Area In Healthy Subjects Research Articles

Feasibility of Ultrasound Measurements of Peripheral Sensory Nerves in Head and Neck Area in Healthy Subjects.

Current diagnostic methods for nerve compression headaches consist of diagnostic nerve blocks. A less-invasive method that can possibly aid in the diagnosis is ultrasound, by measuring the cross-sectional area (CSA) of the affected nerve. However, this technique has not been validated, and articles evaluating CSA measurements in the asymptomatic population are missing in the current literature. Therefore, the aim of this study was to determine the feasibility of ultrasound measurements of peripheral extracranial nerves in the head and neck area in asymptomatic individuals. The sensory nerves of the head and neck in healthy individuals were imaged by ultrasound. The CSA was measured at anatomical determined measurement sites for each nerve. To determine the feasibility of ultrasound measurements, the interrater reliability and the intrarater reliability were determined. In total, 60 healthy volunteers were included. We were able to image the nerves at nine of 11 measurement sites. The mean CSA of the frontal nerves ranged between 0.80 ± 0.42 mm2 and 1.20 ± 0.43 mm2, the mean CSA of the occipital nerves ranged between 2.90 ± 2.73 mm2 and 3.40 ± 1.91 mm2, and the mean CSA of the temporal nerves ranged between 0.92 ± 0.26 mm2 and 1.40 ± 1.11 mm2. The intrarater and interrater reliability of the CSA measurements was good (ICC: 0.75-0.78). Ultrasound is a feasible method to evaluate CSA measurements of peripheral extracranial nerves in the head and neck area. Further research should be done to evaluate the use of ultrasound as a diagnostic tool for nerve compression headache.

Anti-Correlated Myelin-Sensitive MRI Levels in Humans Consistent with a Subcortical to Sensorimotor Regulatory Process-Multi-Cohort Multi-Modal Evidence.

Differential axonal myelination synchronises signalling over different axon lengths. The consequences of myelination processes described at the cellular level for the regulation of myelination at the macroscopic level are unknown. We analysed multiple cohorts of myelin-sensitive brain MRI. Our aim was to (i) confirm a previous report of anti-correlation between myelination in subcortical and sensorimotor areas in healthy subjects, (ii) and thereby test our hypothesis for a regulatory interaction between them. We analysed nine image-sets across three different human cohorts using six MRI modalities. Each image-set contained healthy controls (HC) and ME/CFS subjects. Subcortical and Sensorimotor regions of interest (ROI) were optimised for the detection of anti-correlations and the same ROIs were used to test the HC in all image-sets. For each cohort, median MRI values were computed in both regions for each subject and their correlation across the cohort was computed. We confirmed negative correlations in healthy controls between subcortical and sensorimotor regions in six image-sets: three T1wSE (p = 5 × 10-8, 5 × 10-7, 0.002), T2wSE (p =2 × 10-6), MTC (p = 0.01), and WM volume (p = 0.02). T1/T2 was the exception with a positive correlation (p = 0.01). This myelin regulation study is novel in several aspects: human subjects, cross-sectional design, ROI optimization, spin-echo MRI and reproducible across multiple independent image-sets. In multiple independent image-sets we confirmed an anti-correlation between subcortical and sensorimotor myelination which supports a previously unreported regulatory interaction. The subcortical region contained the brain's primary regulatory nuclei. We suggest a mechanism has evolved whereby relatively low subcortical myelination in an individual is compensated by upregulated sensorimotor myelination to maintain adequate sensorimotor performance.

Reference ranges of tricuspid annulus geometry in healthy adults using a dedicated three-dimensional echocardiography software package.

BackgroundTricuspid annulus (TA) sizing is essential for planning percutaneous or surgical tricuspid procedures. According to current guidelines, TA linear dimension should be assessed using two-dimensional echocardiography (2DE). However, TA is a complex three-dimensional (3D) structure.AimIdentify the reference values for TA geometry and dynamics and its physiological determinants using a commercially available three-dimensional echocardiography (3DE) software package dedicated to the tricuspid valve (4D AutoTVQ, GE).MethodsA total of 254 healthy volunteers (113 men, 47 ± 11 years) were evaluated using 2DE and 3DE. TA 3D area, perimeter, diameters, and sphericity index were assessed at mid-systole, early- and end-diastole. Right atrial (RA) and ventricular (RV) end-diastolic and end-systolic volumes were also measured by 3DE.ResultsThe feasibility of the 3DE analysis of TA was 90%. TA 3D area, perimeter, and diameters were largest at end-diastole and smallest at mid-systole. Reference values of TA at end-diastole were 9.6 ± 2.1 cm2 for the area, 11.2 ± 1.2 cm for perimeter, and 38 ± 4 mm, 31 ± 4 mm, 33 ± 4 mm, and 34 ± 5 mm for major, minor, 4-chamber and 2-chamber diameters, respectively. TA end-diastolic sphericity index was 81 ± 11%. All TA parameters were correlated with body surface area (BSA) (r from 0.42 to 0.58, p < 0.001). TA 3D area and 4-chamber diameter were significantly larger in men than in women, independent of BSA (p < 0.0001). There was no significant relationship between TA metrics with age, except for the TA minor diameter (r = −0.17, p < 0.05). When measured by 2DE in 4-chamber (29 ± 5 mm) and RV-focused (30 ± 5 mm) views, both TA diameters resulted significantly smaller than the 4-chamber (33 ± 4 mm; p < 0.0001), and the major TA diameters (38 ± 4 mm; p < 0.0001) measured by 3DE. At multivariable linear regression analysis, RA maximal volume was independently associated with both TA 3D area at mid-systole (R2 = 0.511, p < 0.0001) and end-diastole (R2 = 0.506, p < 0.0001), whereas BSA (R2 = 0.526, p < 0.0001) was associated only to mid-systolic TA 3D area.ConclusionsReference values for TA metrics should be sex-specific and indexed to BSA. 2DE underestimates actual 3DE TA dimensions. RA maximum volume was the only independent echocardiographic parameter associated with TA 3D area in healthy subjects.

Effects of Different Neck Manual Lymphatic Drainage Maneuvers on the Nervous, Cardiovascular, Respiratory and Musculoskeletal Systems in Healthy Students.

The aim of this study is to describe the short-term effects of manual lymph drainage (MLD) isolated in supraclavicular area in healthy subjects. A 4-week cross-sectional, double-blinded randomized clinical trial was conducted. Participants: 24 healthy participants between 18 and 30 years old were recruited from Universidad Europea de Madrid from December 2018 to September 2019. A total of four groups were studied: control, placebo, Vodder, and Godoy. The order of the interventions was randomized. Resting Heart Rate and Oxygen Saturation, blood pressure, pressure pain threshold of trapezius muscle, respiratory rate, range of active cervical movements were measured before and after every intervention. All the participants fulfilled four different interventions with a one-week-wash-out period. No statistically significant differences were found between groups in descriptive data; neither in saturation of oxygen, diastolic blood pressure and cervical range of motion. Significant differences were found in favor of Vodder (p = 0.026) in heart rate diminution and in cardiac-rate-reduction. A significant difference in respiratory rate diminution is found in favor of the Godoy group in comparison with the control group (p = 0.020). A significant difference is found in favor of the Godoy group in systolic blood pressure decrease (p = 0.015) even in pressure pain threshold (p < 0.05). MLD decreases systolic blood pressure in healthy participants. However, it does not produce any changes in other physiologic outcomes maintaining physiologic values, which may suggest the safety of the technique in patients suffering from other pathologies.

Superficial and Deep Foveal Avascular Zone Area Measurement in Healthy Subjects Using Two Different Spectral Domain Optical Coherence Tomography Angiography Devices.

PurposeTo compare the area of the foveal avascular zone (FAZ) in the superficial and deep retinal layers using two different spectral-domain optical coherence tomography angiography (OCTA) devices.MethodsA cross-sectional comparative study was conducted to obtain macular OCTA images from healthy subjects using Optovue RTVue XR Avanti (Optovue, Inc, Fremont, CA) and Spectralis HRA+OCTA (Heidelberg Engineering, Heidelberg, Germany). Two independent trained graders measured the FAZ area using automated slab segmentation. The FAZ area in the superficial and deep retinal layers were compared.ResultsTwenty-three eyes of 23 subjects were included. The graders agreement was excellent (0.86) for all measurements. The mean FAZ area was significantly larger at the superficial retinal layer as compared to the deep retinal layer on both devices (0.31 0.08 mm vs 0.26 0.08 mm in Optovue and 0.55 0.16 mm vs 0.36 0.13 mm in Spectralis, both P 0.001). The mean FAZ area was significantly greater in the superficial and deep retinal layers using Spectralis as compared to Optovue measurements (P 0.001 for both comparisons).ConclusionIn contrast to previous reports, the FAZ area was larger in the superficial retina as compared to deep retinal layers using updated software versions. Measurements from different devices cannot be used interchangeably.

Ethnic differences in normal retinal capillary density and foveal avascular zone measurements.

The purpose of this study was to quantify retinal capillary density and foveal avascular zone (FAZ) area in healthy subjects according to their ethnicity, using optical coherence tomography angiography (OCTA). In this cross-sectional study, all eyes underwent swept-source OCTA (Triton, Topcon, Tokyo, Japan). Macular OCTA scans (3 × 3mm) were obtained in healthy white Caucasian and black African subjects. The FAZ area and capillary density in both the superficial (SCP) and deep capillary plexuses (DCP) were automatically measured using a custom-made software combining vessel binarization and skeletonization. Twelve eyes of 12 healthy Caucasians and 15 eyes of 15 healthy black Africans were included in the analysis. The mean FAZ area was significantly smaller, and the overall vessel density (VD) was higher in the SCP and DCP of Caucasians compared to black Africans. The mean FAZ area was 0.26 ± 0.008mm2 in the SCP and 0.25 ± 0.05mm2 in the DCP in Caucasians versus 0.33 ± 0.08mm2 in the SCP (p = 0.01) and 0.37 ± 0.1mm2 in the DCP (p = 0.03) in Africans. In the SCP and DCP, the mean VD was, respectively, 40.5 ± 0.8% and 47.1 ± 0.5% in Caucasians versus 34.3 ± 1% (p = 0.008) and 40.6 ± 0.9% in Africans (p < 0.001). In the SCP and DCP, VD is lower in black Africans compared to Caucasians. In OCTA studies on vascular diseases, ethnicity-matched measurements from healthy subjects should be used for comparisons.

Electrical Stimulation Versus Voluntary Exercise on the Navicular Height, Calcaneal Pitch Angle, and Cross-Sectional Area in Healthy Subjects: A Single-Blinded Randomized Controlled Trial

The important function of the intrinsic foot muscles is the dynamic stabilization of the medial longitudinal arch (MLA). Several studies have reported that implementing short foot exercise (SFE) and electrical stimulation (ES) amid the intrinsic foot muscles may increase MLA height. Hence, the aim of this study was to compare the effects of ES versus SFE on navicular drop (ND), calcaneal pitch angle (CPA), and cross sectional area (CSA) of the abductor hallucis (AbdH) muscle. 20 healthy female subjects were randomly assigned to undergo ES (n=10) or SFE (n=10). SFE performed 30 repetitions whereas 20 min per day for ES, 3 days/week, for 4 weeks. ND, CPA, and the CSA of the AbdH muscle were assessed before and after intervention. The results showed that ES group significantly decreased in ND after training (p<0.05) without significant differences between groups. The CPA is a little change in both groups (SFE = 0.4o and ES = 2.4o ; p>0.05). The CSA of the AbdH muscle in both groups was increased (ES =10.93 mm2 and SFE=7.44 mm2 ; p<0.05) with no significant difference between ES and SFE. These results demonstrated that ES and SFE alone could improve intrinsic foot muscle size. Nevertheless, ES tended to increase MLA more than SFE alone. Hence, ES can be considered as an alternative treatment to increase MLA and intrinsic foot muscle size.

Application of Navigated Transcranial Magnetic Stimulation to Map the Supplementary Motor Area in Healthy Subjects.

The supplementary motor area is involved in the planning and coordination of movement sequences. This study investigates the potential of repetitive navigated transcranial magnetic stimulation for systematic mapping of the supplementary motor area by interfering with normal movement coordination processing. Ten healthy females (median age: 23.5 years) performed the Jebsen-Taylor Hand Function Test, first without stimulation (baseline) and afterward during application of repetitive navigated transcranial magnetic stimulation with 10 Hz to 6 cortical sites located within the supplementary motor area of both hemispheres. The test completion times (TCTs) were then compared between baseline performances and performances during stimulation. We found significant slowing of TCTs in simulated page turning (baseline TCT 3.68 ± 0.67 seconds vs. stimulation TCT 4.04 ± 0.63 seconds, P = 0.0136), lifting small objects (baseline TCT 5.11 ± 0.72 seconds vs. stimulation TCT 5.47 ± 0.66 seconds, P = 0.0010), and simulated feeding (baseline TCT 6.10 ± 0.73 seconds vs. stimulation TCT 6.59 ± 0.81 seconds, P = 0.0027). Three other subtests were not affected, whereas one subtest was performed significantly faster (baseline TCT 17.09 ± 7.31 seconds vs. stimulation TCT 15.44 ± 5.72 seconds, P = 0.0073) under stimulation. Repetitive navigated transcranial magnetic stimulation is capable of influencing the performance of healthy participants in a task relying on hand coordination. Our approach can serve as a mapping tool for the supplementary motor area, potentially relevant for preoperative diagnostics in patients with brain tumors, epilepsy, or other brain lesions to improve outcome and potentially predict clinical course and postoperative recovery.

18-25 Yaş Arası Sağlıklı Kişilerde Üst Ekstremite Antropometrik Ölçümlerin Belirlenmesi

Background: The present study was aimed to analyze the morphometric measurements of upper extremity dimensions and estimate the total body surface area, hand and palm area in healthy subjects aged between 18-25 years. Materials and Methods: After taking hand tracing, the length and width measurements were performed, and hand-palm indexes were calculated from 407 adult subjects (243 females; 164 males) aged 18 to 25 years. Also, arm span, height and weight were measured. Additionally, total body surface area was calculated using DuBois Formula and hand and palm area was estimated from hand tracing and the percent of hand and palm surface area were formulated.Results: In females, the mean values of age, weight, height, BMI and arm span were found as 19.68±2.42 years, 55.96±8.32 kg, 164.12±5.93 cm and 20.79±3.03 kg/m2 and 1.60±0.06 m, respectively, whereas the same values were 20.22±3.40 years, 71.48±11.98 kg, 176.96±6.26 cm, 22.80±3.44 kg/m2, and 1.76±0.05 m, respectively in males. Moreover, the significant difference was found between measurements such as height, weight, body mass index and arm span and gender. Total body surface area was estimated as 1.88±0.16 m2 and 1.60±0.12 m2 in males and females, respectively. Also, hand area of males was found as 156.31±11.25 m2 and 154.71±11.92 m2 in right and left side, respectively, whereas the corresponding value of females was measured as 128.15±11.14 m2 and 125.56±10.80 m2 in right and left side, respectively. Palm area of males was estimated 88.30±8.11 m2 and 87.52±8.61 m2 in right and left side, respectively. The same values of females were 71.51±6.19 m2 and 70.24±1.60 m2 in right and left side, respectively. However, there were significant difference in measurements of hand area, palm area, total body surface area, the percents of hand and palm surface area between gender. The hand index was found as 42.33±2.97 (right), 41.67±2.91 (left) in females, whereas the same values were established as 41.95±3.56 (right) and 42.03±2.64 (left) in males. Conclusions: The observations presented in present study, can provide principal knowledge about anatomic parameters. They need to be taken into consideration when surgical procedures are performed in hand region for female and male population. Also, the total body surface area, the percents of hand and palm surface area, hand and palm area values help to determine burns area, or extent of burn and wounds. Moreover, we can say that differences between measurements can depend on some factors such as gender, age, race, ethnic groups, geographical situations.

Detecting a psoriatic antigen analogous to infectious prion proteins

Until now, psoriatic antigen as a specific antigen derived from some infectious agent potentially related to origin of psoriasis has not been identified, thereby strongly arguing against infectious theory of psoriasis. However, the lack of specific psoriasis-associated antigens may be theoretically accounted for by an idea that psoriatic antigen could be analogous to infectious prion proteins (PrPSc analogue). It might be identical to some epidermal protein in psoriasis-free subjects that might differ antigenically from related normal protein by resistance to digestive enzymes similarly to PrPSc. Since PrPSc cytopathogenic effect is associated with its location within cell structures of affected body tissue, by analogy with PrPSc we aimed at identifying a potential carrier of psoriatic antigen by examining peptic hydrolysates of psoriatic squamous elements. Psoriatic squamous elements and epidermal stratum corneum were collected from heel area of healthy subjects with a metal grater for further examination. Squamous elements were homogenized in isotonic saline followed by centrifugation to separate them from soluble components. Homogenates of squamous elements structures and their homogenate supernatants underwent peptic hydrolysis reaction. Antigens and their identity were analysed by Ouchterlony immunoprecipitation in agar with antiserum obtained after immunizing rabbits with homogenate of the psoriatic squamous element structures, before and after hydrolysis, using peptic hydrolysates of squamous element structures and relevant supernatants. It was found that two antigens were precipitated in peptic hydrolysates of homogenates of psoriatic squamous cell structures, underlying acidin-pepsin resistance of antigen carriers. However, compared to the remainder of antigens precipitated in examined substrates only one out of two antigens might be considered as a psoriatic antigen being some PrPSc analogue that was identical to one of supernatant antigens derived from epidermal stratum corneum homogenates collected from healthy subjects. Similar to PrPSc, it differed from antigenically related normal protein by acidin-pepsin resistance. Albeit confirming available reports revealing no psoriasis-associated pathogen-specific antigens, this, nonetheless, might not be sufficient for rejecting infectious theory of psoriasis, as psoriatic antigen exhibits some properties similar to those of PrPSc.

Time-effect reaction observation of micro-invasion embedded poly glycolide-co-lactide suture in Sanyinjiao (SP6) in healthy subjects by using magnetic resonance

To observe the time-effect of stimulation of the embedded poly glycolide-co-lactide (PGLA) suture in Sanyinjiao (SP6) area in normal human body, so as to provide an experimental evidence for clinical application of micro-invasion suture-embedding at an appropriate interval. A total of 8 healthy volunteer students (3 boys and 5 girls, ranging in age from 24 to 27 years) were recruited in the present study. A piece of sterilized PGLA suture was implanted into the left SP6 using minimally invasive surgery after strict local skin disinfection. The fat-suppression T2 weighted magnetic resonance images (MRI, displaying local lesion after eliminating interference of fat tissue signals), and T2 mapping 8-echo train images were acquired before and 8 h, 3, 7, 10 and 14 days after PGLA suture embedment by using a MR imaging system. After transformation of the T2-mapping 8-echo train images into T2-mapping images by using a relevant software, the T2 values (meaning the relaxation time of the local muscle) of the left SP6 were measured, followed by analysis of the signal intensity of T2 weighted fat-suppression images and T2 values at different time-points. Before the suture embedding, no abnormal signals were found in the signal intensity of T2 weighted fat-suppression images. After PGLA suture embedment, the local signal intensity of T2WI fat-suppression images was relatively increased at the 8th h, and on day 3, 7, 10 and 14 relevant to pre-embedment, but gradually atte-nuated on day 10 and 14. The T2 values were significantly increased at the 5 time-points of post-embedment (all P<0.01), but without significant differences among the 8thh, the 3rd and 7thd (P>0.05), and being markedly lowered on day 14 relevant to day 7 (P<0.01) in spite of being still markedly higher than that of pre-embedding (P<0.01). The signal intensity of T2 weighted fat-suppression images and T2 values acquired from PGLA-suture-embedded SP6 acupoint area in healthy subjects may keep at least for 2 weeks, suggesting that the stimulating reaction of suture-embedment persists more than 14 days. Hence, when a micro-invasion embedding with PGLA suture performed, the interval of two weeks would be appropriate.

Application of navigated transcranial magnetic stimulation to map the supplementary motor area in healthy subjects

Objective: The supplementary motor area (SMA) is involved in the planning and coordination of movement sequences. This study investigates the potential of navigated repetitive transcranial magnetic stimulation (nrTMS) for systematic mapping of the SMA by interfering with normal movement coordination processing.

Improved analysis of foveal avascular zone area with optical coherence tomography angiography.

To investigate the relationship between the foveal avascular zone (FAZ) and the inner nuclear layer (INL)-free zone in the center of the fovea in order to provide an improved approach to evaluation of the FAZ area with optical coherence tomography angiography (OCTA). Thirty-six healthy individuals (36 eyes) and 15 age-matched patients (15 eyes) with nonproliferative diabetic retinopathy (nPDR) were included in this study. The FAZ, as well as INL-free zone, was measured on OCTA images. The FAZ area, INL-free zone area, and the ratio of the INL-free zone area to the FAZ area were compared between healthy subjects and nPDR patients. The mean FAZ area in healthy subjects and nPDR patients was 0.33 ± 0.1mm2 and 0.41 ± 0.19mm2 (p < 0.05), respectively. The mean INL-free zone area in healthy subjects and nPDR patients was 0.33 ± 0.07mm2 and 0.25 ± 0.09mm2 (p > 0.05), respectively. The INL-free zone area to the FAZ area ratio in healthy subjects and nPDR patients was 1.08 ± 0.25 and 0.56 ± 0.18 (p < 0.001), respectively. Receiver operating characteristic analysis showed that the INL-free zone area to the FAZ area ratio had a higher area under curve (0.94; 80.0% sensitivity and 97.2% specificity) compared to the FAZ area (0.61; 40.0% sensitivity and 94.4% specificity) for differentiating nPDR from healthy eyes. This study showed that analysis of the FAZ based on the ratio of the INL-free zone area to the FAZ area has better accuracy compared to the conventional FAZ area measurement in differentiating eyes with mild to moderate nPDR without any structural abnormalities in the fovea from healthy eyes.

P1589Right atrial volume is the major determinant of tricuspid annulus area in healthy subjects and in patients with functional tricuspid regurgitation due to various etiologies

P1589Right atrial volume is the major determinant of tricuspid annulus area in healthy subjects and in patients with functional tricuspid regurgitation due to various etiologies

Wide-field Choroidal Vascularity in Healthy Eyes

To report variation of choroidal vascularity index (CVI) in macular and mid-equator areas in healthy subjects using wide-field optical coherence tomography (WF-OCT). Prospective, cross-sectional study. Setting: Two-center study. Twenty eyes of 20 healthy subjects. Single high-definition scans passing through the fovea in both vertical and horizontal meridians were studied. Images were taken in primary gaze and extremes of gaze and a manual montage was created. A previously reported semi-automated algorithm was used to calculate the CVI in macular, superior, inferior, temporal, and nasal quadrants. Difference in CVI in macular area and 4 quadrants. Twenty eyes from 20 subjects were enrolled in the study. The mean age was 28.85 ± 6.29 years with men comprising 9 of the 20 subjects (45.0%). The refractive error (spherical equivalent) ranged from-3.00 to+0.75 diopters. The average CVI in the macular area (40.01 ± 7.67) was significantly smaller than in any of the other fundus areas (all P < .01). The maximum CVI was seen in the nasal quadrant (50.84 ± 5.64), followed by inferior (47.93 ± 9.31), temporal (46.14 ± 7.06), and superior (45.72 ± 7.69). The nasal quadrant was found to have the least coefficient of variation (CV) of CVI (0.11) while the inferior and macular area had the highest CV (0.19). We report CVI in WF-OCT in healthy young individuals. CVI seems to have a wide topographic variation. The macular area had the least CVI. CVI values are more consistent with lesser CV in the nasal quadrant compared to the other quadrants and macular area.

Assessing patterns of T2/T1rho change in grade 1 cartilage lesions of the distal femur using an angle/layer dependent approach

PurposeTo assess changes in the patterns of T2 and T1rho values within grade 1 cartilage lesions of osteoarthritis (OA) patients compared to healthy controls. Materials and methodsTwenty healthy knees and 25 OA knees were examined on a 3 T scanner. Areas of signal heterogeneity within the cartilage of the distal femur were identified using fat suppressed proton density-weighted imagines. T2 and T1rho values in each OA patient with grade 1 lesions were compared to average T2 and T1rho values of the corresponding areas in healthy subjects. ResultsA total of 28 areas including grade 1 lesion were identified. Compared to normal cartilage, the majority of grade 1 cartilage lesions demonstrated either no significant change or a statistically significant increase in both T2 values (18/28, 64%) and T1rho values (23/28, 82%). Compared to T2, T1rho demonstrated a greater proportion of statistically significantly higher values in OA patients than those from the normal controls. However, T2 and T1rho values in grade 1 lesions can be decreased, or demonstrate mixed patterns compared to those in healthy cartilage. ConclusionOur results suggest that early degenerative cartilage lesions can demonstrate various patterns of T2 and T1rho changes.

&lt;b&gt;Pharmacokinetics and Pharmacodynamics of a Single Dose of Scopolamine Ointment Applied to the Postauricular Area in Healthy Subjects &lt;/b&gt;

&lt;b&gt;Pharmacokinetics and Pharmacodynamics of a Single Dose of Scopolamine Ointment Applied to the Postauricular Area in Healthy Subjects &lt;/b&gt;

Personalized analysis of foveal avascular zone with optical coherence tomography angiography

Aim. To investigate the relationship between the foveal avascular zone (FAZ) and inner nuclear layer (INL) free zone in order to provide a personalized approach for evaluation of the FAZ area with optical coherence tomography-angiography (OCTA).&#x0D; Material and methods.Thirty-six healthy individuals (36 eyes) and 9 patients (12 eyes) with nonproliferative diabetic retinopathy (nPDR) were included in this study. The FAZ area as well as INL-free zone were measured in superficial capillary plexus on OCTA images. The FAZ area, INL-free area, and the ratio of the INL-free area to the FAZ area were compared between healthy subjects and nPDR patients.&#x0D; Results. The mean FAZ area in healthy subjects and nPDR patients was 0.33 0.1 and 0.56 0.28 mm2 (p 0.05), respectively. The mean INL-free zone in healthy subjects and nPDR patients was 0.33 0.07 and 0.28 0.1 mm2 (p 0.05), respectively. The ratio of the INL-free area to the FAZ area in healthy subjects and nPDR patients was 1.08 0.25 and 0.57 0.2 (p 0.001), respectively. Receiver operating characteristic analysis showed that the ratio of the INL-free area to the FAZ area had the higher area under curve (0.98; 91.7% sensitivity and 97.2% specificity) compared to the FAZ area (0.8; 66.7% sensitivity and 87.1% specificity) for differentiating nPDR from healthy eyes.&#x0D; Conclusion. This study showed that personalized analysis of the FAZ area based on the relationship between the actual FAZ and INL-free zone has better diagnostic accuracy compared to the conventional FAZ area measurement on OCTA images.

Human jugular vein collapse in the upright posture: implications for postural intracranial pressure regulation

BackgroundIntracranial pressure (ICP) is directly related to cranial dural venous pressure (Pdural). In the upright posture, Pdural is affected by the collapse of the internal jugular veins (IJVs) but this regulation of the venous pressure has not been fully understood. A potential biomechanical description of this regulation involves a transmission of surrounding atmospheric pressure to the internal venous pressure of the collapsed IJVs. This can be accomplished if hydrostatic effects are cancelled by the viscous losses in these collapsed veins, resulting in specific IJV cross-sectional areas that can be predicted from flow velocity and vessel inclination.MethodsWe evaluated this potential mechanism in vivo by comparing predicted area to measured IJV area in healthy subjects. Seventeen healthy volunteers (age 45 ± 9 years) were examined using ultrasound to assess IJV area and flow velocity. Ultrasound measurements were performed in supine and sitting positions.ResultsIJV area was 94.5 mm2 in supine and decreased to 6.5 ± 5.1 mm2 in sitting position, which agreed with the predicted IJV area of 8.7 ± 5.2 mm2 (equivalence limit ±5 mm2, one-sided t tests, p = 0.03, 33 IJVs).ConclusionsThe agreement between predicted and measured IJV area in sitting supports the occurrence of a hydrostatic-viscous pressure balance in the IJVs, which would result in a constant pressure segment in these collapsed veins, corresponding to a zero transmural pressure. This balance could thus serve as the mechanism by which collapse of the IJVs regulates Pdural and consequently ICP in the upright posture.

The Quantitative Measurements of Vascular Density and Flow Areas of Macula Using Optical Coherence Tomography Angiography in Normal Volunteers.

The quantification of the density of macular vascular networks and blood flow areas in the foveal and parafoveal area in healthy subjects using optical coherence tomography angiography (OCTA). Cross-sectional, prospective study in an institutional setting at the Retina Services of Farabi Eye Hospital. One hundred twelve normal volunteers with no known ocular or systemic disease were included, including patient numbers (one or both eyes), selection procedures, inclusion/exclusion criteria, randomization procedure, and masking. En face angiogram OCTA was performed on a 3 mm × 3 mm region centered on the macula. Automated thresholding and measuring algorithm method for foveal and parafoveal blood flow and vascular density (VD) were used. The density of macular vascular networks and blood flow area in the foveal and parafoveal area were measured. A total of 224 healthy eyes from 112 subjects with a mean age of 36.4 years ± 11.3 years were included. In the foveal region, the VD of the superficial capillary network (sCN) was significantly higher than that of the deep capillary network (dCN) (31.1% ± 5.5% vs. 28.3% ± 7.2%; P < .001), whereas in the parafoveal area, VD was higher in the dCN (62.24% ± 2.8% vs. 56.5% ± 2.5%; P < .001). Flow area in the 1-mm radius circle in the sCN was less than in the dCN. Superficial foveal avascular zone (sFAZ) size was negatively correlated with the VD of the foveal sCN, but in the deep FAZ (dFAZ) was not correlated with VD or blood flow area of the fovea. There was no difference between measured VD and blood flow surface area in both eyes of the subjects. OCTA could be used as a noninvasive, repeatable, layer-free method in quantitative evaluation of VD and blood flow of macular area. The normal quantities of the vascular plexus density and flow will help in better understanding the pathophysiological basis of the vascular disease of retina. [Ophthalmic Surg Lasers Imaging Retina. 2017;48:478-486.].