Dementia and Alzheimer’s Disease: LORETA findings

Thanks to Jay Gunkelman who made a very informative post on January 27 on this forum entitled Dementia and Alzheimer’s Disease. There he described the EEG patterns that we should expect and detect when evaluating for AD or other dementias.

I’d like to just throw out there a few other findings that were discovered in a few exploratory investigations while working on some studies with our colleague Alicia Townsend, at the time at Univ. of North Texas. Lexicor funded these projects and now the arrangements are such that I can’t disclose more than was published in the abstracts from our talks at ISNR and AAPB.  I did at least want to point to these very preliminary findings because theoretically they are in concert with your explanations.

First, we explored 10 participants between the ages of 65 and 85 were recruited at the University of North Texas Health Science Center.  Each was diagnosed by the Alzheimer’s Disease Assessment Scale and a medical interview.  The aim of the study was to identify current source density markers in AD.  EEG recording of the eyes closed condition of an AD group was compared to an age-sex matched control group using within-subject multiple t-test procedures. sLORETA difference maps in nine frequency bands were investigated. Interestingly the results showed that there was a significant increase in current source density in the delta and theta bands in the Brodmann Area (BA) 39 of the right temporal lobe and BA 31, the cingulate gyrus respectively.  Additionally there were decreases in alpha in the BA 21 of the right temporal lobe and right inferior parietal lobule (Sherlin, Townsend & Hall, 2006).

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A discussion on LORETA software use and licensing.

April 30, 2009
Leslie Sherlin, PhD

There recently has been some discussion regarding the use of low resolution brain electromagnetic tomography or LORETA, sLORETA and eLORETA. I felt compelled to make a few comments regarding this since there may be some confusion of how LORETA works and the usage of LORETA as an inverse solution specifically the licensing agreements of the KEY Institute for Brain-Mind Research at the University Hospital of Psychiatry, Zurich.

My intention is to very briefly explain the license agreement so that the end user can be informed. I’ll do so in an informal way by telling the story of the implementation of these methods from my perspective. For a more formal description of the use of LORETA families and some examples you can see a recently written chapter 4 by myself (Sherlin, 2009) in the latest edition of the book Introduction to Quantitative EEG and Neurofeedback edited Budzynski, Budzynski, Evans & Arbarbanel.

In 2000 I had the great privilege to visit with Roberto Pascual-Marqui PhD, the developer of the LORETA family, with my colleague and fellow student Marco Congedo. At this time the LORETA-Key software (Pascual-Marqui, 1994, 1999), had not been widely distributed and utilized in the United States. Marco had significant interest in using LORETA for visualizing brain activity and for exploring newer methods for neurofeedback and had many questions for Roberto. So upon the invitation of Roberto, Marco found funding to travel to Zurich and learn the details from the creator and I happen to be standing in the right spot at the right time. Roberto Pascual-Marqui trained us extensively on how to use his software, named LORETA-Key, which had been already released as free academic software. The LORETA-Key software is a collection of independent modules that the user must run in sequence in order to get from raw EEG to LORETA images.

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