Superior Part Research Articles

A standardized protocol for needle placement in the infraspinatus muscle: an anatomical perspective.

This study aimed to evaluate the morphology of the three parts of the infraspinatus muscle based on surface landmarks for precise and effective access, and to propose the most effective fine-wire electrode insertion technique and sites. Fifteen Asian fresh cadavers were used. We investigated the probability of the presence of the superior, middle, and inferior parts in each infraspinatus muscle based on surface landmarks. Based on the positional characteristics of the muscle, we determined the needle insertion method and confirmed its effectiveness by dissection. The superior part was mostly observed near the spine of the scapula. The middle part was broadly observed within the infraspinous fossa. The inferior part showed variable location within the infraspinous fossa. The injection accuracy of the superior, middle, and inferior parts in the infraspinatus muscle was 95.8%, 100%, and 91.7%, respectively. Targeting the superior and middle parts for injection of the infraspinatus muscle is relatively more straightforward than targeting the inferior part. Targeting the inferior part of the infraspinatus muscle in this study was more challenging than targeting the superior and middle parts. Needling for electromyography should be performed with special care to avoid unintended muscle parts, which could lead to inaccurate data acquisition and affect the conclusions about muscle function.

Neurovascular coupling dysfunction in high myopia patients: Evidence from a multi-modal magnetic resonance imaging analysis

Background and purposeTo investigate neurovascular coupling dysfunction in high myopia (HM) patients. Materials and methodsA total of 37 HM patients and 36 healthy controls were included in this study. Degree centrality (DC), regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and fractional ALFF (fALFF) maps were employed to represent neuronal activity. Cerebral blood perfusion was characterized by cerebral blood flow (CBF). The correlation coefficient was calculated to reflect the relationship between neuronal activity and cerebral blood perfusion. Pearson partial correlation analysis was utilized to evaluate the association between HM dysfunction and clinical indicators. ResultsHM patients exhibited significant alterations in neurovascular coupling across 37 brain regions compared to healthy controls. The brain regions with marked changes varied among the four neurovascular coupling patterns, including the middle frontal gyrus, superior occipital gyrus, middle occipital gyrus, and fusiform gyrus. Additionally, the superior frontal gyrus orbital part, medial superior frontal gyrus, inferior occipital gyrus, and dorsolateral superior frontal gyrus displayed significant changes in three coupling patterns. In HM patients, the ReHo-CBF changes in the inferior frontal gyrus orbital part were positively correlated with best-corrected visual acuity (BCVA) and refractive diopter changes. Similarly, the ALFF-CBF changes in the inferior frontal gyrus orbital part showed a positive correlation with refractive diopter changes. ReHo-CBF and ALFF-CBF alterations in the paracentral lobule were positively correlated with BCVA and refractive diopter changes. ConclusionOur findings underscore the abnormal alterations in neurovascular coupling across multiple brain regions in HM patients. These results suggest that neurovascular dysfunction in HM patients may be associated with an aberrant visual regulation mechanism.

P18.08.B COMPARISON OF DOSE CALCULATION PLANNING SYSTEMS FOR RECCURENT MENENGIOMA TREATED WITH FRACTIONATED RE-IRRIDATION

Abstract PURPOSE Meningioma is among the most common tumors of the central nervous system, accounting for approximately one-third of all brain tumors. Surgery is mainstay treatment and Radiotherapy (RT) provides long-term control in many patients, however recurrences following RT may occur and the safety and efficacy of a second course of RT is not well defined, technical and planning features are yet to be clarified. In this study, we compared various treatment planning systems (TPS) used in RT in a patient who had progressed meningioma after three applications of Gammaknife radiosurgery (GK-SRS). Case Presentation: 55-year-old male patient was diagnosed with grade-1 meningioma of the sphenoid wing in 2014 and subtotal excision was performed, with no further treatment. Progression was detected in 2016, and 11 Gy single fraction GK-SRS was applied in two sessions (inferior and superior parts of the tumor was irradiated in separate GK-SRS applications with 2 months apart) to the recurrent lesion in the right spheno-orbital region in a GK center. Patient was well until June 2022 when progression was detected in the right infratemporal region. Another GK-SRS application of 11 Gy was performed to the patient at the same institute.In April 2023 progression of the tumor was detected, tumor was irresectable and patient referred to our department for fractionated radiotherapy. Recurrent tumor was originating from right sfenoid wing and extending to right infratemporal fossa. We obtained the radiation dose distributions from the previous GK-SRS plans. Due to dose limits on the right optic nerve due to previous radiation dose disturbution , the conventional fractionated radiotherapy was planned . The PTV dose was planned to be 45 Gy/25 fx. Eclipse and Brainlab systems were compared for treatment planning. Right optic nerve dose of EQD2 was already above the limits, thus conventional fractionation (45 Gyin 25 fractions) was prescribed. Two separate plans were generated using Varian-Eclipse and Brainlab-Elements TPS, and the dose distribution of those plans were compared. Plan optimization was performed in both planning systems to provide PTV D%95. While the PTV Dmax was 57.24 Gy in BrainLAB, it was 48.7 Gy in Eclipse. Dmax doses for Brainlab and Eclipse were: right optic nerve 10.11 Gy vs. 26.9 Gy, chiasm 6.68 Gy vs. 20.5 Gy respectively. In Eclipse plan optimization, the collimator and table angles were optimized manually, while in Brainlab planning system, they were automatically handled, therefore normal tissues can be better preserved with increase of hot spots inside the PTV. This situation is observed clearly in this case. CONCLUSION Using different table and collimator angles in plan optimization can yield better results in providing normal tissue dose tolerance, especially in the irradiation of central nervous system.

Three-dimension dithering and its effect on the interfacial strength of multi-material and emulated multi-material additive manufacturing processes

Multi-Material Additive Manufacturing (MMAM) offers the potential for superior functional parts by varying properties throughout a structure. Previous work has shown that the interface region of such MMAM parts has great importance on their overall strength. Most of these studies have focused on rigid–compliant interfaces within parts manufactured via material jetting (MJT). This work focuses, initially, on the creation of different interfacial geometries within functionally graded tensile bars by extending two dimensional dithering algorithms from the realm of image processing into the third dimension. It tests these dithered patterns, along with Schwarz P and Gyroid structures, across rigid–complaint MJT interfaces before further exploring the previously unaddressed question of how these different geometries affect interfacial strength across rigid–rigid interfaces for both UV cured materials, via MJT, and thermoplastic materials, via a new prototype electophotographic toner-based AM system. Within the MJT parts, the samples often failed inside the large regions of the more compliant material rather than at the interface itself. In addition, the interfacial length is shown to have more effect on the mechanical properties compared to interface pattern. However, the thermoplastic samples consistently failed within the interface region. The toughness of these thermoplastic parts increased with an increase in the connected surface area in the tensile direction between the largest regions of each of the two materials, with three dimensional random dithering over a 20 mm gradient length exhibiting the toughest interface overall (40.8% increase in the work at break when compared to a control sample with no special interfacial geometry). This work, therefore, provides a new emphasis to explore, within the context of the design of thermoplastic multi-material interfaces, geometries that increase this connected surface area.

A 32-Channel Sleeve Antenna Receiver Array for Human Head MRI Applications at 10.5 T.

For human brain magnetic resonance imaging (MRI), high channel count ( ≥ 32 ) radiofrequency receiver coil arrays are utilized to achieve maximum signal-to-noise ratio (SNR) and to accelerate parallel imaging techniques. With ultra-high field (UHF) MRI at 7 tesla (T) and higher, dipole antenna arrays have been shown to generate high SNR in the deep regions of the brain, however the array elements exhibit increased electromagnetic coupling with one another, making array construction more difficult with the increasing number of elements. Compared to a classical dipole antenna array, a sleeve antenna array incorporates the coaxial ground into the feed-point, resulting in a modified asymmetric antenna structure with improved intra-element decoupling. Here, we extended our previous 16-channel sleeve transceiver work and developed a 32-channel azimuthally arranged sleeve antenna receive-only array for 10.5 T human brain imaging. We experimentally compared the achievable SNR of the sleeve antenna array at 10.5 T to a more traditional 32-channel loop array bult onto a human head-shaped former. The results obtained with a head shaped phantom clearly demonstrated that peripheral intrinsic SNR can be significantly improved compared to a loop array with the same number of elements- except for the superior part of the phantom where sleeve antenna elements are not located.

Impact of constrained humeral liner on impingement-free range of motion and impingement type in reverse shoulder arthroplasty using a computer simulation

Dislocation is a major complication of reverse total shoulder arthroplasty (RSA). Humeral liner may be changed to the constrained type when stability doesn't improve by increasing glenosphere size or lateralization with implants, and patients, particularly women with obesity, have risks of periprosthetic instability that may be secondary to hinge adduction on the thorax, but there are few reports on its impact on the range of motion (ROM). This study aimed to determine the influence of humeral liner constraint on impingement-free ROM and impingement type utilizing an RSA computer simulation model. A virtual simulation model was created using 3D measurement software for conducting a simulation study. This study included twenty-five patients with rotator cuff tears and rotator cuff tear arthropathy. Impingement-free ROM and impingement patterns were measured during flexion, extension, abduction, adduction, external rotation, and internal rotation. Four different simulations of 2×2 were performed in each of the 25 cases, a total of 100 simulations: Glenosphere (38mm normal type vs. lateralized type) and humeral liner constraint (normal type vs. constrained type). There were four combinations: normal glenosphere and normal humeral liner, normal glenosphere and constrained humeral liner, lateralized glenosphere and normal humeral liner, and lateralized glenosphere and constrained humeral liner. Significant differences were found in all impingement-free ROM in one-way ANOVA (abduction: p=0.01, adduction: p<0.01, flexion: p=0.01, extension: p=0.02, external rotation: p<0.01, and internal rotation: p<0.01). Tukey's post-hoc tests showed that the impingement-free ROM was reduced during abduction, external rotation, and internal rotation with the combination of normal glenosphere and constrained humeral liner compared to the other combinations, and improved by glenoid lateralization compared to the combination of the lateralized glenosphere and constrained humeral liner. In the impingement pattern, Pearson's chi-squared test showed significantly greater proportion of impingement of the humeral liner into the superior part of the glenoid neck in abduction occurring in the combination of normal glenosphere and constrained humeral liner group compared to the other groups (p<0.01). Bonferroni post-hoc tests revealed that the combination of normal glenosphere and constrained humeral liner was significantly different from that of lateralized glenosphere and constrained humeral liner (p<0.01). Using constrained liners resulted in early impingement on the superior part of the glenoid neck in the normal glenosphere, whereas glenoid lateralization increased impingement-free ROM. This RSA computer simulation model demonstrated that constrained humeral liners led to decreased impingement-free ROM. However, using lateralized glenosphere improved abduction ROM.

Convergent and divergent intra- and internetwork connectivity in Parkinson's disease with wearing-off.

Our study aimed to explore the functional connectivity alterations between cortical nodes of resting-state networks in Parkinson's disease (PD) patients with wearing-off (WO) at different levels. Resting-state functional magnetic resonance imaging was performed on 36 PD patients without wearing-off (PD-nWO), 30 PD patients with wearing-off (PD-WO), and 35 healthy controls (HCs) to extract functional networks. Integrity, network, and edge levels were calculated for comparison between groups. UPDRS-III, MMSE, MOCA, HAMA, and HAMD scores were collected for further regression analysis. We observed significantly reduced connectivity strength in the dorsal attention network and limbic network in the PD-WO group compared with the HC group. The PD-WO group showed a decreased degree of functional connectivity at 12 nodes, including the bilateral orbital part of the superior frontal gyrus, right olfactory cortex, left medial orbital part of the superior frontal gyrus, bilateral gyrus rectus, right parahippocampal gyrus, right thalamus, left Heschl's gyrus, right superior temporal gyrus part of the temporal pole, left middle temporal gyrus part of the temporal pole, and right inferior temporal gyrus. Furthermore, the PD-WO group showed a significantly lower degree of functional connectivity in the left orbital part of the superior frontal gyrus and right gyrus rectus than the PD-nWO group. Internetwork analysis indicated reduced functional connectivity in five pairs of resting-state networks. Our results demonstrated altered intra- and internetwork connections in PD patients with WO. These findings will facilitate a better understanding of the distinction between the network changes in PD pathophysiology.

Functional magnetic resonance imaging study during resting state and visual oddball task in mild cognitive impairment.

Amnestic mild cognitive impairment (aMCI) is a transitional state between normal aging and dementia, and identifying early biomarkers is crucial for disease detection and intervention. Functional magnetic resonance imaging (fMRI) has the potential to identify changes in neural activity in MCI. We investigated neural activity changes in the visual network of the aMCI patients (n:20) and healthy persons (n:17) using resting-state fMRI and visual oddball task fMRI. We used independent component analysis to identify regions of interest and compared the activity between groups using a false discovery rate correction. Resting-state fMRI revealed increased activity in the areas that have functional connectivity with the visual network, including the right superior and inferior lateral occipital cortex, the right angular gyrus and the temporo-occipital part of the right middle temporal gyrus (p-FDR = 0.008) and decreased activity in the bilateral thalamus and caudate nuclei, which are part of the frontoparietal network in the aMCI group (p-FDR = 0.002). In the visual oddball task fMRI, decreased activity was found in the right frontal pole, the right frontal orbital cortex, the left superior parietal lobule, the right postcentral gyrus, the right posterior part of the supramarginal gyrus, the right superior part of the lateral occipital cortex, and the right angular gyrus in the aMCI group. Our results suggest the alterations in the visual network are present in aMCI patients, both during resting-state and task-based fMRI. These changes may represent early biomarkers of aMCI and highlight the importance of assessing visual processing in cognitive impairment. However, future studies with larger sample sizes and longitudinal designs are needed to confirm these findings.

Strained face during sleep in multiple system atrophy: not just a bad dream.

Patients with Parkinsons'Disease (PD) and Multiple System Atrophy (MSA) may be subject to sleep state dissociation. Motivated by the fortuitous observation of a prominent facial muscle activity during video-polysomnography (vPSG) in patients with MSA, we assessed facial motor activity and chin muscle tone during sleep in MSA compared to PD and controls. A sleep expert blinded to pathology and to sleep stage retrospectively analyzed facial activity in 62 vPSG (11 MSA,38 PD, and 13 controls). Facial movements were classified into six categories: "Eyes closing/opening", "Eyebrows frowning", "Raising eyebrows", "Smiling", "Other mouth movements", and "Strained face", an expression involving both the superior and inferior parts of the face. Chin EMG activity was quantified during REM and NREM sleep using the Atonia Index (AI), a validated algorithm. MSA patients had an increased number of all facial movements compared to controls during NREM. "Strained face" was significantly more frequent in MSA compared to PD, even after adjusting for the presence of RBD. AI was lower in MSA compared to controls and PD during REM and NREM sleep. This difference remained significant compared to PD in NREM sleep during N1 and N2 after adjusting for the presence of RBD. Facial movements during sleep are frequent in MSA, "strained face" appears to be a hallmark of this condition. The presence of increased facial activity and elevated muscle tone during all stages of sleep in MSA may be a manifestation of sleep state dissociation, reflecting a more severe neurodegeneration.

Impaired retinal microcirculation in patients with non-obstructive coronary artery disease.

To quantitatively investigate alterations of retinal microcirculation in patients with non-obstructive coronary artery disease (NOCAD) using optical coherence tomography angiography (OCTA), and to identify the ability of retinal microcirculation parameters in differentiating coronary artery disease (CAD) subtypes. All participants with angina pectoris underwent coronary computed tomography angiography. Patients with lumen diameter reduction of 20-50% in all major coronary arteries were defined as NOCAD, while patients with at least one major coronary artery lumen diameter reduction ≥ 50% were recruited as obstructive coronary artery disease (OCAD). Participants without a history of ophthalmic or systemic vascular disease were recruited as healthy controls. Retinal neural-vasculature was measured quantitatively by OCTA, including peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) of the optic disc, superficial vessel plexus (SVP), deep vessel plexus (DVP), and foveal density (FD 300). p<0.017 is considered significant in multiple comparisons. A total of 185 participants (65 NOCAD, 62 OCAD, and 58 controls) were enrolled. Except for the DVP fovea (p=0.069), significantly reduced VD in all other regions of SVP and DVP was detected in both the NOCAD and OCAD groups compared to control group (all p<0.017), while a more significant decrease was found in OCAD compared to NOCAD. Multivariate regression analysis showed that lower VD in superior hemi part of whole SVP (OR: 0.582, 95% CI: 0.451-0.752) was an independent risk factor for NOCAD compared to controls, while lower VD in the whole SVP (OR: 0.550, 95% CI: 0.421-0.719) was an independent risk factor for OCAD compared to NOCAD. Using the integration of retinal microvascular parameters, the area under the receiver operating characteristic curve (AUC) for NOCAD versus control and OCAD versus NOCAD were 0.840 and 0.830, respectively. Significant retinal microcirculation impairment, while milder than that in OCAD was observed in NOCAD patients, indicating retinal microvasculature assessment might provide a new systemic microcirculation observation window for NOCAD. Furthermore, retinal microvasculature may serve as a new indicator to assess the severity of CAD with good performance of retinal microvascular parameters in identifying different CAD subtypes.

Unravelling the Role of Habenula Subnuclei on Avoidance Response: Focus on Activation and Neuroinflammation.

Understanding the mechanisms responsible for anxiety disorders is a major challenge. Avoidance behavior is an essential feature of anxiety disorders. The two-way avoidance test is a preclinical model with two distinct subpopulations-the good and poor performers-based on the number of avoidance responses presented during testing. It is believed that the habenula subnuclei could be important for the elaboration of avoidance response with a distinct pattern of activation and neuroinflammation. The present study aimed to shed light on the habenula subnuclei signature in avoidance behavior, evaluating the pattern of neuronal activation using FOS expression and astrocyte density using GFAP immunoreactivity, and comparing control, good and poor performers. Our results showed that good performers had a decrease in FOS immunoreactivity (IR) in the superior part of the medial division of habenula (MHbS) and an increase in the marginal part of the lateral subdivision of lateral habenula (LHbLMg). Poor performers showed an increase in FOS in the basal part of the lateral subdivision of lateral habenula (LHbLB). Considering the astroglial immunoreactivity, the poor performers showed an increase in GFAP-IR in the inferior portion of the medial complex (MHbl), while the good performers showed a decrease in the oval part of the lateral part of the lateral complex (LHbLO) in comparison with the other groups. Taken together, our data suggest that specific subdivisions of the MHb and LHb have different activation patterns and astroglial immunoreactivity in good and poor performers. This study could contribute to understanding the neurobiological mechanisms responsible for anxiety disorders.

Functional network dynamics between the anterior thalamus and the cortex in deep brain stimulation for epilepsy.

Due to its unique connectivity profile with cortical brain regions, and its suggested role in the subcortical propagation of seizures, the Anterior Nucleus of the Thalamus (ANT) has been proposed as a key Deep Brain Stimulation (DBS) target in drug-resistant epilepsy (DRE). However, the spatio-temporal interaction dynamics of this brain structure, and the functional mechanisms underlying ANT DBS in epilepsy, remain unknown. Here, we study how the ANT interacts with the neocortex in vivo in humans and provide a detailed neurofunctional characterization of mechanisms underlying the effectiveness of ANT DBS, aiming at defining intraoperative neural biomarkers of responsiveness to therapy, assessed at 6 months post-implantation as the reduction in seizure frequency. A cohort of 15 DRE (N = 6 males, age = ) patients underwent bilateral ANT DBS implantation. Using intraoperative cortical and ANT simultaneous electrophysiological recordings, we found that the ANT is characterized by high amplitude (4-8 Hz) oscillations, mostly in its superior part. The strongest functional connectivity between the ANT and the scalp EEG was also found in the band in ipsilateral centro-frontal regions. Upon intraoperative stimulation in the ANT, we found a decrease in higher EEG frequencies (20-70 Hz) and a generalized increase in scalp-to-scalp connectivity. Crucially, we observed that responders to ANT DBS treatment were characterized by higher EEG oscillations, higher power in the ANT, and stronger ANT-to-scalp θ connectivity, highlighting the crucial role of oscillations in the dynamical network characterization of these structures. Our study provides a comprehensive characterization of the interaction dynamic between the ANT and the cortex, delivering crucial information to optimize and predict clinical DBS response in patients with DRE.

Evaluation of optic nerve head vessels density changes after phacoemulsification cataract surgery using optical coherence tomography angiography.

To evaluate optic nerve head (ONH) vessel density (VD) changes after cataract surgery using optical coherence tomography angiography (OCTA). This was a prospective observational study. Thirty-four eyes with mild/moderate cataracts were included. ONH scans were obtained before and 3mo after cataract surgery using OCTA. Radial peripapillary capillary (RPC) density, all VD, large VD and retinal nerve fiber layer thickness (RNFLT) in total disc, inside disc, and different peripapillary sectors were assessed and analyzed. Image quality score (QS), fundus photography grading and best-corrected visual acuity (BCVA) were also collected, and correlation analyses were performed between VD change and these parameters. Compared with baseline, both RPC and all VD increased in inside disc area 3mo postoperatively (from 47.5%±5.3% to 50.2%±3.7%, and from 57.87%±4.30% to 60.47%±3.10%, all P<0.001), but no differences were observed in peripapillary area. However, large VD increased from 5.63%±0.77% to 6.47%±0.72% in peripapillary ONH region (P<0.001). RPC decreased in inferior and superior peripapillary ONH parts (P=0.019, <0.001 respectively). There were obvious negative correlations between RPC change and large VD change in inside disc, superior-hemi, and inferior-hemi (r=-0.419, -0.370, and -0.439, P=0.017, 0.044, and 0.015, respectively). No correlations were found between VD change and other parameters including QS change, fundus photography grading, postoperative BCVA, and postoperative peripapillary RNFLT. RPC density and all VD in the inside disc ONH region increase 3mo after surgery in patients with mild to moderate cataract. No obvious VD changes are found in peripapillary area postoperatively.

Importance of S-point in the Management of Severe Epistaxis

Although severe epistaxis is uncommon, it is serious. The systematic endoscopic nasal examination is an essential step in identifying the bleeding point and aiding electrocauterization. Currently, the S-point, which is located in the superior part of the nasal septum behind the septal body and corresponding to the axilla of the middle concha, is identified in about 30% of cases with severe epistaxis. Cauterization of this point has an excellent rate of controlling the bleeding and preventing its recurrence. We aimed to highlight the significance of the S-point in the management of severe cases of epistaxis.

Distribution of 50-layer corneal densitometry values and related factors.

To investigate the distribution of 50 layers of corneal densitometry and related factors. Clinical data, including age, sex, central corneal thickness, corneal keratometry, and diopters, were collected from 102 healthy participants (102 eyes) in this retrospective study. The cornea was divided into 50 layers, and densitometry of each layer at 19 points was measured by the Pentacam. The value versus the depth curve was plotted. Paired-sample t test and one-way analysis of variance were used to compare densitometry in different regions or depth. Statistical significance was defined as P < .05. The densitometry values of the Bowman membrane (10-14% depth), anterior stroma (14-30% depth), epithelium (0-10% depth), and Descemet membrane (94-98% depth) decreased sequentially, and the densitometry values of the middle and posterior stroma (30-94% depth) and endothelium (98-100% depth) were the lowest. The higher the degree of astigmatism, the higher the second densitometry peak (R = 0.277, P < .001). The densitometry values of the vertex and superior parts of the cornea were higher than those in the periphery and inferior parts, respectively (all P < .001). In the Bowman membrane, the densitometry is lowest in the inferior nasal part, while in the Descemet membrane, it is lowest in the inferior temporal part. Two densitometry peaks appeared near the Bowman membrane and Descemet membrane. For different depths, the distribution of densitometry within a layer is different. We provide a methodological reference and data basis for corneal research based on local changes in densitometry, and help understand the details of corneal structure from an optical perspective through detailed layering and zoning analysis of densitometry.

Effect of the Presence of Silicone Oil in the Anterior Chamber After Complicated Retinal Detachment Surgery on Corneal Morphology by In Vivo Confocal Microscopy

Purpose This study evaluated the corneal endothelium, stromal keratocytes, subbasal nerve number and density in patients with silicone oil transferred to the anterior camera after pseudophakic complicated retinal detachment surgery by in vivo laser scanning confocal microscopy (IVLSCM). Methods Sequential measurements were made by IVLSCM between 3–6 months after surgery in two groups of patients: a) with silicon oil migration (Group 1) and without silicone oil migration (Group 2). Results A total of 63 cases (Group 1: 32 and Group 2: 31) were examined. The mean ages of patients were 65 ± 12 and 61 ± 11 and M/F ratio was 18/14 and 17/14, respectively. Mean intraocular pressures were 16.60 ± 4.60 and 15.75 ± 5.70 mm Hg, respectively. Changes were detected by IVLSCM mostly on the superior part of the cornea. A significant decrease in endothelial cell density and the number was detected in group 1 (2072 ± 116.2 cells/mm2 vs 2752 ± 512.3 cells/mm2; p < 0.001). Significant increases in posterior keratocyte density and stromal hyperreflective deposits were observed in group 1 (887 ± 45.8 cells/mm2 vs 725 ± 65.8 cells/mm2; p < 0.001). A significant negative correlation was observed between the size of stromal deposits and endothelial cell density (r=–0.758; p < 0.001). The number and density of corneal subbasal nerves were significantly lower in group 1 (1.8 ± 0.8 and 4.8 ± 1.2 vs 420 ± 101 and 701 ± 112 µm/square; p < 0.001). Conclusion IVLSCM is a useful tool for the early detection of corneal abnormalities caused by silicone oil injection. This study verified silicone oil’s detrimental effect on the corneal endothelium and revealed stromal changes in the anterior chamber, which we believe can be also been associated with the presence of silicone oil.

Functional gradients of the medial parietal cortex in a healthy cohort with family history of sporadic Alzheimer’s disease

BackgroundThe medial parietal cortex is an early site of pathological protein deposition in Alzheimer’s disease (AD). Previous studies have identified different subregions within this area; however, these subregions are often heterogeneous and disregard individual differences or subtle pathological alterations in the underlying functional architecture. To address this limitation, here we measured the continuous connectivity gradients of the medial parietal cortex and assessed their relationship with cerebrospinal fluid (CSF) biomarkers, ApoE ε4 carriership and memory in asymptomatic individuals at risk to develop AD.MethodsTwo hundred sixty-three cognitively normal participants with a family history of sporadic AD who underwent resting-state and task-based functional MRI using encoding and retrieval tasks were included from the PREVENT-AD cohort. A novel method for characterizing spatially continuous patterns of functional connectivity was applied to estimate functional gradients in the medial parietal cortex during the resting-state and task-based conditions. This resulted in a set of nine parameters that described the appearance of the gradient across different spatial directions. We performed correlation analyses to assess whether these parameters were associated with CSF biomarkers of phosphorylated tau181 (p-tau), total tau (t-tau), and amyloid-ß1-42 (Aß). Then, we compared the spatial parameters between ApoE ε4 carriers and noncarriers, and evaluated the relationship between these parameters and memory.ResultsAlterations involving the superior part of the medial parietal cortex, which was connected to regions of the default mode network, were associated with higher p-tau, t-tau levels as well as lower Aß/p-tau levels during the resting-state condition (p < 0.01). Similar alterations were found in ApoE ε4 carriers compared to non-carriers (p < 0.003). In contrast, lower immediate memory scores were associated with changes in the middle part of the medial parietal cortex, which was connected to inferior temporal and posterior parietal regions, during the encoding task (p = 0.001). No results were found when using conventional connectivity measures.ConclusionsFunctional alterations in the medial parietal gradients are associated with CSF AD biomarkers, ApoE ε4 carriership, and lower memory in an asymptomatic cohort with a family history of sporadic AD, suggesting that functional gradients are sensitive to subtle changes associated with early AD stages.

Skeletal and dental effects of serial extractions performed with or without maxillary expansion-A retrospective controlled study.

The study aimed to compare severe crowding treatment's skeletal and dental effects by serial extractions or maxillary expansion and serial extractions in the mixed dentition phase. The retrospective controlled study included lateral cephalograms of 78 subjects aged 8.5 ± 1.4 years, 52 consecutively treated because of severe crowding, and 26 untreated controls matched for baseline age and observational period. Subjects were clustered according to the treatment modality, either serial extraction (EX) or expansion and extraction (EXP-EX) group. Sagittal and vertical skeletal as well as dental cephalometric parameters were assessed at baseline and after the eruption of all permanent posterior teeth, and group comparisons were performed. Both treatment modalities significantly affected the vertical skeletal parameters in terms of decreasing the mandibular and occlusal plane inclination and increasing the facial height index. A distinct treatment effect on the gonial angle was observed, with a significant decrease in its superior part observed in both extraction groups. The annualized changes in the superior part of the gonial angle significantly differ (P = .036) between the Control (-0.04 ± 0.6), EX (-0.44 ± 0.6) and EXP-EX (-0.34 ± 0.5) groups. Upper and lower incisor inclination did not change significantly in any of the groups; however, the interincisal angle at follow-up was significantly smaller in the Control compared with both treated groups. Serial extractions and a combination of maxillary expansion and serial extractions have similar significant skeletal effects, mainly affecting vertical cephalometric parameters if performed during the pre-pubertal growth phase.

Brain alterations in patients with intractable tinnitus before and after rTMS: A resting-state functional magnetic resonance imaging study.

To observe abnormal tinnitus activity by evaluating the amplitude of low-frequency fluctuation (ALFF) changes in the brain was which detected by resting-state functional magnetic resonance imaging (rs-fMRI) in patients with intractable tinnitus before and after repetitive transcranial magnetic stimulation (rTMS). We hypothesized that rTMS could progressively revert local brain function back to a relatively normal range. This prospective observational research study recruited 25 patients with intractable tinnitus, with 28 healthy controls matched by age, sex, and education level. Participants' Tinnitus Handicap Inventory (THI) scores and the visual analog scale (VAS) were used to determine the severity of their tinnitus before and after treatment. We processed the brain spontaneous neural activity of intractable tinnitus patients by ALFF, then, we determined its association with clinically evaluated indicators of intractable tinnitus. The total and the three sub-modules (functional [F], emotional [E], and catastrophic [C]) score of the THI and VAS in patients with intractable tinnitus decreased after treatment (P<0.001). The effective rate of tinnitus patients was 66.9%. A few patients had a slight left facial muscle tremor or temporary mild scalp pain during treatment. Compared with healthy controls, participants with tinnitus significantly reduced ALFF within the left and right medial superior frontal gyrus (P<0.005). After rTMS treatment, the left fusiform gyrus and right superior cerebellar lobe increased ALFF in those with tinnitus (P<0.005). The changes in THI, VAS, and ALFF were positively correlated (P<0.05). RTMS is effective in the treatment of tinnitus. It significantly reduces the THI/VAS score and improves the symptoms of tinnitus. No serious adverse reaction during rTMS were reported. The changes in the left fusiform gyrus and right superior part of the cerebellum may explain the mechanism of rTMS treatment in intractable tinnitus.

The Role of Optical Coherence Tomography Angiography in Non-Arteritic Ischemic Optic Neuropathy: A Case Report

Introduction: Non-arteritic ischemic optic neuropathy (NAION) is the second most common optic neuropathy in adults. Since circulatory insufficiency is presumed to have a role in pathogenesis of NAION, optical coherence tomography angiography (OCTA) is suggested as a tool in assessing NAION patients, while optical coherence tomography (OCT) can detect structural changes. This case report aims to describe the congruity of visual field defect with OCT and OCTA result in a case of bilateral NAION, highlighting the role of both OCT and OCTA in NAION. Case Report: A 52-years-old male came due to painless, progressive blurry vision in both eyes, especially in lower visual field, for the past 7 months. Humphrey visual field examination revealed inferior visual field defects in both eyes. OCTA showed reduced retinal perfusion in the superior part bilaterally. OCT revealed ganglion cell loss in the superior part of his right eye and almost all parts of his left eye. Retinal nerve fiber layer (RNFL) thinning was found in the superior part bilaterally. Discussion: In this case, the congruity of visual field defect, reduced perfusion, ganglion cell-inner plexiform layer (GCIPL), and RNFL thinning portrayed the connection of hypoperfusion as the presumed underlying mechanism of NAION, neuron loss as the result of the hypoperfusion, and the visual field loss as the presenting symptom in NAION. Conclusion: This finding demonstrates the role of OCT-A and OCT in diagnosing and monitoring progression in patients with NAION.OCT-A is a useful tool to evaluate microvascular changes, while OCT can be used to evaluate RNFL and GCIPL thinning.