A drug that could eventually help paralysed people regain muscle movement – and possibly even walk again – has been discovered by scientists in the USA.
In a study described as “unprecedented”, researchers were able to activate the paralysed muscles of disabled rats, using a daily injection of a newly-developed chemical compound they believe can reconnect nerve connections. They said that the “very promising” compound was now being moved forward into larger trials.
It is the latest in a string of recent discoveries that have given renewed hope that people disabled by spinal cord injuries could be helped to walk again. Previous studies have focused on therapies using stem cells or electronic stimulation. Earlier this year, doctors reported on the case of a man in Poland with a severed spine who was able to walk again, following treatment with an implant of regenerative cells.
However, the discovery of a candidate drug opens up new ground.
So far the compound, known as intracellular sigma peptide (ISP), has only been tested in a small number of rats, so it is too early to say for certain whether it would work in humans. However, scientists have described early evidence as “exciting”.
Of 26 rats injected, 21 regained the ability to walk, balance or control their bladder movements. Some regained all three; others two of the three.
Jerry Silver, professor of neurosciences at Case Western Reserve University School of Medicine, in Cleveland, Ohio, who led the research team, said these rates of recovery were “unprecedented”.
“Each of the 21 animals got something back in terms of function,” he said. “For any spinal cord-injured patient today, it would be considered extraordinary to regain even one of these functions, especially bladder function.”
The rats were injected daily with the ISP for several weeks. The study is published in the journal Nature.
Thousands of people are left disabled by spinal cord injuries every year. The injuries crush and sever nerve fibres – long slender projections of nerve cells – that facilitate communication between the brain and the body and enable muscle movement and function.
After injury, nerve communication is blocked off by scarring around the injury site. Build-ups of proteins called proteoglycans in scar tissue react with enzymes in nerve tissues and cut off nerve signals. The ISP drug appears to work by blocking this enzyme, enabling nerve communication across this previously impenetrable barrier.
The researchers said that if development into a drug were successful, ISP could be used either as a standalone treatment or potentially in combination with other ground-breaking therapies to give spinal-injured people in the future the best possible chance of recovery.
Dan Burden, 38, from Hertfordshire, who broke his back 13 years ago and is a spokesperson for the UK’s Spinal Injuries Association, said that the possibility of a drug therapy – as opposed to surgery or electrodes – was particularly promising.
“An eventual treatment for spinal cord injury may come from a combination of things – for example, this drug therapy combined with the surgical intervention we’ve seen in Poland,” he said. “It’s very promising to hear all of these different methods that are having beneficial results.
“In this study they have also specifically mentioned that the rats were able to regain control of their bladder function. This is a really big issue for spinal cord injured people. Time and time again when research priorities are sought from spinal cord-injured people, bladder function, bowel function and sexual function will figure more highly than walking.”
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