"Way back in 1996 we wrote a letter to the Annals of Neurology highlighting the possibility of dehydration being a confounding factor when assessing MS'ers with progressive disease."
Giovannoni et al. Urinary myelin basic protein-like material as a correlate of the progression of multiple sclerosis. Ann Neurol. 1996 Jul;40(1):128-9.
"What we had found in our own studies is that the concentration of particular substance in urine correlated with disability. Why? We subsequently showed that the reason for this was voluntary dehydration; MS'ers with urinary symptoms often restrict their fluid intake to control troublesome urinary frequency, especially when quick access to toilet facilities may be limited, for example during hospital visits. Why is this important for CCSVI? The venous system is a capacitance system; i.e. it stores blood. When MS'ers dehydrate themselves they will almost certainly reduce the amount of blood in the venous system, which will result in a higher chance of finding collapsed veins when doing ultrasound or doppler studies as part of a work-up for CCSVI. This may explain why it is more common in MS'ers with progressive disease; they are more likely to have bladder problems and hence more likely to dehydrate themselves."
"I wonder if the CCSVI investigators' have considered this? Do you dehydrate yourself to control your bladder?"