Altered thalamic neurotransmitters metabolism and functional connectivity during the development of chronic constriction injury induced neuropathic pain

BACKGROUND: To investigate the thalamic neurotransmitters and functional connections in the development of chronic constriction injury (CCI)-induced neuropathic pain. METHODS: The paw withdrawal threshold was measured by mechanical stimulation the right hind paw with the von frey hair in the rats of CCI-induced neuropathic pain. The N-acetylaspartate (NAA) and Glutamate (Glu) in thalamus were detected by magnetic resonance spectrum (MRS) process. The thalamic functional connectivity with other brain regions was scanned by functional magnetic resonance image (fMRI). RESULTS: The paw withdrawal threshold of the ipsilateral side showed a noticeable decline during the pathological process. Increased concentrations of Glu and decreased levels of NAA in the thalamus were significantly correlated with mechanical allodynia in the neuropathic pain states. The thalamic regional homogeneity (ReHo) decreased during the process of neuropathic pain. The functional connectivity among the thalamus with the insula and somatosensory cortex were significantly increased at different time points (7, 14, 21 days) after CCI surgery. CONCLUSION: Our study suggests that dynamic changes in thalamic NAA and Glu levels contribute to the thalamic functional connection hyper-excitation during CCI-induced neuropathic pain. Enhanced thalamus-insula functional connection might have a significant effect on the occurrence of neuropathic pain.

Electroacupuncture ameliorate learning and memory by improving N -acetylaspartate and glutamate metabolism in APP/PS1 mice

OBJECTIVE: To explore the precise mechanism of electroacupuncture (EA) to delay cognitive impairment in Alzheimer disease. Methods N -Acetylaspartate (NAA), glutamate (Glu) and myoinositol (mI) metabolism were measured by magnetic resonance spectroscopy, learning and memory of APP/PS1 mouse was evaluated by the Morris water maze test and the step-down avoidance test, neuron survival number and neuronal structure in the hippocampus were observed by Nissl staining, and BDNF and phosphorylated TrkB detected by Western blot. RESULTS: EA at DU20 acupuncture significantly improve learning and memory in behavioral tests, up-regulate NAA, Glu and mI metabolism, increase the surviving neurons in hippocampus, and promote the expression of BDNF and TrkB in the APP/PS1 transgenic mice. CONCLUSION: These findings suggested that EA is a potential therapeutic for ameliorate cognitive dysfunction, and it might be due to EA could improve NAA and Glu metabolism by upregulation of BDNF in APP/PS1 mice.

Bacterial colonization due to increased nurse workload in an intensive care unit / Colonização bacteriana por causa do aumento da carga de trabalho da equipe de enfermagem em unidade de terapia intensiva / Colonización bacteriana debido al aumento de la carga de trabajo del equipo de enfermería en una unidad de cuidados intensivos

INTRODUCTION: The rates of multiresistant bacteria colonization or infection (MRB+) development in intensive care units are very high. The aim of this study was to determine the possible association between the risk of development of nosocomial infections and increased daily nurse workload due to understaffing in intensive care unit. METHODS: We included 168 patients. Intensity of workload and applied procedures to patients were scored with the Project de Recherché en Nursing and the Omega scores, respectively. The criteria used for infections were those defined by the Centers for Disease Control. RESULTS: Of the 168 patients, 91 (54.2%) were female and 77 (45.8%) were male patients. The mean age of female and male was 64.9 ± 6.2 years and 63.1 ± 11.9 years, respectively. The mean duration of hospitalization in intensive care unit was 18.4 ± 6.1 days. Multiresistant bacteria were isolated from cultures of 39 (23.2%) patients. The development of MRB+ infection was correlated with length of stay, Omega 1, Omega 2, Omega 3, Total Omega, daily PRN, and Total PRN (p < 0.05). There was no correlation between development of MRB+ infection with gender, age and APACHE-II scores (p > 0.05). CONCLUSION: The risk of nosocomial infection development in an intensive care unit is directly correlated with increased nurse workload, applied intervention, and length of stay. Understaffing in the intensive care unit is an important health problem that especially affects care-needing patients. Nosocomial infection development has laid a heavy burden on the economy of many countries. To control nosocomial infection development in the intensive care unit, nurse workload, staffing level, and working conditions must be arranged. .

INTRODUÇÃO: As taxas de desenvolvimento de infecção ou colonização por bactérias multirresistentes (BMR+) em unidades de terapia intensiva são muito elevadas. O objetivo deste estudo foi determinar a possível associação entre o risco de desenvolvimento de infecções hospitalares e o aumento da carga de trabalho diária da equipe de enfermagem devido à insuficiência de pessoal em unidade de terapia intensiva. MÉTODOS: Cento e sessenta e oito pacientes foram incluídos. O volume da carga de trabalho e os procedimentos realizados em pacientes foram avaliados com o uso de instrumentos de medidas como o Projeto de Pesquisa em Enfermagem (Project de Recherché en Nursing) e o Omega, respectivamente. Os critérios usados para definir infecções foram os definidos pelos Centros de Controle de Doenças. RESULTADOS: Dos 168 pacientes, 91 (54,2%) eram do sexo feminino e 77 (45,8%) do sexo masculino. As médias das idades de mulheres e homens foram 64,9 ± 6,2 e 63,1 ± 11,9 anos, respectivamente. A média do tempo de internação em unidade de terapia intensiva foi de 18,4 ± 6,1 dias. As bactérias multirresistentes foram isoladas a partir de culturas de 39 (23,2%) pacientes. O desenvolvimento de infecção por BMR+ foi correlacionado com tempo de internação, Omega 1, Omega 2, Omega 3, Omega total, PPE diário e PPE total (p < 0,05). Não houve correlação entre desenvolvimento de infecção por BMR+ e gênero, idade e escores no APACHE-II (p > 0,05). CONCLUSÃO: O risco de desenvolvimento de infecção hospitalar em unidade de terapia intensiva está diretamente relacionado com o aumento da carga de trabalho de enfermagem, as intervenções praticadas e o tempo de internação. A falta de pessoal em unidade de terapia intensiva é um problema de saúde importante que afeta principalmente os pacientes que requerem cuidados. A infecção hospitalar colocou um fardo pesado sobre a economia de muitos países. Para controlar o desenvolvimento de infecção hospitalar em UTI, a carga ...

INTRODUÇÃO: as taxas de desenvolvimento de infecção ou colonização por bactérias multirresistentes [BMR (+)] em unidades de terapia intensiva são muito elevadas. O objetivo deste estudo foi determinar a possível associação entre o risco de desenvolvimento de infecções hospitalares e o aumento da carga de trabalho diária da equipe de enfermagem por causa da insuficiência de pessoal em unidade de terapia intensiva. MÉTODOS: foram incluídos 168 pacientes. O volume da carga de trabalho e os procedimentos feitos em pacientes foram avaliados com o uso de instrumentos de medidas como o Projeto de Pesquisa em Enfermagem (Project de Recherché en Nursing) e o Omega, respectivamente. Os critérios usados para definir infecções foram os estabelecidos pelos Centros de Controle de Doenças. RESULTADOS: dos 168 pacientes, 91 (54,2%) eram do sexo feminino e 77 (45,8%) do masculino. As médias das idades de mulheres e homens foram 64,9 ± 6,2 e 63,1 ± 11,9 anos, respectivamente. A média do tempo de internação em unidade de terapia intensiva foi de 18,4 ± 6,1 dias. As bactérias multirresistentes foram isoladas a partir de culturas de 39 (23,2%) pacientes. O desenvolvimento de infecção por BMR (+) foi correlacionado com tempo de internação, Omega 1, Omega 2, Omega 3, Omega total, PPE diário e PPE total (p < 0,05). Não houve correlação entre desenvolvimento de infecção por BMR (+) e gênero, idade e escores no Apache-II (p > 0,05). CONCLUSÃO: o risco de desenvolvimento de infecção hospitalar em unidade de terapia intensiva está diretamente relacionado com o aumento da carga de trabalho de enfermagem, as intervenções praticadas e o tempo de internação. A falta de pessoal em unidade de terapia intensiva é um problema de saúde importante que afeta principalmente os pacientes que requerem cuidados. A infecção hospitalar colocou um fardo pesado sobre a economia de muitos países. Para controlar o desenvolvimento de infecção hospitalar em UTI, a carga de trabalho ...

INTRODUCCIÓN: Las tasas de desarrollo de infección o colonización por bacterias multirresistentes en unidades de cuidados intensivos son muy elevadas. El objetivo de este estudio fue determinar la posible asociación entre el riesgo de desarrollo de infecciones hospitalarias y el aumento de la carga de trabajo diaria del equipo de enfermería debido a la falta de personal en la unidad de cuidados intensivos. MÉTODOS: Ciento sesenta y ocho pacientes fueron incluidos. El volumen de la carga de trabajo y los procedimientos realizados en pacientes fueron evaluados con el uso de instrumentos de medidas como el Proyecto de Investigación en Enfermería (Project de Recherché en Nursing) y el Omega, respectivamente. Los criterios usados para definir infecciones fueron los definidos por los Centros de Control de Enfermedades. RESULTADOS: De los 168 pacientes, 91 (54,2%) eran del sexo femenino y 77 (45,8%) del sexo masculino. La edad media de las mujeres y de los hombres fueron 64,9 ± 6,2 y 63,1 ± 11,9 años, respectivamente. El tiempo medio de ingreso en la unidad de cuidados intensivos fue de 18,4 ± 6,1 días. Las bacterias multirresistentes fueron aisladas a partir de cultivos de 39 (23,2%) pacientes. El desarrollo de infección por bacterias multirresistentes fue correlacionado con el tiempo de ingreso, Omega 1, Omega 2, Omega 3, Omega total, PPE diario y PPE total (p < 0,05). No hubo correlación entre el desarrollo de la infección por bacterias multirresistentes y el sexo, la edad y las puntuaciones en el APACHE-II (p > 0,05). CONCLUSIÓN: El riesgo de desarrollo de infección hospitalaria en una unidad de cuidados intensivos está directamente relacionado con el aumento de la carga de trabajo de enfermería, las intervenciones practicadas y el tiempo de ingreso. La falta de personal en la unidad de cuidados intensivos es un problema de sanidad importante que afecta principalmente a los pacientes que necesitan esos cuidados. La infección hospitalaria ...

Proton magnetic spectroscopy agreed better with magnetic resonance image to lateralization of epileptogenic zone than with surface electroencephalography / Espectroscopia de protons de hidrogenio na investigacao ambulatorial das epilepsias extra-temporais

Objective To analyze the agreement rate of proton magnetic spectroscopy with magnetic resonance image (MRI) and surface electroence-phalography (EEG) in extratemporal neocortical epilepsies. Methods A cross-sectional study, type series of cases included 33 patients, age range 13–59 years old, of both gender, presenting structural alteration identified by MRI (75.8%) or by neurophysiologic techniques (72.7%). The variables were alterations of N-acetyl-aspartate/choline, N-acetyl-aspartate/creatine, choline/creatine, and N-acetyl-aspartate/cho-line+creatine coefficient of asymmetry. Results Agreement rates of lateralization by coefficient of asymmetry of NAA/Cho, NAA/Cr, Co/Cr, and NAA/Cho+Cr with MRI, independent of alteration of surface EEG, were equal to 93.3, 57.9, 15.4, and 93.3%, respectively, modifying to 100, 33.3, 0, and 100%, in 16 patients, with lateralization agreement of MRI and surface EEG. Conclusion Proton magnetic spectroscopy agreed better with MRI to lateralization of epileptogenic zone than with surface EEG. .

Objetivo Analisar a taxa de concordância da espectroscopia de prótons de hidrogênio com imagem de ressonância magnética (IRM) e o eletrencefalograma (EEG) de superfície nas epilepsias neocorticais extratemporais. Métodos Estudo transversal, série de casos, incluiu 33 pacientes, com idade de 13 a 59 anos, de ambos os gêneros, apresentando alteração estrutural à IRM (75,8%) ou neurofisiológica à (72,7%). As variáveis estudadas foram as alterações dos coeficientes de assimetria de N-acetil-aspartato/colina, N-acetil-aspartato/crea-tina, Colina/Creatina e N-acetil-aspartato/colina+creatina. Resultados As taxas de concordância de lateralização dos coeficientes de assimetria de NAA/Co, NAA/Cr, Co/Cr e NAA/Co+Cr com a IRM, independentemente de alterações do EGG de superfície, passaram de 93,3, 57,9, 15,4, 93,3%, respectivamente, para 100, 33,3, zero, 100%, em 16 pacientes, mostrando concordância de lateralização entre IRM e EEG de superfície. Conclusão A espectroscopia de prótons de hidrogênio concordou melhor com a lateralização da zona epileptogênica pela IRM do que com o EEG de superfície. .

Thalamic metabolic abnormalities in patients with Huntington's disease measured by magnetic resonance spectroscopy

Huntington's disease (HD) is a neurologic disorder that is not completely understood; its fundamental physiological mechanisms and chemical effects remain somewhat unclear. Among these uncertainties, we can highlight information about the concentrations of brain metabolites, which have been widely discussed. Concentration differences in affected, compared to healthy, individuals could lead to the development of useful tools for evaluating the progression of disease, or to the advance of investigations of different/alternative treatments. The aim of this study was to compare the thalamic concentration of metabolites in HD patients and healthy individuals using magnetic resonance spectroscopy. We used a 2.0-Tesla magnetic field, repetition time of 1500 ms, and echo time of 135 ms. Spectra from 40 adult HD patients and 26 control subjects were compared. Quantitative analysis was performed using the LCModel method. There were statistically significant differences between HD patients and controls in the concentrations of N-acetylaspartate+N-acetylaspartylglutamate (NAA+NAAG; t-test, P<0.001), and glycerophosphocholine+phosphocholine (GPC+PCh; t-test, P=0.001) relative to creatine+phosphocreatine (Cr+PCr). The NAA+NAAG/Cr+PCr ratio was decreased by 9% and GPC+PCh/Cr+PCr increased by 17% in patients compared with controls. There were no correlations between the concentration ratios and clinical features. Although these results could be caused by T1 and T2 changes, rather than variations in metabolite concentrations given the short repetition time and long echo time values used, our findings point to thalamic dysfunction, corroborating prior evidence.

Magnetic resonance imaging study cannot individually distinguish individuals with mild cognitive impairment, mild Alzheimer's disease, and normal aging / Estudo por ressonância magnética não pode diferenciar individualmente os indivíduos com declínio cognitivo leve, doença de Alzheimer leve e envelhecimento normal

Objective: To evaluate the volumetric and spectroscopy aspects of hippocampus in patients with mild Alzheimer's disease (AD) and mild cognitive impairment (MCI). Methods: A series of patients older than 65 years and with memory deficit were studied. Results: The evocation of words test presented a significant reduction in the number of words recalled by the patients with MCI and mild AD as compared with the control group. Bilateral reduction of the hippocampus volume in the AD group was observed when compared to the control group. There were no statistical differences in the values of NAA/Cr, mI/Cr, Cho/Cr and mI/NAA between the groups. Conclusions: Magnetic resonance imaging study failed to individually distinguish patients with MCI, mild AD and normal aging. However, patients with mild AD presented loss of asymmetry between the right and left hippocampus, and a reduction in hippocampus volume. .

Objetivo: Avaliar volume e espectroscopia do hipocampo em pacientes com doença de Alzheimer leve e declínio cognitivo leve. Métodos: Foi estudada uma série de pacientes com 65 anos de idade ou mais, com déficit de memória. Resultados: O teste de evocação de palavras mostrou redução significativa no número de palavras lembradas pelos pacientes com declínio cognitivo leve e doença de Alzheimer leve, em comparação com o grupo controle. Foi observada redução bilateral do volume do hipocampo no grupo com doença de Alzheimer quando comparado com o grupo controle. Não houve diferença estatística nos valores de NAA/Cr, mI/Cr, Cho/Cr e mI/NAA entre os grupos. Conclusão: Estudo pela ressonância magnética não diferencia individualmente os pacientes com declínio cognitivo leve, doença de Alzheimer leve e envelhecimento normal. No entanto, pacientes com quadro leve de doença de Alzheimer apresentam perda de assimetria entre os hipocampos direito e esquerdo e redução no volume do hipocampo. .

NAA and NAAG variation in neuronal activation during visual stimulation

N-acetyl-aspartyl-glutamate (NAAG) and its hydrolysis product N-acetyl-L-aspartate (NAA) are among the most important brain metabolites. NAA is a marker of neuron integrity and viability, while NAAG modulates glutamate release and may have a role in neuroprotection and synaptic plasticity. Investigating on a quantitative basis the role of these metabolites in brain metabolism in vivo by magnetic resonance spectroscopy (MRS) is a major challenge since the main signals of NAA and NAAG largely overlap. This is a preliminary study in which we evaluated NAA and NAAG changes during a visual stimulation experiment using functional MRS. The paradigm used consisted of a rest period (5 min and 20 s), followed by a stimulation period (10 min and 40 s) and another rest period (10 min and 40 s). MRS from 17 healthy subjects were acquired at 3T with TR/TE = 2000/288 ms. Spectra were averaged over subjects and quantified with LCModel. The main outcomes were that NAA concentration decreased by about 20% with the stimulus, while the concentration of NAAG concomitantly increased by about 200%. Such variations fall into models for the energy metabolism underlying neuronal activation that point to NAAG as being responsible for the hyperemic vascular response that causes the BOLD signal. They also agree with the fact that NAAG and NAA are present in the brain at a ratio of about 1:10, and with the fact that the only known metabolic pathway for NAAG synthesis is from NAA and glutamate.

Protective Effect of Hypoxic Preconditioning on Hypoxic-Ischemic Injured Newborn Rats

Brief episodes of cerebral hypoxia-ischemia cause transient ischemic tolerance to subsequent ischemic events that are otherwise lethal. This study was conducted to evaluate the protective effect of hypoxic preconditioning on hypoxic-ischemic injury in the neonatal rat and the persistence of a protective window after hypoxic preconditioning. The rats were preconditioned with hypoxia (8% oxygen, 92% nitrogen) for three hours, subjected to ischemia using ligation of the right common carotid artery, and then exposed to another three hours of hypoxia. Using proton magnetic resonance spectroscopy, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) staining, and morphologic scores, this study shows that hypoxic preconditioning 6-hr to 1-day before hypoxic-ischemic injury increases survival rates and has neuroprotective effects against subsequent hypoxic-ischemic injury. The mechanism of the protective effects of hypoxic preconditioning in the newborn rat brain may involve downregulation of apoptotic cell death.

Proton magnetic resonance spectroscopy of brain in obstructive sleep apnoea in north Indian Asian subjects.

Background & objectives: Repeated apnoeic/hypoapnoeic episodes during sleep may produce cerebral damage in patients with obstructive sleep apnoea (OSA). The aim of this study was to determine the absolute concentration of cerebral metabolites in apnoeic and non-apnoeic subjects from different regions of the brain to monitor the regional variation of cerebral metabolites. Methods: Absolute concentration of cerebral metabolites was determined by using early morning proton magnetic resonance spectroscopy (1H MRS) in 18 apnoeic patients with OSA (apnoeics) having apnoea/hypopnoea index (AHI) >5/h, while 32 were non-apnoeic subjects with AHI< 5/h. Results: The absolute concentration of tNAA [(N-acetylaspartate (NAA)+N-acetylaspartylglutamate (NAAG)] was observed to be statistically significantly lower (P<0.05) in apnoeics in the left temporal and left frontal gray regions compared to non-apnoeics. The Glx (glutamine, Gln + glutamate, Glu) resonance showed higher concentration (but not statistically significant) in the left temporal and left frontal regions of the brain in apnoeics compared to non-apnoeics. The absolute concentration of myo-inositol (mI) was significantly high (P<0.03) in apnoeics in the occipital region compared to non-apnoeics. Interpretation & conclusions: Reduction in the absolute concentration of tNAA in apnoeics is suggestive of neuronal damage, probably caused by repeated apnoeic episodes in these patients. NAA showed negative correlation with AHI in the left frontal region, while Cho and mI were positively correlated in the occipital region and Glx showed positive correlation in the left temporal region of the brain. Overall, our results demonstrate that the variation in metabolites concentrations is not uniform across various regions of the brain studied in patients with OSA. Further studies with a large cohort of patients to substantiate these observations are required.

Thalamic nuclear abnormalities as a contributory factor in sudden cardiac deaths among patients with schizophrenia

Patients with schizophrenia have a two- to three-fold increased risk of premature death as compared to patients without this disease. It has been established that patients with schizophrenia are at a high risk of developing cardiovascular disease. Moreover, an important issue that has not yet been explored is a possible existence of a "cerebral" focus that could trigger sudden cardiac death in patients with schizophrenia. Along these lines, several structural and functional alterations in the thalamic complex are evident in patients with schizophrenia and have been correlated with the symptoms manifested by these patients. With regard to abnormalities on the cellular and molecular level, previous studies have shown that schizophrenic patients have fewer neuronal projections from the thalamus to the prefrontal cortex as well as a reduced number of neurons, a reduced volume of either the entire thalamus or its subnuclei, and abnormal glutamate signaling. According to the glutamate hypothesis of schizophrenia, hypofunctional corticostriatal and striatothalamic projections are directly involved in the pathophysiology of the disease. Animal and post-mortem studies have provided a large amount of evidence that links the sudden unexpected death in epilepsy (SUDEP) that occurs in patients with schizophrenia and epilepsy to thalamic changes. Based on the results of these prior studies, it is clear that further research regarding the relationship between the thalamus and sudden cardiac death is of vital importance.

Espectroscopia cerebral em candidatos a transplante hepático / Cerebral magnetic resonance spectroscopy in patients with hepatic encephalopathy: analysis before and after liver transplantation

OBJETIVOS: Determinar os níveis dos metabólitos (mio-inositol [MI], colina [Cho], glutamina [Glx], creatina [Cr] e N-acetilaspartato [NAA]) por meio da espectroscopia por ressonância magnética em portadores de hepatopatia crônica, antes e após o transplante hepático, correlacionando com a avaliação clínica. MÉTODOS: Foram estudados prospectivamente 25 pacientes portadores de hepatopatia crônica do Serviço de Transplante Hepático da Universidade Federal do Paraná por meio de avaliação clínica e espectroscópica. Trinta voluntários sadios formaram o grupo controle, sendo submetidos às mesmas avaliações. Dezesseis dos 25 pacientes também foram avaliados após o transplante. RESULTADOS: Antes do transplante hepático reduções significativas nos índices de MI/Cr e Cho/Cr e aumento significativo no índice de Glx/Cr foram observadas nos pacientes portadores de encefalopatia hepática comparados ao grupo controle. Os critérios quantitativos de Ross para diagnóstico espectroscópico da encefalopatia hepática (MI/Cr e Cho/Cr < média + 2 desvios padrão do grupo controle) demonstraram uma sensibilidade de 61,54 por cento, especificidade de 91,67 por cento e precisão de 76 por cento, sendo que a Cho/Cr foi o melhor parâmetro isolado. A espectroscopia após o transplante mostrou mudanças nos índices metabólicos comparados com o status pré-transplante. CONCLUSÃO: A espectroscopia permite um diagnóstico preciso da encefalopatia hepática. A melhora dos níveis metabólicos após o transplante hepático sugere um importante papel do MI e da Cho no desenvolvimento da encefalopatia hepática.

OBJECTIVES: To determine the metabolite levels (myo-inositol [MI], choline [Cho], glutamate [Glx], creatine [Cr] and N-acetylaspartate [NAA]) visible on magnetic resonance spectroscopy in patients with chronic hepatic failure, before and after liver transplantation and to correlate these data with results of neuropsychiatric tests and clinical findings. METHODS: Twenty five patients with chronic hepatic failure from the Liver Transplantation Unit of the Federal University of Parana were prospectively studied. Patients were submitted to clinical evaluation and magnetic resonance spectroscopy. Thirty healthy volunteers also submitted to the same evaluations. Sixteen of the 25 patients were evaluated after liver transplantation. RESULTS: Before liver transplantation, significant reductions in MI/Cr and Cho/Cr and a significant increase in Glx/Cr were observed in patients with hepatic encephalopathy compared with healthy subjects. The Ross's criteria for spectroscopic diagnosis of the hepatic encephalopathy (MI/Cr and Cho/Cr lower than 2 SD of controls) demonstrated a sensitivity of 61.54 percent, specificity of 91.67 percent and accuracy of 76 percent, further Cho/Cr was the best parameter. Spectroscopy after liver transplantation showed changes in the metabolite ratios compared with the pretransplantation status. CONCLUSION: Magnetic resonance spectroscopy permits an accurate diagnosis of hepatic encephalopathy. Improvement of metabolic ratios after liver transplantation suggests an important role of MI and Cho in the development of hepatic encephalopathy.

Proton magnetic resonance spectroscopy of the frontal, cingulate and perirolandic cortices and its relationship to skin conductance in patients with schizophrenia

The aim of the present study was to determine whether specific subgroups of schizophrenic patients, grouped according to electrodermal characteristics, show differences in the N-acetylaspartate/creatine plus choline (NAA / (Cr + Cho)) ratios in the frontal, cingulate and perirolandic cortices. Skin conductance levels (SCL) and skin conductance responses to auditory stimulation were measured in 38 patients with schizophrenia and in the same number of matched healthy volunteers (control). All subjects were submitted to multivoxel proton magnetic resonance spectroscopic imaging. When compared to the control group, patients presented significantly lower NAA / (Cr + Cho) ratios in the right dorsolateral prefrontal cortex (schizophrenia = 0.95 ± 0.03; control = 1.12 ± 0.04) and in the right (schizophrenia = 0.88 ± 0.02; control = 0.94 ± 0.03) and left (schizophrenia = 0.84 ± 0.03; control = 0.94 ± 0.03) cingulates. These ratios did not differ between electrodermally responsive and non-responsive patients. When patients were divided into two groups: lower SCL (less than the mean SCL of the control group minus two standard deviations) and normal SCL (similar to the control group), the subgroup with a lower level of SCL showed a lower NAA / (Cr + Cho) ratio in the left cingulate (0.78 ± 0.05) than the controls (0.95 ± 0.02, P < 0.05) and the subgroup with normal SCL (0.88 ± 0.03, P < 0.05). There was a negative correlation between the NAA / (Cr + Cho) ratio in the left cingulate of patients with schizophrenia and the duration of the disease and years under medication. These data suggest the existence of a schizophrenic subgroup characterized by low SCL that could be a consequence of the lower neuronal viability observed in the left cingulate of these patients.

Proton MR spectroscopy of the foramen of Monro region in patients with tuberous sclerosis complex / Espectroscopia de prótons por RM da região do forame de Monro em pacientes com complexo esclerose tuberosa

PURPOSE: To evaluate with 1H-magnetic resonance spectroscopy (MRS) the metabolites rations of the foramen of Monro's region in patients with tuberous sclerosis complex (TSC). METHOD: Twelve patients with TSC and an age and gender-matched control group underwent MR imaging at a 1.5T scanner, and 1H-MRS at the foramen of Monro level with a multivoxel acquisition. Similar volumes of interest were selected in each side of the foramen of Monro and in the basal ganglia (lentiform nuclei). The obtained N-acetylaspartate (NAA), creatine (Cr) and choline (Cho) peak amplitude values and ratios were studied. The statistical analysis was performed and p<0.05 was considered statically significant. RESULTS: There was no significant difference between the NAA/Cr and Cho/Cr ratios near to the foramen of Monro and basal ganglia of the TSC patients compared with the controls (p>0.05). CONCLUSION: The NAA/Cr and Cho/Cr ratios near to the foramen of Monro and basal ganglia of TSC patients are similar to the rations obtained in the control group.

OBJETIVO: Avaliar através de espectroscopia de prótons as relações dos metabólitos da região do forame de Monro em pacientes com complexo esclerose tuberosa (CET). MÉTODO: Doze pacientes com CET e um grupo controle pareado por sexo e idade realizaram RM em aparelho de 1,5T, e a espectroscopia de prótons foi obtida ao nível do forame de Monro com aquisição multi-voxel. Volumes de interesse similares foram posicionados em cada lado do forame de Monro e nos gânglios da base (núcleos lentiformes). Os valores das relações e amplitudes de pico do N-acetilaspartato (NAA), creatina (Cr) e colina (Cho) foram estudados. A análise estatística foi realizada e valores de p<0,05 foram considerados estatisticamente significativos. RESULTADOS: Não houve diferença significativa entre as relações NAA/Cr e Cho/Cr na região do forame de Monro e nos gânglios da base dos pacientes com CeT comparados com os controles (p>0,05). CONCLUSÃO: As relações NAA/Cr e Cho/Cr na região do forame de Monro e nos gânglios da base de pacientes com CET são semelhantes àquelas obtidas no grupo controle.

Merosin-positive congenital muscular dystrophy: neuroimaging findings

Congenital muscle dystrophy (CMD) is a heterogeneous group of autosomal recessive myopathies. It is known that CMD may affect the central nervous system (CNS). Some authors have shown that merosin-negative CMD patients may have encephalic metabolic disturbances. In order to study metabolic changes within the brain, the authors performed a magnetic resonance spectroscopy (MRS) study in a 1-year-old girl with merosin-positive CMD (MP-CMD). MRS of brain demonstrated that NAA/Cr ratio was decreased (1.52), while Cho/Cr ratio was increased (1.78). These findings suggest that metabolic changes in CNS can also be found in patients with MP-CMD.

A distrofia muscular congênita (DMC) é um grupo heterogêneo de miopatias autossômicas recessivas que também podem afetar o sistema nervoso central (SNC). Alguns autores mostraram previamente que pacientes com DMC por deficiência da merosina podem apresentar alterações metabólicas no encéfalo. Com o objetivo de estudar as possíveis alterações metabólicas no SNC, os autores realizaram um estudo por ressonância magnética com espectroscopia em uma paciente de 1 ano com DMC sem deficiência da merosina. A razão NAA/Cr estava reduzida (1,52), enquanto que a razão Cho/Cr estava aumentada (1,78). Estes achados sugerem que alterações metabólicas no SNC também podem ser encontradas em pacientes com DMC merosina-positiva.

Neuroprotective Effects of Growth Hormone Against Hypoxic-Ischemic Brain Injury in Neonatal Rats: 1H Magnetic Resonance Spectroscopic Study

Using 1H-MRS, we evaluated the effects of growth hormone (GH) as a caspase inhibitor on hypoxic-ischemic injury in neonatal rat brains. The right common carotid arteries of rats were ligated, allowed to recover for 3 hr, and exposed to 8% oxygen for 2 hr. GH was given just prior to HI insult and animals were divided into four groups: control, intracerebroventricular (ICV), intracerebroventricular/intraperitoneal (ICV/IP), and intraperitoneal (IP). Localized in vivo 1H-MRS and TUNEL staining were performed 24 hr after HI injury. Lipid/N-acetyl aspartate (NAA) and lipid/creatine (Cr) ratios were used as apoptotic markers. Gross morphologic changes at 2 weeks were used to evaluate the effects of GH. The lipid/NAA ratio was lower in the ICV and ICV/IP groups than in the control, and the lipid/Cr ratio was lower in the ICV group than in the control. The number of TUNEL positive cells was decreased in the ICV and ICV/IP groups, and the degree of morphologic change indicative of brain injury was lower in the ICV group and somewhat lower in the ICV/IP group. The degree of morphologic change correlated with the lipid/NAA and lipid/Cr ratios. These findings suggest that GH exerts neuroprotective effects in cerebral hypoxicischemic injury.

MRI and ¹H-MRS findings of three patients with Sjõgren-Larsson syndrome

A síndrome de Sjögren-Larsson (SJL) é distúrbio raro, autossômico recessivo, caracterizado pela tríade clássica de ictiose congênita, retardo mental e tetraplegia ou diplegia espástica. Trata-se de um erro inato do metabolismo dos lipídios, causado pela deficiência da enzima microssômica aldeído graxo desidrogenase. Os achados de imagem do encéfalo na SJL demonstram atrofia cerebral e alteração da substância branca. A espectroscopia de prótons, com poucos casos relatados, caracteriza-se pelo elevado pico de lipídios e redução de N-acetil-aspartato. Apresentamos três casos de SJL, com ênfase nos achados da ressonância magnética e da espectroscopia de prótons.

Espectroscopia de prótons na doença de Alzheimer e no comprometimento cognitivo sem demência: estudo de uma amostra comunitária / Proton spectroscopy in Alzheimer's disease and cognitive impairment not dementia: a community study

OBJETIVO: Descrever os achados da espectroscopia de prótons (¹H-ERM) na doença de Alzheimer (DA) e no comprometimento cognitivo sem demência (CIND) em uma amostra da comunidade. MÉTODO: Foram avaliados seis pacientes com DA, sete com CIND e sete controles normais, originários da comunidade. ¹H-ERM foi realizada com voxel de 8 cm³ nas regiões temporal direita, parietal esquerda e occipital medial e estudados os metabólitos: N-acetilaspartato (NAA), creatina (Cr), colina (Cho) e mio-inositol (mI). RESULTADOS: O NAA foi maior nos indivíduos controles do que nos DA e intermediário no CIND. Análise de função discriminante mostrou que as associações Cr parietal-Cr occipital e Cr parietal-Cho occipital identificaram corretamente 92,3 por cento da amostra comparando Controle vs DA. Na comparação Controle vs CIND O mI temporal identificou corretamente 78,6 por cento dos indivíduos. CONCLUSÃO: A espectroscopia pode contribuir para o diagnóstico e seguimento de indivíduos com comprometimento cognitivo; avaliações de pacientes da comunidade podem revelar achados diferentes quanto à distribuição dos metabólitos cerebrais.

Alzheimer's disease and proton magnetic resonance spectroscopy of limbic regions: a suggestion of a clinical-spectroscopic staging

OBJETIVO: Comparar dados de espectroscopia de prótons por ressonância magnética com clínicos e propor um estadiamento espectroscópico da doença de Alzheimer(DA).MÉTODO: Sujeitos (n=46), normais (12) e com DA (34), emparelhados por idade (CDR0-CDR3); diagnóstico de DA de acordo com os critérios DSM-IV/NINCDS-ADRDA; 1H-MRS com Signa Horizon LX-GE, 1.5T; voxel único em região hipocampal/RHC e área posterior do cíngulo/APC. RESULTADOS: Redução estatisticamente significativa (p<0.01) apenas de Naa/Cr - na RHC entre CDR0, CDR1+CDR2 e CDR3, e na APC entre CDR0 e CDR1+CDR2 em relação a CDR3. CONCLUSÃO: A RHC é a primeira a apresentar redução de Naa (CDR1). A APC é acometida mais tardiamente (CDR3). Esses valores declinam progressivamente de acordo com os estágios de gravidade. Considerando as disparidades entre a RHC e a APC é possível sugerir um estadiamento espectroscópico (metabólico) (MS) da DA como segue: MS0 (CDR0)=RHC e APC ambos normais, MS1-2 (CDR1-2)=RHC anormal e APC normal e MS3 (CDR3)=RHC e APC ambos anormais. Esses resultados permitem um diagnóstico precoce, o seguimento do processo degenerativo ao longo da evolução e sugerir um estadiamento espectroscópico relacionado aos estágios clínicos da DA.

Proton magnetic resonance spectroscopy of the frontal lobe in schizophrenics: a critical review of the methodology

Pacientes esquizofrênicos submetidos à espectroscopia de próton por ressonância magnética demonstram alterações nos níveis de N-acetilaspartato em diversas regiões cerebrais, suportando a hipótese de disfunção neuronal nestas áreas. Objetiva-se apresentar uma revisão da literatura, sobre os principais estudos de espectroscopia de próton por ressonância magnética na região frontal em esquizofrênicos. Utilizou-se o indexador MEDLINE, no período entre 1991 e março de 2004, com o cruzamento dos termos spectroscopy, schizophrenia, proton e frontal. Foram selecionados 27 artigos originais, cujos resultados mostram-se discordantes quanto à alteração nos valores de N-acetilaspartato (19 artigos apresentaram alterações nos níveis de N-acetilaspartato e oito estudos não apresentam alterações). A presente revisão sugere que esta diversidade de resultados pode ser atribuída aos seguintes fatores: 1-número de participantes; 2- variação nas características clínicas e demográficas dos grupos; 3- pouca padronização dos parâmetros de aquisição dos espectros. Os artigos que satisfazem os critérios metodológicos mais rígidos sugerem diminuição de NAA no lobo frontal de esquizofrênicos do sexo masculino.

Proton Magnetic Resonance Spectroscopic Changes of the Primary Motor Cortex and Supplementary Motor Area in Hemiparetic Patients with Corticospinal Tract Injury due to Deep Intracerebral Hematoma

This study was conducted to investigate the metabolic changes in the motor and motor association cortices following axonal injury in the internal capsule that was caused by deep intracerebral hematoma. Using proton magnetic resonance spectroscopy (1H MRS), the authors studied the primary motor cortices (M-1) and sup-plementary motor areas (SMA) of 9 hemiparetic patients with documentable hemi-paresis of varying severity, and we studied 10 normal volunteers as controls. To measure the M-1 and SMA biochemical changes, 4 separate single volumes of inter-est(VOIs) were located bilaterally in the affected and unaffected hemisphere (AH and UH).1H MRS provided a neuronal and axonal viability index by measuring levels of N-acetylaspartate (NAA) and creatine/phosphocreatine (Cr). The M-1/SMA NAA/Cr ratios of the AH and UH in patients, and the AH and normal volunteers were com-pared. The NAA/Cr ratios of the M-1 and SMA in AH, and the SMA in UH were sig-nificantly lower than those of normal volunteers. These 1H MRS findings indicate that axonal injury in the descending motor pathway at the level of internal capsule could induce metabolic changes in the higher centers of the motor pathway.