Magnetoencephalography an emerging biological marker for neurodegenerative and neuropsychiatric disorders
Magnetoencephalography Combined with MRI( Emerging Biological Marker for Neurodegenerative disorders and PTSD)MagnetoEncephaloGraphy (known as MEG) is a technique used to study brain activity. In the outermostlayer of the cerebral cortex there are around 10,000,000,000 neuronal cells. The signals that allow thesecells to communicate with one another use electrical currents. The electrical currents also havemagnetic fields associated with them and this is what is detectable using the MEG system. Themeasurement of these ‘neuromagnetic fields allows us to determine both when and where theactivation is occurring in the brain.Magnetoencephalography (MEG) scan is the newest technique used to precisely map functional areas ofthe brain. The MEG scanner generates a real-time movie of brain activity as a patient is asked to dospecific exercises.How does MEG work?Here is a very short video about how MEG works:http://www.youtube.com/watch?v=KoS2UXr0yMgThe alterations in brain function that are detected with MEG, especially those in the temporal regions,are significantly correlated with the relative volume of the lateral and medial temporal lobes. Thisestablishes a link between altered brain structure and altered brain function measured in two differentmodalities (i.e., MRI and MEG).Why MEG and not fMRI? 1. fMRI measures neuronal activity indirectly, relying on the hemodynamic response. 2. MEG has a much greater temporal resolution (it is better able to measure such subtle delays in local and regional responses). 3. Metallic fragments in the body are not contra-indications for the scan Read more: http://www.hindawi.com/journals/ijad/2011/280289/What about a combination of MEG and fMRI?The alterations in brain function that are detected with MEG, especially those in the temporal regions,are significantly correlated with the relative volume of the lateral and medial temporal lobes. Thisestablishes a link between altered brain structure and altered brain function measured in two differentmodalities (i.e., MRI and MEG).It has been demonstrated recently that simultaneous visualization using MRI and MEG is possible. Thiscan be done with the help ofa hybrid multichannel helmet-shaped MEG-MRI device, which is capable ofsimultaneously recording ultra-low-field MRI and MEG.
Researchers at Aalto University in Finland have developed the world’s first device designed for mappingthe human brain that combines whole-head magnetoencephalography (MEG) and magnetic resonanceimaging (MRI) technology. MEG measures the electrical function and MRI visualizes the structure of thebrain. The merging of these two technologies has the ability to produce unprecedented accuracy inlocating brain electrical activity non-invasively.Here is a video of this very new technique:http://www.youtube.com/watch?v=cfb87-lrimAIn the US, The Hoglund Brain Imaging Center (HBIC), University of Kansas, wasrecently awarded afederal High End Instrumentation grant to purchase new state-of-the-art equipment that combines MEGand MRI.http://www.kumc.edu/school-of-medicine/hoglund-brain-imaging-center/facilities-and-resources.htmlMEG in PTSD:MEG has been used in the diagnosis and management of PTSD for a few years. The research conductedby Georgopouloset al. (2010) opened an avenue for an objective diagnosis of PTSD and the potential forevaluating the effectiveness of interventions of treatments.This study involved 74 United States veterans who underwent magnetoencephalography (MEG) that forthe first time allowed scientists to objectively diagnose PTSD with a ninety percent accuracy rate. Theresearchers were able to identify individuals who suffer from PTSD separately from healthy volunteersin the study.http://iopscience.iop.org/1741-2552/7/1/016011The MEG combined with Diffusion Tensor Imaging (fMRI) might increase the accuracy of diagnosingPTSD beyond 90% which is accomplished by MEG alone.Here is a slide show presentation byMingxiongHuang (PhD) from University of San Diego along with VASDHS and NMCSD:http://www.slideshare.net/adonissfera/magnetoencephalography-meg-and-diffusion-tensor-imagingADONIS SFERA, MD