In Dr Zamboni's Dec '08 paper he talks about the different types he saw, most all the progressive patients had a specific pattern of stenosis, all the stenosis were in the vertebral veins which means the spinal cord was getting whacked.
Type A (30%): This pattern is characterized by a steno-obstruction of the
proximal azygous, associated with a closed stenosis of one of the two IJVs
(red crosses). Reflux is always present, under all postural conditions, in
the stenosed IJV (red arrow), with a compensatory controlateral IJV that
appears with an ample CSA. Reflux in the DCVs was detected by the
means of TCCS in 60% of cases. In the azygous vein the reflux has an
effect as far as the lumbar veins, being able to re-enter the caval circle
either through the system of the hemiazygous vein- left renal vein, or by
rising again inside the rachis.
• Type B (38%): This pattern is characterized by significant stenoses of both
IJVs and the proximal azygous (red crosses). Reflux is present in all three
venous segments (red arrows). Cerebral venous outflow for overcoming
the IJVs stenosis re-enters the heart mainly through cervical collateral
circles (Fig. 1b); for the hampered azygous vein outflow, the collateral
circles include again the intra-rachidian pathway (Fig.3), or the system of
• Type C (14%): This pattern is characterized by bilateral stenosis in both
IJVs, with a normal azygous system (red crosses). Reflux (red arrows)
occurs in the IJVs but not in the VVs, with cervical or intracranial collateral
circles that shunt blood towards the superior vena cava or the azygous
vein system, respectively. The resulting overload of the azygous system is
depicted by black bold arrows.
• Type D (18%): In this pattern the azygous system was constantly affected
in various segments (red crosses), resulting in a forced venous drainage
towards the intrarachidian circles in an upward direction (red arrows)
(Fig.3). The vertebral veins appeared to be refluent, and the intracranial
collateral circles seek to gain the IJVs, as confirmed by reflux detection in
DCVs in 90% of cases. At times, the IJVs were also affected (6 cases,
50%), causing an additional obstruction in these patients.
Out of 10 people with PPMS, 9 had type D patterns; one had type B.
This suggests that the cause of the types of MS are anatomically based.
Dr dake feels that these "types" are more lilmited than the real population of MSers will show and we will have more variteis than that.
But this for me was one of the COOLEST things about the Ferrara research, genera medical research has spent untold years trying to figure out what is "different " about PPMS...is it the genes? is it the specfic cell that is reacting? is it that RRMS is one disease and PPMS another?
This very neatly and efficiently expains the difference. Occam's razor; given a complicated explanation and a simple one the simple one is more likely to be true.