A system that includes electronics implanted directly on the spinal cord, to reactivate the neurons that regulate blood pressure, has allowed a patient suffering from a debilitating neurodegenerative disease to get up and walk again after being bedridden for over a year.
The patient in the study suffers from multiple system atrophy-parkinsonian type (MSA-P), a neurodegenerative disease that afflicts several parts of the nervous system, including the sympathetic nervous system. After being bedridden for 18 months, the patient can now walk up to 250 meters.
Orthostatic hypotension (low blood pressure upon standing up) is a cardinal feature of multiple-system atrophy. The implant functions by preventing the patient from losing consciousness every time she’s in an upright position.
The study was published in The New England Journal of Medicine in the paper titled. “Implanted System for Orthostatic Hypotension in Multiple System Atrophy.”
MSA-P leads to the loss of sympathetic neurons that regulate blood pressure, which tends, therefore, to drop dramatically as soon as patients are in an upright position, in some cases causing them to faint. This makes them more likely to fall, limits their ability to stand and walk around, and can eventually shorten life expectancy. Patients’ quality of life is reduced considerably since they must remain in a reclined position to avoid passing out.
The implant used here had already been used to treat low blood pressure in tetraplegic patients, but this was the first time it was applied to this kind of neurodegenerative disease, substantially improving the patient’s quality of life.
This work follows several other scientific breakthroughs, by Bloch and Courtine, that have allowed people to walk who otherwise cannot. In 2018, the pair published a study showing that three patients with chronic paraplegia regained the ability to walk through a targeted neurotechnology which uses electrical stimulation to reactivate spinal neurons. The individuals had sustained a spinal cord injury more than four years earlier. Earlier this year, the team reported an enhanced system with more sophisticated implants controlled by AI software. In that work, personalized spinal cord electrical stimulation—using electrode paddles designed specifically for spinal cord injuries—has been shown to restore independent motor movements within a few hours of the onset of therapy in three patients with complete sensorimotor paralysis.
In this more recent study, the implant consists of electrodes connected to an electrical-impulse generator that’s commonly used to treat chronic pain. After implanting their device directly on the patient’s spinal cord, the scientists found an improvement in the body’s capacity to regulate blood pressure, enabling the patient to remain conscious for longer periods in an upright position and to begin physical therapy to walk again.
For Bloch, this advance paves the way to important clinical breakthroughs in treating degenerative diseases: “We’ve already seen how this type of therapy can be applied to patients with a spinal cord injury. But now, we can explore applications in treating deficiencies resulting from neurodegeneration. This is the first time we’ve been able to improve blood-pressure regulation in people suffering from MSA.”
“This technology was initially intended for pain relief, not for this kind of application,” added Courtine. “Going forward, we and our company Onward Medical plan to develop a system targeted specifically to orthostatic hypotension that can help people around the world struggling with this disorder.”
