Friday, October 16, 2009
Morphometics Part II
The next measurement on my morphometrics sheet of interest to me is the
The first installment of this series dealt with the measurement between the basion, the part of the skull in front of the big hole (foramen magnum) that your spinal cords travels up through to your brain, becoming your brainstem, AND the tip of the dens (pointy finger of bone sticking up from the C2). That was the basion-dens interval.
But now, we are looking at the basion-atlas interval. The distance between the basion (described above) and the atlas, or C1. Normies average 1.8 mm in this distance with a span of 0 mm and 3.0.
This measurement is so small because, in normies, your skull is sitting right on the C1!! Remember, I said in the last installment that the C1 and the occipital bones mesh together? That that was what became dislocated in my anatomy when I fell onto my head? That is why, in the normal range, you see it starts with 0 mm and runs up to only 3.0 mm.
What is MY distance between the basion, the area in front of the foramen magnum (big hole) and my C1 (atlas)?
Lying down. Supine.
When I am sitting up, under CT, the distance becomes even larger: 12.1, 12.6, 12.8.
I'm struggling to wrap my mind around this, to understand what this means. I know I'm no doctor...but I've been studying this for over five years as I've been my sole advocate for my care, as I've battled my way through various neurosurgeons who have not always had my best interests at heart.
My NY neurosurgeon told me many times that I was a pain in the ass patient. He told me that most neurosurgeons would have nothing to do with me but that he was willing to take me on as a patient and to help. He meant that I was a pain in the ass to other neurosurgeons who have never seen anyone in my situation before and would not know what to do with me. But I was not a "PIA" to him.
So, my skull is very, very close to the tip of the C2, the odontoid. Much closer than normal, much closer than the lowest control study patient.
But...my skull is further away from the C1, A LOT further than away than normies's skulls are from their C1s. Remember, you normies have your skulls about 1.8 mm on average from your atlas bone, C1, because the skull does sit on the atlas bone. At the occipital condyles.
But...MY occipital condyles were dislocated due to the injury/fall. And now, my skull is almost 13 mm (upright) from MY C1.
there's the skull, C1, C2, working consecutively from the top down.
My skull is closer to the C2 than normal, but further away from the C1 than normal.
How is this even possible?
The only premise that makes sense is that my skull slid forward and downward. Moving the skull further from the C1...but closer to the C2.
In fact, my other NY neuro told me, when these morphometrics were done and after several doctors stood around the computer screens for an hour while I hung in the invasive traction, that when I broke my C1 into four pieces, that was not the only injury I incurred.
I also had my skull break loose from my C1 and slide forward and down. He told me that my skull had, in fact, fused back into place in that position. A wrong position, but hey, it works, sort of.
This doesn't really answer ALL of my questions. I'm not exactly "getting it." But it is giving me more of an understanding of just how messed up my "cranio cervical junction" is!
Posted by By His Grace at 9:13 PM