Scotland’s community of 10,000 multiple sclerosis sufferers will be focused intently on a hotel in Clydebank this weekend, where the potential of a controversial new treatment will be debated by clinical experts.

Specialists from Poland, Canada, Bulgaria, Jordan and the UK will come together to discuss the theories of Dr Paulo Zamboni, an Italian vascular surgeon, who claims that the symptoms of MS can be treated by clearing the blocked veins which cause toxic build-ups in the brain.

Already, dozens of Scots with MS have travelled to eastern Europe to be treated for Chronic Cerebro-Spinal Venous Insufficiency (CCSVI), which involves balloon angioplasties or stents being fitted into the jugular and azygos veins in the neck.

The procedure to tackle CCSVI is the most talked-about MS regimen in recent years, and is already a multi-million-pound industry with treatments costing around £7000. Now, a group of doctors from the fields of vascular, neurological and radiological medicine will meet in Glasgow to discuss Dr Zamboni’s theories.

But does CCSVI work? Six months ago, Barry McArthur, 29, from Paisley, stood on the steps of his Katowice hotel the morning after his procedure and announced to the world in an exhilarated voice he felt “a million times better”. His dizziness had gone, he could stand upright unaided for the first time in months and his speech was no longer slurred.

Stephen Law, 47, of Hamilton, was “almost suicidal” before he travelled to Poland, due to the extreme exhaustion he suffered all day and every day and his incredibly poor quality of life. In the weeks after the procedure, however, he felt so well he could clock up 14 kilometres at a time on his stationary exercise bike.

The same effects were heralded by others who had gone through the CCSVI operation in Poland. Train driver Kevin Quinn, from Glasgow, was “totally energised” after his angioplasties. He could walk greater distances and his eyesight and memory improved. Glasgow-born radio presenter “Tiger” Tim Stevens felt a warmth return to his feet for the first time in years. The spasms in his left leg abated. He felt “wonderful”. Meanwhile, a Californian schoolteacher, Deegie Phelps, 69, threw down her crutches and walked unaided, in a scene straight out of an evangelical church healing.

Six months on, however, the reports are disheartening. Barry McArthur has returned to his wheelchair. Stephen Law has lost his new burst of energy and is tired again and, while his cramps are not so severe, they have returned. Kevin Quinn has also regressed. “I’m still working as a train driver but I’ve lost the energy I had. I believe the balloons I had inserted in my veins have collapsed and I’m back to square one.”

Tim Stevens has since returned to Poland for a second procedure. The balloon angioplasty he’d had carried out on the left side of his chest had collapsed and he had a stent inserted. Tim’s voice is again slurred, however, and he still can’t walk unaided. “I tried to climb up a single step the other day,” he said. “My brain thought it could but the leg told it otherwise.”

But why have so many of those treated later regressed? Dr Tomasz Ludyga, of the Euromedic Clinic in Katowice, who carried out the Scots’ procedures, offers an explanation.

“We can’t explain this entirely but we think when there is a blocked circulation some substances are secreted in the brain to protect it, which results in damage.”