Multiple Sclerosis is a neurological condition that was first recognised around 150 years ago. It attacks the brain, eyes and spinal cord. Inflammation in those parts of the nervous system can flare up to affect vital functions, including eyesight, balance, strength in the arms or legs, and control of bladder function. Many people with MS experience tiredness, and some encounter problems with their memory.
MS usually starts with attacks of neurological symptoms which are termed relapses. These relapses usually last for several weeks before the symptoms gradually improve. Relapses often occur less frequently as the years pass, but can then give way to a slow build up of disability, which is termed secondary progression. In a few, progression dominates from the beginning. For people with MS, who are all too aware of its reputation for causing disability, these processes can translate into an unpredictable and frightening illness. Handling these issues, and the uncertainty they generate about the future, is an important part of managing MS from the outset.
MS occurs throughout the world, with women affected more commonly than men. It is also more common in temperate regions. This may be partly to do with genetics, exposure to environmental factors (possibly viruses), and lack of exposure to sunshine and a resulting deficiency of vitamin D. On the other hand, MS is not entirely a developed world disease, and it is being increasingly recognised in countries where it was previously considered a typically Western condition. Awareness of MS is increasing substantially throughout the world, and it is an area of very active research.
Even though the actual cause of MS remains unknown, research has revealed some of the ways in which it can cause symptoms and disability. Relapses are thought to occur when inflammation flares up in various parts of the nervous system. Within these inflamed areas, also called lesions or plaques, the nerve fibres can lose their insulating fatty layer (myelin). This prevents them from carrying electrical signals from one part of the nervous system to another, and the disconnection gives rise to symptoms. Natural recovery from relapses happens as the attack of inflammation dies down, and when some of the myelin regrows.
In addition, it has been appreciated increasingly that MS can damage the nerve cells themselves and cause them to degenerate. This neurodegeneration, which cannot heal, is now thought to be the main cause of permanent and progressive disability.
Like many long term conditions, such as diabetes or hypertension, there is no cure as such, but MS is becoming more and more treatable. People with MS are generally aware that a good diet, which is low in animal fat and red meat, can be helpful, and vitamin D is often recommended as well. Smoking seems to make the condition worse. Infections can trigger relapses and need to be treated quickly, or prevented by annual flu immunisations. Some of the symptoms of MS can also be treated to make them less intrusive, and there is a great deal to be gained through optimal use of drugs and physical therapy for this purpose.
There is also greater and greater scope for tackling the fundamental processes by which MS causes damage, through preventing inflammation and relapse. The first drugs of this kind became available in the 1990s and were of the beta interferon class. These drugs work by disrupting the communication between immune cells which leads to the formation of MS plaques. The beta interferons were followed by copaxone, which looks chemically like myelin and prevents the immune system from attacking the natural myelin in the brain. These so-called first line drugs, which are all taken by injection, have been in continuous use for more than a decade, and seem to be safe for long term use.
Five other drugs, including some which are given as tablets and others as infrequent injections, have since become available, and others are on the way. These drugs work on different aspects of immunological function to prevent attacks, and are becoming increasingly powerful. In fact, there is real hope that, if used properly, they can stabilise many of the cases of relapsing MS. However, access to treatment remains unequal, partly because of limited awareness of treatment among physicians, and partly because of the high cost of the medication.
Major challenges remain. Problems with thinking and memory are well recognised but not yet treatable. Profound fatigue can also be a major cause of disability and remains poorly understood. The major unmet need, however, is for treatments which can prevent nerve degeneration and progressive disability, and for treatments which can repair the nervous system once it is damaged. Both are areas of active research through a major effort involving national and international teams of scientists.
It can take around 15 years for promising scientific leads to be developed into effective treatments through clinical trials, because a lot of testing has to be done to make sure that a drug is safe and effective. The amount of work required for this process also means that these drugs are expensive.
At the moment, quite apart from drugs for relapsing MS, there are trials either planned or under way for drugs to protect nerve cells and to repair myelin. Stem cell treatment is also being tested to address these twin needs for so-called neuroprotection and neurorepair. This pace of discovery suggests that breakthroughs are likely to occur in the next few years, allowing physicians to offer real optimism to their patients for the future.
Raj Kapoor is a consultant neurologist at the National Hospital for Neurology and Neurosurgery in London, and reader in Neurology at UCL. He graduated from the University of Oxford in 1981, and completed his neurological training in London after carrying out research for a doctorate on Neurobiology in New York and Oxford. He specialises in multiple sclerosis, and is heavily involved in the international programme to develop new treatments for it.
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