Scientists have developed the first pill to help multiple sclerosis sufferers walk properly.

The twice-a-day tablet boosts leg strength and significantly increases walking speed.

Within 15 years of an MS diagnosis, 50 per cent of patients often require assistance walking, and in later stages up to a third are unable to walk at all.

There are drugs that can slow the progression of the disease. However, there is no treatment to restore a patient’s lost mobility.

The new drug, called Acorda, which has been undergoing tests for several years, works by improving the way damaged nerve cells send signals to each other.

Each nerve cell has a very short protrusion called an axon that it uses to send electrical signals to other nerve cells throughout the body. Most axons have a covering of myelin that acts as insulation to preserve and speed up the signals. (This is similar to the way the insulating cover of an electrical cord helps preserve the transmission of electricity.) However, if the myelin is damaged, potassium ions can leak out of the axon.

These ions are important because they help to conduct the electrical current in the nerve signals. Once they escape, the current becomes weak and messages to the body’s muscles and limbs do not get through.

In tests, Acorda has been shown to prevent the escape of potassium ions and help electrical signals to pass through areas of damage.

When researchers at a number of hospitals in the U.S. and Canada tested it on 240 MS patients, they found 43 per cent showed a significant improvement in walking speed over a two-month period.

They measured this by checking how long it took each one to walk 25ft. Those who responded to the drug took 25 per cent less time than they did before they were put on the medicine.

Separate tests showed that many patients scored better on leg strength tests, too.

However, the drug does not slow the progression of the disease and can have side effects such as urinary tract infections, insomnia, headaches and nausea.

Acorda Therapeutics, the U.S. firm which made the drug, plans to apply for a licence in the U.S. then Europe. It means the drug could be available in the UK within the next two years.

‘This new research is exciting news,’ says Laura Bell, research communications officer at the MS Society.

‘MS can severely affect people’s mobility and, in turn, their sense of independence.

‘We would welcome any drug that is proven to help with walking disability and allow people with MS to regain some of their freedom.’