Trucks may also be more heavily taxed to reflect the damage they do to roads.

ECONOMIST: Driving Britain off the roads

Brain scans can reveal inflammation and scarring, but it is not clear how early these changes might occur in the disease and whether they accurately reflect ongoing damage.

BBC: Simple eye scan can reveal extent of Multiple Sclerosis

Social and Family Affairs Minister Mary Hanafin has said anyone who chose to shop north of the border should reflect on the damage they were doing to the economy.

BBC: Striking workers head north for bargains