More on my hippocamups volume

Since my last post about my MRI, I've had a chance to talk to my new neurologist about the results and to get the actual volumes the radiologist saw.  I don't know if they're transitioning me to the new neurologist, or if she's just working with me on my increasingly serious balance problems.  However, she said that the two neurologists had reviewed the results together, and they were quite pleased.  (So was I.)

Unfortunately, the MRI gave no clues about my balance, which was the reason they had it done.  Or maybe that's a good thing, because a problem showing up in the MRI might be more serious.  Like the balance problems my grandfather had from a brain tumor.  In any event, they want me back in Seattle in January for a follow up.  (We're supposed to have extra snow this year, so the mountain pass getting to Seattle could be dicey.)

But the neurologist also gave me something I'd been hoping to see -- the actual volumes of my hippocampus and ventricles.  We saw that my standing by percentile has improved, but I was wondering about actual volumes.  It appears that I've improved when compared to other men my age, but they are also losing ground at the same time, even due to normal aging.  So has my hippocampus actually grown, or has it simply shriveled up more slowly than everyone else?  Here are the numbers from 2015, 2017, and 2021.  (If you read Beating the Dementia Monster, you know that the volume of the ventricles is a proxy for overall brain tissue loss.  So bigger is bad.)

Year   Hippocampus volume/percentile         Lateral Ventricles volume/percentile

2015           8.88 cc^3 / 36%                                         90.86 cc^3 / >99%

2017           8.18 cc^3 / <1%                                         100.76 cc^3 / >99%

2021           7.42 cc^3 / 52%                                         126.88 cc^3 / >99%

A couple of things stand out.

• My hippocampus is not growing.
• The ventricles have grown a lot. 
  
• I don't know how to norm these, but the rate of change of hippocampus volume does seem to have slowed.  Hippocampus volume lost 8% between 2015 and 2017 (4%/year), and it lost 7.3% between 2017 and 2021 (1.8%/year).  That's a pretty substantial difference, but I don't know how fair my simplistic mathematical approach is to the meaningfulness of the numbers.

The neurologist said that, while they are very pleased with these results, the radiologists may have changed how they norm the scores to get percentiles since 2017.  

 

So, who knows?  I'll just say that I feel as well about my memory and cognition as I did in 2017.  My main intuitive measure is how well I speak Spanish with Carlos in Ecuador over Skype.  We talk in Spanish twice a week, and my fluency fluctuates, apparently as my brain fights the disease.  Lately it's been quite good.  My big problem is my deteriorating balance.