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Development on new fast MRI scanners resulted in rising number of prostate examinations. High-spatial resolution of MRI examinations performed on 3T scanners allows recognition of very fine anatomical structures previously not demarcated on performed scans. We present current status of MR imaging in the context of recognition of most important anatomical structures.
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Síndrome do Túnel Carpal , Técnicas de Imagem por Elasticidade , Antebraço , Humanos , Nervo Mediano , PunhoRESUMO
BACKGROUND: In the diagnosis of brain death (BD), computed tomography angiography (CTA) results in some cases show intracranial filling, leading to diagnostic confusion. Because cerebral circulatory arrest commences at the capillary level, we hypothesized that computed tomography perfusion (CTP) would be a more sensitive approach than CTA; therefore, the aim of the study was to compare the sensitivities of CTP and CTA in the diagnosis of BD. MATERIAL AND METHODS: Whole brain CTP was performed in patients in the intensive care unit diagnosed with BD and CTA was derived from CTP datasets. Cerebral blood flow (CBF) and volume (CBV) were calculated in all brain regions. The CTP findings were interpreted as being consistent with a diagnosis of BD (positive) when CBF and CBV in all regions of interest (ROIs) were below 10 ml/100 g/min and 1.0 ml/100 g, respectively. The CTA findings were interpreted using a 4-point grading system. RESULTS: A total of 50 patients were included in the study. The CTP results revealed CBF from 0.00 to 9.98 ml/100 g/min (mean, 1.98 ± 1.68 ml/100 g/min) and CBV from 0.00 to 0.99 ml/100 g (mean, 0.14 ± 0.12 ml/100 g) and were thus interpreted as positive in all 50 patients. In contrast, the CTA results suggested 7 negative cases, providing a sensitivity of 86%. The difference between the CTP and CTA sensitivity results for the diagnosis of BD was statistically significant (p = 0.006). CONCLUSION: Whole brain CTP may potentially be a feasible and highly sensitive test for diagnosing BD: therefore, performing CTP in combination with CTA in cases when CTA results are negative for BD could increase the sensitivity of CTA.
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Morte Encefálica/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Idoso , Volume Sanguíneo , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Angiografia Cerebral/métodos , Circulação Cerebrovascular , Angiografia por Tomografia Computadorizada , Reações Falso-Negativas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto JovemRESUMO
An interesting alternative to traditional diagnostic techniques of the upper extremity nerve entrapments might be an ultrasound elastography that has started to gain attention in recent research. The aim of this preliminary study was to verify whether a quantitative analysis of the ulnar nerve stiffness by shear-wave elastography can be used to diagnose ulnar tunnel syndrome (UTS), an ulnar nerve neuropathy at Guyon's canal. The study included 46 patients (39 women) and 39 healthy controls (34 women). All diagnoses in patients and controls were confirmed with nerve conduction studies. Measurements of nerve stiffness were taken at three levels: Guyon's canal (G), distal forearm (DF), and mid forearm (MF). Additionally, the ulnar nerve cross-sectional area at the canal's level was determined by ultrasonography. Patients with UTS presented with significantly greater nerve stiffness than the controls (mean, 99.41â¯kPa vs. 49.08â¯kPa, Pâ¯<â¯0.001). No significant intergroup differences were found in the nerve elasticity at DF and MF levels (Pâ¯<â¯0.836 and Pâ¯<â¯0.881, respectively). An ulnar nerve stiffness value of 80â¯kPa and G:DF and G:MF ratios equal to 1.5 provided 100% sensitivity, specificity, and positive and negative predictive values in the detection of the syndrome. The mean nerve cross-sectional area in the Guyon's canal was significantly greater in patients than in the controls (4.63 mm2, range, 2-7 mm2 vs. 3.23 mm2, range, 2-5 mm2, Pâ¯<â¯0.001). In conclusion, we believe that shear-wave elastography has the potential to become a useful adjunct diagnostic test for UTS.
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Técnicas de Imagem por Elasticidade/métodos , Síndromes de Compressão do Nervo Ulnar/diagnóstico por imagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Síndromes de Compressão do Nervo Ulnar/patologiaRESUMO
Treatment of asthma, the most common chronic respiratory disease in children, includes long-term inhaled corticosteroids (ICS). The purpose of this study was to analyze the impact of chronic inhaled steroids in children with asthma on changes in the central nervous system (CNS). Eleven children (8-17 years) on at least 4 years inhaled corticosteroid therapy were assessed with magnetic resonance imaging (MRI). All participants underwent a pediatric and neurological examination and spirometry. MRI data were obtained using a 1.5 T scanner with parallel imaging capability. Structural images consisted of axial T1, T2 using turbo spin echo, FLAIR and DWI sequences using typical parameters. Images were assessed in three planes (axial, coronal, and sagittal). Pediatric and neurological examination were normal in all children. In six, the MRI studies revealed small subcortical hyperintense foci. Three had more than five lesions, all of which were smaller than 3 mm. Features of mild supratentorial cortical atrophy were apparent in four. The cerebellum was unremarkable in all children imaged. In conclusion, patients receiving chronic inhaled corticosteroids had small subcortical hyperintense foci and features of mild supratentorial cortical atrophy. These findings suggest that ICS exposure may be associated with the development of organic changes in CNS. Further studies are needed to detail the extent of brain ICS-induced changes in children on chronic inhalative corticosteroid therapy as well as delayed impact of these changes on psychomotor functioning in adulthood.
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Corticosteroides/efeitos adversos , Antiasmáticos/efeitos adversos , Asma/tratamento farmacológico , Encéfalo/efeitos dos fármacos , Administração por Inalação , Adolescente , Corticosteroides/administração & dosagem , Antiasmáticos/administração & dosagem , Asma/fisiopatologia , Encéfalo/patologia , Mapeamento Encefálico , Criança , Doença Crônica , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Estudos RetrospectivosRESUMO
INTRODUCTION: The standardized diagnostic criteria for computed tomographic angiography (CTA) in diagnosis of brain death (BD) are not yet established. The aim of the study was to compare the sensitivity and interobserver agreement of the three previously used scales of CTA for the diagnosis of BD. METHODS: Eighty-two clinically brain-dead patients underwent CTA with a delay of 40 s after contrast injection. Catheter angiography was used as the reference standard. CTA results were assessed by two radiologists, and the diagnosis of BD was established according to 10-, 7-, and 4-point scales. RESULTS: Catheter angiography confirmed the diagnosis of BD in all cases. Opacification of certain cerebral vessels as indicator of BD was highly sensitive: cortical segments of the middle cerebral artery (96.3 %), the internal cerebral vein (98.8 %), and the great cerebral vein (98.8 %). Other vessels were less sensitive: the pericallosal artery (74.4 %), cortical segments of the posterior cerebral artery (79.3 %), and the basilar artery (82.9 %). The sensitivities of the 10-, 7-, and 4-point scales were 67.1, 74.4, and 96.3 %, respectively (p<0.001). Percentage interobserver agreement in diagnosis of BD reached 93 % for the 10-point scale, 89 % for the 7-point scale, and 95 % for the 4-point scale (p=0.37). CONCLUSIONS: In the application of CTA to the diagnosis of BD, reducing the assessment of vascular opacification scale from a 10- to a 4-point scale significantly increases the sensitivity and maintains high interobserver reliability.
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Morte Encefálica/diagnóstico , Angiografia Cerebral , Tomografia Computadorizada por Raios X , Adulto , Idoso , Morte Encefálica/fisiopatologia , Circulação Cerebrovascular , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
INTRODUCTION: Stasis filling, defined as delayed, weak, and persistent opacification of proximal segments of the cerebral arteries, is frequently found in brain dead patients. This phenomenon causes a major problem in the development of reliable computed tomographic angiography (CTA) protocol in the diagnosis of brain death (BD). The aim of our study was to characterize stasis filling in the diagnosis of BD. To achieve this, we performed a dynamic evaluation of contrast enhancement of the cerebral and extracranial arteries in patients with BD and controls. METHODS: Study population included 30 BD patients, who showed stasis filling in computed tomographic perfusion (CTP) series. Thirty patients, after clipping of an intracranial aneurysm, constituted the control group. The study protocol consisted of CTA, CTP, and angiography. Time-density curves (TDCs) of cerebral and extracranial arteries were generated using 40-s series of CTP. RESULTS: Cerebral TDCs in BD patients represented flat curves in contrast to TDCs in controls, which formed steep and narrow Gaussian curves. We found longer time to peak enhancement in BD patients than in controls (32 vs. 21 s; p < 0.0001). In BD patients, peak enhancement in the cerebral arteries occurred with a median delay of 14.5 s to peak in extracranial arteries, while no delay was noted in controls (p < 0.0001). Cerebral arteries in BD patients showed lower peak enhancement than controls (34.5 vs. 81.5 HU; p < 0.0001). In all BD patients, CTP revealed zero values of cerebral blood flow and volume. Angiography showed stasis filling in 14 (46.7 %) and non-filling in 16 (53.3 %) cases. CONCLUSION: A confrontation of stasis filling with CTP results showed that stasis filling is not consistent with preserved cerebral perfusion, thus does not preclude diagnosis of BD.
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Morte Encefálica , Angiografia Cerebral/métodos , Artérias Cerebrais/diagnóstico por imagem , Transtornos Cerebrovasculares/complicações , Transtornos Cerebrovasculares/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Adulto JovemRESUMO
PURPOSE: The purpose of this study was to assess the role of proton magnetic resonance spectroscopy (1H MRS) in the detection of changes in cerebral metabolite levels in autistic children. MATERIAL AND METHODS: Study group consisted of 12 children, aged 8-15 years, who were under the care of Pediatric Neurology Department and Pediatric Rehabilitation Department of Medical University of Bialystok. The diagnosis of autism was established by neurologist, psychiatrist and psychologist in every case. All patients matched the clinical criteria of the disease according to International Statistical Classification of Diseases and Related Health Problems (ICD-10). The control group included 16 healthy children aged 7-17. 1H MRS was performed with a single-voxel method (TE-36, TR-1500, NEX-192). The volume of interest (VOI) was located in the frontal lobe regions, separately on each side. RESULTS: We showed lower N-acetylaspartate/creatine (NAA/Cr), γ-aminobutyric acid /creatine (GABA/Cr) and glutamate/creatine (Glx/Cr) in the frontal lobes in the study group comparing with healthy controls. The ratio of myoinositol/creatine (mI/Cr) was increased in autistic children. No differences in choline/creatine (Cho/Cr) ratio in study group and controls were found. There was a correlation between age and NAA/Cr in autistic children (R=0.593 p=0.041). No significant differences in metabolite ratios between right and left hemisphere in ASD and controls were found. CONCLUSIONS: (1)H MRS can provide important information regarding abnormal brain metabolism. Differences in NAA/Cr, GABA/Cr, Glx/Cr and mI/Cr may contribute to the pathogenesis of autism.
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Transtorno Autístico/metabolismo , Imageamento por Ressonância Magnética/métodos , Adolescente , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Criança , Colina/metabolismo , Creatina/metabolismo , Feminino , Humanos , Masculino , Ácido gama-Aminobutírico/metabolismoRESUMO
INTRODUCTION: Proton magnetic resonance spectroscopy (¹H MRS) enables the observation of brain function in vivo. The aim of our study was to evaluate the effects of antipsychotic medication on metabolite levels in the brain of schizophrenic patients based on a ¹H MRS examination. METHODS: We examined 42 patients previously diagnosed with chronic schizophrenia twice: firstly, after the neuroleptic wash-out (baseline) and secondly, under stable medication (follow-up, after treatment). The study had a naturalistic design and several different neuroleptic medications were used during the treatment phase. The clinical evaluation, MRI and MRS procedures were performed. The group of 26 healthy controls were also examined to compare MRS results. RESULTS: We found a significantly lower NAA/Cr (N-acetylaspartate/creatine) ratio in the frontal lobe and thalamus in patients (after the wash-out) as compared to controls. After treatment a significant decrease of the Glx/Cr ratio in the temporal lobe and a trend for an increase of the NAA/Cr ratio in the thalamus were observed. CONCLUSION: Our results confirm that antipsychotic medication modifies brain metabolism measured by means of ¹H MRS. The pattern of the changes suggests a neuroprotective action of antipsychotic medication in schizophrenia.
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Antipsicóticos/uso terapêutico , Química Encefálica/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Neurônios/efeitos dos fármacos , Esquizofrenia/tratamento farmacológico , Esquizofrenia/metabolismo , Adulto , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Manual Diagnóstico e Estatístico de Transtornos Mentais , Feminino , Seguimentos , Análise de Fourier , Lobo Frontal/metabolismo , Ácido Glutâmico/metabolismo , Glutamina/metabolismo , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Neurônios/metabolismo , Escalas de Graduação Psiquiátrica , Tálamo/metabolismo , Adulto Jovem , Ácido gama-Aminobutírico/metabolismoRESUMO
INTRODUCTION: According to Polish brain death (BD) criteria, instrumental confirmatory tests should be used in certain clinical situations, particularly any case for which clinical examinations seem inadequate. Electrophysiological tests are often unavailable. Therefore, cerebral perfusion testing is the method of choice with four-vessel digital subtraction angiography (DSA), the gold standard. Unfortunately, DSA is an expensive and invasive examination that requires an experienced neuroradiologist and the availability of an angiography suite. Recently, multirow computed tomographic devices became available, even in smaller hospitals in Poland. Despite this fact, computed tomographic angiography (CTA) and computed tomographic perfusion (CTP) are not accepted in BD diagnosis protocols in Poland because of limited experience and a lack of widely accepted criteria. In this situation, we started a multicenter trial to determine the accuracy of CTA and CTP to confirm BD. METHODS: We examined 24 patients who fulfilled standard clinical BD criteria. We recognized the absence of brain perfusion in CTA examination following the criteria proposed by the French Society of Neuroradiology, namely, the absence of opacification of M4 middle cerebral artery segments (M4-MCA) and of deep cerebral veins. RESULTS: In all of our patients, CTA showed absence of opacification of M4 segments and of deep cerebral veins. In addition, three patients had CTA showing weak opacification of A2 segments of the anterior cerebral artery (A2-ACA) and M2 or M3-MCA. Opacification of the basilar artery or of the posterior cerebral arteries was not noted in any case. In all patients, CTP revealed zero values of regional cerebral blood volume and regional cerebral blood flow. Conventional angiography confirmed cerebral circulatory arrest in all 24 cases. CONCLUSION: CTA and CTP seem to be promising radiological examinations for the diagnosis of BD. They may be noninvasive alternatives to conventional cerebral angiography, and to the other instrumental confirmatory tests, that are unavailable or inadequate.
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Angiografia , Morte Encefálica/diagnóstico , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Polônia , Fluxo Sanguíneo RegionalRESUMO
BACKGROUND: To evaluate the clinical and radiological effectiveness of [DOTA(0), D-Phe(1), Tyr(3)]-octreotate (DOTATATE) Y-90 in patients with extensive progressive gastroenteropancreatic neuroendocrine carcinomas (GEP-NETs). MATERIALS AND METHODS: Sixty patients with histologically proven GEP-NETs were treated with DOTATATE Y-90. Clinical responses were assessed 6 weeks after completing therapy and then after each of the 3- to 6-month intervals. The radiological response was classified according to RECIST criteria. RESULTS: At 6 months after final treatment, radiological partial response (PR; at least a 30% decrease in the sum of the longest diameter of target lesions) was observed in 13 patients (23%), and the remaining patients had stable disease (SD; less than 30% decrease in the sum of the longest diameter of target lesions or less than 20% increase in the sum of the longest diameter of target lesions) (77%). Clinical PR at 6 months was in 43 patients (72%), nine patients had SD and progressive disease (PD) was noted in eight patients. Median progression-free survival (PFS) was 17 months, while the median overall survival (OS) was 22 months. In eight patients with early PD, the PFS was 4.5 and OS 9.5 months, while in those with SD or PR, PFS and OS were 19.5 and 23.5 months, respectively. After 12 months of follow-up, five patients had World Health Organization (WHO) grade 2 or 3 renal toxicity. Haematological toxicity (WHO grade 3 and 4) was noted during therapy in 10% of patients and persisted in 5%. CONCLUSIONS: DOTATATE Y-90 therapy is effective and relatively safe in patients with GEP-NET. Standard doses of DOTATATE Y-90 result in a relatively low risk of myelotoxicity. However, due to ongoing risk of renal toxicity, careful monitoring of the kidney is recommended.
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Carcinoma Neuroendócrino/diagnóstico por imagem , Neoplasias Gastrointestinais/diagnóstico por imagem , Octreotida/análogos & derivados , Compostos Organometálicos/uso terapêutico , Neoplasias Pancreáticas/diagnóstico por imagem , Radioisótopos de Ítrio/uso terapêutico , Adulto , Idoso , Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Carcinoma Neuroendócrino/patologia , Progressão da Doença , Feminino , Neoplasias Gastrointestinais/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Octreotida/administração & dosagem , Octreotida/efeitos adversos , Octreotida/uso terapêutico , Neoplasias Pancreáticas/patologia , Cintilografia , Resultado do Tratamento , Adulto Jovem , Radioisótopos de Ítrio/efeitos adversosRESUMO
This paper presents a computer assisted support of ischemic stroke diagnosis based on nonenhanced CT examinations acquired in the hyperacute phase of stroke. Computational analysis, recognition, and image understanding methods were used for extraction of the subtlest signs of hypodensity in diagnostically important areas. Starting from perception improvement, suggestive and coarse image data visualization was designed as a complement of the standard diagnosis procedure based on CT scan soft-copy review. The proposed method includes an evidence-based description of ischemic conditions and changes, de-skulling and segmenting of unusual areas, the analysis of hypodensity signs across scales and subbands with noise reduction, and hypodensity extraction. Following visualization, forms of empowered hypodensity symptoms localize suggested ischemic areas in source brain image space. Increased visibility of cerebral ischemia for difficult-to-diagnose cases was experimentally noticed and improved diagnostic value of CT was concluded.
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Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Mapeamento Encefálico , HumanosRESUMO
BACKGROUND: Renal allograft survival depends on a number of factors, however, no reliable simple parameter has been shown to predict long-term outcome after transplantation. Ultrasound is recognized and relatively inexpensive, providing information about renal location, contour, and size. Doppler ultrasonography shows kidney morphology and hemodynamics. The aim of this study was the evaluation of whether Doppler ultrasound of renal arteries performed in the early stage after transplantation was a valuable predictor for long-term-outcomes. MATERIAL AND METHODS: The study included 17 female and 24 male patients, aged 17-69 years with stable graft function. The Doppler ultrasound of renal flow was done on the 1st and 3rd day after transplantaion, and estimated glomerular filtration rate (eGFR) on the 20th day. The measured indices were as follows: maximum blood flow velocity (V(max)), minimum blood flow velocity (V(min)), resistive index (RI), and pulsatile index (PI). The creatinine concentration was evaluated, and eGFR calculated. RESULTS: Mean renal and intrarenal artery RI increased to day 3 after transplantation, and then reduced. The mean renal and intrarenal V(max) at day 3 correlated positively with eGFR (r = 0.38; P = .015); (r = 0.45; P = .003, respectively). Mean renal and intrarenal V(min) correlated positively with eGFR (r = 0.50; P = .001; r = 0.41; P = .008, respectively). The mean renal and intrarenal V(max) and V(min) on day 1 did not correlate with eGFR. CONCLUSIONS: Early Doppler Ultrasonography of renal graft hemodynamics may be a valuable predictor of graft survival and long-term outcomes. Blood flow velocity within renal arteries seemed to be an important factor.
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Velocidade do Fluxo Sanguíneo , Sobrevivência de Enxerto/fisiologia , Transplante de Rim/fisiologia , Circulação Renal/fisiologia , Adolescente , Adulto , Idoso , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Operatório , Valor Preditivo dos Testes , Pulso Arterial , Artéria Renal/fisiologia , Ultrassonografia DopplerRESUMO
Interleukin-6 (IL-6) has been shown to be involved in the pathogenesis of several bone diseases characterized by a negative balance between bone resorption and formation. The aim of the study was to estimate serum markers of bone turnover: osteoclast-derived tartrate-resistant acid phosphatase form 5a (TRACP 5b) reflecting resorption, and osteocalcin as a marker of bone formation in IL-6 knock-out mice to assess the role of IL-6 in the pathogenesis of thyrotoxicosis-related disturbances of bone metabolism. The study was performed on forty, 14-15 weeks old, female mice: C57BL/6J (wild-type; WT) and C57BL/6J (IL6-/-Kopf) (IL-6 knock-out; IL6KO). The mice were randomly divided into 4 groups with 10 mice in each one: 1. WT mice in thyrotoxicosis (WT-thx), 2. WT controls (WT-ctrl), 3. IL6KO mice with thyrotoxicosis (IL6KO-thx), and 4. IL6KO controls. Experimental model of hyperthyroidism was induced by intraperitoneal injection of levothyroxine at a dose of 1 microg/g, daily over 21 days. The serum levels of TRACP 5b and osteocalcin were determined by ELISA. Serum concentration of TRACP 5b (median and interquartile ranges) were significantly increased in both groups of mice with thyrotoxicosis: WT [28.2(18.8-41.6) U/l] and IL6KO [26.4(23.0-31.2) U/l] as compared to the respective controls. Osteocalcin serum levels in IL6KO-thx mice [111.9(103.1-175.6) ng/ml] were significantly elevated in comparison to WT-thx animals [46.1(32.5-58.9) ng/ml]. In summary, the results of the present study suggest that IL-6 plays a crucial role in thyrotoxicosis-related disturbances of bone turnover in mice, determining the imbalance between bone resorption and bone formation caused by excess of thyroid hormones predominantly by inhibition of bone formation.
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Doenças Ósseas/patologia , Interleucina-6/metabolismo , Tireotoxicose/patologia , Fosfatase Ácida/sangue , Animais , Biomarcadores/sangue , Densidade Óssea , Densitometria , Feminino , Genótipo , Isoenzimas/sangue , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteocalcina/sangue , Fosfatase Ácida Resistente a Tartarato , Glândula Tireoide/patologiaRESUMO
A 32-year-old woman diagnosed with very rapidly progressing early-onset Alzheimer's disease (EOAD), age of onset 29 years, and S170F mutation in presenilin 1 gene (PSEN1) is presented. Neuroimaging conducted 2 years after the first symptoms was typical for the advanced stage of Alzheimer's disease (AD), showing cortical brain atrophy, particularly within hippocampus, frontal and temporal cortex. The unaffected parents of the proband are not carriers of the mutation. The paternity was confirmed by microsatellite typing, strongly suggesting de novo origin of S170F mutation. In silico modeling of S170F mutation impact on presenilin 1 (PS1) transmembrane structure indicates that the mutation considerably alters putative interactions of PS1 with other proteins within gamma-secretase complex.
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Doença de Alzheimer/genética , Mutação , Presenilina-1/genética , Adulto , Doença de Alzheimer/diagnóstico , Encéfalo/patologia , Progressão da Doença , Feminino , Humanos , Imageamento por Ressonância Magnética , Modelos Moleculares , Fenilalanina , Serina , Fatores de TempoRESUMO
BACKGROUND AND PURPOSE: Functional imaging studies suggest that poststroke recovery is related to the reorganization in both contralesional and ipsilesional prefrontal cortex. Little is known, however, about how longitudinal metabolic changes in prefrontal regions relate to the improvement after stroke. We sought to determine whether poststroke recovery is associated with changes in N-acetylaspartate/creatine (NAA/Cr) ratio within contralesional prefrontal regions. MATERIALS AND METHODS: Twenty-seven patients with a first ischemic stroke located outside the frontal lobes were included. Proton MR spectroscopy ((1)H-MRS) was performed on a 1.5T scanner. Point-resolved spectroscopy sequence (PRESS) was used. NAA/Cr was measured both in ipsilesional and contralesional prefrontal regions in early (14 +/- 6 days after stroke) and chronic phases of the disease (110 +/- 30 days after). Patients' neurologic status was assessed using Scandinavian Stroke Scale (SSS) at discharge from the stroke unit and during second (1)H-MRS examination. RESULTS: Subjects showing increased contralesional NAA/Cr from first to follow-up examination improved significantly more on the SSS than patients not showing this increase. Analysis was performed while correcting for change in NAA/Cr levels in the ipsilesional hemisphere. For the whole group, the change in contralesional NAA/Cr was significantly correlated to the change in SSS scores (r = 0.40, P = .03). Change in the ipsilesional NAA/Cr measures did not correlate with the change in SSS scores. CONCLUSION: Poststroke recovery was related to the increase in contralesional prefrontal NAA/Cr. This association may reflect recovery mechanisms involving the nonaffected hemisphere. Further assessment of these regions may provide information about mechanisms contributing to neurologic improvement.
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Espectroscopia de Ressonância Magnética , Córtex Pré-Frontal/metabolismo , Córtex Pré-Frontal/patologia , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Idoso , Idoso de 80 Anos ou mais , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Isquemia Encefálica/metabolismo , Isquemia Encefálica/patologia , Creatina/metabolismo , Feminino , Seguimentos , Lateralidade Funcional , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , PrótonsRESUMO
Classification of cranial encephalocele is based on the anatomic location of the skull defect. Basal sphenoidal encephaloceles are the least common form of encephalocele whose pathogenesis can be congenital, traumatic, tumoral or spontaneous. We present a case of a very rare basal encephalocele protruding through a defect in the greater wing of the sphenoid bone into the pterygoid fossa.
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Diffusion-weighted imaging (DWI) provides information on tissue integrity and shows increased sensivity in detecting brain white matter disease compared to traditional T2-weighted MRI. We compared apparent diffusion coefficient (ADC) values in brain lesions and normal appearing white matter (NAWM) in patients with tuberous sclerosis complex (TSC) to normal brain tissue in the control group. MRI and DWI were performed in 14 patients with TSC (age range 7-16 years) and in 18 age-matched normal control subjects. ADC values measured from 44 supratentorial cortical tubers, 37 white matter lesions, 80 NAWM were compared to those in control subjects. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U tests. The highest ADCs were measured in cortical tubers (mean ADC, 1.24×10-3 mm(2)/s), followed in descending order by WM lesions (mean ADC, 1.07×10-3 mm(2)/s), NAWM (mean ADC, 0.83×10-3 mm(2)/s). We found a significant difference in ADC values of gray, WM lesions and NAWM in TSC patients compared to the control group (p<0,0001). Elevated ADC values in NAWM in TSC patients may be caused by subtle depletion of myelin sheaths and looseness of structures within the brain parenchyma due to underlying migration disorders.
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The magnitude of the motor deficit in patients with stroke depends not only on the size and location of the destroyed brain tissue, but also on axonal injury in the descending motor pathways which appears after stroke. After cerebral ischemia, there are no visible abnormalities in conventional MRI in the intact pyramidal tracts despite the process of neuronal destruction by Wallerian degeneration. Conventional MRI is not a sensitive test for Wallerian degeneration in the acute or subacute time period as it shows no changes within the first four weeks. Magnetic resonance spectroscopy (MRS) has been used for better quantification of the extent or severity of fibre damage by evaluating metabolite alterations in normal-appearing corticospinal and corticopontal tracts. This study assessed the role of 1H MRS in the detection of changes in cerebral metabolite levels in pyramidal tracts after cortical/ subcortical infarction and to compare metabolite alterations to clinical outcome (assessed by Barthel index, Scandinavian Stroke Scale). The study included 31 patients who had suffered an ischemic cortical/subcortical stroke involving the motor cortex or the descending fibers. Ratios of NAA/Cr, Cho/Cr, lip/Cr and Lac/Cr from internal capsules and cerebral peduncles were measured and compared with clinical status assessed by Barthel index and Scandinavian Stroke Scale (SSS). The ratio of NAA/Cr was significantly decreased (p<0.001) in the normal-appearing ipsilateral internal capsule in comparison with the control group. Cho/Cr and lac/Cr ratios were increased compared to the control group (p=0.019). Decrease of NAA/Cr ratio correlated with clinical status assessed by Barthel index and there was a correlation between clinical improvement (assessed by SSS) and lac/Cr ratio. Tissue metabolite concentrations distant from the infarcted region correlated with the clinical course and had predictive value. Proton MRS is very useful tool for evaluating major changes in metabolite levels in pyramidal tracts after brain stroke.