Preoperative and Postoperative Diffusion Tensor Imaging in Patients with Extra-Axial Lesions at the Frontal or Temporal Regions of the Brain and Their Correlations with Neuropsychological Outcomes

The underlying changes in the neuronal connectivity adjacent to brain tumours cannot always be depicted by conventional MR imaging. The hypothesis of this study was that preoperative neuropsychological deficits were associated with impairment of diffusivity in association fibre bundles. Hence, we investigated the potential of combined diffusion tensor imaging (DTI) fibre tracking and fractional anisotropy (FA) values of the fibres to determine changes in association fibres and their correlation to neuropsychological scores. Our study consisted of eighteen patients with extra-axial brain tumours in areas adjacent to the frontal and temporal lobes. They were assessed pre- and postoperatively with DTI and neuropsychological assessments. MR examinations were performed on a 3T-scanner. FA values were calculated for the uncinate fasciculus, arcuate fasciculus, superior fronto-occipital fasciculus, inferior fronto-occipital fasciculus and corticospinal tracts ipsilateral and contralateral to the tumor. These values were compared with neuropsychological scores for language, memory and attention. The analysis revealed marked differences in pre- and post-excision of the tumor in both FA values and neuropsychological scores. Quantitative DTI was able to show significant differences in diffusivity of the association fibres before and after the surgery (P < 0.05). The additional use of DTI-fibre integrity and neuropsychological tests may aid in prognostication and decision making prior to surgery.

Principles, Anatomical Origin and Applications of Brainwaves: A Review, Our Experience and Hypothesis Related to Microgravity and the Question on Soul

Brainwave is a kind of traceable neurophysiological energy in a living brain. Invisible to human eyes, it is only detectable using electroencephalography (EEG), electrocorticography (ECoG) and magnetoencephalography (MEG). The waves or oscillations or rhythms are produced mainly by the oscillatory networks of the brain. Three main oscillatory networks are thalamocortical, extrathalamic-cortical and cortical-cortical networks. Greater limbic system (reticular system, hypothalamus, thalamus, basal forebrain nuclei, limbic system) has a great influence on these oscillatory networks. This system which is in microgravity position lies deep inside and surrounded by the ventricles of the brain. It receives all information from inside and outside of our body and then projects to all areas of the brain (from all to one and from one to all—nearly similar concept to “from God back to God”). Therefore, the greater limbic system could be regarded as “a core of the neuroaxis” which lies in microgravity compartment and in microgravity position (“T”-shape or curving shape;whilst gravity position is “I”-shape or vertical shape). By knowing the origin of the brainwaves and methods to detect them, one may study seizure networks, normal and abnormal brain networks and arguably, even to explore the relationship between the “invisibles”: “invisible” brainwaves and “invisible” soul.