic databases including PubMed, Google Scholar, Iran Medex, and Scientific Information Database. Manual search of reference lists was carried out to identify any additional studies such as relevant abstracts and also recent review articles which may have been missed. Potentially related studies were retrieved and the selection criteria were applied. Eligible articles were reviewed. Results: From 4176 studies identified, 18 eligible studies were included. It was reported that in Iran, the prevalence of IBS was in the range of 1.1% to 25% and was more common in women. In addition, the difference in frequency of different age groups was minimal. There was a minimal difference in IBS prevalence within different age groups. Conclusions: In Iran, the incidence of IBS was in the wide range. Since there are not enough population-based studies, researchers should focus on developing well-designed population-based studies to determine the epidemiology of IBS in Iran. Moreover, cohort studies should be conducted in order to investigate the natural history of IBS. Investigating the etiology of IBS and attempt to organize health promotion programs are highly suggested

Optogenetically transduced human ES cell-derived neural progenitors and their neuronal progenies: Phenotypic characterization and responses to optical stimulation.

Optogenetically engineered human neural progenitors (hNPs) are viewed as promising tools in regenerative neuroscience because they allow the testing of the ability of hNPs to integrate within nervous system of an appropriate host not only structurally, but also functionally based on the responses of their differentiated progenies to light. Here, we transduced H9 embryonic stem cell-derived hNPs with a lentivirus harboring human channelrhodopsin (hChR2) and differentiated them into a forebrain lineage. We extensively characterized the fate and optogenetic functionality of hChR2-hNPs in vitro with electrophysiology and immunocytochemistry. We also explored whether the in vivo phenotype of ChR2-hNPs conforms to in vitro observations by grafting them into the frontal neocortex of rodents and analyzing their survival and neuronal differentiation. Human ChR2-hNPs acquired neuronal phenotypes (TUJ1, MAP2, SMI-312, and synapsin 1 immunoreactivity) in vitro after an average of 70 days of coculturing with CD1 astrocytes and progressively displayed both inhibitory and excitatory neurotransmitter signatures by immunocytochemistry and whole-cell patch clamp recording. Three months after transplantation into motor cortex of naïve or injured mice, 60-70% of hChR2-hNPs at the transplantation site expressed TUJ1 and had neuronal cytologies, whereas 60% of cells also expressed ChR2. Transplant-derived neurons extended axons through major commissural and descending tracts and issued synaptophysin+ terminals in the claustrum, endopiriform area, and corresponding insular and piriform cortices. There was no apparent difference in engraftment, differentiation, or connectivity patterns between injured and sham subjects. Same trends were observed in a second rodent host, i.e. rat, where we employed longer survival times and found that the majority of grafted hChR2-hNPs differentiated into GABAergic neurons that established dense terminal fields and innervated mostly dendritic profiles in host cortical neurons. In physiological experiments, human ChR2+ neurons in culture generated spontaneous action potentials (APs) 100-170 days into differentiation and their firing activity was consistently driven by optical stimulation. Stimulation generated glutamatergic and GABAergic postsynaptic activity in neighboring ChR2- cells, evidence that hChR2-hNP-derived neurons had established functional synaptic connections with other neurons in culture. Light stimulation of hChR2-hNP transplants in vivo generated complicated results, in part because of the variable response of the transplants themselves. Our findings show that we can successfully derive hNPs with optogenetic properties that are fully transferrable to their differentiated neuronal progenies. We also show that these progenies have substantial neurotransmitter plasticity in vitro, whereas in vivo they mostly differentiate into inhibitory GABAergic neurons. Furthermore, neurons derived from hNPs have the capacity of establishing functional synapses with postsynaptic neurons in vitro, but this outcome is technically challenging to explore in vivo. We propose that optogenetically endowed hNPs hold great promise as tools to explore de novo circuit formation in the brain and, in the future, perhaps launch a new generation of neuromodulatory therapies