Publications by authors named "Ricardo Bernardi Soder"

23 Publications

  • Page 1 of 1

Neuroanatomical Correlates of Macrolinguistic Aspects in Narrative Discourse in Unilateral Left and Right Hemisphere Stroke: A Voxel-Based Morphometry Study.

J Speech Lang Hear Res 2021 Apr 12:1-16. Epub 2021 Apr 12.

Linguistics Department, School of Humanities, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil.

Background A growing body of literature has demonstrated the importance of discourse assessment in patients who suffered from brain injury, both in the left and right hemispheres, as discourse represents a key component of functional communication. However, little is known about the relationship between gray matter density and macrolinguistic processing. Purpose This study aimed to investigate this relationship in a group of participants with middle-low to low socioeconomic status. Method Twenty adults with unilateral left hemisphere ( = 10) or right hemisphere ( = 10) chronic ischemic stroke and 10 matched (age, education, and socioeconomic status) healthy controls produced three oral narratives based on sequential scenes. Voxel-based morphometry analysis was conducted using structural magnetic resonance imaging. Results Compared to healthy controls, the left hemisphere group showed cohesion impairments, whereas the right hemisphere group showed impairments in coherence and in producing macropropositions. Cohesion positively correlated with gray matter density in the right primary sensory area (PSA)/precentral gyrus and the pars opercularis. Coherence, narrativity, and index of lexical informativeness were positively associated with the left PSA/insula and the superior temporal gyrus. Macropropositions were mostly related to the left PSA/insula and superior temporal gyrus, left cingulate, and right primary motor area/insula. Discussion Overall, the present results suggest that both hemispheres are implicated in macrolinguistic processes in narrative discourse. Further studies including larger samples and with various socioeconomic status should be conducted. Supplemental Material https://doi.org/10.23641/asha.14347550.
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http://dx.doi.org/10.1044/2020_JSLHR-20-00500DOI Listing
April 2021

Cortical thickness and subcortical volume abnormalities in male crack-cocaine users.

Psychiatry Res Neuroimaging 2021 Apr 23;310:111232. Epub 2020 Nov 23.

Department of Neuroscience, Pontifical Catholic University of Rio Grande do Sul, 90619900, Porto Alegre, Brasil.

Crack-cocaine offers a higher risk of abuse than intranasal and intravenous use of cocaine. Yet, current treatments remain disappointing and our understanding of the mechanism of crack-cocaine neurotoxicity is still incomplete. Magnetic resonance images studies on brain changes of crack-cocaine addicts show divergent data. The present study investigated gray matter (GM) abnormalities in crack-cocaine dependents (n = 18) compared to healthy controls (n = 17). MRI data was analysed using FreeSurfer and voxel-based morphometry (VBM). FreeSurfer analysis showed that CD had decreased cortical thickness (CT) in the left inferior temporal cortex (lTC), left orbitofrontal cortex (lOFC) and left rostro frontal cortex (lRFC), enlargement in left inferior lateral ventricle, and smaller GM volume in right hippocampus and right ventral diencephalon. VBM analysis showed that CD had significantly decreased GM volume in left Putamen and left nucleus accumbens. Furthermore, we found a negative correlation between duration of crack-cocaine use and lTC CT. These results provide compelling evidence for GM abnormalities in CD and also suggest that duration of crack-cocaine use may be associated with CT alterations.
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http://dx.doi.org/10.1016/j.pscychresns.2020.111232DOI Listing
April 2021

Control of drop attacks with selective posterior callosotomy: Anatomical and prognostic data.

Epilepsy Res 2021 Mar 5;171:106544. Epub 2021 Jan 5.

Porto Alegre Epilepsy Surgery Program, Neurology and Neurosurgery Services, Hospital São Lucas, Brazil; School of Medicine, Pontificia Universidade Catolica do Rio Grande do Sul (PUCRS), Porto Alegre, Brazil. Electronic address:

Objective: In a previous proof of concept study, selective posterior callosotomy achieved similar degree of control of drop attacks as total callosotomy, while sparing prefrontal interconnectivity. The present study aims to confirm this finding in a larger cohort and to provide anatomical and prognostic data.

Methods: Fifty-one patients with refractory drop attacks had selective posterior callosotomy and prospective follow up for a mean of 6.4 years. Twenty-seven patients had post-operative magnetic resonance imaging (MRI) and 18 had tractography (DTI) of remaining callosal fibers. Pre and postoperative falls were quantified and correlated with demographic, clinical and imaging data.

Results: Mean monthly frequency of drop attacks had a 95 % reduction, from 297 before to 16 after the procedure. Forty- one patients (80 %) had either complete or greater than 90 % control of the epileptic falls. Age and duration of epilepsy at surgery correlated with outcome (p values, respectively, 0.042 and 0.005). Mean index of callosal section along the posterior-to-anterior axis was 53.5 %. Extending the posterior section anterior to the midbody of the corpus callosum did not correlate with seizure control (p 0.91), providing fibers interconnecting the primary motor (M1) and caudal supplementary motor areas (SMA) were sectioned. Only one patient had a notable surgical complication which resolved in two days.

Conclusions: This level III cohort study with objective outcome assessment confirms that selective posterior callosotomy is safe and effective to control epileptic falls. Younger patients with smaller duration of epilepsy have better results. A posterior section contemplating the splenium, isthmus and posterior half of the body (posterior midbody) seems sufficient to achieve complete or almost complete control of drop attacks.
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http://dx.doi.org/10.1016/j.eplepsyres.2020.106544DOI Listing
March 2021

Prevalence of patellar chondropathy on 3.0 T magnetic resonance imaging.

Radiol Bras 2020 Nov-Dec;53(6):375-380

Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil.

Objective: To establish the prevalence of patellar chondropathy using 3T magnetic resonance imaging (MRI) and to correlate the findings with individual features such as gender, age, and body mass index.

Materials And Methods: Data consisted of collecting 3T MRIs of patients' knees obtained between October 2016 and September 2017, comprising a period of 12 months. These MRIs were assessed by an experienced musculoskeletal radiologist who confirmed the presence of patellar chondropathy and, when present, rated the finding into the four grades ascribed by the International Cartilage Repair Society.

Results: A total number of 291 patients were assessed during the period with 389 MRI scans. Of those patients, 308 (79.2%) were diagnosed with patellar chondropathy, while 81 (20.8%) were not. Chondropathy was more prevalent in the female gender, in subjects above 40 years of age, and in obese patients. When the results were weighed in International Cartilage Repair Society classification, the milder grades (1 and 2) were seen in younger men (< 30 years of age), while the more severe grades (3 and 4) were mostly present in females, those above 40 years of age, and in obese patients.

Conclusion: There was a high prevalence of patellar chondropathy in patients who had undergone high-field knee MRIs (79.2%), being highest in the female gender and in subjects above 40 years of age. The most prevalent group was graded as 4 by the International Cartilage Repair Society classification.
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http://dx.doi.org/10.1590/0100-3984.2019.0105DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7720672PMC
December 2020

Review of neuroimaging findings in congenital Zika virus syndrome and its relation to the time of infection.

Neuroradiol J 2020 Apr 2;33(2):152-157. Epub 2020 Jan 2.

Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Brazil.

Background: Many original articles and case series have been published emphasizing the neuroimaging findings of congenital Zika virus (ZIKV) infection. The majority of these studies do not follow a neuroradiological methodology to describe malformations and brain abnormalities resulting from ZIKV infection. The cause-and-effect correlation between the gestational period of maternal infection and the severity of encephalic changes at birth has rarely been reported. A systematic literature review was conducted on the neuroimaging findings in children affected with microcephaly due to ZIKV.

Methods: PubMed, Cochrane Library and Web of Science were searched for full-text articles published up to July 2019. Duplicate entries were removed. Two independent reviewers performed a quality assessment of all the studies included.

Results: A total of 2214 publications were identified. Of these 2170 were excluded by analysis of titles and abstracts, resulting in the inclusion of only eight articles. Chi-square and Fisher's exact tests were performed with a 95% confidence interval to verify the statistically significant differences in the neuroradiological findings between the cases of ZIKV infection in the first or second trimester of gestation. The studies published so far have described image abnormalities at random, without utilizing any pre-established neuroradiological criteria, and imaging modalities with different sensitivity and accuracy have been used, which jeopardizes a reliable and adequate statistical analysis.

Conclusions: Neuroimaging abnormalities are much more prevalent and severe when the infection by ZIKV is contracted in the first or second trimester of pregnancy.
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http://dx.doi.org/10.1177/1971400919896264DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7140307PMC
April 2020

Posterior reversible encephalopathy syndrome (PRES): Is DWI a prognosis factor?

J Clin Neurosci 2020 Feb 24;72:357-359. Epub 2019 Dec 24.

Hospital São Lucas-PUCRS and Brain Institute (BraIns), Avenida Ipiranga, 6690 sala 220, Porto Alegre, Brazil.

Introduction: Posterior reversible encephalopathy syndrome is a clinicoradiologic entity with typical MR imaging showing a white matter vasogenic edema predominantly affecting the occipital and parietal lobes of the brain. The aim of this article is evaluated the importance of DWI as a prognosis factor in patients with PRES.

Materials And Methods: We reviewed data from 70 patients with PRES (35 with restricted DWI and 35 with no DWI abnormalities), that were admitted to Hospital São Lucas-PUCRS. These two groups were evaluated in age, sex, previous diseases and past medical history, use of medications, the neurologic manifestations, the highest blood pressure during the neurologic presentation and the highest creatinine during the period of observation.

Results: Evaluating 70 patients with PRES with a mean age of 25.4 years old (range from 2 to 74 years old; 55 female and 15 male) we identified 35 cases were brain MRI presents with restricted DWI. Restricted DWI was associated with higher mortality in 90 days (14.2% vs 0.0%; p: 0.027).

Conclusions: Few articles present new data that will help clinicians in therapeutic decisions or that modify the knowledge of this syndrome. We suggested that restricted DWI is associated with a worst prognosis in PRES.
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http://dx.doi.org/10.1016/j.jocn.2019.12.023DOI Listing
February 2020

Violence and Latin-American preadolescents: A study of social brain function and cortisol levels.

Dev Sci 2019 09 20;22(5):e12799. Epub 2019 Feb 20.

PUCRS, Brain Institute of Rio Grande do Sul (BraIns), Porto Alegre, Brazil.

The present study investigated exposure to violence and its association with brain function and hair cortisol concentrations in Latin-American preadolescents. Self-reported victimization scores (JVQ-R2), brain imaging (fMRI) indices for a social cognition task (the 'eyes test'), and hair cortisol concentrations were investigated, for the first time, in this population. The eyes test is based on two conditions: attributing mental state or sex to pictures of pairs of eyes (Baron-Cohen, Wheelwright, Hill, Raste, & Plumb, 2001). The results showed an association among higher victimization scores and (a) less activation of posterior temporoparietal right-hemisphere areas, in the mental state condition only (including right temporal sulcus and fusiform gyrus); (b) higher functional connectivity indices for the Amygdala and Right Fusiform Gyrus (RFFG) pair of brain regions, also in the mental state condition only; (c) higher hair cortisol concentrations. The results suggest more exposure to violence is associated with significant differences in brain function and connectivity. A putative mechanism of less activation in posterior right-hemisphere regions and of synchronized Amygdala: RFFG time series was identified in the mental state condition only. The results also suggest measurable effects of exposure to violence in hair cortisol concentrations, which contribute to the reliability of self-reported scores by young adolescents. The findings are discussed in light of the effects of exposure to violence on brain function and on social-cognitive development in the adolescent brain. A video abstract of this article can be viewed at https://www.youtube.com/watch?v=qHcXq7Y9PBk.
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http://dx.doi.org/10.1111/desc.12799DOI Listing
September 2019

Microsurgical Clipping of Low-Riding Basilar Bifurcation Aneurysm.

World Neurosurg 2018 Dec 31. Epub 2018 Dec 31.

Department of Neurosurgery, Universidade Federal de Sao Paulo, São Paulo-SP, Brazil. Postal adress: Doutor Diogo de Faria, 775, conjunto 91, 04037-002, São Paulo-SP, Brazil.

Basilar bifurcation is a challenging site for aneurysm clipping. Anatomical factors such as size and projection of the aneurysm, distance between the aneurysm neck and the dorsum sellae, and location of the basilar bifurcation contribute to surgical complexity. Endovascular treatment has been used more frequently than microsurgical clipping, especially for posterior circulation lesions. Thus, the upcoming generation of neurosurgeons will have increasingly less access to the microsurgical treatment of such lesions. We present the case of a 45-year-old female patient who presented sudden mental confusion characterized by disorientation in time, space, and person. Investigative acute cerebral magnetic resonance imaging revealed diffusion restriction in the left posterior cerebral and superior cerebellar arteries. The clinical and cardiologic investigations revealed no abnormalities, but computed tomographic angiography and digital arteriography revealed a low-riding basilar bifurcation aneurysm and a very small aneurysm in the right internal carotid artery. The wide neck precluded coil embolization, and the appropriate stent was not covered by our public health insurance. Considering the young age, surgical treatment was proposed. Microsurgical clipping was performed using the right pre-temporal approach. In this two-dimensional video, we show the steps to reach the low-riding basilar bifurcation aneurysm neck. The positioning, transzygomatic pterional craniotomy, intradural anterior clinoidectomy, and posterior cavernous sinus opening are shown, and the surrounding anatomy is illustrated.
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http://dx.doi.org/10.1016/j.wneu.2018.12.093DOI Listing
December 2018

Quantification of Abdominal Fat in Obese and Healthy Adolescents Using 3 Tesla Magnetic Resonance Imaging and Free Software for Image Analysis.

PLoS One 2017 27;12(1):e0167625. Epub 2017 Jan 27.

Imaging Center Coordinator, Brain Institute (InsCer), PUCRS, Porto Alegre, Rio Grande do Sul, Brazil.

Background And Aims: Computed tomography, which uses ionizing radiation and expensive software packages for analysis of scans, can be used to quantify abdominal fat. The objective of this study is to measure abdominal fat with 3T MRI using free software for image analysis and to correlate these findings with anthropometric and laboratory parameters in adolescents.

Methods: This prospective observational study included 24 overweight/obese and 33 healthy adolescents (mean age 16.55 years). All participants underwent abdominal MRI exams. Visceral and subcutaneous fat area and percentage were correlated with anthropometric parameters, lipid profile, glucose metabolism, and insulin resistance. Student's t test and Mann-Whitney's test was applied. Pearson's chi-square test was used to compare proportions. To determine associations Pearson's linear correlation or Spearman's correlation were used.

Results: In both groups, waist circumference (WC) was associated with visceral fat area (P = 0.001 and P = 0.01 respectively), and triglycerides were associated with fat percentage (P = 0.046 and P = 0.071 respectively). In obese individuals, total cholesterol/HDL ratio was associated with visceral fat area (P = 0.03) and percentage (P = 0.09), and insulin and HOMA-IR were associated with visceral fat area (P = 0.001) and percentage (P = 0.005).

Conclusions: 3T MRI can provide reliable and good quality images for quantification of visceral and subcutaneous fat by using a free software package. The results demonstrate that WC is a good predictor of visceral fat in obese adolescents and visceral fat area is associated with total cholesterol/HDL ratio, insulin and HOMA-IR.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0167625PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5271344PMC
August 2017

Selective posterior callosotomy for drop attacks: A new approach sparing prefrontal connectivity.

Neurology 2016 Nov 12;87(19):1968-1974. Epub 2016 Oct 12.

From the Porto Alegre Epilepsy Surgery Program, Neurology and Neurosurgery Services, Hospital São Lucas (E.P., W.A.M., N.A., M.P., T.M.F., J.C.d.C., M.H., A.P.), The Brain Institute (M.P., R.B.S., J.C.d.C.), and Faculty of Medicine (E.P., N.A., M.P., L.P., R.S., C.S., J.R.H., R.B.S., J.C.d.C., M.H., A.P.), Pontificia Universidade Catolica do Rio Grande do Sul, Porto Alegre, Brazil; and Department of Neurosurgery (T.T.), Universitaire Ziekenhuizen Leuven, Belgium.

Objective: To evaluate a novel approach to control epileptic drop attacks through a selective posterior callosotomy, sparing all prefrontal interconnectivity.

Methods: Thirty-six patients with refractory drop attacks had selective posterior callosotomy and prospective follow-up for >4 years. Falls, episodes of aggressive behavior, and IQ were quantified. Autonomy in activities of daily living, axial tonus, and speech generated a functional score ranging from 0 to 13. Subjective effect on patient well-being and caregiver burden was also assessed.

Results: Median monthly frequency of drop attacks decreased from 150 to 0.5. Thirty patients (83%) achieved either complete or >90% control of the falls. Need for constant supervision decreased from 90% to 36% of patients. All had estimated IQ below 85. Median functional score increased from 7 to 10 (p = 0.03). No patient had decrease in speech fluency or hemiparesis. Caregivers rated the effect of the procedure as excellent in 40% and as having greatly improved functioning in another 50%. Clinical, EEG, imaging, and cognitive variables did not correlate with outcome.

Conclusions: This cohort study with objective outcome assessment suggests that selective posterior callosotomy is safe and effective to control drop attacks, with functional and behavioral gains in patients with intellectual disability. Results are comparable to historical series of total callosotomy and suggest that anterior callosal fibers may be spared.

Classification Of Evidence: This study provides Class III evidence that selective posterior callosotomy reduces falls in patients with epileptic drop attacks.
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http://dx.doi.org/10.1212/WNL.0000000000003307DOI Listing
November 2016

Hypertrophic olivary degeneration: unveiling the triangle of Guillain-Mollaret.

Arq Neuropsiquiatr 2016 May;74(5):426-7

Departamento de Neurologia, Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brasil.

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http://dx.doi.org/10.1590/0004-282X20160049DOI Listing
May 2016

Posterior Reversible Encephalopathy Syndrome: Clinical Differences in Patients with Exclusive Involvement of Posterior Circulation Compared to Anterior or Global Involvement.

J Stroke Cerebrovasc Dis 2016 Jul 18;25(7):1776-1780. Epub 2016 Apr 18.

Neurology Department of Hospital São Lucas and Instituto do Cérebro (Inscer), Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, Rio Grande do Sul, Brazil.

Introduction: Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiologic syndrome not yet fully understood and characterized by transient neurologic symptoms in addition to typical radiological findings. There are only a few articles that describe the clinical differences between patients with PRES that involve carotid and vertebrobasilar circulations. Our study aims to further evaluate the differences between predominantly anterior and posterior circulation PRES.

Methods: We review 54 patients who had received the diagnosis of PRES from 2009 to 2015. The patients were divided into 2 groups: (1) exclusively in posterior zones; and (2) anterior plus posterior zones or exclusively anterior zones. Several clinical characteristics were evaluated, including the following: age, sex, previous diseases, the neurologic manifestations, the highest blood pressure in the first 48 hours of presentation, highest creatinine level during symptoms, and the neuroimaging alterations in brain magnetic resonance imaging.

Results: Mean age at diagnosis was 28.5 years old (9 men and 45 women) and mean systolic blood pressure among patients with lesions only in posterior zones was 162.1 mmHg compared to 179.2 mmHg in the anterior circulation. The most common symptoms in the 2 groups were headache and visual disturbances.

Discussion: PRES may have several radiological features. A higher blood pressure seems to be 1 of the factors responsible for developing widespread PRES, with involvement of carotid vascular territory. This clinical-radiological difference probably occurs because of the larger number of autonomic receptors in the carotid artery in comparison to the vertebral-basilar system.
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http://dx.doi.org/10.1016/j.jstrokecerebrovasdis.2016.03.042DOI Listing
July 2016

Microcephaly and Zika virus: a clinical and epidemiological analysis of the current outbreak in Brazil.

J Pediatr (Rio J) 2016 May-Jun;92(3):230-40. Epub 2016 Apr 15.

School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS), Porto Alegre, RS, Brazil; Zika-Team, Instituto do Cérebro do Rio Grande do Sul (Inscer), Porto Alegre, RS, Brazil.

Objective: This study aimed to critically review the literature available regarding the Zika virus outbreak in Brazil and its possible association with microcephaly cases.

Sources: Experts from Instituto do Cérebro do Rio Grande do Sul performed a critical (nonsystematic) literature review regarding different aspects of the Zika virus outbreak in Brazil, such as transmission, epidemiology, diagnostic criteria, and its possible association with the increase of microcephaly reports. The PubMed search using the key word "Zika virus" in February 2016 yielded 151 articles. The manuscripts were reviewed, as well as all publications/guidelines from the Brazilian Ministry of Health, World Health Organization and Centers for Disease Control and Prevention (CDC - United States).

Summary Of Findings: Epidemiological data suggest a temporal association between the increased number of microcephaly notifications in Brazil and outbreak of Zika virus, primarily in the Brazil's Northeast. It has been previously documented that many different viruses might cause congenital acquired microcephaly. Still there is no consensus on the best curve to measure cephalic circumference, specifically in preterm neonates. Conflicting opinions regarding the diagnosis of microcephaly (below 2 or 3 standard deviations) that should be used for the notifications were also found in the literature.

Conclusion: The development of diagnostic techniques that confirm a cause-effect association and studies regarding the physiopathology of the central nervous system impairment should be prioritized. It is also necessary to strictly define the criteria for the diagnosis of microcephaly to identify cases that should undergo an etiological investigation.
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http://dx.doi.org/10.1016/j.jped.2016.02.009DOI Listing
February 2017

Accuracy of computer-aided ultrasound as compared with magnetic resonance imaging in the evaluation of nonalcoholic fatty liver disease in obese and eutrophic adolescents.

Radiol Bras 2015 Jul-Aug;48(4):225-32

PhD, Coordinator for the Imaging Center of Instituto do Cérebro - Pontifícia Universidade Católica do Rio Grande do Sul (InsCer-PUCRS), Porto Alegre, RS, Brazil.

Objective: To compare the accuracy of computer-aided ultrasound (US) and magnetic resonance imaging (MRI) by means of hepatorenal gradient analysis in the evaluation of nonalcoholic fatty liver disease (NAFLD) in adolescents.

Materials And Methods: This prospective, cross-sectional study evaluated 50 adolescents (aged 11-17 years), including 24 obese and 26 eutrophic individuals. All adolescents underwent computer-aided US, MRI, laboratory tests, and anthropometric evaluation. Sensitivity, specificity, positive and negative predictive values and accuracy were evaluated for both imaging methods, with subsequent generation of the receiver operating characteristic (ROC) curve and calculation of the area under the ROC curve to determine the most appropriate cutoff point for the hepatorenal gradient in order to predict the degree of steatosis, utilizing MRI results as the gold-standard.

Results: The obese group included 29.2% girls and 70.8% boys, and the eutrophic group, 69.2% girls and 30.8% boys. The prevalence of NAFLD corresponded to 19.2% for the eutrophic group and 83% for the obese group. The ROC curve generated for the hepatorenal gradient with a cutoff point of 13 presented 100% sensitivity and 100% specificity. As the same cutoff point was considered for the eutrophic group, false-positive results were observed in 9.5% of cases (90.5% specificity) and false-negative results in 0% (100% sensitivity).

Conclusion: Computer-aided US with hepatorenal gradient calculation is a simple and noninvasive technique for semiquantitative evaluation of hepatic echogenicity and could be useful in the follow-up of adolescents with NAFLD, population screening for this disease as well as for clinical studies.
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http://dx.doi.org/10.1590/0100-3984.2014.0074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4567361PMC
September 2015

Resting state executive control network adaptations in amnestic mild cognitive impairment.

J Alzheimers Dis 2014 ;40(4):993-1004

Translational Neuroimaging Laboratory, Douglas Hospital, McGill University, Montreal, QC, Canada McGill Centre for Studies in Aging (MCSA), McGill University, Montreal, QC, Canada McConnell Brain Imaging Centre, Montreal Neurological Institute, Montreal, QC, Canada.

Executive dysfunction is frequently associated with episodic memory decline in amnestic mild cognitive impairment (aMCI) patients. Resting state executive control network (RS-ECN) represents a novel approach to interrogate the integrity of brain areas underlying executive dysfunction. The present study aims to investigate RS-ECN in aMCI and examine a possible link between changes in brain functional connectivity and declines in executive function. aMCI individuals (n = 13) and healthy subjects (n = 16) underwent cognitive assessment including executive function and high field functional magnetic resonance imaging. Individual RS-ECN maps were estimated using a seed-based cross-correlation method. Between groups RS-ECN functional connectivity comparison was assessed using voxel-wise statistic parametric mapping. aMCI individuals had reduced RS-ECN connectivity in the anterior cingulate cortex (ACC) and dorsal lateral prefrontal cortex (DLPFC), bilaterally. In contrast, aMCI showed increased connectivity in ventral lateral and anterior prefrontal cortex, bilaterally. Connectivity strength was associated with executive function in the ACC (r = 0.6213, p = 0.023) and right DLPFC (r = 0.6454, p = 0.017). Coexistence between connectivity declines and recruitment of brain regions outside the RS-ECN as reported here fits a brain reserve conceptual framework in which brain networks undergo remodeling in aMCI individuals.
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http://dx.doi.org/10.3233/JAD-131574DOI Listing
January 2015

MRI-diagnosed nonalcoholic fatty liver disease is correlated to insulin resistance in adolescents.

Acad Radiol 2013 Nov;20(11):1436-42

Department of Radiology, Hospital Sao Lucas Hospital, Pontifícia Universidade Católica do Rio Grande do Sul, 90470320 Porto Alegre, Rio Grande do Sul, Brazil.

Rationale And Objectives: To evaluate the presence of nonalcoholic fatty liver disease (NAFLD) in eutrophic and obese adolescents with magnetic resonance imaging (MRI) and its relationship to insulin resistance and other potential biomarkers.

Materials And Methods: A total of 50 adolescents (aged 11-17 years), including 24 obese and 26 eutrophic adolescents, were evaluated using MRI exams for NAFLD diagnosis. Blood analysis was performed to measure glucose, insulin, total cholesterol, high-density lipoprotein cholesterol, triglycerides, fibrinogen, aminotransferases, alkaline phosphatase, gamma-gt, and C-reactive protein. The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) index was also calculated. Laboratory test results and anthropometric assessment were statistically analyzed to determine potential correlation with NAFLD prevalence.

Results: The prevalence of NAFLD among the obese was significantly higher (83.3%; CI 95: 64.5-94.5%) than that of the eutrophic group (19.2%; CI 95: 7.4-37.6%). In multivariate analysis, only HOMA-IR was an independent risk factor for diagnosis NAFLD using MRI. Compared to eutrophic adolescents, the obese adolescents had significantly higher levels for all parameters measured except for total and high-density lipoprotein cholesterol, which were significantly lower.

Conclusion: The prevalence of NAFLD was 19.2% among eutrophic patients and 83.3% among obese patients. Only HOMA-IR was determined to be an independent risk factor for NAFLD.
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http://dx.doi.org/10.1016/j.acra.2013.08.016DOI Listing
November 2013

Cow's milk allergy: color Doppler ultrasound findings in infants with hematochezia.

J Pediatr (Rio J) 2013 Nov-Dec;89(6):554-8. Epub 2013 Sep 12.

Department of Pediatric Gastroenterology, Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil. Electronic address:

Objective: ultrasound (US) has been an important diagnostic tool to identify several causes of gastrointestinal bleeding. Infants with cow's milk allergy (CMA) may present hematochezia and the confirmation of the diagnosis can be difficult. The aim of this study is to describe grayscale and color Doppler ultrasound findings in patients with CMA.

Methods: we retrospectively studied 13 infants with CMA. All infants presented severe hematochezia and abdominal pain. All underwent an US study with the diagnosis of allergic colitis. This diagnosis was based on clinical findings, recovery after infant or mother exclusion diets in the case of exclusive breastfeeding and positive oral challenge test.

Results: the mean age ranged from 1 to 6 months (mean=3.53). Seven out of 13 infants (53.8%) had grayscale and color Doppler sonographic repeated after exclusion diet. Twelve out of 13 (92,3%) showed abnormalities at US and CDUS at beginning. The positive findings suggesting colitis were thickened bowel walls and increased vascularity, especially in the descending and sigmoid colon. Colonoscopy and histopathological findings were compatible with allergic colitis. After a diet change the 13 infants recovered and their oral challenge tests were positive.

Conclusion: Doppler US may be very useful in diagnosing secondary colitis, such as CMA, and to exclude several other abdominal diseases that can emulate this disease.
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http://dx.doi.org/10.1016/j.jped.2013.03.021DOI Listing
September 2015

Posterior Reversible Encephalopathy Syndrome Associated with FOLFOX Chemotherapy.

Case Rep Oncol Med 2013 27;2013:306983. Epub 2013 Feb 27.

Hospital São Lucas/Instituto do Cérebro (Inscer), Pontificia Universidade Católica do Rio Grande do Sul (PUCRS), Avenida Ipiranga 6690, 90610-000 Porto Alegre, RS, Brazil.

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiologic entity characterized by headaches, altered mental status, seizures, visual loss, and characteristic imaging pattern in brain MRI. The cause of PRES is not yet understood. We report a case of a 27-year-old woman that developed PRES after the use of FOLFOX 5 (oxaliplatin/5-Fluoracil/Leucovorin) chemotherapy for a colorectal cancer.
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http://dx.doi.org/10.1155/2013/306983DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3600224PMC
March 2013

Gray-scale and color Doppler ultrasound findings in children with cow's milk allergy.

AJR Am J Roentgenol 2011 Jun;196(6):W817-22

Serviço de Gastroenterologia Pediátrica, Hospital São Lucas da Pontifícia Universidade Católica do Rio Grande do Sul, Avenue Ipiranga 6690, Porto Alegre, RS 90610-000, Brazil.

Objective: The objective of our study was to evaluate whether gray-scale and color Doppler ultrasound can reveal intestinal inflammation in infants with cow's milk allergy (CMA).

Subjects And Methods: This study evaluated the clinical findings and grayscale and color Doppler sonograms of 34 infants. Seventeen 0- to 6-month-old infants with suspected CMA and 17 nonsymptomatic age-matched infants were evaluated by a blinded investigator who determined the percentage of vessel density and the thickness of different parts of the bowel. Clinical and sonographic variables were evaluated in the same regions of bowel considering three time points: presentation, after 4 weeks of feeding only amino acid-based formula, and after challenge test. Likelihood ratios and receiver operating characteristic (ROC) curves were used to define a cutoff point for vascular density percentage.

Results: The difference in the percentage of vessel density between patients with CMA (mean, 28.1%) and control infants (mean, 7.77%) was statistically significant. ROC analysis showed that a cutoff point of 18.7% could differentiate between patients with CMA and control infants with 81.8% sensitivity and 94.1% specificity. The area under the curve was 0.941. We found statistical differences in bowel wall thickness between control patients and patients with CMA.

Conclusion: There was a significant increase in vessel density in infants younger than 6 months with CMA compared with healthy age-matched infants. The most appropriate cutoff point for vessel density was 18.7%. The results of this study suggest that Doppler ultrasound could be used as a screening tool to diagnose CMA.
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http://dx.doi.org/10.2214/AJR.10.5840DOI Listing
June 2011

MRI of the knee in asymptomatic adolescent swimmers: a controlled study.

Br J Sports Med 2012 Mar 3;46(4):268-72. Epub 2011 Apr 3.

Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, RS, Brazil.

Background: Swimming is a widespread sporting activity generally regarded as an ideal form of exercise, which has little or no impact on the knees. However, overuse or repetitive microtrauma injuries may often affect the knee joint of young competitive swimmers. These early lesions are frequently asymptomatic for a considerable period of time before causing discomfort or joint pain.

Purpose: The aim of the present study is to use MRI to evaluate the knee joints of asymptomatic young elite swimmers and to compare them with age- and sex-matched controls who do not practice any impact sports regularly.

Study Design: Cross-sectional case-control study.

Material And Methods: The authors performed a cross-sectional controlled study to evaluate 54 knees of 27 asymptomatic male adolescents aged 14-15 years, paired by age and weight. Participants were divided in two groups: 13 elite swimmers and 14 control adolescents. The authors performed all the exams using a 0.35-T open-field MRI unit and evaluated by two experienced radiologists blinded to study groups. The images were evaluated to detect the presence or absence of abnormalities.

Results: One or more imaging abnormalities were detected in 18 knees in the group of swimmers (69.2%; p=0.013). The most prevalent findings in the athletes were infrapatellar fat pad edema (53.8%; p=0.049), followed by bone marrow edema (26.9%; p=0.022), edema of prefemoral fat pad (19%; p=0.022) and joint effusion (15.3%; p=0.047).

Conclusion: Significantly more MRI abnormalities were found in the knee joints of asymptomatic adolescent elite swimmers. This high prevalence of positive imaging findings in swimmers may correspond to benign changes or preclinical lesions, which should be evaluated in a follow-up study.
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http://dx.doi.org/10.1136/bjsm.2010.083345DOI Listing
March 2012

MRI of the knee joint in asymptomatic adolescent soccer players: a controlled study.

AJR Am J Roentgenol 2011 Jan;196(1):W61-5

Graduate School of Medicine, Pontifícia Universidade Católica do Rio, Grande do Sul, Avenida Ipiranga, 6690, Porto Alegre, RS, Brazil, CEP 90610-000.

Objective: The knee is the joint that is most frequently injured in boys 12-15 years old who practice soccer, and MRI is an accurate method of diagnosing sports-related injuries. The objective of this cross-sectional case-control study was to evaluate the knees of asymptomatic adolescent soccer players using open MRI.

Subjects And Methods: We evaluated 56 knees of 28 asymptomatic male adolescents 14-15 years old. Participants were divided into two groups and paired by age and weight: soccer players (28 knees) and control subjects (28 knees). All the examinations were performed using a 0.35-T open-field MRI unit and were evaluated by two experienced radiologists blinded to study groups. Bone marrow signal, articular cartilage, meniscus, and fat pad abnormalities and the amount of fluid were assessed.

Results: In the group of soccer players, 18 knees (64.3%) had one or more MRI abnormalities, whereas in the control group nine knees (32.1%) had at least one MRI abnormality (p = 0.03). The prevalence of bone marrow edema was much greater in the group of soccer players (14 knees, 50%), whereas the same abnormality was found in only one knee (3.6%) in the control group (p = 0.0001). Other abnormalities that were not statistically significant with regard to study group were also found in the two groups: infrapatellar fat pad edema, popliteal cysts, and ganglion cysts.

Conclusion: Bone marrow edema is a prevalent abnormal finding on MRI scans of knees of asymptomatic adolescent soccer players. MRI findings should be interpreted cautiously and in close correlation with clinical findings.
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http://dx.doi.org/10.2214/AJR.10.4928DOI Listing
January 2011

Spine abnormalities depicted by magnetic resonance imaging in adolescent rowers.

Am J Sports Med 2011 Feb 2;39(2):392-7. Epub 2010 Oct 2.

Graduate School of Medicine, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.

Background: Most lesions of the spine of athletes, which often are detected incidentally, do not cause important symptoms or make the athletes discontinue their physical activities. To better understand the significance of these lesions, new imaging studies have been conducted with asymptomatic athletes in several sports, aiming to detect potentially deleterious and disabling abnormalities.

Purpose: To compare the magnetic resonance imaging (MRI) lumbar spine findings in a group of asymptomatic adolescent rowers and in a control group of adolescents matched according to age and sex who do not practice any regular physical activity.

Study Design: Cohort study (prevalence); Level of evidence, 3.

Methods: Our study evaluated 44 asymptomatic adolescent boys distributed in 2 groups of 22 rowers and 22 control subjects. All the examinations were performed using a 0.35-T open-field MRI unit and evaluated by 2 experienced radiologists blinded to the study groups. Each MRI scan was analyzed for the presence of disc degeneration/desiccation, herniated or bulging disc, pars interarticularis stress reaction, and spondylolysis. The Student t test and the Fisher exact test were used for statistical analyses.

Results: Nine rowers (40.9%) had at least 1 abnormality detected by MRI in the lumbar spine, whereas only 2 participants (9.1%) in the control group had at least 1 MRI abnormality (P = .03). Seven disc changes (31.8%) and 6 pars abnormalities (27.3%) were found in the group of elite rowers. In the control group, 3 disc changes (13.6%) and no pars abnormalities were found in the MR scans. The comparison between groups showed statistically significant differences in stress reaction of the pars articularis.

Conclusion: Disc disease and pars interarticularis stress reaction are prevalent abnormalities of the lumbar spine of high-performance rowers.
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http://dx.doi.org/10.1177/0363546510381365DOI Listing
February 2011

Computer-assisted ultrasound analysis of liver echogenicity in obese and normal-weight children.

AJR Am J Roentgenol 2009 May;192(5):W201-5

Department of Radiology, Hospital São Lucas, Pontifícia Universidade Católica do Rio Grande do Sol, Av. Ipiranga 6690, Porto Alegre, RS, Brazil.

Objective: No simple computer-assisted method for assessing liver echogenicity has been developed to date. This study describes an accessible and reproducible computer-assisted method for measuring liver echogenicity in obese (body mass index [BMI] >/= 97th percentile) and normal-weight (BMI from 25th to 75th percentile) children and correlates the results with laboratory test results.

Subjects And Methods: Twenty-two children (age range, 6-11 years) were assigned to one of two groups of 11 children each and paired by sex and age. All children underwent ultrasound, anthropometric measurements, and laboratory tests. A hepatorenal index was calculated using software to analyze the difference in echogenicity between the liver parenchyma and kidney cortex. The Student's t test and Mann-Whitney U test were used for statistical analyses.

Results: The hepatorenal index was statistically different between the obese and normal-weight children (33.9 +/- 6.6 vs 14.1 +/- 6.1, p < 0.001). The analysis of laboratory tests of obese and normal-weight children revealed statistically significant differences in the values of glucose (p = 0.034), insulin (p = 0.008), triglycerides (p = 0.036), uric acid (p < 0.001), and alkaline phosphatase (p = 0.045).

Conclusion: Computer-assisted analysis of ultrasound liver echogenicity using the software is an accessible, reproducible, and easy-to-use diagnostic tool for calculating the hepatorenal index. This tool may be used for follow-up and control in the treatment of fat infiltration in the liver of obese children.
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http://dx.doi.org/10.2214/AJR.08.2061DOI Listing
May 2009