Correlation between macular and retinal nerve fibre layer Fourier-domain OCT measurements and visual field loss in chiasmal compression

Purpose The aim of this study was to test the correlation between Fourier-domain (FD) optical coherence tomography (OCT) macular and retinal nerve fibre layer (RNFL) thickness and visual field (VF) loss on standard automated perimetry (SAP) in chiasmal compression. Methods A total of 35 eyes with permanent temporal VF defects and 35 controls underwent SAP and FD-OCT (3D OCT-1000; Topcon Corp.) examinations. Macular thickness measurements were averaged for the central area and for each quadrant and half of that area, whereas RNFL thickness was determined for six sectors around the optic disc. VF loss was estimated in six sectors of the VF and in the central 16 test points in the VF. The correlation between VF loss and OCT measurements was tested with Spearman`s correlation coefficients and with linear regression analysis. Results Macular and RNFL thickness parameters correlated strongly with SAP VF loss. Correlations were generally stronger between VF loss and quadrantic or hemianopic macular thickness than with sectoral RNFL thickness. For the macular parameters, we observed the strongest correlation between macular thickness in the inferonasal quadrant and VF loss in the superior temporal central quadrant (rho=0.78; P<0.001) whereas for the RNFL parameters the strongest correlation was observed between the superonasal optic disc sector and the central temporal VF defect (rho=0.60; P<0.001).

Quality of life and neuropsychological changes in mild head trauma - Late analysis and correlation with S100B protein and cranial CT scan performed at hospital admission

Introduction: mild head trauma (MHT) is defined as a transient neurological deficit after trauma with a history of impairment or loss of consciousness lasting less than 15 min and/or posttraumatic amnesia, and a Glasgow Coma Scale between 13 and 15 on hospital admission. We evaluated 50 MHT patients 18 months after the trauma, addressing signs and symptoms of post-concussion syndrome, quality of life and the presence of anxiety and depression. We correlate those findings with the S100B protein levels and cranial CT scan performed at hospital admission after the trauma. Method: patients were asked to fill out questionnaires to assess quality of life (SF36), anxiety and depression (HADS), and signs and symptoms of post-concussion syndrome. For the control group, we asked the patient`s household members, who had no history of head trauma of any type, to answer the same questionnaires for comparison. Results: total quality of life index for patients with MHT was 58.16 (+/-5), lower than the 73.47 (+/-4) presented by the control group. Twenty patients (55.2%) and four (11.1%) controls were depressed. Seventeen patients (47.2%) presented anxiety, whereas only eight (22.2%) controls were considered anxious. Victims of MHT complained more frequently of loss of balance, dry mouth, pain in the arms, loss of memory and dizziness than their respective controls (p < 0.05). We found no correlation between the presence of these signs and symptoms, quality of life, presence of anxiety and depression with S100B protein levels or with presence of injury in the cranial CT performed at hospital admission. Conclusion: MHT is associated with a higher incidence of post-concussion syndrome symptoms, lower quality of life and anxiety than their respective controls even 18 months after the trauma. (C) 2007 Elsevier Ltd. All rights reserved.

A prospective study evaluating the efficacy of the artificial sphincter AMS 800 for the treatment of postradical prostatectomy urinary incontinence and the correlation between preoperative urodynamic and surgical outcomes

OBJECTIVES We have evaluated prospectively the long-term efficacy of the artificial urinary sphincter (AUS) AMS 800 for the treatment postradical prostatectomy urinary incontinence (PRPUI) patients. We also evaluated the correlation between preoperative urodynamic findings and surgical outcomes. METHODS From May 1997 to April 2003, 40 consecutive patients with PRPUI caused by intrinsic sphincter deficiency (ISD) were treated with the AMS 800. Mean age was 68.3 +/- 6.3 years. Continence status was evaluated on the basis of pad count, impact of urinary incontinence on the quality of life, complications, and surgical revisions. Preoperative urodynamic findings were correlated with surgical outcomes. RESULTS Follow-up ranged from 27 to 132 months (mean = 53.4 +/- 21.4 months). There was a significant reduction in pad count from 4.0 +/- 0.9 to 0.62 +/- 1.07 diapers per day (P <0.001) leading to continence in 90%. There was a significant reduction on the impact of incontinence decreasing from 5.0 +/- 0.7 to 1.4 +/- 0.93 (P <0.001) in a visual analogue scale (VAS). Surgical revision rate was 20%. Preoperative urodynamics was useful to identify sphincter deficiency. Except by a tendency of worse results in patients with reduced bladder compliance (RBC), other urodynamic parameters did not correlate with a worse surgical outcome. CONCLUSIONS The AMS 800 offers good long-term continence to most PRPUI patients. Preoperative findings like detrusor hyperactivity (DH), impaired detrusor contraction (IDC), low Valsalva leak point pressure, bladder outlet obstruction (BOO), and mild RBC were not associated with worse surgical outcomes.

Correlation between the Body Mass Index (BMI) of Pregnant Women and the Development of Hypotension after Spinal Anesthesia for Cesarean Section

Nani FS, Torres MLA - Correlation between the Body Mass Index (BMI) of Pregnant Women and the Development of Hypotension after Spinal Anesthesia for Cesarean Section. Background and objectives: Very few publications correlate hypotension in obese pregnant women, and especially morbidly obese, after spinal anesthesia for cesarean section. The objective of the present study was to evaluate the incidence of hypotension according to the BMI. Methods: Forty-nine patients with pregestational BMI below 25 kg.m(-2) were included in the Eutrophia group, and 51 patients with BMI >= 25 kg.m(-2) were included in the Overweight group. After spinal anesthesia, blood pressure, volume of crystalloid infused, and dose of vasopressors used until delivery were recorded. A fall in systolic blood pressure below 100 mmHg or 10% reduction of the initial systolic blood pressure (SBP) was considered as hypotension and it was corrected by the administration of vasopressors. Results: Episodes of hypotension were fewer in the Eutrophia group (5.89 +/- 0.53 vs. 7.80 +/- 0.66, p = 0.027), as well as the amount of crystalloid administered (1,298 +/- 413.6 mL vs. 1,539 +/- 460.0 mL; p = 0.007), and use of vasopressors (5.87 +/- 3.45 bolus vs. 7.70 +/- 4.46 bolus; p = 0.023). As for associated diseases, we observed higher incidence of diabetes among obese pregnant women (29.41% vs. 9.76%, RR 1.60, 95%CI: 1.15-2.22, p = 0.036), however, differences in the incidence of pregnancy-induced hypertension (PIN) were not observe between both groups (overweight: 21.57%, normal weight: 12.20%, RR 1.30, 95%CI: 0.88-1.94, p = 0.28). Conclusions: In the study sample, pregestational BMI >= 25 kg.m(-2) was a risk factor for hypotension after spinal anesthesia in patients undergoing cesarean section. The same group of patients required higher doses of vasopressors. Those results indicate that the anesthetic techniques in those patients should be improved to reduce the consequences of post-spinal anesthesia hypotension, both in pregnant women and fetuses.

Identification of intracellular and extracellular domains mediating signal transduction in the inhibitory glycine receptor chloride channel

Fast synaptic neurotransmission is mediated by transmitter-activated conformational changes in ligand-gated ion channel receptors, culminating in opening of the integral ion channel pore. Human hereditary hyperekplexia, or startle disease, is caused by mutations in both the intracellular or extracellular loops flanking the pore-lining M2 domain of the glycine receptor alpha 1 subunit. These flanking domains are designated the M1-M2 loop and the M2-M3 loop respectively. We show that four startle disease mutations and six additional alanine substitution mutations distributed throughout both loops result in uncoupling of the ligand binding sites from the channel activation gate. We therefore conclude that the M1-M2 and M2-M3 loops act in parallel to activate the channel. Their locations strongly suggest that they act as hinges governing allosteric control of the M2 domain. As the members of the ligand-gated ion channel superfamily share a common structure, this signal transduction model may apply to all members of this superfamily.

Prevalence of Metabolic Syndrome in Patients With Intermittent Claudication and its Correlation With the Segment of Arterial Obstruction

The metabolic syndrome (MetS) is associated with increased cardiovascular morbidity and mortality. Intermittent claudication reflects the presence of peripheral arterial disease (PAD). The aim of this study is to determine the prevalence of the MetS in claudicants and its correlation with age, gender, localization of arterial obstruction, and symptomatic coronary disease. Patients (n = 170) with intermittent claudication were studied. The mean age was 65 years (33-89). Metabolic syndrome was diagnosed in 98 patients (57.6%). The mean age of patients with MetS was 63.5 years compared with 67.0 years for patients without MetS (P = .027). Considering patients aged >= 65 years, MetS was present in 46 (48.9%) individuals and in 52 (68.4%) patients younger than 65 years (P = .011). Metabolic syndrome must be actively searched for in claudicant patients.

Early Changes in Postprandial Gallbladder Emptying in Morbidly Obese Patients Undergoing Roux-en-Y Gastric Bypass: Correlation with the Occurrence of Biliary Sludge and Gallstones

Gallstones have been frequently diagnosed after Roux-en-Y gastric bypass (RYGBP). Gallbladder stasis associated with duodenal exclusion may play a role in their pathogenesis. Gallbladder emptying was studied before and on the 30th and 31st postoperative days (POD) after RYGBP in 20 morbidly obese patients. Gallbladder volume after fasting and every 15 min during a 2-h period following administration of a standard liquid meal was determined by sonography. On the 31st POD, the meal was administered through the gastrostomy in order to promote its transit through the duodenum. Fasting volume (FV), maximum ejection fraction (Max EF), and residual volume (RV) were determined. Biliary sludge and calculi were investigated after 1 and 6 months, respectively. FV was 39.4 +/- 20.2 ml, 50.1 +/- 22.7 ml, and 47.9 +/- 23.4 ml, respectively, for the preoperative and two postoperative assessments (P = 0.09). RV was 7.6 +/- 8.7 ml, 25.1 +/- 20.0 ml, and 24.6 +/- 20.9 ml; and Max EF was 80.5 +/- 20.9%, 54.3 +/- 21.4%, and 50.5 +/- 29.0%, respectively, for the pre-, postoral, and postgastrostomy infusion measurements. There was only a significant difference between the preoperative value and the two postoperative values (P < 0.001). Biliary sludge was detected in 65% of the patients and 46% of them subsequently developed gallstones. Gallbladder emptying became significantly compromised after RYGBP. This impairment was unrelated to duodenal exclusion but it was associated with biliary sludge and stone formation.

Correlation between CD34(+) and exercise capacity, functional class, quality of life and norepinephrine in heart failure patients

Background: A previous study associated CD34(+) levels with NYHA functional class in heart failure patients. The aim of this study was to correlate CD34(+) levels to exercise capacity, functional class, quality of life and norepinephrine in heart failure patients. Methods: Twenty three sedentary patients (52 +/- 7 years, 78% male) answered the Minnesota Living with Heart Failure Questionnaire and rested for 20 minutes before an investigator collect a blood sample. After this, patients performed a cardiopulmonary exercise test to determine the heart rate at anaerobic and ventilatory threshold and oxygen consumption at peak effort, at anaerobic and ventilatory threshold. One other blood sample was collected during the peak effort to investigate the norepinephrine and CD34(+) levels. Results: Rest percentage of CD34(+) did not show correlation with: left ventricle ejection fraction (r = 0.03, p = 0.888), peakVO(2) (r = 0.32, p = 0.13), VO(2) at anaerobic threshold (VO(2)AT) (r = 0.03, p = 0.86), VO(2) at ventilatory threshold (VO(2)VT) (r = 0.36, p = 0.08), NYHA functional class (r = -0.2, p = 0.35), quality of life (Minnesota) (r = -0.17, p = 0.42). CD34(+) did not show correlation, either, with: peak VO(2) (r = 0.38, p = 0.06), VO(2)AT (r = 0.09, p = 0.65), VO(2)VT (r = 0.43, p = 0.4), NYHA functional class (r = -0.13, p = 0.54), quality of life (r = 0.00, p = 0.99). Conclusions: CD34(+) levels did not correlate with exercise capacity, functional class, quality of life and norepinephrine. Percentage of CD34(+) levels did not increase during the cardiopulmonary exercise test in heart failure patients. (Cardiol J 2009; 16, 5: 426-431)

Analyzing the connectivity between regions of interest: An approach based on cluster Granger causality for NRI data analysis

The identification, modeling, and analysis of interactions between nodes of neural systems in the human brain have become the aim of interest of many studies in neuroscience. The complex neural network structure and its correlations with brain functions have played a role in all areas of neuroscience, including the comprehension of cognitive and emotional processing. Indeed, understanding how information is stored, retrieved, processed, and transmitted is one of the ultimate challenges in brain research. In this context, in functional neuroimaging, connectivity analysis is a major tool for the exploration and characterization of the information flow between specialized brain regions. In most functional magnetic resonance imaging (fMRI) studies, connectivity analysis is carried out by first selecting regions of interest (ROI) and then calculating an average BOLD time series (across the voxels in each cluster). Some studies have shown that the average may not be a good choice and have suggested, as an alternative, the use of principal component analysis (PCA) to extract the principal eigen-time series from the ROI(s). In this paper, we introduce a novel approach called cluster Granger analysis (CGA) to study connectivity between ROIs. The main aim of this method was to employ multiple eigen-time series in each ROI to avoid temporal information loss during identification of Granger causality. Such information loss is inherent in averaging (e.g., to yield a single ""representative"" time series per ROI). This, in turn, may lead to a lack of power in detecting connections. The proposed approach is based on multivariate statistical analysis and integrates PCA and partial canonical correlation in a framework of Granger causality for clusters (sets) of time series. We also describe an algorithm for statistical significance testing based on bootstrapping. By using Monte Carlo simulations, we show that the proposed approach outperforms conventional Granger causality analysis (i.e., using representative time series extracted by signal averaging or first principal components estimation from ROIs). The usefulness of the CGA approach in real fMRI data is illustrated in an experiment using human faces expressing emotions. With this data set, the proposed approach suggested the presence of significantly more connections between the ROIs than were detected using a single representative time series in each ROI. (c) 2010 Elsevier Inc. All rights reserved.

Improved detection of incipient vascular changes by a biotechnological platform combining post mortem MRI in situ with neuropathology

The histopathological counterpart of white matter hyperintensities is a matter of debate. Methodological and ethical limitations have prevented this question to be elucidated. We want to introduce a protocol applying state-of-the-art methods in order to solve fundamental questions regarding the neuroimaging-neuropathological uncertainties comprising the most common white matter hyperintensities [WMHs] seen in aging. By this protocol, the correlation between signal features in in situ, post mortem MRI-derived methods, including DTI and MTR and quantitative and qualitative histopathology can be investigated. We are mainly interested in determining the precise neuroanatomical substrate of incipient WMHs. A major issue in this protocol is the exact co-registration of small lesion in a tridimensional coordinate system that compensates tissue deformations after histological processing. The protocol is based on four principles: post mortem MRI in situ performed in a short post mortem interval, minimal brain deformation during processing, thick serial histological sections and computer-assisted 3D reconstruction of the histological sections. This protocol will greatly facilitate a systematic study of the location, pathogenesis, clinical impact, prognosis and prevention of WMHs. (C) 2009 Elsevier B.V. All rights reserved.

Ligaments of the Posterior and Lateral Talar Processes: MRI and MR Arthrography of the Ankle and Posterior Subtalar Joint with Anatomic and Histologic Correlation

OBJECTIVE. MRI and combined ankle and posterior subtalar MR arthrography in cadavers were used to evaluate the ligaments of the posterior and lateral talar processes. Subsequent anatomic and histologic correlation was performed. MATERIALS AND METHODS. Ten cadaveric ankles were used. Routine radiography and MRI were initially performed. Ankle and posterior subtalar MR arthrography, followed by anatomic and histologic analysis, was then performed to allow better assessment of the ligaments of the lateral and posterior talar process. RESULTS. In all subjects, MR arthrography provided superior delineation of the articular and periarticular structures, as well as the ligaments. The lateral talocalcaneal and medial talocalcaneal ligaments were best seen in the axial and coronal planes, respectively. The axial plane was best for visualizing the fibulotalocalcaneal ligament, and the sagittal plane was best for evaluating the posterior talocalcaneal ligament. The anterior and posterior talofibular ligaments and the posterior tibiotalar ligament (superficial and deep portions) were best seen in the axial plane. Histologic analysis was correlated to anatomic sectioning and showed the attachment sites of these ligaments. CONCLUSION. Combined ankle and posterior subtalar MR arthrography enhances visualization of the ligaments attaching to the posterior and lateral talar processes, including the posterior, lateral, and medial talocalcaneal and fibulotalocalcaneal ligaments.

Peritumoral brain edema in benign meningiomas: correlation with clinical, radiologic, and surgical factors and possible role on recurrence

Background: Approximately 60% of meningiomas are associated with peritumoral edema. Various causative factors have been discussed in the literature. The objective of this study was to investigate the correlation of PTBE with clinical, radiologic, and surgical aspects and recurrence of meningiomas. Methods: Sixty-one patients with benign meningiomas were chosen for surgical treatment by the Group of Brain Tumors and Metastasis of the Department of Neurosurgery. All patients underwent complete surgical resection (Simpson grades I and 2), and those with atypical and malignant histopathologic grades were excluded. Tumors located in the cavernous sinus, tuberculum sellae, foramen magnum, ventricles, and petroclival region were excluded. Results: Edema extension had a positive correlation with the higher recurrence rates (P=.042) and with the presence of irregular margins (P<.011) on bivariate analysis. Meningiomas with larger edema sizes also showed correlation with large meningiomas (P=.035), and the ones with smaller edema sizes correlated with the tentorial location (P=.032). Multivariate analysis showed an association between PTBE and the presence of seizures (odds ratio, 3.469), large meningiomas (odds ratio, 15.977), and for each cubic centimeter added to its size, the risk of edema increased 1.082 times (odds ratio). Conclusion: Peritumoral brain edema may be related to the invading potential of meningiomas and may play a role in the recurrence potential of the tumor. As a consequence, it is reasonable to consider the presence of edema as an additional factor to be taken into account when mapping out strategies for the treatment of meningiomas. (C) 2008 Elsevier Inc. All rights reserved.

Assessment of factors that confound MRI and neuropathological correlation of human postmortem brain tissue

In spite of considerable technical advance in MRI techniques, the optical resolution of these methods are still limited. Consequently, the delineation of cytoarchitectonic fields based on probabilistic maps and brain volume changes, as well as small-scale changes seen in MRI scans need to be verified by neuronanatomical/neuropathological diagnostic tools. To attend the current interdisciplinary needs of the scientific community, brain banks have to broaden their scope in order to provide high quality tissue suitable for neuroimaging- neuropathology/anatomy correlation studies. The Brain Bank of the Brazilian Aging Brain Research Group (BBBABSG) of the University of Sao Paulo Medical School (USPMS) collaborates with researchers interested in neuroimaging-neuropathological correlation studies providing brains submitted to postmortem MRI in-situ. In this paper we describe and discuss the parameters established by the BBBABSG to select and to handle brains for fine-scale neuroimaging-neuropathological correlation studies, and to exclude inappropriate/unsuitable autopsy brains. We tried to assess the impact of the postmortem time and storage of the corpse on the quality of the MRI scans and to establish fixation protocols that are the most appropriate to these correlation studies. After investigation of a total of 36 brains, postmortem interval and low body temperature proved to be the main factors determining the quality of routine MRI protocols. Perfusion fixation of the brains after autopsy by mannitol 20% followed by formalin 20% was the best method for preserving the original brain shape and volume, and for allowing further routine and immunohistochemical staining. Taken to together, these parameters offer a methodological progress in screening and processing of human postmortem tissue in order to guarantee high quality material for unbiased correlation studies and to avoid expenditures by post-imaging analyses and histological processing of brain tissue.

Complex distal insertions of the tibialis posterior tendon: detailed anatomic and MR imaging investigation in cadavers

Purpose The purpose of this report was to demonstrate the normal complex insertional anatomy of the tibialis posterior tendon (TPT) in cadavers using magnetic resonance (MR) imaging with anatomic and histologic correlation. Material and methods Ten cadaveric ankles were used according to institutional guidelines. MR T1-weighted spin echo imaging was performed to demonstrate aspects of the complex anatomic distal insertions of the TPT in cadaveric specimens. Findings on MR imaging were correlated with those derived from anatomic and histologic study. Reults Generally, the TPT revealed a low signal in all MR images, except near the level of the medial malleolus, where the TPT suddenly changed direction and ""magic angle"" artifact could be observed. In five out of ten specimens (50%), a type I accessory navicular bone was found in the TPT. In all cases with a type I accessory navicular bone, the TPT had an altered signal in this area. Axial and coronal planes on MR imaging were the best in identifying the distal insertions of the TPT. A normal division of the TPT was observed just proximal to the insertion into the navicular bone in five specimens (100%) occurring at a maximum proximal distance from its attachment to the navicular bone of approximately 1.5 to 2 cm. In the other five specimens, in which a type I accessory navicular bone was present, the TPT directly inserted into the accessory bone and a slip less than 1.5 mm in thickness could be observed attaching to the medial aspect of the navicular bone (100%). Anatomic inspection confirmed the sites of the distal insertions of the components of the TPT. Conclusion MR imaging enabled detailed analysis of the complex distal insertions of the TPT as well as a better understanding of those features of its insertion that can simulate a lesion.