With recent advances in the field, we take a look into the attempts researchers have made when ‘curing’ paralysis
by Maria Mellor
Paralysis is most often caused by damage to nerve tissue, either through a stroke or break in the spine, and it is so far untreatable. Recent innovations in science, however, have meant that the damage can be bypassed to allow someone to walk using machinery or even play Guitar Hero with the aid of artificial electronic impulses.
It is the job of the nerves to send and receive information through electronic impulses. Information from our senses is sent for the brain to translate, and instructions are sent back from the brain to the muscles. Therefore if these nerves are damaged in some way, the part of the body they lead to will be unable to move nor feel sensations such as touch and pain. You can break your spine without becoming paralysed, however if the spinal cord where all the nerves lead up to the brain is damaged, a whole area of the body will be left paralysed.
So what is so difficult about fixing damaged nerves? Unfortunately nerves are very tiny, very delicate things. They are highly individual cells that are so specialised they are unable to heal themselves. Even if it was even remotely possible to reattach damaged nerves, there are so many variables that could go wrong. A surgeon would have to reattach each individual nerve with disastrous results in the wrong nerve was put in the wrong place. There are risks of harming the patient further, and it’s simply not feasible for such a thing to happen today.
The simplest solution, but perhaps not the cheapest, is to give a paraplegic person an exoskeleton. These machines strap to the paralysed area and use motors to move the joints. The wearer is then able to control their movements through a series of buttons. It’s purpose isn’t just to let a paraplegic person move their legs again, but it also allows them to get out of their wheelchair in order to minimise secondary health problems they may gain due to extended sitting. Exoskeletons do have their problems: they’re expensive, bulky and overall not all that practical in day to day life.
This doesn’t mean there aren’t other options. Researchers have found ways to mimic the electronic signals the nerves transmit, bypassing the damage and going straight from the brain to the paralysed area.
Ian Burkhart from Ohio, US, has just had a chip implanted into his brain to hopefully give him a new lease of life. The chip reads signals from his brain which are interpreted by a computer that sends precise electronic impulses to control the muscles in his hand. He sustained damage to his spinal cord following a diving accident five years ago that meant he was paralysed from the elbows down and left unable to walk. This is the first time this kind of technology has been used to successfully allow a person with paralysis to move their hand.
Six months ago Gair Rhydd reported on a breakthrough in the technology, when a paraplegic man was the first to be able to walk again without the use of an exoskeleton or prosthetics. He was trained to control walking and idling (staying still), and went on to walk a 3.66 metre course with the aid of a walking frame and harness.
The technology is still in it’s infancy: the equipment is too bulky and too expensive to be used in everyday life, but there are hopes that with development researchers can make adjustments to make it more practical to be used by anyone who needs it
What about attempts to actually cure paralysis? While it would be impossible to reattach damaged nerves, there is a possibility that they could be encouraged to mend themselves. There is the method of epidural stimulation, where an electrical current is passed at different frequencies and intensities just below the injured part to activate the nerve circuits. Participants in a study are reported to have regained some voluntary movements as well as improved cardiovascular and bowel health, even after the device was switched off.
Another method which attempts to encourage the nerves to heal themselves is through the use of stem cells. Stem cells are effectively the ‘master cells’ and can be found in bone marrow. These cells are able to become any type of specialised cell, whether it’s a muscle cell, a blood cell or a nerve cell. The idea is that these stem cells are injected at the site of damage in the hopes that the nerve cells would re-attach and work again. It’s incredibly risky with limited success rates, but it could be possible with some fine-tuning.
Paralysis is a terrible thing to happen to a person, and the key to its reversal is much desired by both scientists and doctors alike. There are many paths being followed at the moment with a few breakthroughs in technology, but unfortunately nothing good enough for permanent use. All we can hope is for one or more of these technologies to be refined in the near future.