Evidences of Brain Plasticity and Motor Control Modulation after Hemodialysis Session by Helixone Membrane: BOLD-fMRI Study.

OBJECTIVE: The aim of this paper is to demonstrate the impact of hemodialysis (HD) using synthetic Helixone membrane on brain functional control reorganization and plasticity in the cortical area generated while Oxidative Stress (OS) would be the main impacting agent. METHODS: Indeed, 9 chronic HD patients underwent identical brain BOLD-fMRI assessment using the motor paradigm immediately before and after the same HD sessions. To assess the oxidative stress, the same patients underwent biological-assessment, including Malondialdehyde (MDA) and Total- Antioxidant-Activity (TAOA) reported in earlier papers. RESULTS: BOLD-fMRI maps of motor areas obtained from HD-patients before and after HD sessions revealed a significant enhancement of activation volume of the studied motor cortex after HD reflecting brain plasticity. Results were correlated with OS assessed by the measurement of MDA and TAOA; this correlation was close to 1. CONCLUSION: Indeed, HD enhances the inflammatory state of brain tissues reflected by the increased OS. The functional brain reaction demonstrated a functional activity reorganization to overcome the inflammatory state and OS enhanced by HD process. This functional activity reorganization reveals brain plasticity induced by OS originated by HD.

Blood Oxygenation Level-Dependent Functional MRI of Early Evidences of Brain Plasticity after Hemodialysis Session by Helixone Membrane of Patients with Indices of Adrenal Deficiency.

BACKGROUND: Various alterations of hypothalamic-pituitary-adrenal axis function have been described in patients with chronic renal failure. Nevertheless, controversial evidences were stated about the association between adrenal function deficiency (AD) and hemodialysis (HD). PURPOSE: The goal of this paper was to estimate indirect indices of the adrenal gland dysfunction which is potentially influenced by oxidative stress (OS) that still generates brain plasticity and reorganization of the functional control. METHODS: Two male patients undergoing HD by the synthetic Helixone membrane for more than 6 months at the HD Center of the University Hospital of Fez, Fez, Morocco, were recruited. They underwent identical assessment immediately before and after the full HD session; this consisted of a blood ionogram revealing rates of sodium and calcium, and brain blood oxygenation level-dependent functional MRI (BOLD-fMRI) using a motor paradigm in block design. RESULTS: The blood ionogram revealed hypercalcemia and hyponatremia in both patients. Both biological assessment and BOLD-fMRI study results revealed a high level of OS that induced activation of a significantly large brain volume area suggesting the occurrence of possible brain plasticity and functional control reorganization induced by free radicals and enhanced by AD. CONCLUSION: The occurrence of brain plasticity and functional control reorganization was demonstrated in both patients studied who were undergoing HD by BOLD-fMRI with a notable sensitivity; this plasticity is induced by elevated OS occasioned by HD technique itself and probably amplified by AD. Similar results were found in a previous study performed on the same patients undergoing HD by a polysulfone membrane.

Implications of oxidative stress in the brain plasticity originated by fasting: a BOLD-fMRI study.

OBJECTIVES: The goal of this study was assessing the intermittent fasting effect on brain plasticity and oxidative stress (OS) using blood-oxygenation-level dependent (BOLD)-functional magnetic resonance image (fMRI) approach. Evidences of physiological and molecular phenomena involved in this process are discussed and compared to reported literature. METHOD: Six fully healthy male non-smokers volunteered in this study. All volunteers were right handed, and have an equilibrated, consistent and healthy daily nutritional habit, and a healthy lifestyle. Participants were allowed consuming food during evening and night time while fasting with self-prohibiting food and liquids during 14 hours/day from sunrise to sunset. All participants underwent identical brain BOLD-fMRI protocol. The images were acquired in the Department of Radiology and Clinical Imaging of the University Hospital of Fez, Fez, Morocco. The anatomical brain and BOLD-fMRIs were acquired using a 1.5-Tesla scanner (Signa, General Electric, Milwaukee, United States). BOLD-fMRI image acquisition was done using single-shot gradient echo echo-planer imaging sequence. BOLD-fMRI paradigm consisted of the motor task where volunteers were asked to perform finger taping of the right hand. Two BOLD-fMRI scan sessions were performed, the first one between the 5th and 10th days preceding the start of fasting and the second between days 25th and 28th of the fasting month. All sessions were performed between 3:30 PM and 5:30 PM. Although individual maps were originated from different individual participants, they cover the same anatomic area in each case. Image processing and statistical analysis were conducted with Statistical Parameter Mapping version 8 (2008, Welcome Department of Cognitive Neurology, London UK). RESULTS AND DISCUSSION: The maximal BOLD signal changes were calculated for each subject in the motor area M1; Activation maps were calculated and overlaid on the anatomical images. Group analysis of the data was performed, and the average volume and the maximum intensity of BOLD signal in the activated area M1 was determined for all studied volunteers. The current study allowed measuring regional brain volumes and neural network activity before and during an extended period of fasting using BOLD-fMRI. This demonstrated and confirmed the impact of fasting on human brain structure and function. Further studies are required to elucidate mechanisms and enable direct inference of a diet-induced OS effect on the brain.

Indices of adrenal deficiency involved in brain plasticity and functional control reorganization in hemodialysis patients with polysulfone membrane: BOLD-fMRI study.

This work purpose was to estimate the implication of suspected adrenal function deficiencies, which was influenced by oxidative stress (OS) that are generating brain plasticity, and reorganization of the functional control. This phenomenon was revealed in two-hemodialysis patients described in this paper. Blood oxygenation level dependent functional magnetic resonance imaging (BOLD-fMRI) revealed a significant activation of the motor cortex. Hemodialysis seems to originate an inflammatory state of the cerebral tissue reflected by increased OS, while expected to decrease since hemodialysis eliminates free radicals responsible for OS. Considering adrenal function deficiencies, sensitivity to OS and assessed hyponatremia and hypercalcemia, adrenal function deficiencies is strongly suspected in both patients. This probably contributes to amplify brain plasticity and a reorganization of functional control after hemodialysis that is compared to earlier reported studies. Brain plasticity and functional control reorganization was revealed by BOLD-fMRI with a remarkable sensitivity. Brain plastic changes are originated by elevated OS associating indices of adrenal function deficiencies. These results raise important issues about adrenal functional deficiencies impact on brain plasticity in chronic hemodialysis-patients. This motivates more global studies of plasticity induced factors in this category of patients including adrenal functional deficiencies and OS.