Cognitive and functional deficits are associated with white matter abnormalities in two independent cohorts of patients with schizophrenia

Background Significant evidence links white matter (WM) microstructural abnormalities to cognitive impairment in schizophrenia (SZ), but the relationship of these abnormalities with functional outcome remains unclear. Methods In two independent cohorts (C1, C2), patients with SZ were divided into two subgroups: patients with higher cognitive performance (SZ-HCP-C1, n = 25; SZ-HCP-C2, n = 24) and patients with lower cognitive performance (SZ-LCP-C1, n = 25; SZ-LCP-C2, n = 24). Healthy controls (HC) were included in both cohorts (HC-C1, n = 52; HC-C2, n = 27). We compared fractional anisotropy (FA) of the whole-brain WM skeleton between the three groups (SZ-LCP, SZ-HCP, HC) by a whole-brain exploratory approach and an atlas-defined WM regions-of-interest approach via tract-based spatial statistics. In addition, we explored whether FA values were associated with Global Assessment of Functioning (GAF) scores in the SZ groups. Results In both cohorts, mean FA values of whole-brain WM skeleton were significantly lower in the SCZ-LCP group than in the SCZ-HCP group. Whereas in C1 the FA of the frontal part of the left inferior fronto-occipital fasciculus (IFOF) was positively correlated with GAF score, in C2 the FA of the temporal part of the left IFOF was positively correlated with GAF score. Conclusions We provide robust evidence for WM microstructural abnormalities in SZ. These abnormalities are more prominent in patients with low cognitive performance and are associated with the level of functioning.

The Retina in Patients With Triple A Syndrome: A Window Into Neurodegeneration?

ObjectiveExperimental evidence suggests that the clinical manifestations of Triple A syndrome result from oxidative stress. Several conditions caused by oxidative stress display retinal involvement. Our objective was to assess the retina and optic nerve involvement in children with Triple A syndrome.MethodsEleven patients with genetically proven Triple A syndrome followed-up in our centre were approached for study participation. The main outcome was the measurement of the thicknesses of the different retinal layers by Optical Coherence Tomography (OCT).Results9 patients with triple A syndrome had OCT measurements. 7 patients were children and 2 were adults; 4 were females and 5 were males. The 7 paediatric patients had at least two OCT measured at a mean interval of 7.9 months after the first one. The average Retinal Nerve Fibre Layer thickness was 74 ± 10 µm in patients compared to the paediatric reference range of 100 ± 2 µm (p<0.05).Conclusions and RelevanceThis is the first study to document retinal layer thicknesses in a series of patients with Triple A syndrome. Nearly all retinal thickness and peripapillary RNFL measurements were very significantly inferior to the reference range in Triple A patients, whatever their age. RNFL thinning was more marked at the temporal part of the optic nerve. OCT being non-invasive, it represents a promising tool to assess the severity of neurodegeneration in patients with Triple A syndrome.

Visual pursuit behavior in mice maintains the pursued prey on the retinal region with least optic flow

Mice have a large visual field that is constantly stabilized by vestibular ocular reflex (VOR) driven eye rotations that counter head-rotations. While maintaining their extensive visual coverage is advantageous for predator detection, mice also track and capture prey using vision. However, in the freely moving animal quantifying object location in the field of view is challenging. Here, we developed a method to digitally reconstruct and quantify the visual scene of freely moving mice performing a visually based prey capture task. By isolating the visual sense and combining a mouse eye optic model with the head and eye rotations, the detailed reconstruction of the digital environment and retinal features were projected onto the corneal surface for comparison, and updated throughout the behavior. By quantifying the spatial location of objects in the visual scene and their motion throughout the behavior, we show that the prey image consistently falls within a small area of the VOR-stabilized visual field. This functional focus coincides with the region of minimal optic flow within the visual field and consequently area of minimal motion-induced image-blur, as during pursuit mice ran directly toward the prey. The functional focus lies in the upper-temporal part of the retina and coincides with the reported high density-region of Alpha-ON sustained retinal ganglion cells.

The results of treatment of serous retinal detachment in the optic nerve fossa. Clinical case

Purpose. Demonstration of our own case of treatment of serous retinal detachment with a fossa of the optic nerve disc (OND). Material and methods. We observed patient B. at the age of 24 years with a diagnosis of optic nerve disc anomaly, central serous retinal detachment. Visual acuity on admission: 0.1, does not correct. A 25G endovitreal intervention was performed. With the help of tweezers, a flap of the internal limiting membrane (ILM) with a wide base was formed from the temporal part of the macula, within the vascular arcades. Then, liquid-air replacement was carried out, followed by placing the inverted flap of the ILM in the area of the OND fossa. Result. On the 5th day after the operation, visual acuity improved to 0.2, metamorphopsias decreased. According to the data of optical coherence tomography (OCT), a significant decrease in the height of neuroepithelial detachment was noted. After 4 months visual acuity reached 0.4. Complaints about metamorphopsia were stopped. The OCT picture showed a complete absence of retinal detachment. In this case, the inverted flap of the ILM in the area of the OND fossa was clearly visualized. Conclusion. 1. The displaced inverted flap of the ILM can be used to close the defect in the OND fossa. 2. This method made it possible to stop serous retinal detachment and significantly improve visual functions. 3. Given the rather rare occurrence of this pathology, further replication of this method is necessary to test its effectiveness. Key words: serous retinal detachment, fossa of the optic nerve disc, inverted flap of the internal limiting membrane.

Freely-moving mice visually pursue prey using a retinal area with least optic flow

Mice have a large visual field that is constantly stabilized by vestibular ocular reflex driven eye rotations that counter head-rotations. While maintaining their extensive visual coverage is advantageous for predator detection, mice also track and capture prey using vision. However, in the freely moving animal quantifying object location in the field of view is challenging. Here, we developed a method to digitally reconstruct and quantify the visual scene of freely moving mice performing a visually based prey capture task. By isolating the visual sense and combining a mouse eye optic model with the head and eye rotations, the detailed reconstruction of the digital environment and retinal features were projected onto the corneal surface for comparison, and updated throughout the behavior. By quantifying the spatial location of objects in the visual scene and their motion throughout the behavior, we show that the image of the prey is maintained within a small area, the functional focus, in the upper-temporal part of the retina. This functional focus coincides with a region of minimal optic flow in the visual field and consequently minimal motion-induced image blur during pursuit, as well as the reported high density-region of Alpha-ON sustained retinal ganglion cells.

Modal-Polar Representation of Evoked Response Potentials in Multiple Arousal States

An expansion of the corticothalamic transfer function into eigenmodes and resonant poles is used to derive a simple formula for evoked response potentials (ERPs) in various states of arousal. The transfer function corresponds to the cortical response to an external stimulus, which encodes all the information and properties of the linear system. This approach links experimental observations of resonances and characteristic timescales in brain activity with physically based neural field theory (NFT). The present work greatly simplifies the formula of the analytical ERP, and separates its spatial part (eigenmodes) from the temporal part (poles). Within this framework, calculations involve contour integrations that yield an explicit expression for ERPs. The dominant global mode is considered explicitly in more detail to study how the ERP varies with time in this mode and to illustrate the method. For each arousal state in sleep and wake, the resonances of the system are determined and it is found that five poles are sufficient to study the main dynamics of the system in waking eyes-open and eyes-closed states. Similarly, it is shown that six poles suffice to reproduce ERPs in rapid-eye movement sleep, sleep state 1, and sleep state 2 states, whereas just four poles suffice to reproduce the dynamics in slow wave sleep. Thus, six poles are sufficient to preserve the main global ERP dynamics of the system for all states of arousal. These six poles correspond to the dominant resonances of the system at slow-wave, alpha, and beta frequencies. These results provide the basis for simplified analytic treatment of brain dynamics and link observations more closely to theory.

Relationship between the Types of Malocclusion and the Localization of Headaches in Adults

The aim of this study was to investigate the manifestations of headaches in adult patients with types of malocclusion and occlusion deformities. Methods and Results: The study was conducted in 171 adult patients (43 men and 128 women) with malocclusion and occlusion deformities at the age of 18 to 62 years old, who were examined in the orthopedic dentistry clinic. The nature of the dentition closing was studied directly in the patient's oral cavity, and with the help of the "Gnatomat" universal articulator on diagnostic plaster models of the jaws. The occlusal relationships of the teeth were analyzed in the position of the central, anterior, lateral and dynamic occlusions. The biomechanics of the lower jaw movements were studied in 3 mutually perpendicular directions. The detected anomalies and deformities of the occlusion were grouped as sagittal, transversal and vertical. Each group was diagnosed as independent forms of malocclusion, and combined with other anomalies and deformities of the dentoalveolar system. All the subjects were asked to answer the questions of a questionnaire specially developed for our study. The unified questionnaire was developed based on a modified rating questionnaire and the determination of the life disorders index in neck pain. The questionnaire includes blocks of questions aimed at identifying the localization of the headache in the temporal, parietal (in one or both) regions, occipital, frontal regions and in the longitudinal seam region. We identified complaints of patients with pain in adjacent regions of the head. Of the 171 examined adult patients with malocclusion and occlusion deformities, 99 (57.9%) complained of headaches. The presence of a headache in the parietal region of the head was associated most often with sagittal and transversal malocclusions. The presence of a headache in the temporal part of the head was associated often with vertical malocclusion The results of correlation analysis showed that pain in 2 regions of the head was associated with malocclusion: the temporal region (rb=0.9892, P=0.0013) and parietal region (rb=0.9712, P=0.0058). Other regions were not statistically significantly associated with malocclusion. Conclusion: There is a certain relationship between the types of malocclusion, occlusion deformities and localization of headaches in adults. Headaches in the parietal and temporal regions of the head are associated with malocclusion and occlusion deformities more often. The obtained data can serve as a basis for the development of recommendations for appropriate corrective measures in orthodontic practice.

STUDY OF PERIPHERAL REFRACTION IN CHILDREN WITH MYOPIA WITH ORTHOKERATOLOGY LENSES OF COMBINED DESIGN

Progressive myopia is a leading problem in modern optometry and ophthalmology in general. In recent years, refractive therapy with orthokeratology lenses has gained popularity among methods to control myopia progression. The aim: To study peripheral refraction in children with myopia with the use of orthokeratology lenses (OKL) of combined design. Methods. We followed up 60 children (117 eyes) diagnosed with uncomplicated mild to moderate myopia. All children underwent a complete ophthalmological examination as well as corneal keratotopography and peripheral refraction determination. Statistical analysis of correlations between peripheral corneal refraction under the influence of OKL, peripheral defocus, and axial length growth gradient was performed. Results. An inverse correlation relationship of -0.2 (p=0.03) was obtained between corneal differential power in the return 6 mm zone and peripheral refraction in its corresponding peripheral refraction of 23° on the temporal side. A positive correlation with a correlation coefficient of 0.21 (p=0.026) was obtained between the defocus in the temporal part and the gradient of myopia progression over one year, while the same result was obtained in the nasal part with a correlation coefficient of 0.2 (p=0.036). Concluсions. Difference corneal power at the periphery may be prognostic in relation to the course of myopia in OКL users. With an aboveaverage pupil diameter, combined design orthokeratology lenses are more effective in controlling myopia due to the greater influence of the formed corneal refractive ring on peripheral refraction.

En-face analysis of short posterior ciliary arteries crossing the sclera to choroid using wide-field swept-source optical coherence tomography

To study the topographic distribution of the short posterior ciliary arteries (SPCA) entry sites into the choroid in normal eyes using structural en-face swept source optical coherence tomography (SS-OCT). Retrospective analysis of SS-OCT scans (wide-field structural SS-OCT 12 × 12 mm) of 13 healthy subjects was performed. Cross-sectional swept-source OCT scans derived from a volume scan were represented as en-face image display following the Choroid-Scleral Interface to obtain en-face OCT. SPCAs in their last scleral location before choroidal entrance were identified manually, counted and localized by two masked observers. Correlations between two masked observers were analyzed using inter- and intra-class correlation. Accuracy for the choroidal inner and outer border segmentation was 95–99%. Eighteen eyes from 13 normal subjects were included for SPCA analysis. The mean number of arteries was 13.8 ± 3.5 per eye. Thirty-six percent were in the center of the posterior pole image; however, 21% were in the temporal part of the posterior pole. Median accuracy of the detection is 0.94. The correlation between the two observers was fair (0.54). Our algorithm allows visualization of the SPCA at the posterior pole of the eye using wide-field en-face SS-OCT. It can also help the clinicians to study the SPCAs in numerous ocular diseases, particularly its relationship with focal choroidal diseases.

Dynamic Bayesian Network-Based Escape Probability Estimation for Coach Fire Accidents

Coach emergency escape research is an effective measure to reduce casualties under serious vehicle fire accidents. A novel experiment method employing a wireless transducer was implemented and the head rotation speed, rotation moment and rotation duration were collected as the input variables for the classification and regression tree (CART) model. Based on this model, the classification result explicitly pointed out that the exit searching efficiency was evolving. By ignoring the last three unimportant factors from the Analytic Hierarchy Process (AHP), the ultimate Dynamic Bayesian Network (DBN) was built with the temporal part of the CART output and the time-independent part of the vehicle characteristics. Simulation showed that the most efficient exit searching period is the middle escape stage, which is 10 seconds after the emergency signal is triggered, and the escape probability clearly increases with the efficient exit searching. Furthermore, receiving emergency escape training contributes to a significant escape probability improvement of more than 10%. Compared with different failure modes, the emergency hammer layout and door reliability have a more significant influence on the escape probability improvement than aisle condition. Based on the simulation results, the escape probability will significantly drop below 0.55 if the emergency hammers, door, and aisle are all in a failure state.