06 May 2001
By Tom Peterkin Health Correspondent
SCOTLAND on Sunday’s campaign for multiple sclerosis awareness this week turns the spotlight on the science of a disease which is still baffling many experts - and on the Scottish Executive’s failure to fund research which might help unlock its mysteries.
Until the scientific mechanisms behind MS are fully understood, a cure remains elusive. Yet the disease is so complex and variable that even the most basic of questions - such why does it affect some people and not others, or how quickly will it progress - are difficult to answer.
Despite this uncertainty, coupled with the fact that Scotland is the MS capital of the world, the Executive admitted last week that the Chief Scientist’s Office is not directly financing any MS studies in Scotland. The lack of money coupled with inadequate research equipment is thwarting efforts to beat MS.
Yet, although this culture of financial hardship means academics run marathons in order to raise cash for their work, Scotland is still managing to produce some world-class research into the mystifying illness.
Many theories have been advanced in an attempt to unravel the mysteries surrounding the disease. For example, it has been suggested that the prevalence of MS in northern latitudes is because it is more likely to be carried by people of Viking descent.
Another hypothesis suggests that environmental factors could be to blame for the high prevalence in Scotland. But it now seems that the complex disorder, which affects 10,400 Scots, is likely to be caused by a combination of different factors working together.
The Multiple Sclerosis Society, which is backing Scotland on Sunday’s campaign, funds a number of projects nationwide, including work carried out by Professor Peter Brophy at Edinburgh University’s veterinary school.
Brophy’s team is looking at the fundamental science behind MS. His team has been responsible for a major break-through that could hold the key to understanding the molecular mechanisms that cause it.
Brophy’s investigations have centred on a substance known as myelin. In healthy people, myelin forms a protective sheath around nerve fibres in the brain and spinal cord, acting as an insulator to ensure that nerves transmit electrical impulses efficiently.
MS occurs when the myelin is damaged. Understanding the causes of that damage is regarded as a crucial area for MS research.
Last year Brophy’s team discovered the first molecule believed to be responsible for manufacturing the myelin sheaths.
"We are trying to find out how cells are made in the central nervous system and how they make the myelin sheath," said Brophy.
"We know very little about how these myelin sheaths develop at the moment. The big challenge is trying to figure out how to persuade the cells which make them to remyelinate the damaged nerve systems in multiple sclerosis."
The new molecule, which has been named neurofascin, is believed to play an important role in that process.
Researchers at the Tayside Research Unit in Dundee are taking a different approach. The director of the unit, Dr Jonathan O’Riordan, has been working on a theory that was first aired by scientists from Nashville, Tennessee, in 1999. The team has found a link between MS and a common infectious bug, which gives carriers flu-like symptoms.
Since then the Tayside team have been investigating the association between the disease and chlamydia pneumonia - a cousin of the sexually-transmitted chlamydia trachomatis bug. Chlamydia pneumonia is carried by around 80% of the population at some point in their lives.
O’Riordan found that more than half of MS patients had chlamydia pneumonia antibodies, compared with just 30% of those with other neurological disorders.
However, the Tayside MS Research Unit has largely had to rely on its own fund-raising efforts and the backing of drug companies, which support their trials.
Another MS enigma is the fact that the disease strikes three times as many women as men. One intriguing area of research is being investigated by Sally Wilson, the research co-ordinator for the Tayside MS Unit.
Wilson examined the relationship between MS and the menstrual cycle. Her results, which have not yet been published but will shortly be presented to the World Congress of Neurology, indicate that MS symptoms worsen during the days leading up to the monthly period, suggesting the disease could be related to hormonal changes.
"Quite a lot of women say their symptoms get worse when they are pre-menstrual," said Wilson. " This was not totally attributable to the pre-menstrual symptoms, which means that there is something else going on which is hormonally related."
MS has been traditionally regarded as one of the hardest diseases for scientists to research, because the brain and spinal cord are so inaccessible. In recent years this has changed with the advent of Magnetic Resonance Imaging, which enables scientists to see inside the brain.
Dr Colin O’Leary, a consultant neurologist with a special interest at the Southern General Hospital in Glasgow, admitted that a chronic shortage of MRI scanners was hindering work.
"One of the major problems we have is that to do clinical studies requires Magnetic Resonance Imaging facilities and currently in this centre we have just one machine, which is under tremendous pressure for routine scanning."
A spokeswoman for the Scottish Executive said: "The Chief Scientist’s Office has previously provided funding for MS research. However, it has not recently received any proposals of a sufficiently high standard on multiple sclerosis and is therefore currently not providing funding for any directly funded projects."