Alterations on magnetic resonance imaging of the neonatal brain: correlations with prenatal risk factors and transfontanellar ultrasound findings / Achados de ressonância magnética de encéfalo neonatal: correlação com fatores de risco pré-natais e ultrassonografia transfontanelar

Abstract Objective: To describe the alterations seen on magnetic resonance imaging (MRI) of the brain in newborns, correlating those alterations with the transfontanellar ultrasound (TFUS) findings, and to describe the main risk factors identified. Materials and Methods: We evaluated the examinations of 51 patients who were submitted to brain MRI with a neonatal protocol during hospitalization. We evaluated the MRI findings and correlated them with previous TFUS findings, using the last TFUS performed in order to minimize the risk of bias. Data were obtained from medical records, and the images were reviewed by a radiologist specializing in neuroimaging. Results: Of the 51 patients evaluated, 21 (41.2%) were extremely preterm infants and 22 (43.1%) were extremely-low-birth-weight infants. Alterations were seen on 16 (31.4%) of the TFUS examinations and on 30 (58.8%) of the brain MRI scans, the most common finding being germinal matrix hemorrhage. The positive and negative predictive values of TFUS in relation to MRI were 87% and 54%, respectively. Conclusion: Because TFUS proved to be capable of distinguishing mild and moderate (grade I and II) germinal matrix hemorrhage from the severe forms (grades III and IV), it can be considered a good tool for screening and follow-up, especially in infants with severe disease and risk factors.

Resumo Objetivo: Avaliar alterações encontradas nas ressonâncias magnéticas (RMs) encefálicas neonatais, correlacionando com a ultrassonografia transfontanelar (USTF), e descrever os principais fatores de risco encontrados. Materiais e Métodos: Foram avaliados exames de 51 pacientes que realizaram RM utilizando protocolo neonatal durante internação hospitalar, correlacionando com resultados da USTF prévia, sendo utilizada, para minimizar as chances de viés, a última USTF realizada. Os dados foram obtidos de prontuário médico e as imagens foram revisadas por médico radiologista especialista em neuroimagem. Resultados: A população foi composta majoritariamente de recém-nascidos prematuros extremos (21; 41,2%) e de extremo baixo peso (22; 43,1%). Foram encontradas alterações em 16 (31,4%) das USTFs e em 30 (58,8%) das RMs, sendo a hemorragia da matriz germinativa o achado mais frequente. Os valores preditivos positivo e negativo da USTF em relação à RM foram de 87% e 54%, respectivamente. Conclusão: A USTF mostrou-se importante na distinção entre os graus de hemorragia da matriz germinativa leve e moderada (I e II) dos graus acentuados (III e IV), sendo considerada um bom exame de rastreio e acompanhamento, principalmente em pacientes mais graves e com fatores de risco.

Association between altered proton magnetic resonance spectroscopy (1H MRS) findings and clinical symptoms of schizophrenia

Objective: To assess the metabolic alterations of the thalamus in subjects with schizophrenia compared to healthy subjects and to investigate whether specific schizophrenic symptoms are associated with metabolic alterations measured by 1H MRS. Methods: This is a case-control study including patients with schizophrenia diagnosed usingthe Diagnostic and Statistical Manual of Mental Disorders - Fourth Edition, DMS-IV and the Operational CriteriaChecklist for Psychotic Illness (OPCRIT). Proton magnetic resonance spectroscopy (1H MRS) was used to assess metabolite concentrations (N-acetylaspartate, choline, creatinine, myoionositol and lactacte) in the left and rightthalamus of 13 patients with schizophrenia and 13 healthy controls. Results: In this study, concentrations of specific metabolites in the thalamus, determined by 1H MRS, were similar for individuals with schizophrenia andcontrols. It was observed that cases with family history of schizophrenia and disorganized speech demonstrated areduction in the ratio of the metabolites NAA /Cho in the thalamic nuclei on the right side. However, those withorganized delusions, hallucinations and non-affective auditory hallucinations had an increase of metabolites on theright side compared to the left thalamus. Decreased thalamic metabolic activity in patients with positive symptomswas observed in contrast with those who had well-organized delusions and auditory non-affective hallucinations,core symptoms of schizophrenia. Conclusion: A lateralized thalamic involvement was verified, suggesting thatorganic and genetic factors compromise the right thalamus and that the disorganization associated with delusionsand hallucinations compromises the left thalamic nuclei. Further studies to investigate the correlation betweensymptoms and thalamic dysfunction are warranted. (Rev Neuropsiquiatr 2011;74:183-190).

Objetivo: Evaluar las alteraciones metabólicas del tálamo en personas con esquizofrenia comparándolas con controles sanos e investigar si los síntomas específicos de la esquizofrenia están vinculados a alteraciones metabólicas medidas por 1H MRS. Métodos: Se realizó la espectroscopía por resonancia magnética (1H-MRS) para estimar concentraciones de metabolitos (N-acetil- aspartato, colina creatinina, mioionositol y lactato) en el tálamo izquierdo y derecho de 13 pacientes con esquizofrenia y 13 controles. Resultados: Las concentraciones de metabolitos específicos en el tálamo fueron iguales para las personas con esquizofrenia y los controles. Se observó que los pacientes con historia familiar de esquizofrenia y aquellos que presentaban lenguaje desorganizado tenían una reducción de los metabolitos NAA/Co en los núcleos talámicos de la derecha. Sin embargo, en aquellos delirios ordenados, alucionaciones no afectivas y alucinaciones auditivas los metabolitos del lado derecho tuvieron cierto aumento con relación a los núcleos talámicos de la izquierda. Se encontró una reducción en la actividad metabólica talámica en los pacientes con síntomas positivos, al contrario de aquellos que presentaron delirios bien ordenados y alucinaciones auditivas no afectivas, los síntomas más nucleares de la esquizofrenia. Conclusión: Se verificó cierta lateralización del envolvimiento talámico, sugiriendo que los factores orgánicos y los genéricos comprometen el tálamo derecho y que la desorganización asociada a los delirios y alucionaciones compromete los núcleos talámicos de la izquierda. Más estudios son necesarios para investigar la validez de la correlación entre síntomas y disfunción talámica.

Origen y trayecto anómalos del nervio musculocutáneo / Anomalus origin and traject of musculocutaneous nerve

El nervio musculocutáneo se origina del fascículo lateral en el plexo braquial y sus fibras emergen principalmente de las raíces nerviosas anteriores de C5 y C6. Durante la disección de rutina del plexo braquial en un cadáver formolizado, fue encontrada una variación del origen y trayecto de este nervio. El nervio musculocutáneo se originaba de la cara lateral del nervio mediano y después del origen, cruzaba anteriormente al músculo coracobraquial, sin perforarlo, de medial hacia lateral y de proximal hacia distal, para después ramificarse. Las variaciones anatómicas encontradas contribuyen para el estudio de la anatomía y sirven para el cirujano en intervenciones en la fosa axilar y en la parte anterior del brazo, previniendo, así, complicaciones operatorias.

The musculocutaneous is originated from the lateral fascicle in the brachial plexus and its fibers emerge mainly from the anterior nervous roots C5 and C6. During the routine dissection of the brachial plexus in a formolized corpse, its origin variation and passage was found. The nerve was originated on the lateral face of the median nerve and after its origin, crossed anteriorly to the coracobrachial muscle, without perforating it, from medial to lateral, proximal to distal, after to branch off. The anatomical variations found contribute to the anatomy study and they serve as alert for the surgeon in interventions in the axillary's cavity and in the previous store of the arm, preventing, thus, operational complications.