To date we have studied 35 people with MS and 35 healthy control subjects, so we are just over one third of the way towards completion,” reports A/Prof Chambers. “Preliminary blinded analysis of the whole 70 cases, using the criteria proposed by Zamboni, indicates that CCSVI (chronic cerebrospinal venous insufficiency) is less prevalent than expected.” In fact, preliminary analysis has revealed that no subjects so far studied have CCSVI according to the criteria proposed by Zamboni. “Since our MS cohort are in the early stages of disease, this would imply that if CCSVI does occur in MS, it does not have a causal role, and it may only develop in more advanced MS,” explains A/Prof Chambers. “It is possible that CCSVI is mainly observed in advanced MS. This is supported by our observations in out-of-trial advanced MS patients.”
Analysis of preliminary results, before the completion of a study, must always be interpreted with caution and final conclusions can only be drawn at study completion. The investigators will continue to recruit their planned sample size of 100 patients and control pairs. Discussions with international investigators, including Zamboni, at the recent
Australasian Phlebology College meeting in Melbourne indicated that others use broader ultrasound criteria for diagnosing CCSVI. However, as yet there are no standardised validated criteria.
“Our data set includes a number of ultrasound parameters not included in the Zamboni definitions,” explains A/Prof Chambers. “We intend to apply advanced statistical methods to determine which if any ultrasound variables are more prevalent in MS. Our results in healthy controls will also provide the best available venous ultrasound data to give a ‘normal range’ for comparison.”
Wow, that's messed up. So, they're using something more rigid than the Zamboni definitions and are finding nothing in anyone?
So, if I am trying to diagnose a broken arm the way to do it is to conclude the arm is broken if:
1. An x-ray shows the break
2. The patient has bad breath
3. The patient has at least one wart
Am I reading that right? How can they possibly draw conclusions at this point, and then they discuss that it's more prevalent in more advanced cases? Why are they drawing conclusions based on people that aren't in the study? OK, is this some kind of joke?