Epidural stimulation is a form of spinal cord stimulation. This article will focus on its use in the treatment of spinal cord injury (SCI). During the past years, the effects of spinal cord stimulation (SCS) on restoration of function in SCI have been studied more and more. The results of these studies seem promising.
Effects of epidural stimulation on motor relearning for SCI patients
Epidural stimulation has been around for a while, but mainly for pain relief. If you’re interested in this, another method that uses electrical stimulation for fighting pain is through TENS treatment. The finding that epidural stimulation offers beneficial effects for motor recovery in SCI patients is much more recent. It has been shown that epidural stimulation can allow people with an incomplete SCI to stand up and ‘walk’ again. Walk is between brackets here, because studies only show limited walking at a slow tempo with walking aids. However, enabling people with a spinal cord injury to walk again is certainly an amazing accomplishment. Examples of this are studies by the University of Louisville and the Mayo clinic in Minnesota and UCLA that are now in the news as they were released yesterday.
The above video may give an incorrect image of epidural stimulation that is too good as it is commercial. However, it does give a proper and well-animated impression of what epidural stimulation is. And for as far as I know, they’re not lying. I have no further connections with this party.
In the studies mentioned above, patients did not just get the stimulation without having to do anything. Patients went through months of training in combination with the epidural stimulation. Further research is being performed all over the world to see if it is possible to eventually implement this technique in rehabilitation practice. Many things still need to be found out, such as the perfect stimulation pattern for maximal recovery.
How do spinal cord stimulation and epidural stimulation work?
The SCS-device locally activates nerve circuits in the spinal cord by ‘imitating’ signals from the brain. Treatment with SCS works by means of neuroplasticity. Neuroplasticity means that the ‘patterns’ in the spine and brain are getting changed. In this case, changing these patterns means reconnecting the wires that run through the spinal cord. As a consequence, it can again become possible to let signals from the brain and spine reach muscles that couldn’t be reached before. Even when the stimulator is off. This, in turn, can enable SCI patients to perform movements that were not possible before.
Invasive and non-invasive spinal cord stimulation
This stimulation can be provided non-invasively, by means of sticky electrodes on the skin, as well as invasively, in which the stimulator is implanted in the body through surgery. These are respectively called transcutaneous spinal cord stimulation and epidural spinal cord stimulation. A certain space on your spinal cord is called the epidural space. An implanted stimulator enters this space. A benefit of an implanted epidural stimulator is that treatment can easily be started again and again once the stimulator is implanted. Another benefit of an implanted stimulator is that it is possible to stimulate very precise and deeper areas. The main benefits of transcutaneous SCS are that there are no surgery risks and costs. It has been shown that transcutaneous stimulation can offer equal neuromodular effects compared to implanted epidural stimulation1.
Research to epidural stimulation and spinal cord stimulation
The following may sound familiar, as it is the case in many great inventions. The story goes that a coincidence was the reason why it was first discovered that epidural stimulation can enable people with an SCI to move ‘paralysed’ muscles again. Thereafter, research to the effects of SCS on motor relearning in people has thus far mainly been aimed at moving the legs and these studies are small in size. Further research to this technique may provide exciting information for therapies for the recovery of function of SCI patients. Some big parties that aim their research at epidural stimulation are:
If you are furtherly interested in clear and understandable information about research to the treatment of spinal cord injuries, I recommend you to read the e-book Don’t call it a miracle written by Kate Willette. You can download it on this website for free. Reading it has really improved my understanding about spinal cord injuries and possibilities for fighting them.
Epidural stimulation is not the only method that is being studied for treating spinal cord injuries. Other examples include physiological trainings based on reflexes, stem cell research, trainings that make use of muscle (EMG) signals, and trainings in which Brain Machine Interfaces are used.
Feel free to look around if you would like to know more about electrical stimulation. Electrical stimulation is not only applied to the spinal cord. You can read about what electrical stimulation is and what it offers here. Furtherly, you can read more about how to apply (neuromuscular) electrical stimulation here. Under some circumstances, however, it is not very wise to apply electrical stimulation. You can read about these so-called contra-indications for electrical stimulation here.
I do not ask for any fees for the links I’ve mentioned. If you feel like you know a research (party) concerning epidural or spinal cord stimulation that should be included, let me know. Further questions, discussion points, and remarks are welcome as well. You can leave a comment or send an email to firstname.lastname@example.org.
*1: Hofstoetter US, Freundl B, Binder H, Minassian K (2018) Common neural structures activated by epidural and transcutaneous lumbar spinal cord stimulation: Elicitation of posterior root-muscle reflexes. PLoS ONE 13(1)