The first patient to receive a spinal implant to treat advanced Parkinson’s disease has described experiencing “a rebirth” after the treatment allowed him to walk again without falling over.
Marc, 63, from Bordeaux, France, was diagnosed with the degenerative disease more than 20 years ago and had developed severe mobility problems, including balance impairments and freezing of gait. After receiving the implant, which aims to restore normal signalling to the leg muscles from the spine, he has been able to walk more normally and regained his independence.
“I practically could not walk any more without falling frequently, several times a day. In some situations, such as entering a lift, I’d trample on the spot, as though I was frozen there, you might say,” he said. “Right now, I’m not even afraid of the stairs any more. Every Sunday I go to the lake, and I walk around 6 kilometres [3.7 miles]. It’s incredible.”
The implant is yet to be tested in a full clinical trial. But the Swiss team, who have a longstanding programme to develop brain-machine interfaces to overcome paralysis, hope that their technology could offer an entirely new approach to treating movement deficits in those with Parkinson’s disease.
“It is impressive to see how by electrically stimulating the spinal cord in a targeted manner, in the same way as we have done with paraplegic patients, we can correct walking disorders caused by Parkinson’s disease,” said Jocelyne Bloch, neurosurgeon and professor at the CHUV Lausanne University hospital, who co-led the work.
Parkinson’s disease is caused by the progressive loss of dopamine-producing neurons. For about 90% of patients with advanced illness, this leads to difficulties with walking, including balance deficits and freezing of gait. Conventional treatments, such as the drug Levodopa, can improve symptoms but are unable to completely restore normal movement. The implant aims to overcome this by directly targeting the spinal area responsible for activating leg muscles during walking.
First, the team developed a personalised anatomical map of Marc’s spinal cord that identified the precise locations that were involved in signalling to the leg to move. Electrodes were then implanted at these locations, allowing stimulation to be delivered directly into the spine.
The patient wears a movement sensor on each leg and when walking is initiated the implant automatically switches on and begins delivering pulses of stimulation to the spinal neurons. The aim is to correct abnormal signals that are sent from the brain, down the spine, to the legs in order to restore normal movement. “At no point is [the patient] controlled by the machine,” said Prof Eduardo Martin Moraud, of Lausanne University hospital. “It’s just enhancing his capacity to walk.”
The study, published in Nature Medicine, found that the implant improved walking and balance deficits and when Marc’s walking was analysed it more closely resembled that of healthy controls than that of other Parkinson’s patients. Marc also reported significant improvements in his quality of life.
The authors said a full clinical trial was needed to demonstrate clinical efficacy and have enrolled a further six patients to assess whether the apparent benefits are replicated. “At this stage it’s a proof of concept,” said Prof Grégoire Courtine, a neuroscientist at EPFL, who co-led the work. “Of course it’s not tomorrow, it will be at least five years of development and testing.”
Prof Karunesh Ganguly, a neurologist at University of California San Francisco, who was not involved in the work, said: “This study describes a new approach for modulating the spinal cord in order to improve gait in Parkinson’s disease [and the] treatment can also potentially address freezing of gait, which is currently hard to treat. It will be exciting to see how this generalises to a larger population of patients.”
