More on my MRIs

After yesterday's post, I got an email from my Mom about the last paragraph.  She correctly perceived that I had some pretty ugly MRI results, but I may have been confused about how much I've said about this in the past.  The MRIs in question came about after publication of the first edition of Beating the Dementia Monster, but I will be giving them a thorough treatment in the second edition.  I'm still working on the second edition, so I may sometimes get confused between what I've shared here and what I've written into the new edition.  If I have given my MRIs adequate discussion here, it was a while ago.  So I should probably recap.

I had five MRIs of my brain from 2012 to 2018.  The first one was to look for the brain tumor I had thought might be causing my initial issues, but it found nothing of concern.  However, they were not looking for neurodegenerative disease, and they did not measure volumes.

Regarding volumes, there are two key volumes when diagnosing Alzheimer's disease.  One is the volume of the hippocampus and others are the volumes of the ventricles.  When mine were measured in 2015, 2017, and 2018, they were normalized with respect to other men of my age.  Results were expressed as to what percentile of men my age my volumes would fit.

The hippocampus translates short term memory into long term memory.  It also keeps you oriented in time and space, so that you know where you are, what day it is, etc.  The ventricles are void spaces in the brain that are filled with cerebrospinal fluid.  They expand to compensate for the loss of brain mass, and an increase in their volume is therefore a proxy for general brain atrophy.

If February 2017, I had two MRIs in the same week in the same facility at the U of Washington.  One was for the insulin study, and the other was for a database and library of MRIs they were creating of people with Alzheimer's disease.  I asked why they couldn't use the same image for both, but they weren't able to explain it.  Nevertheless, I lay in the very narrow tunnel of the machine for 40 minutes, twice in one week.  I was able to obtain the radiologist report for the insulin study MRI, but I don't think I got one for the other one.  Or maybe I did, and I lost it.  The 2018 MRI was to complete the insulin study, and the radiologist report simply said that my brain had been stable between 2017 and 2018.

The baseline MRI is the one I received in 2015 for my initial diagnosis at Harborview.  It found that the volume of my lateral ventricles placed me in the > 99 percentile for men my age, and the volume of my hippocampus placed me in the 36 percentile for men my age. 

However, the 2017 insulin study MRI found that the lateral ventricle volume could still fit > 99 percentile for men my age, but my hippocampus volume now fit < 1 percentile.  In other words, in a room of 100 men my age, I would have the smallest hippocampus and the most loss of brain volume.

There was a note in the radiologist report indicating that the difference in hippocampus volumes might reflect a "difference in technique."  If that's the case, which was correct -- 2015 or 2017?  (This might not be a meaningful question, since different techniques might reflect finding different kinds of information.)  I would say from this that it's likely that my hippocampus volume was already at the < 1 percentile in 2015 because the lateral ventricles were already > 99 percentile.

So how could I have such good cognition after so much damage to my brain?  The nun study found that some (a few) women retained good cognition despite considerable damage to their brains.  Perhaps these nuns were doing all of the things we discuss in Beating the Dementia Monster.