Spinal implant allows man with Parkinson's to walk again

There’s been considerable excitement following the news that a man with advanced Parkinson's disease, which had caused severe problems with walking, is up and about again, covering literally miles each day. This is thanks to a special implant that stimulates nerves in his spine. Marc Gauthier - who is a 63-year-old from Bordeaux in France - is the first person to try out the device and he says it has given him a second chance in life. Neurosurgeon Jocelyne Bloch fitted Monsieur Gauthier’s device…

Jocelyne - So the device is composed of two parts: electrodes that are stimulating the spinal cord and the pacemaker or a neurostimulator. Everything is under the skin. So when we stimulate the spinal cord, we can reactivate the muscles of the legs in order to improve the gait of people. So this was developed many years ago to treat people with spinal cord injury, and now we apply this treatment to people with Parkinson's disease.

Chris - How are you doing that? Are you eavesdropping on the signals that are coming so you can work out what the person's intention is and then reinforcing it?

Jocelyne - Yes. First of all, we implant electrodes in the region of the spinal cord that is controlling each movement, each muscle. And the stimulator is going to be programmed in order to follow what the patient wants to do. I'll give you an example. If the patient has an asymmetry when he's walking, he has less hip flexion on the right, or less ankle extension on the left, we can compensate this with the spinal cord stimulation and we look at what he's doing and we can adapt the stimulation while he's walking.

Chris - Was there a sort of learning phase then when you turned into what those nerve signals that would normally make him move and not move very well were, and then train your system to deliver the right sort of compensation to balance things up.

Jocelyne - So what we've seen is that in the laboratory, when we have all the possibility to look at his gait and adapt the stimulation, the response is immediate. He could walk properly immediately after the implantation. But then it took a while to train him with the stimulation and to also use it outside from the laboratory and use it outside, walking in a department store, walking upstairs, visiting any type of building. And that took a little bit more time.

Chris - Is there any improvement in his baseline function without the device? Has it helped him to overcome any of the difficulties or is he completely disabled without it, or back to how he was, and as soon as he turns it on he's better.

Jocelyne - So we recently met him again, you know, and we did a lot of tests without stimulation and with stimulation. And there is a huge difference. I would say, we implanted this patient two years ago and within two years his disease has evolved and he's now worse than he used to be. And without stimulation, he's almost falling all the time. And, the stim is still very efficient and he really needs it to be better in his everyday activity.

Chris - How tricky is it to do this sort of surgery? Is it relatively simple to implant these devices?

Jocelyne - So these devices were already implanted in many patients, but for other indications. Namely to treat neuropathic pain. The difference in our case is that we have to insert the electrodes very precisely in order to be able to control each muscle of the legs. And to prepare this surgery we modelise the patient's spinal cord and we know where the different roots that are then going to innervate the different muscles are located. And it helps the surgeon to precisely position the electrodes. We also, during the surgery, do tests. Give an impulse to the spinal cord and you see the muscle reaction at the moment of the stimulation to make sure that the electrodes are well positioned. So I would say it's quite a common procedure, but done very precisely in that case.

Chris - And how long do you think it will last, the implant? Is it rechargeable or does it have an external power pack? Does it just clap out eventually and you're gonna need to go in and replace it?

Jocelyne - So we've selected the rechargeable stimulator, but we know that it's not an internal device. And in general, after 15 years, 20 years, you have to replace it, but it's only the battery that needs to be changed, the neurostimulator and not the electrodes. So it's quite a simple surgery that can be done under local anaesthesia. Just open the skin and remove the old battery and change it.

Chris - And how generalisable do you think this intervention is? Could many Parkinson's patients who have problems with walking benefit from this or is this a special case?

Jocelyne - No, we hope that more people will benefit, but it's early to tell who is going to benefit from this therapy. So we have a good example, but we need to work on many more people to be able to have criteria that gives you the knowledge of who is going to be a good responder, and who is not. And for that we'll have a next phase trial that is supposed to be started next year that is going to support six more patients. And I'm sure that after this trial we'll have more knowledge on this application.