Evidence against the involvement of chronic cerebrospinal venous abnormalities in multiple sclerosis. A case-control study.

OBJECTIVE: Multiple sclerosis (MS) is a chronic neurodegenerative disease of the CNS. Recently a controversial vascular hypothesis for MS, termed chronic cerebrospinal venous insufficiency (CCSVI), has been advanced. The objective of this study was to evaluate the relative prevalence of the venous abnormalities that define CCSVI. METHODS: A case-control study was conducted in which 100 MS patients aged between 18-65 y meeting the revised McDonald criteria were randomly selected and stratified into one of four MS subtypes: relapsing/remitting, secondary progressive, primary progressive and benign. Control subjects (16-70 y) with no known history of MS or other neurological condition were matched with the MS cases. All cases and controls underwent ultrasound imaging of the veins of the neck plus the deep cerebral veins, and magnetic resonance imaging of the neck veins and brain. These procedures were performed on each participant on the same day. RESULTS: On ultrasound we found no evidence of reflux, stenosis or blockage in the internal jugular veins (IJV) or vertebral veins (VV) in any study participant. Similarly, there was no evidence of either reflux or cessation of flow in the deep cerebral veins in any subject. Flow was detected in the IJV and VV in all study participants. Amongst 199 participants there was one MS subject who fulfilled the minimum two ultrasound criteria for CCSVI. Using MRI we found no significant differences in either the intra- or extra-cranial venous flow velocity or venous architecture between cases and controls. CONCLUSION: This case-control study provides compelling evidence against the involvement of CCSVI in multiple sclerosis.

Considering the source: commercialisation and trust in agri-environmental information and advisory services in England.

Recent decades have seen the emergence and increasing prominence of a range of public and private sector providers of agricultural information and advice, owing to state transition away from direct provision of agricultural advisory services. In this paper, we evaluate the establishment of trust in agri-environmental agricultural advisory services in England. Qualitative field research was undertaken with farmers, advisors and promoters engaged in four contrasting agri-environmental advisory initiatives. Findings suggest that longevity and expertise in service provision are more important than the public, private or charitable status of specific advisory service in engendering trust. Consistent funding allocated to well-known agencies or their affiliates is thus more likely influence farmer behaviour in the short term than 'contract' advisory projects awarded to novice service providers. Study participants also put their trust in services that were perceived as 'impartial' or actively 'pro-agriculture'. However, we suggest this 'pro-farmer' orientation can negatively impact on environmental outcomes: advisors may be incentivised to provide information on the easiest access to agri-environmental grants, rather than the actions with the most environmental benefit.