ABSTRACT
@#Introduction: Intracranial brain tumour like meningiomas and glioblastomas are most prevalent tumour. The metastasis to the brain is one of the major issues in the tumours of the central nervous system. The diagnosis of metastatic and primary brain tumour is incomprehensible with standard magnetic resonance imaging (MRI). The magnetic resonance spectroscopy (MRS) is basically performed in standard clinical setting for diagnosing and tracking the brain tumour. Method: It is a retrospective study containing 53 patients with MRS. The patients with metastatic tumour (n=10), glioblastomas (n=8) and meningiomas (n=20) are included in the study. Single voxel technique is applied in the tumour core to determine the metabolites. The tumour N-acetyl aspartate (NAA), Choline (Cho), Creatine (Cr), Lactate, Alanine and lipids were analysed. The ratios of NAA/Cr, Cho/NAA and Cho/Cr were recorded and compared between the three tumours. The metabolites were detected between short echo time (TE) to long echo time (TE) during MRS. Results: There is a sharp fall of NAA peak in metastatic tumour. The resonance of creatine, lactate and alanine is higher in glioblastomas. A high lipid mean value of 3.13(0.17) is seen in metastatic tumour. The ROC curve shows a low NAA/Cr specificity of 46.7%, high sensitivity of 83.3% in Cho/NAA and Cho/Cr ratio. Conclusion: The metabolic profiles of metastatic brain tumour, glioblastomas and meningioma illustrate a divergence in their description that will assist in planning therapeutic and surgical intervention of these tumours.
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Background: Sex is a psychobiological factor that is important in the process of emotion.This study determines the effect of sex on the electropsychological process of various intensities ofemotional arousal.Methods: In the Event-related Potential (ERP) session, electroencephalographic (EEG)data was recorded for 90 participants, 60% of whom were females. The participants responded to30 universal emotional pictures, randomly chosen from the International Affective Picture System(IAPS), which were classified as invoking high, moderate, and low intensity of emotional arousal.Results: From the analysis of variance of two-way mixed design, the interaction betweensex and emotional intensity was observed in the occipital regions (O2), indexed by the amplitudeof P300 and N200 components. Males exhibited higher amplitude of P300 and N200 components(in the occipital region) as responded to high and low emotional arousal stimuli than females.Conclusion: Sex is a fundamental factor that modulates psychological states in reaction toemotional stimuli.
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@#The present study discussed functional reorganization and alteration in respond to the slow-growing tumour,hemangiopericytoma in the occipital cortex. Visual evoked field (VEF) and auditory evoked field (AEF) usingmagnetoencephalography (MEG) was used to evaluate the source localization and brain activity. Results of VEF sourcelocalization show a typical brain waves. Brain activity of the occipital lobe demonstrate low activation in the ipsilateralto the tumour. However, result shows the activation on the contralateral hemisphere was high and bigger in activationvolume. AEF result shows an identical source localization and both side of the temporal lobe are activated. This resultsuggests that there is a positive plasticity in auditory cortex and slow-growing tumour can induce functional reorganizationand alteration to the brain.
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@#Neuroplasticity has been subjected to a great deal of research in the last century. Recently, significant emphasis has beenplaced on the global effect of localized plastic changes throughout the central nervous system, and on how these changesintegrate in a pathological context. The present study aimed to demonstrate the functional cortical reorganization beforeand after surgery using magnetoencephalography (MEG) in a participant with brain tumor. Results of Visual EvokedMagnetic Field (VEF) based on functional MEG study revealed significantly different of MEG N100 waveforms before andafter surgery. Larger and additional new locations for visual activation areas after the surgery were found suggestingneuroplasticity. The present study highlight a physiological plasticity in a teenage brain and the alterations regardingneural plasticity and network remodeling described in pathological contexts in higher-order visual association areas.
ABSTRACT
Background: Previous studies have revealed that self-related tasks (items) receive more attention than non-self-related, and that they elicit event-related potential (ERP) components with larger amplitudes. Since personality has been reported as one of the biological correlates influencing these components, as well as our behavioural differences, it is important to examine how it affects our self-consciousness in relation to tasks of varied relevance and the neurological basis. Methods: A total of 33 male and female undergraduate Malaysian medical students of Universiti Sains Malaysia (USM) participated in the study. The participants were divided into two groups, Ambivert (n = 18) and Extravert (n = 15) groups, using the USM personality inventory questionnaire. In the ERP experiment, squares containing standard stimuli of any word other than self and non-self-related nouns (e.g., Bola, Gigi, Anak, etc.; in English: Ball, Teeth, Kids, etc., respectively), those containing self-related pronouns (Saya, Kami or Kita; in English: I, Us or We, respectively), and non-self-related pronouns (Dia, Anda or Mereka; in English: He/She, You or They, respectively), were shown 58%, 21% and 21% of the time, respectively, in a three-stimulus visual oddball paradigm. All words were presented in Bahasa Melayu. The participants were instructed to press 1 for self and 2 for non-self, and ignore standard stimuli. Results: Comparison of both N200 and P300 amplitudes for self-related and non-selfrelated pronouns in the Extravert group revealed significant differences at seven electrode sites, with self-related having larger amplitude at anterior electrodes and less at posterior. This was not seen in the Ambivert group. Conclusion: The present study suggests that self-relevant pronouns are psychologically more important to extraverts than to ambiverts; hence, they have more self-awareness. This may be due to large amount of dopamine in the brains of extraverts, which is more concentrated in the frontal lobe.