Simultaneous MEG/EEG recordings for the study of source domain brain connectivity in neurodegenerative diseases

Abstract

Recently, the understanding of the brain function has shifted from the classic localizationism, sometimes called phrenological model, to the modern model of the connectome. In this new framework the different brain regions, although specialized, are highly connected in such a way that the brain, as a whole, carries out the cognitive functions. Within this framework, some neurological diseases have started to be studied from the viewpoint of connectomics. Classic neurological diseases, such as Alzheimer's disease or epilepsy, are nowadays considered as disconnection or hiperconnection syndromes, respectively. 1.2.2. Single-Photon Emission Computed Tomography Single-photon emission computed tomography (SPECT) is an imaging technique based on the gamma decay principle. A set of  cameras, calibrated to be sensitive to a specific  radiation, can easily be used to detect an accumulation of unstable atoms. As these accumulations do not occur in nature, they have to be artificially created. In the SPECT imaging, a radiopharmaceutical compound is used, a molecule containing an unstable atom that will decay, emitting -radiation in the process. Radiopharmaceuticals are designed to mimic organic compounds absorbed by a given organ, or to show affinity to a given tissue. In both cases, Figure 1.5 Different types of collimators used in SPECT. Left: Parallel-hole collimator, that rejects photons whose trajectory is not perpendicular. Center: Fan beam collimator, that rejects photons whose trajectory is not radial. Right: Pinhole collimator, that acts like a pinhole camera. Adapted from (van Audenhaege et al., 2015).

Caracterización de personas con alto riesgo para el desarrollo de demencia mediante técnicas de neuroimagen

“…A visual summary of the temporal and spatial resolution and the invasiveness of the most used functional neuroimaging techniques. Reproduced from (Bruña, 2019).…”