RESUMO
Pharmacological functional magnetic resonance imaging (phMRI) is a valuable tool for the investigation of pharmacological effects of a drug on pain processing. We hypothesized that the ibuprofen-arginine combination, in line with its characteristic analgesic properties, may influence the phMRI response at the central level, as compared to placebo. Ten healthy subjects underwent a double-blind, placebo-controlled, randomized, cross-over phFMRI study with somatosensory painful stimulation of the right median nerve. We measured the blood oxygen level dependent (BOLD) signal variations induced in conditions of pain after oral administration of either ibuprofen-arginine or placebo formulations. Independent component analysis (ICA) was used for the analysis of the fMRI data, without assuming a specific hemodynamic response function (HRF), which may be altered by drug administration. Median nerve electrical painful stimulation mainly activated the primary contralateral and the secondary somatosensory cortices, the insula, the supplementary motor area, and the middle frontal gyrus. Placebo and ibuprofen-arginine administration induced activation bilaterally in the premotor cortex, and an overall reduction in the other pain-related areas, which was more prominent in the left hemisphere. A task-related increase of BOLD signal between drug and placebo was observed bilaterally in the primary somatosensory area and the middle frontal gyrus without any changes in subjective pain scores. Overall, our findings show that ibuprofen-arginine, in line with the characteristic analgesic properties of ibuprofen, influences the BOLD response in specific pain-related brain areas with respect to placebo, with a vasoactive effect possibly due to arginine.
Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Arginina/uso terapêutico , Ibuprofeno/uso terapêutico , Dor/tratamento farmacológico , Dor/patologia , Adolescente , Adulto , Encéfalo/patologia , Mapeamento Encefálico , Química Farmacêutica , Estudos Cross-Over , Método Duplo-Cego , Combinação de Medicamentos , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Medição da Dor/efeitos dos fármacos , Análise de Componente Principal , Adulto JovemRESUMO
BACKGROUND AND PURPOSE: The hand motor cortex (HMC) has been classically described as having an omega or epsilon shape in axial-plane images obtained with CT and MR imaging. The aim of this study was to use MR imaging and Talairach normalization in a large sample population that was homogeneous for age and handedness to evaluate in a sex model a new classification with 5 morphologic variants of the HMC in the axial plane (omega, medially asymmetric epsilon, epsilon, laterally asymmetric epsilon, and null). MATERIALS AND METHODS: Structural brain MR images were obtained from 257 right-handed healthy subjects (143 men and 114 women; mean age, 23.1 +/- 1.1 years) via a Talairach space transformed 3D magnetization-prepared rapid acquisition of gradient echo sequence. The frequencies of the different HMC variants were reported for hemisphere and sex. RESULTS: The new variants of the HMC (medially asymmetric epsilon, laterally asymmetric epsilon, and null) were observed in 2.9%, 7.0%, and 1.8% of the hemispheres, respectively. Statistically significant sex differences were observed: The epsilon variant was twice as frequent in men, and an interhemispheric concordance for morphologic variants was observed only for women. CONCLUSION: The large study population permitted the description of a new morphologic classification that included 3 new variants of the HMC. This new morphologic classification should facilitate the identification of the precentral gyrus in subsequent studies and in everyday practice.
Assuntos
Mãos/fisiologia , Imageamento por Ressonância Magnética , Córtex Motor/anatomia & histologia , Córtex Motor/fisiologia , Adulto , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Variações Dependentes do Observador , Valores de Referência , Reprodutibilidade dos Testes , Caracteres Sexuais , Método Simples-CegoRESUMO
Anterograde amnesia in Wernicke-Korsakoff syndrome is associated with diencephalic lesions, mainly in the anterior thalamic nuclei. Whether diencephalic and temporal lobe amnesias are distinct entities is still not clear. We investigated episodic memory for faces using functional MRI (fMRI) in eight controls and in a 34-year-old man with Wernicke-Korsakoff syndrome and diencephalic lesions but without medial temporal lobe (MTL) involvement at MRI. fMRI was performed with a 1.5 tesla unit. Three dual-choice tasks were employed: (i) face encoding (18 faces were randomly presented three times and subjects were asked to memorize the faces); (ii) face perception (subjects indicated which of two faces matched a third face); and (iii) face recognition (subjects indicated which of two faces belonged to the group they had been asked to memorize during encoding). All activation was greater in the right hemisphere. In controls both the encoding and recognition tasks activated two hippocampal regions (anterior and posterior). The anterior hippocampal region was more activated during recognition. Activation in the prefrontal cortex was greater during recognition. In the subject with Wernicke-Korsakoff syndrome, fMRI did not show hippocampal activation during either encoding or recognition. During recognition, although behavioural data showed defective retrieval, the prefrontal regions were activated as in controls, except for the ventrolateral prefrontal cortex. fMRI activation of the visual cortices and the behavioural score on the perception task indicated that the subject with Wernicke-Korsakoff syndrome perceived the faces, paid attention to the task and demonstrated accurate judgement. In the subject with Wernicke-Korsakoff syndrome, although the anatomical damage does not involve the MTL, the hippocampal memory encoding has been lost, possibly as a consequence of the hippocampal-anterior thalamic axis involvement. Anterograde amnesia could therefore be the expression of damage to an extended hippocampal system, and the distinction between temporal lobe and diencephalic amnesia has limited value. In the subject with Wernicke-Korsakoff syndrome, the preserved dorsolateral prefrontal cortex activation during incorrect recognition suggests that this region is more involved in either the orientation or attention at retrieval than in retrieval. The lack of activation of the prefrontal ventrolateral cortex confirms the role of this area in episodic memory formation.
Assuntos
Amnésia Anterógrada/fisiopatologia , Diencéfalo/lesões , Processamento de Imagem Assistida por Computador , Síndrome de Korsakoff/fisiopatologia , Imageamento por Ressonância Magnética , Adulto , Amnésia Anterógrada/etiologia , Amnésia Anterógrada/psicologia , Análise de Variância , Estudos de Casos e Controles , Diencéfalo/fisiopatologia , Humanos , Síndrome de Korsakoff/complicações , Síndrome de Korsakoff/psicologia , Masculino , Memória , Testes Neuropsicológicos , PercepçãoRESUMO
BACKGROUND AND PURPOSE: The loss of contrast on T1-weighted MR images at 3T may affect the detection of hyperintense punctate lesions indicative of periventricular leukomalacia in preterm neonates. The aim of the present study was to determine which 3T T1-weighted sequence identified the highest number of hyperintense punctate lesions and to explore the relationship between the number of hyperintense punctate lesions and clinical outcome. MATERIALS AND METHODS: The presence of hyperintense punctate lesions was retrospectively evaluated in 200 consecutive preterm neonates on 4 axial T1-weighted sequences: 3-mm inversion recovery and spin-echo and 1- and 3-mm reformatted 3D-fast-field echo. Statistically significant differences in the number of hyperintense punctate lesions were evaluated by using a linear mixed-model analysis. Logistic regression analysis was used to assess the relation between the number of hyperintense punctate lesions and neuromotor outcome at 3 months. RESULTS: Thirty-one neonates had at least 1 hyperintense punctate lesion indicative of periventricular leukomalacia in at least 1 of the 4 sequences. The 1-mm axial reformatted 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions (P < .001). No statistically significant differences were found among the 3-mm T1-weighted sequences. The greater number of hyperintense punctate lesions detected by the 1-mm reformatted T1 3D-fast-field echo sequence in the central region of the brain was associated with a worse clinical outcome. CONCLUSIONS: At 3T, the 1-mm axial reformatted T1 3D-fast-field echo sequence identified the greatest number of hyperintense punctate lesions in the central region of preterm neonate brains, and this number was associated with neuromotor outcome.
Assuntos
Encéfalo/patologia , Leucomalácia Periventricular/patologia , Imageamento por Ressonância Magnética/métodos , Feminino , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Modelos Lineares , Masculino , Estudos RetrospectivosRESUMO
Seventeen young patients with relapsing schizophrenia and 13 normal controls matched for age, gender, and educational level underwent magnetic resonance imaging (MRI) scans. Three sagittal, eight axial, and seven coronal images were obtained for all subjects. Schizophrenic patients showed a reduction of brain tissue in the temporal lobes. Among the several brain structures identified, left temporal lobe area, but not ventricular brain ratio (VBR), discriminated between the two groups. As VBR has been reported to be increased in the more severe forms of schizophrenia, temporal lobe abnormalities may characterize the less severe cases of schizophrenia.
Assuntos
Imageamento por Ressonância Magnética , Esquizofrenia/patologia , Psicologia do Esquizofrênico , Lobo Temporal/patologia , Adulto , Encéfalo/patologia , Ventrículos Cerebrais/patologia , Doença Crônica , Corpo Caloso/patologia , Dominância Cerebral/fisiologia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/instrumentação , Masculino , Escalas de Graduação Psiquiátrica , Software , Tomografia Computadorizada por Raios XRESUMO
The topographical organization of SI and SII somatosensory areas was investigated using fMRI at 1.5 T and electrical sensory stimulation. Electrical stimuli were delivered unilaterally to the median nerve at the wrist and to the tibial nerve at the medial malleolus, during a block paradigm study. In all subjects, activation was observed, contralaterally to the stimulated side, in the post-central gyrus, in the posterior parietal cortex, in the mesial pre-frontal region and, bilaterally, in the supratemporal region at the level of the Sylvian fissure. The latter region, corresponding presumably to SII, showed a rough but clearcut topographical organization, with the median nerve areas located more posteriorly. In addition, weaker activations were observed in some subjects in the ipsilateral mesial prefrontal region and in the ipsilateral posterior parietal cortex. Information contained in the present study represent an interesting database for future investigations on the effects of sensorimotor learning in normal individuals on plastic reorganization following a lesion of the primary sensorimotor centers, i.e. in stroke patients, on the topography and balance between upper and lower limb representations in primary and secondary somatosensory cortices.
Assuntos
Mapeamento Encefálico , Córtex Somatossensorial/fisiologia , Adulto , Estimulação Elétrica , Feminino , Lobo Frontal/fisiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Nervo Mediano/fisiologia , Lobo Parietal/fisiologia , Valores de Referência , Nervo Tibial/fisiologiaRESUMO
A patient with post-thyroidectomy hypoparathyroidism, basal ganglia calcification, parkinsonism and seizures is reported. The parkinsonism was resistant to levodopa therapy but was not significantly improved by the correction of hypoparathyroidism. Previously reported cases are discussed, as well as the relationship between hypoparathyroidism, calcification of basal ganglia, parkinsonism and epilepsy.
Assuntos
Doenças dos Gânglios da Base/etiologia , Calcinose/etiologia , Epilepsia/etiologia , Hipoparatireoidismo/complicações , Doença de Parkinson/etiologia , Doenças dos Gânglios da Base/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Feminino , Humanos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Tireoidectomia , Fatores de Tempo , Tomografia Computadorizada por Raios XRESUMO
Two cases of Creutzfeldt-Jakob Disease (CJD) are reported. In both cases, pathologically confirmed, magnetic resonance imaging (MRI) showed bilateral altered signal areas in the basal ganglia, early in the course of the disease. The CT scan, although performed later than MRI, confirmed these findings. Only in one patient did electroencephalography (EEG) show typical triphasic sharp-waves, but this support to clinical diagnosis was obtained 1 month after the appearance of MRI alterations.
Assuntos
Encéfalo/patologia , Síndrome de Creutzfeldt-Jakob/diagnóstico , Imageamento por Ressonância Magnética , Encéfalo/diagnóstico por imagem , Síndrome de Creutzfeldt-Jakob/diagnóstico por imagem , Eletroencefalografia , Feminino , Humanos , Pessoa de Meia-Idade , Tomografia Computadorizada por Raios XRESUMO
Magnetic resonance imaging of optic nerves was obtained in 13 patients with acute optic neuritis and in 13 patients with a previous history of optic neuritis (ON), assessed by clinical, visual fields and visual evoked potentials evaluations. Results of the conventional short tau inversion recovery (STIR) sequence obtained with short time echo (STE-STIR: 22 ms) were compared with long time echo (LTE-STIR: 80 ms) sequence. The conventional STE-STIR sequence revealed lesions in 78.5% of acute ON and in 58.8% of optic nerves affected by previous ON. The LTE-STIR sequence was diagnostic in 92.8% of acutely symptomatic nerves, in 94.1% of nerves with previous ON. The calculated length of optic nerve lesions was significantly longer in imaging obtained with the LTE-STIR sequence than with the conventional STE-STIR sequences, both in acute and previous ON.
Assuntos
Imageamento por Ressonância Magnética/métodos , Nervo Óptico/patologia , Neurite Óptica/diagnóstico , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
The authors report the first case of abnormal length of respiratory cilia in a domestic animal (18 microns versus normal length about 5 microns). These cilia lie on the carpet of cilia of normal length. The width of some of these cilia is also abnormal, measuring 0.5-0.6 microns. Other cilia have hook-shaped tips that could be responsible for an effective beat. We suggest that the ineffective ciliary beat could also be due to the undulating movements of abnormally long cilia, and stress the need for further morphological and biochemical studies of respiratory cilia in pigs. Respiratory pathology is a very common finding in pigs and is responsible for remarkable economical losses.
Assuntos
Cílios/ultraestrutura , Transtornos da Motilidade Ciliar/veterinária , Doenças dos Suínos/patologia , Traqueia/ultraestrutura , Animais , Transtornos da Motilidade Ciliar/patologia , Modelos Animais de Doenças , Feminino , Microscopia Eletrônica de Varredura , Mucosa/ultraestrutura , SuínosRESUMO
The characterization of peripheral blood T-cell subpopulations in 29 multiple sclerosis (MS) patients is studied. A direct immunofluorescence assay was performed using monoclonal antibodies (OK series) directed to lymphocytes surface antigens. In transverse study, the patients suffering from progressive MS showed T4+ lymphocytes and T4+/T8+ ratio significantly high (p less than 0.05) compared to controls; furthermore T8+ lymphocyte values were low. T3+ lymphocytes were low (p less than 0.05) during the relapse in the MS remitting relapsing patients. A six month follow-up of the patients showed, during relapse, a reduction and, immediately after, a recovery of T3+ and T4+ lymphocyte values; T8+ lymphocytes didn't show remarkable fluctuations.
Assuntos
Esclerose Múltipla/imunologia , Linfócitos T/imunologia , Adulto , Anticorpos Monoclonais , Doença Crônica , Feminino , Imunofluorescência , Humanos , Contagem de Leucócitos , Masculino , Esclerose Múltipla/terapia , Recidiva , Indução de Remissão , Linfócitos T/classificaçãoRESUMO
The diagnostic value of magnetic resonance angiography (MR-Angio) in the study of intracranial vascular diseases was compared with that of basic magnetic resonance (MR) in 35 patients presenting with a total of 45 pathologies (13 vascular malformations, 17 aneurysms, 3 vascular stenoses, all also examined by standard angiography, and 12 cases of dolichobasilar artery). A joint reading of the results was carried out by two radiologists who evaluated the basic MR and MR-Angio separately and thereafter filled in a fixed-choice answer form. In the author's opinion, MR-Angio may be considered a complementary technique to basic MR, offering a greater capacity for identification and characterization of these intracranial lesions. In vascular malformations and aneurysms, MR-Angio may be performed as a preliminary to digital subtraction angiography.
Assuntos
Transtornos Cerebrovasculares/diagnóstico , Imageamento por Ressonância Magnética/métodos , Aneurisma/diagnóstico , Aneurisma/diagnóstico por imagem , Angiografia Digital , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/diagnóstico por imagem , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/diagnóstico por imagem , Transtornos Cerebrovasculares/diagnóstico por imagem , Feminino , Hemangioma/diagnóstico , Hemangioma/diagnóstico por imagem , Humanos , Aumento da Imagem , Malformações Arteriovenosas Intracranianas/diagnóstico , Malformações Arteriovenosas Intracranianas/diagnóstico por imagem , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE: To evaluate diffusion-weighted imaging (DWI) for assessment of treatment response in locally advanced rectal cancer (LARC) 8 weeks after neoadjuvant chemoradiotherapy (CRT). METHODS AND MATERIALS: A total of 28 patients with LARC underwent magnetic resonance imaging (MRI) prior to and 8 weeks after CRT. Tumor volume (TV) was calculated on T2-weighted MRI scans as well as the apparent diffusion coefficient (ADC) was calculated using Echo-planar DWI-sequences. All data were correlated to surgical results and histopathologic tumor regression grade (TRG), according to Mandard's classification. Post-treatment difference ADC (%ΔADC) and TV (%ΔTV) changes at 8 weeks were compared complete response (CR; TRG1) and non-complete response tumors (non-CR; TRG2-5). RESULTS: The mean % ADC increase of CR group was significantly higher compared to non-CR group (77.2 ± 54.63% vs. 36.0 ± 29.44%; p = 0.05). Conversely, the mean % TV reduction did not significantly differ in CR group from non-CR group (73.7% vs. 63.77%; p = 0.21). Accordingly, the diagnostic accuracy of the mean % ADC increase to discriminate CR from non-CR group was significantly higher than that of the mean % TV reduction (0.913 vs. 0.658; p = 0.022). No correlation was found between mean % TV reduction and TRG (rho = 0.22; p = 0.3037), whereas a negative correlation between mean % ADC increase and TRG was recorded (r = -0.69; p = 0.006). CONCLUSION: The mean % ADC increase appears to be a reliable tool to differentiate CR from non-CR after CRT in patients with LARC.
Assuntos
Quimiorradioterapia Adjuvante , Imagem de Difusão por Ressonância Magnética/métodos , Neoplasias Retais/patologia , Neoplasias Retais/terapia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Resultado do TratamentoRESUMO
A magnetic resonance (MR) diffusion tensor imaging (DTI) study was performed in a newborn with bilateral subependymal heterotopia (SE). White matter fractional anisotropy (FA), axial diffusivity (AD) and radial diffusivity (RD) were compared to values obtained in four newborns with moderate perinatal asphyxia and normal MRI findings. The reduction of FA and increase of AD and RD in the newborn with SE were the in vivo late expression of alterations in the intermediate zone, with an underlying arrest of neuronal migration.
Assuntos
Imagem de Tensor de Difusão , Epilepsia/complicações , Epilepsia/diagnóstico , Doenças Fetais/diagnóstico , Malformações do Desenvolvimento Cortical do Grupo II/complicações , Malformações do Desenvolvimento Cortical do Grupo II/diagnóstico , Fibras Nervosas Mielinizadas/patologia , Adulto , Feminino , Humanos , Recém-Nascido , GravidezRESUMO
BACKGROUND AND PURPOSE: fcMRI measures spontaneous and synchronous fluctuations of BOLD signal between spatially remote brain regions. The present study investigated potential LN fcMRI modifications induced by left hemisphere brain gliomas. MATERIALS AND METHODS: We retrospectively evaluated fcMRI in 39 right-handed patients with a left hemisphere brain glioma and 13 healthy controls. Patients and controls performed a verb-generation task to identify individual BOLD activity in the left IFG (Broca area); the active region was used as seed to create whole-brain background connectivity maps and to identify the LN (including bilateral regions of the IFG, STS, and TPJ) following regression of task-evoked activity. We assessed differences between patients and controls in the pattern of functional connectivity of the LN, as well as potential effects of tumor position, histopathology, and volume. RESULTS: Global fcMRI of the LN was significantly reduced in patients with tumor compared with controls. Specifically, fcMRI was significantly reduced within seed regions of the affected hemisphere (left intrahemispheric fcMRI) and between the TPJ of the 2 hemispheres. In patients, the left TPJ node showed the greatest decrease of functional connectivity within the LN. CONCLUSIONS: The presence of a brain tumor in the left hemisphere significantly reduced the degree of fcMRI between language-related brain regions. The pattern of fcMRI was influenced by tumor position but was not restricted to the area immediately surrounding the tumor because the connectivity between remote and contralateral areas was also affected.
Assuntos
Neoplasias Encefálicas/fisiopatologia , Encéfalo/fisiopatologia , Conectoma/métodos , Glioma/fisiopatologia , Idioma , Rede Nervosa/fisiopatologia , Plasticidade Neuronal , Adulto , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , MasculinoRESUMO
BACKGROUND AND PURPOSE: Subtle linguistic dysfunction and reorganization of the language network were described in patients with epilepsy, suggesting the occurrence of plasticity changes. We used resting state FC-MRI to investigate the effects induced by chronic epilepsy on the connectivity of the language-related brain regions and correlated it with language performance. MATERIALS AND METHODS: FC-MRI was evaluated in 22 right-handed patients with drug-resistant epilepsy (11 with LE and 11 with RE) and in 12 healthy volunteers. Neuropsychological assessment of verbal IQ was performed. Patients and controls underwent BOLD fMRI with a verb-generation task, and language function was lateralized by an LI. Intrinsic activity fluctuations for FC analysis were extracted from data collected during the task. Six seeding cortical regions for speech in both hemispheres were selected to obtain a measure of the connectivity pattern among the language networks. RESULTS: Patients with LE presented atypical language lateralization and an overall reduced connectivity of the language network with respect to controls. In patients with both LE and RE, the mean FC was significantly reduced within the left (dominant) hemisphere and between the 2 hemispheres. In patients with LE, there was a positive correlation between verbal IQ scores and the left intrahemispheric FC. CONCLUSIONS: In patients with intractable epilepsy, FC-MRI revealed an overall reduction and reorganization of the connectivity pattern within the language network. FC was reduced in the left hemisphere regardless of the epileptogenic focus side and was positively correlated with linguistic performance only in patients with LE.
Assuntos
Encéfalo/fisiopatologia , Epilepsia/fisiopatologia , Transtornos da Linguagem/fisiopatologia , Imageamento por Ressonância Magnética/métodos , Rede Nervosa/fisiopatologia , Plasticidade Neuronal , Adolescente , Adulto , Anticonvulsivantes/uso terapêutico , Resistência a Medicamentos , Epilepsia/complicações , Epilepsia/tratamento farmacológico , Feminino , Humanos , Transtornos da Linguagem/complicações , Masculino , Pessoa de Meia-Idade , Vias Neurais/fisiopatologia , Adulto JovemRESUMO
BACKGROUND AND PURPOSE: An alternative technique, which is less influenced by tumor- and patient-related factors, is required to overcome the limits of GLM analysis of fMRI data in patients. The aim of this study was to statistically assess differences in the identification of language regions and hemispheric lateralization of language function between controls and patients as estimated by both the GLM and a novel combined ICA-GLM procedure. MATERIALS AND METHODS: We retrospectively evaluated 42 patients with pathologically confirmed brain gliomas of the left frontal and/or temporoparietal lobes and a control group of 14 age-matched healthy volunteers who underwent BOLD fMRI to lateralize language functions in the cerebral hemispheres. Data were processed by using a classic GLM and ICA-GLM. RESULTS: ICA-GLM demonstrated a higher sensitivity in detecting language activation, specifically in the left TPJ of patients. There were no significant differences between the GLM and ICA-GLM in controls; however, statistically significant differences were observed by using ICA-GLM for the LI in patients. For the computation of the LI, ICA-GLM was less influenced by the chosen statistical threshold compared with the GLM. CONCLUSIONS: We suggest the use of the ICA-GLM as a valid alternative to the classic GLM method for presurgical mapping in patients with brain tumors and to replicate the present results in a broader sample of patients.