Claudia Ferreira Leite - Academia.edu (original) (raw)

Papers by Claudia Ferreira Leite

AJNR. American journal of neuroradiology, 2006

We describe how proton MR spectroscopy ((1)H-MR spectroscopy) was useful in elucidating the diagn... more We describe how proton MR spectroscopy ((1)H-MR spectroscopy) was useful in elucidating the diagnosis of galactosemia in an undiagnosed 6-month-old infant. In vivo (1)H-MR spectroscopy of the brain showed a doublet at 3.7 parts per million, which was identified as galactitol (Gal-ol) by in vitro (1)H-MR spectroscopy of the urine. Galactosemia was subsequently confirmed by laboratory tests and treatment was initiated. A follow-up brain MR imaging and (1)H-MR spectroscopy study revealed resolution of white matter lesions and disappearance of Gal-ol peaks.

Singapore medical journal, 2000

A 2-year-old Brazilian boy presented with bilateral leg weakness and constipation, followed by de... more A 2-year-old Brazilian boy presented with bilateral leg weakness and constipation, followed by development of progressive paraparesis and bladder dysfunction. Neurological examination revealed flaccid paraparesis. Blood tests and CSF analysis showed eosinophilia. The MR examination revealed a spinal cord mass extending from T9 to L1 levels, with a heterogeneously-enhancing solid component and a cystic component. Stool tests for Schistosoma mansoni eggs were positive. The patient underwent surgery, the intramedullary mass was partially resected, and the diagnosis of spinal cord infection by Schistosoma mansoni was confirmed. After surgery, the patient was treated with praziquantel and oxamniquine. He was discharged with partial improvement of the lower extremity weakness and bowel/bladder function. The clinical and imaging features of spinal cord schistosomiasis are reviewed.

AJNR. American journal of neuroradiology, 1998

Extensive MR signal change in the craniad spinal cord parenchyma was found to be an ancillary sig... more Extensive MR signal change in the craniad spinal cord parenchyma was found to be an ancillary sign of disease advancement in three patients with clinically progressive posttraumatic syringomyelia. This craniad margin of parenchymal spinal cord T2 hyperintensity resolved after cystoperitoneal shunt placement. There was a concomittant reduction or disappearance of the cyst in each instance, a halt in the progression of neurologic deficit, and some reversal of signs and symptoms.

Translational psychiatry, 2014

Various functional magnetic resonance imaging studies addressed the effects of antidepressant dru... more Various functional magnetic resonance imaging studies addressed the effects of antidepressant drugs on brain functioning in healthy subjects; however, none specifically investigated positive mood changes to antidepressant drug. Sixteen subjects with no personal or family history of psychiatric disorders were selected from an ongoing 4-week open trial of small doses of clomipramine. Follow-up interviews documented clear positive treatment effects in six subjects, with reduced irritability and tension in social interactions, improved decision making, higher self-confidence and brighter mood. These subjects were then included in a placebo-controlled confirmatory trial and were scanned immediately after 4 weeks of clomipramine use and again 4 weeks after the last dose of clomipramine. The functional magnetic resonance imaging (fMRI) scans were run during emotion-eliciting stimuli. Repeated-measures analysis of variance of brain activity patterns showed significant interactions between g...

Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) is a non-invasive method that provides us... more Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) is a non-invasive method that provides useful information about metabolism and phosphoenergetic status in both physiologic and pathologic conditions of the human brain. With the progressive advances in magnetic resonance imaging (MRI) technology, particularly with higher magnetic field strengths, 31P-MRS has been more easily implemented and more readily available in the past few years, which has increasingly extended its access and favored its use in different research fields. However, the current knowledge about this advanced neuroimaging modality is still scarce and fragmented in the literature. Hence, in order to contribute to future researches and to shorten the gap between neuroscientific studies and common clinical routines, we present a comprehensive review about the basic technical aspects and biomedical applications of 31P-MRS.

Revista do Hospital das Clínicas, 2002

This is a double-blind, placebo-controlled study of the efficacy, safety, and tolerability of sib... more This is a double-blind, placebo-controlled study of the efficacy, safety, and tolerability of sibutramine in the management of obese patients for a 6-month period. METHOD: Sixty-one obese patients (BMI >30, <40 kg/m2), aged 18-65 years were evaluated. In the first phase of the study (30 days), the patients were given a placebo. We monitored compliance with a low-calorie diet (1200 kcal/day) and to the placebo. In the next stage, the double-blind phase (6 months), we compared placebo and sibutramine (10 mg/day). The criteria for evaluating efficacy were weight loss, reduction in body mass index (BMI), and abdominal and hip circumferences. Tolerability was assessed based on reported side effects, variation in arterial blood pressure and heart rate, metabolic profile (fasting glucose, total cholesterol and its fractions, and triglycerides), laboratory tests (renal and hepatic functions), and flow Doppler echocardiogram. RESULTS: We observed a greater weight loss (7.3 kg, 8% vs 2....

The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP), Jan 31, 2014

The hippocampus has been highly implicated in the pathophysiology of bipolar disorder (BD). Never... more The hippocampus has been highly implicated in the pathophysiology of bipolar disorder (BD). Nevertheless, no study has longitudinally evaluated hippocampal metabolite levels in bipolar depression under treatment with lithium. Nineteen medication-free BD patients (78.9% treatment-naïve and 73.7% with BD type II) presenting an acute depressive episode and 17 healthy controls were studied. Patients were treated for 6 weeks with lithium in an open-label trial. N-acetyl aspartate (NAA), creatine, choline, myo-Inositol, and glutamate levels were assessed in the left hippocampus before (week 0) and after (week 6) lithium treatment using 3T proton magnetic resonance spectroscopy (1H-MRS). The metabolite concentrations were estimated using internal water as reference and voxel segmentation for partial volume correction. At baseline, acutely depressed BD patients and healthy controls exhibited similar hippocampal metabolites concentrations, with no changes after 6 weeks of lithium monotherapy...

Neuropsychiatric Disease and Treatment, 2015

Background: Anhedonia constitutes a coherent construct, with neural correlates and negative clini... more Background: Anhedonia constitutes a coherent construct, with neural correlates and negative clinical impact, independent of depression. However, little is known about the neural correlates of anhedonia in stroke patients. In this study, we investigated the association of post-stroke anhedonia with salivary cortisol levels and stroke location and volume. Patients and methods: A psychiatrist administered the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition to identify anhedonia in 36 inpatients, without previous depression, consecutively admitted in a neurology clinic in the first month after a first-ever ischemic stroke. Salivary cortisol levels were assessed in the morning, evening, and after a dexamethasone suppression test. We used magnetic resonance imaging and a semi-automated brain morphometry method to assess stroke location, and the MRIcro program according to the Brodmann Map to calculate the lesion volume. Results: Patients with anhedonia had significantly larger diurnal variation (P-value =0.017) and higher morning levels of salivary cortisol (1,671.9±604.0 ng/dL versus 1,103.9±821.9 ng/dL; P-value =0.022), and greater stroke lesions in the parahippocampal gyrus (Brodmann area 36) compared to those without anhedonia (10.14 voxels; standard deviation ±17.72 versus 0.86 voxels; standard deviation ±4.64; P-value =0.027). The volume of lesion in the parahippocampal gyrus (Brodmann area 36) was associated with diurnal variation of salivary cortisol levels (rho=0.845; P-value =0.034) only in anhedonic patients. Conclusion: Our findings suggest that anhedonia in stroke patients is associated with the volume of stroke lesion in the parahippocampal gyrus and with dysfunction of the hypothalamic-pituitary-adrenal axis.

Pituitary, Jan 15, 2014

Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress ... more Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress to combined pituitary hormone deficiency (CPHD) during follow-up. To evaluate the development of CPHD in a group of childhood-onset IGHD followed at a single tertiary center over a long period of time. We retrospectively analyzed data from 83 patients initially diagnosed as IGHD with a mean follow-up of 15.2 years. The Kaplan-Meier method and Cox regression analysis was used to estimate the temporal progression and to identify risk factors to development of CPHD over time. From 83 patients initially with IGHD, 37 (45 %) developed CPHD after a median time of follow up of 5.4 years (range from 1.2 to 21 years). LH and FSH deficiencies were the most common pituitary hormone (38 %) deficiencies developed followed by TSH (31 %), ACTH (12 %) and ADH deficiency (5 %). ADH deficiency (3.1 ± 1 years from GHD diagnosis) presented earlier and ACTH deficiency (9.3 ± 3.5 years) presented later during...

Journal of Endocrinological Investigation, 1997

Familial hypopituitarism represents a clinically and genetically heterogeneous disorder. In a sub... more Familial hypopituitarism represents a clinically and genetically heterogeneous disorder. In a subset of these families, defects in Pit-I, a transcription factor essential for proper pituitary development have been identified as underlying molecular cause. These patients present extreme short stature, GH, PRL and TSH deficiency but intact ACTH, LH and FSH secretion. The pituitary is usually hypoplastic. In this report we describe a consanguineous family (the parents are first cousins) with thirteen siblings. Of the ten living siblings, four (two males and two females) have panhypopituitarism with severe growth failure. They had evidence of growth hormone, prolactin and gonadotropin deficiencies and developed central hypothyroidism late in life. ACTH secretion was normal. Bone age was retarded and dual-photon bone densitometry indicated severe osteoporosis. Combined provocative tests for pituitary hormones indicated blunted responses for GH, LH, FSH and a modest rise in serum PRL and TSH. A clonidine-test failed to induce pituitary GH response. A corticotropin-releasing factor (CRF) provocative test was conducted after 6 months without the use of prednisone with a normal ACTH response after CRF in the affected sibling. Plasma IGF-I and IGF-BP3 were below normal levels. Serum E2 (females) and serum testosterone (males) levels were very low. MRI evaluation of the pituitary indicated pituitary aplasia in all subjects. The phenotype described in this kindred is different from families reported with Pit-1 mutations. However, it resembles previously published kindreds with similar clinical and biochemical findings. The relative preservation of ACTH suggests a genetic defect early in pituitary gland development.

Hypertension, 2006

We used microneurography to measure muscle sympathetic nerve activity (MSNA) in 25 hypertensive s... more We used microneurography to measure muscle sympathetic nerve activity (MSNA) in 25 hypertensive subjects and correlated these results with the presence or absence of signs of neurovascular compression (NVC) at the rostral ventrolateral (RVL) medulla on MRI. Subjects were divided into 3 groups based on MRI findings: NVC − , no MRI evidence of NVC (N=9); NVC+contact, image showing artery in contact but not compressing the RVL medulla (N=8); and NVC+compression, image showing arterial compression of the RVL medulla (N=8). The MSNA measurements were performed at rest, after a hypothermic stimulus, and during isometric exercise. The MSNA during rest in the NVC+compression group was significantly higher than that in the NVC+contact and NVC − groups (30.4±3.4 versus 17.5±1.1 and 21.4±3.2 spikes per minute, respectively). However, the blood pressure in the NVC+compression group was slightly but not significantly higher than that in the other 2 groups (183±7/115±8, 174±6/108±7, and 171±5/110...

Endocrine Reviews, 2010

Prolactin (PRL) is tonically inhibited by dopamine (DA) released from neurons in the arcuate and ... more Prolactin (PRL) is tonically inhibited by dopamine (DA) released from neurons in the arcuate and periventricular nuclei. Kisspeptin plays a pivotal role in LH regulation. In rodents, kisspeptin neurons are found mostly in the anteroventral periventricular and arcuate nuclei, but the physiology of arcuate kisspeptin neurons is not completely understood. We investigated the role of kisspeptin in the control of hypothalamic DA and pituitary PRL secretion in adult rats. Intracerebroventricular kisspeptin-10 (Kp-10) elicited PRL release in a dose-dependent manner in estradiol (E2)-treated ovariectomized rats (OVXϩE2), whereas no effect was found in oil-treated ovariectomized rats (OVX). Kp-10 increased PRL release in males and proestrous but not diestrous females. Associated with the increase in PRL release, intracerebroventricular Kp-10 reduced Fos-related antigen expression in tyrosine hydroxylase-immunoreactive (ir) neurons of arcuate and periventricular nuclei in OVXϩE2 rats, with no effect in OVX rats. Kp-10 also decreased 3,4dihydroxyphenylacetic acid concentration and 3,4-dihydroxyphenylacetic acid-DA ratio in the median eminence but not striatum in OVXϩE2 rats. Double-label immunofluorescence combined with confocal microscopy revealed kisspeptin-ir fibers in close apposition to and in contact with tyrosine hydroxylase-ir perikarya in the arcuate. In addition, Kp-10 was not found to alter PRL release from anterior pituitary cell cultures regardless of E2 treatment. We provide herein evidence that kisspeptin regulates PRL release through inhibition of hypothalamic dopaminergic neurons, and that this mechanism is E2 dependent in females. These findings suggest a new role for central kisspeptin with possible implications for reproductive physiology.

British Journal of Psychiatry, 2007

BackgroundIn low-and middle-income countries people with schizophrenia are reported to experience... more BackgroundIn low-and middle-income countries people with schizophrenia are reported to experience better outcomes than those in high-income countriesAimsTo examine structural brain differences in people with first-episode psychosis and controls in BrazilMethodMagnetic resonance imaging using voxel-based morphometry was performed on 122 people with first-episode psychosis and 94 controlsResultsThere were significant decreases in grey matter in the left superior temporal and inferior prefrontal cortices, insula bilaterally and the right hippocampal region in first-episode psychosis (P<0.05, corrected for multiple comparisons). The subgroup of people with schizophrenia (n=62) exhibited a similar pattern of decrease in grey matter relative to controlsConclusionsStructural abnormalities reported in psychosis in high-income countries are also present in first-episode psychosis in Brazil

Brazilian Journal of Medical and Biological Research, 2008

Happy emotional states have not been extensively explored in functional magnetic resonance imagin... more Happy emotional states have not been extensively explored in functional magnetic resonance imaging studies using autobiographic recall paradigms. We investigated the brain circuitry engaged during induction of happiness by standardized scriptdriven autobiographical recall in 11 healthy subjects (6 males), aged 32.4 ± 7.2 years, without physical or psychiatric disorders, selected according to their ability to vividly recall personal experiences. Blood oxygen level-dependent (BOLD) changes were recorded during auditory presentation of personal scripts of happiness, neutral content and negative emotional content (irritability). The same uniform structure was used for the cueing narratives of both emotionally salient and neutral conditions, in order to decrease the variability of findings. In the happiness relative to the neutral condition, there was an increased BOLD signal in the left dorsal prefrontal cortex and anterior insula, thalamus bilaterally, left hypothalamus, left anterior cingulate gyrus, and midportions of the left middle temporal gyrus (P < 0.05, corrected for multiple comparisons). Relative to the irritability condition, the happiness condition showed increased activity in the left insula, thalamus and hypothalamus, and in anterior and midportions of the inferior and middle temporal gyri bilaterally (P < 0.05, corrected), varying in size between 13 and 64 voxels. Findings of happiness-related increased activity in prefrontal and subcortical regions extend the results of previous functional imaging studies of autobiographical recall. The BOLD signal changes identified reflect general aspects of emotional processing, emotional control, and the processing of sensory and bodily signals associated with internally generated feelings of happiness. These results reinforce the notion that happiness induction engages a wide network of brain regions.

Arthritis Care & Research, 2013

ObjectiveTo investigate the efficacy and safety of creatine supplementation in fibromyalgia patie... more ObjectiveTo investigate the efficacy and safety of creatine supplementation in fibromyalgia patients.MethodsA 16‐week, randomized, double‐blind, placebo‐controlled, parallel‐group trial was conducted. Fibromyalgia patients were randomly assigned to receive either creatine monohydrate or placebo in a double‐blind manner. The patients were evaluated at baseline and after 16 weeks. Muscle function, aerobic conditioning, cognitive function, quality of sleep, quality of life, kidney function, and adverse events were assessed. Muscle phosphorylcreatine content was measured through 31P magnetic resonance spectroscopy.ResultsAfter the intervention, the creatine group presented higher muscle phosphorylcreatine content when compared with the placebo group (+80.3% versus −2.7%; P = 0.04). Furthermore, the creatine group presented greater muscle strength than the placebo group in the leg press and chest press exercises (+9.8% and +1.2% for creatine versus −0.5% and −7.2% for placebo, respective...

Arquivos de Neuro-Psiquiatria, 2007

OBJECTIVE: To report a case of ganglioneuroblastoma of cerebellum, with emphasis to the neuroimag... more OBJECTIVE: To report a case of ganglioneuroblastoma of cerebellum, with emphasis to the neuroimaging and pathological findings. CASE REPORT: A one year and eight-month-old girl presented with a two-month history of hypoactivity and tremor in the legs. The MRI showed an enhancing cerebellar mass hypointense on T1 and hyperintense on T2-weighted images. The patient underwent a craniotomy with resection of the lesion. The histological and immunohistochemical studies defined the diagnosis of ganglioneuroblastoma. CONCLUSION: The MRI findings of our case showed no features which could help in the differentiation between ganglioneuroblastoma and the other common types of posterior fossa neoplasms in the pediatric population.

Arquivos de Neuro-Psiquiatria, 2005

We describe a case of bilateral olivary hypertrophy and palatal tremor after unilateral cerebella... more We describe a case of bilateral olivary hypertrophy and palatal tremor after unilateral cerebellar infarction. Hypertrophic olivary degeneration (HOD) is associated with hypersignal in the inferior olivary nucleus (ION), on T2-weighted images. HOD has been more often observed ipsilaterally to a central tegmentum tract lesion or contralaterally to a dentate nucleus or a superior cerebellar peduncle lesion. Double innervation of each ION from either dentate nucleus may have underlied the imaging and clinical findings in this 63 year-old male patient.

Arquivos de Neuro-Psiquiatria, 2005

High signal in the cerebral cortex and/or basal ganglia on diffusion-weighted magnetic resonance ... more High signal in the cerebral cortex and/or basal ganglia on diffusion-weighted magnetic resonance imaging (DW-MRI) has been described as a good diagnostic marker for sporadic Creutzfeldt-Jakob disease (sCJD). We report a case of sCJD with atypical clinical evolution and unusual DW-MRI findings. A 53-year-old man was seen with a 2-year history of a rapidly progressive dementia and cerebellar ataxia. Cerebrospinal fluid analysis, including the test for 14-3-3 protein, was normal. EEG did not show periodic activity. However, DW-MRI showed gyriform hyperintensity involving practically the entire cortical ribbon of the left hemisphere, whilst being limited to the posterior cingulate gyrus in the right hemisphere. DNA analysis showed no mutations or insertions in the prion protein gene, and homozigozity for methionine in codon 129. A subsequent brain biopsy confirmed the diagnosis of CJD. Thus, high signal on DW-MRI may be limited to the cerebral cortex and may present a very asymmetric di...

Arquivos Brasileiros de Cardiologia, 1998

Ação de droga não é fator etiopatogênico habitualmente cogitado perante valvopatia adquirida. Não... more Ação de droga não é fator etiopatogênico habitualmente cogitado perante valvopatia adquirida. Não obstante, efeitos adversos de remédios anti-enxaqueca 1-5 e anorexígenos 6,7 estão vinculados a casos de cardiopatia valvar, alguns inclusive submetidos à correção cirúrgica. Derivados do ergot Metisergida 2-5,8-Nas décadas de 60/70, o derivado do ergot metisergida era o mais eficaz profilático para enxaqueca. Na ocasião, estimava-se o consumo em 500 mil pessoas. Em 1964, John Graham, então diretor da Headache Research Foundations, em Boston, foi alertado sobre a ausculta de sopros de insuficiência mitral ou aórtica durante uso contínuo da droga. Uma primeira avaliação, compreendendo 27 pacientes com casos de fibrose retroperitonial induzida pela metisergida, revelou sete (26%) casos com sopro cardíaco. Em período de dois anos, o pesquisador pôde observar o desenvolvimento sem outra causa aparente de sopro cardíaco expressivo em 16 de seus pacientes. Dez anos após a constatação original, revisão publicada pelo mesmo Serviço incluiu não mais do que 48 casos de vínculo da droga com sopro cardíaco. Este número restrito de casos foi suficiente para incorporar as seguintes observações ao conhecimento sobre cardiopatia valvar: 1) taxa de 3,6% dos pacientes sob uso continuado de metisergida desenvolve sopro cardíaco. Devemos conjecturar que lesões valvares subclínicas, atualmente identificáveis pela ecocardiografia, possam ter ficado à margem desta proporção; 2) a maioria dos pacientes não apresentava sopro cardíaco previamente ao uso; 3) não havia outra causa de sopro cardíaco; 4) a intensidade do sopro cardíaco mostrou-se inicialmente crescente; 5) a suspensão da droga associou-se à regressão total (46%) ou parcial (12%) do sopro cardíaco em 58% dos casos; 6) os sopros reveladores de estenose e/ou insuficiência tinham origem nas valvas mitral, aórtica e tricúspide; 7) sopro cardíaco superpôs-se em 26% ao desenvolvimento de fibrose retroperitonial, condição também, potencialmente, reversí-volume 70, (nº 3), 1998 Grinberg e col O vínculo droga valvopatia

American Journal of Roentgenology, 1997

The purpose of our study was to retrospectively review the MR imaging findings in a group of pati... more The purpose of our study was to retrospectively review the MR imaging findings in a group of patients with clinically proven cysticercosis involving the spinal cord, the spinal subarachnoid space. or both. MATERIALS AND METHODS. We retrospectively reviewed images of I 6 patients with clinically diagnosed spinal cysticercosis to summarize the imaging characteristics. All

AJNR. American journal of neuroradiology, 2006

We describe how proton MR spectroscopy ((1)H-MR spectroscopy) was useful in elucidating the diagn... more We describe how proton MR spectroscopy ((1)H-MR spectroscopy) was useful in elucidating the diagnosis of galactosemia in an undiagnosed 6-month-old infant. In vivo (1)H-MR spectroscopy of the brain showed a doublet at 3.7 parts per million, which was identified as galactitol (Gal-ol) by in vitro (1)H-MR spectroscopy of the urine. Galactosemia was subsequently confirmed by laboratory tests and treatment was initiated. A follow-up brain MR imaging and (1)H-MR spectroscopy study revealed resolution of white matter lesions and disappearance of Gal-ol peaks.

Singapore medical journal, 2000

A 2-year-old Brazilian boy presented with bilateral leg weakness and constipation, followed by de... more A 2-year-old Brazilian boy presented with bilateral leg weakness and constipation, followed by development of progressive paraparesis and bladder dysfunction. Neurological examination revealed flaccid paraparesis. Blood tests and CSF analysis showed eosinophilia. The MR examination revealed a spinal cord mass extending from T9 to L1 levels, with a heterogeneously-enhancing solid component and a cystic component. Stool tests for Schistosoma mansoni eggs were positive. The patient underwent surgery, the intramedullary mass was partially resected, and the diagnosis of spinal cord infection by Schistosoma mansoni was confirmed. After surgery, the patient was treated with praziquantel and oxamniquine. He was discharged with partial improvement of the lower extremity weakness and bowel/bladder function. The clinical and imaging features of spinal cord schistosomiasis are reviewed.

AJNR. American journal of neuroradiology, 1998

Extensive MR signal change in the craniad spinal cord parenchyma was found to be an ancillary sig... more Extensive MR signal change in the craniad spinal cord parenchyma was found to be an ancillary sign of disease advancement in three patients with clinically progressive posttraumatic syringomyelia. This craniad margin of parenchymal spinal cord T2 hyperintensity resolved after cystoperitoneal shunt placement. There was a concomittant reduction or disappearance of the cyst in each instance, a halt in the progression of neurologic deficit, and some reversal of signs and symptoms.

Translational psychiatry, 2014

Various functional magnetic resonance imaging studies addressed the effects of antidepressant dru... more Various functional magnetic resonance imaging studies addressed the effects of antidepressant drugs on brain functioning in healthy subjects; however, none specifically investigated positive mood changes to antidepressant drug. Sixteen subjects with no personal or family history of psychiatric disorders were selected from an ongoing 4-week open trial of small doses of clomipramine. Follow-up interviews documented clear positive treatment effects in six subjects, with reduced irritability and tension in social interactions, improved decision making, higher self-confidence and brighter mood. These subjects were then included in a placebo-controlled confirmatory trial and were scanned immediately after 4 weeks of clomipramine use and again 4 weeks after the last dose of clomipramine. The functional magnetic resonance imaging (fMRI) scans were run during emotion-eliciting stimuli. Repeated-measures analysis of variance of brain activity patterns showed significant interactions between g...

Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) is a non-invasive method that provides us... more Phosphorus-31 magnetic resonance spectroscopy (31P-MRS) is a non-invasive method that provides useful information about metabolism and phosphoenergetic status in both physiologic and pathologic conditions of the human brain. With the progressive advances in magnetic resonance imaging (MRI) technology, particularly with higher magnetic field strengths, 31P-MRS has been more easily implemented and more readily available in the past few years, which has increasingly extended its access and favored its use in different research fields. However, the current knowledge about this advanced neuroimaging modality is still scarce and fragmented in the literature. Hence, in order to contribute to future researches and to shorten the gap between neuroscientific studies and common clinical routines, we present a comprehensive review about the basic technical aspects and biomedical applications of 31P-MRS.

Revista do Hospital das Clínicas, 2002

This is a double-blind, placebo-controlled study of the efficacy, safety, and tolerability of sib... more This is a double-blind, placebo-controlled study of the efficacy, safety, and tolerability of sibutramine in the management of obese patients for a 6-month period. METHOD: Sixty-one obese patients (BMI >30, <40 kg/m2), aged 18-65 years were evaluated. In the first phase of the study (30 days), the patients were given a placebo. We monitored compliance with a low-calorie diet (1200 kcal/day) and to the placebo. In the next stage, the double-blind phase (6 months), we compared placebo and sibutramine (10 mg/day). The criteria for evaluating efficacy were weight loss, reduction in body mass index (BMI), and abdominal and hip circumferences. Tolerability was assessed based on reported side effects, variation in arterial blood pressure and heart rate, metabolic profile (fasting glucose, total cholesterol and its fractions, and triglycerides), laboratory tests (renal and hepatic functions), and flow Doppler echocardiogram. RESULTS: We observed a greater weight loss (7.3 kg, 8% vs 2....

The international journal of neuropsychopharmacology / official scientific journal of the Collegium Internationale Neuropsychopharmacologicum (CINP), Jan 31, 2014

The hippocampus has been highly implicated in the pathophysiology of bipolar disorder (BD). Never... more The hippocampus has been highly implicated in the pathophysiology of bipolar disorder (BD). Nevertheless, no study has longitudinally evaluated hippocampal metabolite levels in bipolar depression under treatment with lithium. Nineteen medication-free BD patients (78.9% treatment-naïve and 73.7% with BD type II) presenting an acute depressive episode and 17 healthy controls were studied. Patients were treated for 6 weeks with lithium in an open-label trial. N-acetyl aspartate (NAA), creatine, choline, myo-Inositol, and glutamate levels were assessed in the left hippocampus before (week 0) and after (week 6) lithium treatment using 3T proton magnetic resonance spectroscopy (1H-MRS). The metabolite concentrations were estimated using internal water as reference and voxel segmentation for partial volume correction. At baseline, acutely depressed BD patients and healthy controls exhibited similar hippocampal metabolites concentrations, with no changes after 6 weeks of lithium monotherapy...

Neuropsychiatric Disease and Treatment, 2015

Background: Anhedonia constitutes a coherent construct, with neural correlates and negative clini... more Background: Anhedonia constitutes a coherent construct, with neural correlates and negative clinical impact, independent of depression. However, little is known about the neural correlates of anhedonia in stroke patients. In this study, we investigated the association of post-stroke anhedonia with salivary cortisol levels and stroke location and volume. Patients and methods: A psychiatrist administered the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition to identify anhedonia in 36 inpatients, without previous depression, consecutively admitted in a neurology clinic in the first month after a first-ever ischemic stroke. Salivary cortisol levels were assessed in the morning, evening, and after a dexamethasone suppression test. We used magnetic resonance imaging and a semi-automated brain morphometry method to assess stroke location, and the MRIcro program according to the Brodmann Map to calculate the lesion volume. Results: Patients with anhedonia had significantly larger diurnal variation (P-value =0.017) and higher morning levels of salivary cortisol (1,671.9±604.0 ng/dL versus 1,103.9±821.9 ng/dL; P-value =0.022), and greater stroke lesions in the parahippocampal gyrus (Brodmann area 36) compared to those without anhedonia (10.14 voxels; standard deviation ±17.72 versus 0.86 voxels; standard deviation ±4.64; P-value =0.027). The volume of lesion in the parahippocampal gyrus (Brodmann area 36) was associated with diurnal variation of salivary cortisol levels (rho=0.845; P-value =0.034) only in anhedonic patients. Conclusion: Our findings suggest that anhedonia in stroke patients is associated with the volume of stroke lesion in the parahippocampal gyrus and with dysfunction of the hypothalamic-pituitary-adrenal axis.

Pituitary, Jan 15, 2014

Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress ... more Children initially diagnosed with isolated GH deficiency (IGHD) have a variable rate to progress to combined pituitary hormone deficiency (CPHD) during follow-up. To evaluate the development of CPHD in a group of childhood-onset IGHD followed at a single tertiary center over a long period of time. We retrospectively analyzed data from 83 patients initially diagnosed as IGHD with a mean follow-up of 15.2 years. The Kaplan-Meier method and Cox regression analysis was used to estimate the temporal progression and to identify risk factors to development of CPHD over time. From 83 patients initially with IGHD, 37 (45 %) developed CPHD after a median time of follow up of 5.4 years (range from 1.2 to 21 years). LH and FSH deficiencies were the most common pituitary hormone (38 %) deficiencies developed followed by TSH (31 %), ACTH (12 %) and ADH deficiency (5 %). ADH deficiency (3.1 ± 1 years from GHD diagnosis) presented earlier and ACTH deficiency (9.3 ± 3.5 years) presented later during...

Journal of Endocrinological Investigation, 1997

Familial hypopituitarism represents a clinically and genetically heterogeneous disorder. In a sub... more Familial hypopituitarism represents a clinically and genetically heterogeneous disorder. In a subset of these families, defects in Pit-I, a transcription factor essential for proper pituitary development have been identified as underlying molecular cause. These patients present extreme short stature, GH, PRL and TSH deficiency but intact ACTH, LH and FSH secretion. The pituitary is usually hypoplastic. In this report we describe a consanguineous family (the parents are first cousins) with thirteen siblings. Of the ten living siblings, four (two males and two females) have panhypopituitarism with severe growth failure. They had evidence of growth hormone, prolactin and gonadotropin deficiencies and developed central hypothyroidism late in life. ACTH secretion was normal. Bone age was retarded and dual-photon bone densitometry indicated severe osteoporosis. Combined provocative tests for pituitary hormones indicated blunted responses for GH, LH, FSH and a modest rise in serum PRL and TSH. A clonidine-test failed to induce pituitary GH response. A corticotropin-releasing factor (CRF) provocative test was conducted after 6 months without the use of prednisone with a normal ACTH response after CRF in the affected sibling. Plasma IGF-I and IGF-BP3 were below normal levels. Serum E2 (females) and serum testosterone (males) levels were very low. MRI evaluation of the pituitary indicated pituitary aplasia in all subjects. The phenotype described in this kindred is different from families reported with Pit-1 mutations. However, it resembles previously published kindreds with similar clinical and biochemical findings. The relative preservation of ACTH suggests a genetic defect early in pituitary gland development.

Hypertension, 2006

We used microneurography to measure muscle sympathetic nerve activity (MSNA) in 25 hypertensive s... more We used microneurography to measure muscle sympathetic nerve activity (MSNA) in 25 hypertensive subjects and correlated these results with the presence or absence of signs of neurovascular compression (NVC) at the rostral ventrolateral (RVL) medulla on MRI. Subjects were divided into 3 groups based on MRI findings: NVC − , no MRI evidence of NVC (N=9); NVC+contact, image showing artery in contact but not compressing the RVL medulla (N=8); and NVC+compression, image showing arterial compression of the RVL medulla (N=8). The MSNA measurements were performed at rest, after a hypothermic stimulus, and during isometric exercise. The MSNA during rest in the NVC+compression group was significantly higher than that in the NVC+contact and NVC − groups (30.4±3.4 versus 17.5±1.1 and 21.4±3.2 spikes per minute, respectively). However, the blood pressure in the NVC+compression group was slightly but not significantly higher than that in the other 2 groups (183±7/115±8, 174±6/108±7, and 171±5/110...

Endocrine Reviews, 2010

Prolactin (PRL) is tonically inhibited by dopamine (DA) released from neurons in the arcuate and ... more Prolactin (PRL) is tonically inhibited by dopamine (DA) released from neurons in the arcuate and periventricular nuclei. Kisspeptin plays a pivotal role in LH regulation. In rodents, kisspeptin neurons are found mostly in the anteroventral periventricular and arcuate nuclei, but the physiology of arcuate kisspeptin neurons is not completely understood. We investigated the role of kisspeptin in the control of hypothalamic DA and pituitary PRL secretion in adult rats. Intracerebroventricular kisspeptin-10 (Kp-10) elicited PRL release in a dose-dependent manner in estradiol (E2)-treated ovariectomized rats (OVXϩE2), whereas no effect was found in oil-treated ovariectomized rats (OVX). Kp-10 increased PRL release in males and proestrous but not diestrous females. Associated with the increase in PRL release, intracerebroventricular Kp-10 reduced Fos-related antigen expression in tyrosine hydroxylase-immunoreactive (ir) neurons of arcuate and periventricular nuclei in OVXϩE2 rats, with no effect in OVX rats. Kp-10 also decreased 3,4dihydroxyphenylacetic acid concentration and 3,4-dihydroxyphenylacetic acid-DA ratio in the median eminence but not striatum in OVXϩE2 rats. Double-label immunofluorescence combined with confocal microscopy revealed kisspeptin-ir fibers in close apposition to and in contact with tyrosine hydroxylase-ir perikarya in the arcuate. In addition, Kp-10 was not found to alter PRL release from anterior pituitary cell cultures regardless of E2 treatment. We provide herein evidence that kisspeptin regulates PRL release through inhibition of hypothalamic dopaminergic neurons, and that this mechanism is E2 dependent in females. These findings suggest a new role for central kisspeptin with possible implications for reproductive physiology.

British Journal of Psychiatry, 2007

BackgroundIn low-and middle-income countries people with schizophrenia are reported to experience... more BackgroundIn low-and middle-income countries people with schizophrenia are reported to experience better outcomes than those in high-income countriesAimsTo examine structural brain differences in people with first-episode psychosis and controls in BrazilMethodMagnetic resonance imaging using voxel-based morphometry was performed on 122 people with first-episode psychosis and 94 controlsResultsThere were significant decreases in grey matter in the left superior temporal and inferior prefrontal cortices, insula bilaterally and the right hippocampal region in first-episode psychosis (P<0.05, corrected for multiple comparisons). The subgroup of people with schizophrenia (n=62) exhibited a similar pattern of decrease in grey matter relative to controlsConclusionsStructural abnormalities reported in psychosis in high-income countries are also present in first-episode psychosis in Brazil

Brazilian Journal of Medical and Biological Research, 2008

Happy emotional states have not been extensively explored in functional magnetic resonance imagin... more Happy emotional states have not been extensively explored in functional magnetic resonance imaging studies using autobiographic recall paradigms. We investigated the brain circuitry engaged during induction of happiness by standardized scriptdriven autobiographical recall in 11 healthy subjects (6 males), aged 32.4 ± 7.2 years, without physical or psychiatric disorders, selected according to their ability to vividly recall personal experiences. Blood oxygen level-dependent (BOLD) changes were recorded during auditory presentation of personal scripts of happiness, neutral content and negative emotional content (irritability). The same uniform structure was used for the cueing narratives of both emotionally salient and neutral conditions, in order to decrease the variability of findings. In the happiness relative to the neutral condition, there was an increased BOLD signal in the left dorsal prefrontal cortex and anterior insula, thalamus bilaterally, left hypothalamus, left anterior cingulate gyrus, and midportions of the left middle temporal gyrus (P < 0.05, corrected for multiple comparisons). Relative to the irritability condition, the happiness condition showed increased activity in the left insula, thalamus and hypothalamus, and in anterior and midportions of the inferior and middle temporal gyri bilaterally (P < 0.05, corrected), varying in size between 13 and 64 voxels. Findings of happiness-related increased activity in prefrontal and subcortical regions extend the results of previous functional imaging studies of autobiographical recall. The BOLD signal changes identified reflect general aspects of emotional processing, emotional control, and the processing of sensory and bodily signals associated with internally generated feelings of happiness. These results reinforce the notion that happiness induction engages a wide network of brain regions.

Arthritis Care & Research, 2013

ObjectiveTo investigate the efficacy and safety of creatine supplementation in fibromyalgia patie... more ObjectiveTo investigate the efficacy and safety of creatine supplementation in fibromyalgia patients.MethodsA 16‐week, randomized, double‐blind, placebo‐controlled, parallel‐group trial was conducted. Fibromyalgia patients were randomly assigned to receive either creatine monohydrate or placebo in a double‐blind manner. The patients were evaluated at baseline and after 16 weeks. Muscle function, aerobic conditioning, cognitive function, quality of sleep, quality of life, kidney function, and adverse events were assessed. Muscle phosphorylcreatine content was measured through 31P magnetic resonance spectroscopy.ResultsAfter the intervention, the creatine group presented higher muscle phosphorylcreatine content when compared with the placebo group (+80.3% versus −2.7%; P = 0.04). Furthermore, the creatine group presented greater muscle strength than the placebo group in the leg press and chest press exercises (+9.8% and +1.2% for creatine versus −0.5% and −7.2% for placebo, respective...

Arquivos de Neuro-Psiquiatria, 2007

OBJECTIVE: To report a case of ganglioneuroblastoma of cerebellum, with emphasis to the neuroimag... more OBJECTIVE: To report a case of ganglioneuroblastoma of cerebellum, with emphasis to the neuroimaging and pathological findings. CASE REPORT: A one year and eight-month-old girl presented with a two-month history of hypoactivity and tremor in the legs. The MRI showed an enhancing cerebellar mass hypointense on T1 and hyperintense on T2-weighted images. The patient underwent a craniotomy with resection of the lesion. The histological and immunohistochemical studies defined the diagnosis of ganglioneuroblastoma. CONCLUSION: The MRI findings of our case showed no features which could help in the differentiation between ganglioneuroblastoma and the other common types of posterior fossa neoplasms in the pediatric population.

Arquivos de Neuro-Psiquiatria, 2005

We describe a case of bilateral olivary hypertrophy and palatal tremor after unilateral cerebella... more We describe a case of bilateral olivary hypertrophy and palatal tremor after unilateral cerebellar infarction. Hypertrophic olivary degeneration (HOD) is associated with hypersignal in the inferior olivary nucleus (ION), on T2-weighted images. HOD has been more often observed ipsilaterally to a central tegmentum tract lesion or contralaterally to a dentate nucleus or a superior cerebellar peduncle lesion. Double innervation of each ION from either dentate nucleus may have underlied the imaging and clinical findings in this 63 year-old male patient.

Arquivos de Neuro-Psiquiatria, 2005

High signal in the cerebral cortex and/or basal ganglia on diffusion-weighted magnetic resonance ... more High signal in the cerebral cortex and/or basal ganglia on diffusion-weighted magnetic resonance imaging (DW-MRI) has been described as a good diagnostic marker for sporadic Creutzfeldt-Jakob disease (sCJD). We report a case of sCJD with atypical clinical evolution and unusual DW-MRI findings. A 53-year-old man was seen with a 2-year history of a rapidly progressive dementia and cerebellar ataxia. Cerebrospinal fluid analysis, including the test for 14-3-3 protein, was normal. EEG did not show periodic activity. However, DW-MRI showed gyriform hyperintensity involving practically the entire cortical ribbon of the left hemisphere, whilst being limited to the posterior cingulate gyrus in the right hemisphere. DNA analysis showed no mutations or insertions in the prion protein gene, and homozigozity for methionine in codon 129. A subsequent brain biopsy confirmed the diagnosis of CJD. Thus, high signal on DW-MRI may be limited to the cerebral cortex and may present a very asymmetric di...

Arquivos Brasileiros de Cardiologia, 1998

Ação de droga não é fator etiopatogênico habitualmente cogitado perante valvopatia adquirida. Não... more Ação de droga não é fator etiopatogênico habitualmente cogitado perante valvopatia adquirida. Não obstante, efeitos adversos de remédios anti-enxaqueca 1-5 e anorexígenos 6,7 estão vinculados a casos de cardiopatia valvar, alguns inclusive submetidos à correção cirúrgica. Derivados do ergot Metisergida 2-5,8-Nas décadas de 60/70, o derivado do ergot metisergida era o mais eficaz profilático para enxaqueca. Na ocasião, estimava-se o consumo em 500 mil pessoas. Em 1964, John Graham, então diretor da Headache Research Foundations, em Boston, foi alertado sobre a ausculta de sopros de insuficiência mitral ou aórtica durante uso contínuo da droga. Uma primeira avaliação, compreendendo 27 pacientes com casos de fibrose retroperitonial induzida pela metisergida, revelou sete (26%) casos com sopro cardíaco. Em período de dois anos, o pesquisador pôde observar o desenvolvimento sem outra causa aparente de sopro cardíaco expressivo em 16 de seus pacientes. Dez anos após a constatação original, revisão publicada pelo mesmo Serviço incluiu não mais do que 48 casos de vínculo da droga com sopro cardíaco. Este número restrito de casos foi suficiente para incorporar as seguintes observações ao conhecimento sobre cardiopatia valvar: 1) taxa de 3,6% dos pacientes sob uso continuado de metisergida desenvolve sopro cardíaco. Devemos conjecturar que lesões valvares subclínicas, atualmente identificáveis pela ecocardiografia, possam ter ficado à margem desta proporção; 2) a maioria dos pacientes não apresentava sopro cardíaco previamente ao uso; 3) não havia outra causa de sopro cardíaco; 4) a intensidade do sopro cardíaco mostrou-se inicialmente crescente; 5) a suspensão da droga associou-se à regressão total (46%) ou parcial (12%) do sopro cardíaco em 58% dos casos; 6) os sopros reveladores de estenose e/ou insuficiência tinham origem nas valvas mitral, aórtica e tricúspide; 7) sopro cardíaco superpôs-se em 26% ao desenvolvimento de fibrose retroperitonial, condição também, potencialmente, reversí-volume 70, (nº 3), 1998 Grinberg e col O vínculo droga valvopatia

American Journal of Roentgenology, 1997

The purpose of our study was to retrospectively review the MR imaging findings in a group of pati... more The purpose of our study was to retrospectively review the MR imaging findings in a group of patients with clinically proven cysticercosis involving the spinal cord, the spinal subarachnoid space. or both. MATERIALS AND METHODS. We retrospectively reviewed images of I 6 patients with clinically diagnosed spinal cysticercosis to summarize the imaging characteristics. All