SCYNAPSIS
#neurosciences
#neurosciences
#neurosciences
Image credit by CHUV / Gilles Weber
Image credit by CHUV / Gilles Weber
Image credit by CHUV / Gilles Weber
Pablo Ávalos Prado
Pablo Ávalos Prado
Pablo Ávalos Prado
Neuroscientist & Medical Writer
Neuroscientist & Medical Writer
Neuroscientist & Medical Writer
May 25, 2023
May 25, 2023
May 25, 2023
Learning to walk again
Learning to walk again
Learning to walk again
A digital bridge made of wireless implanted devices between the brain and the spinal cord has enabled an individual with chronic tetraplegia to stand and walk naturally in community settings. Moreover, neurorehabilitation mediated neurological improvements that persisted even when the bridge was switched off.
To walk, the brain delivers executive electrical signals to muscles through nerves that emerge from the spinal cord. But when an accident damages the neurons in the spinal cord involved in this connection, the consequence is permanent paralysis. This is the case of Gert-Jan Oskam, who twelve years ago had a cycling accident that damaged the spinal cord in his neck, causing total paralysis of his legs.
Some years ago, a research group from the Ecole Polytechnique Fédérale of Lausanne developed a program that combined epidural electrical stimulation in the spinal cord with neurorehabilitation seasons, enabling Oskam to regain the ability to step with the help of a front-wheel walker. The same group has recently developed an implanted electronic “bridge” connecting his brain activity to a device that delivers electrical pulses in real time to his legs, allowing Oskam to walk with full (mind) control of his pace.
Now for the first time in a decade Oskam is able to stand up and have a beer with his friends at the bar.
A digital system connecting his brain to his legs
The digital “bridge” consists of a three-component system of implanted devices enabling recording and processing of cortical activity and stimulation of the lumbosacral spinal cord wirelessly and in real time.
The first component of the bridge is based on a couple of implants made of 64 electrodes embedded in the skull that record the brain activity of the sensorimotor cortex, the part of the brain that controls voluntary movements.
These implants transmit ultrahigh frequency (402-405 mHz) signals in real time to the second component, a portable base station in a backpack worn by the patient, which generates online predictions of motor intentions on the basis of these signals.
Then the decoded motor intentions are converted into stimulation commands that are transferred into an implantable pulse generator, similar to those used by Parkinson’s patients to deliver deep brain stimulation. The authors upgraded this last component with wireless communication modules and implanted it into the targeted dorsal root zones to specifically stimulate the lower limb muscles.
The result of this integrated and wireless chain of hardware and software is a brain-spine interface that converts brain activity into analogue electrical stimulation enabling the self-controlled activity of the legs through mind. In the words of Oskam: “The stimulation before (with the old system) was controlling me and now I am controlling stimulation by my thought”.
Towards recovery of natural walking
One of the reasons that prompted Oskam to use this digital bridge was that, after three years of regular neurorehabilitation with stimulation only, his motor skills stopped improving. With this new system, now he is not only able to voluntarily move his legs and feet, he can also walk in complex terrains like steep surfaces and climb stairs, which require adaptive modulation of the amplitude of muscle activity.
Moreover, after 40 seasons of neurorehabilitation combining stimulation with physiotherapy, Oskam recovered great control of hip flexor movements even when the device was switched-off and could walk short distances with the help of crutches, suggesting recovery of nerve cells (neuronal plasticity) that were not totally damaged after the accident.
A new hope for spinal cord injuries
In spite of the hopeful results, the authors of this work underline in the article, published this week in Nature, that the digital bridge was only validated in a single individual with partial - and not total- damage of the spinal cord and therefore it remains unclear whether this system would work on other tetraplegic patients. In fact, the research team is currently recruiting three patients to test if a similar device can also restore arm movements.
It is likely that next approaches will be focused in developing non-invasive devices and in the use of other interventions like stem cells that could restore (or replace) the activity of injured neurons to achieve a more natural walk for these patients.
Original article
A digital bridge made of wireless implanted devices between the brain and the spinal cord has enabled an individual with chronic tetraplegia to stand and walk naturally in community settings. Moreover, neurorehabilitation mediated neurological improvements that persisted even when the bridge was switched off.
To walk, the brain delivers executive electrical signals to muscles through nerves that emerge from the spinal cord. But when an accident damages the neurons in the spinal cord involved in this connection, the consequence is permanent paralysis. This is the case of Gert-Jan Oskam, who twelve years ago had a cycling accident that damaged the spinal cord in his neck, causing total paralysis of his legs.
Some years ago, a research group from the Ecole Polytechnique Fédérale of Lausanne developed a program that combined epidural electrical stimulation in the spinal cord with neurorehabilitation seasons, enabling Oskam to regain the ability to step with the help of a front-wheel walker. The same group has recently developed an implanted electronic “bridge” connecting his brain activity to a device that delivers electrical pulses in real time to his legs, allowing Oskam to walk with full (mind) control of his pace.
Now for the first time in a decade Oskam is able to stand up and have a beer with his friends at the bar.
A digital system connecting his brain to his legs
The digital “bridge” consists of a three-component system of implanted devices enabling recording and processing of cortical activity and stimulation of the lumbosacral spinal cord wirelessly and in real time.
The first component of the bridge is based on a couple of implants made of 64 electrodes embedded in the skull that record the brain activity of the sensorimotor cortex, the part of the brain that controls voluntary movements.
These implants transmit ultrahigh frequency (402-405 mHz) signals in real time to the second component, a portable base station in a backpack worn by the patient, which generates online predictions of motor intentions on the basis of these signals.
Then the decoded motor intentions are converted into stimulation commands that are transferred into an implantable pulse generator, similar to those used by Parkinson’s patients to deliver deep brain stimulation. The authors upgraded this last component with wireless communication modules and implanted it into the targeted dorsal root zones to specifically stimulate the lower limb muscles.
The result of this integrated and wireless chain of hardware and software is a brain-spine interface that converts brain activity into analogue electrical stimulation enabling the self-controlled activity of the legs through mind. In the words of Oskam: “The stimulation before (with the old system) was controlling me and now I am controlling stimulation by my thought”.
Towards recovery of natural walking
One of the reasons that prompted Oskam to use this digital bridge was that, after three years of regular neurorehabilitation with stimulation only, his motor skills stopped improving. With this new system, now he is not only able to voluntarily move his legs and feet, he can also walk in complex terrains like steep surfaces and climb stairs, which require adaptive modulation of the amplitude of muscle activity.
Moreover, after 40 seasons of neurorehabilitation combining stimulation with physiotherapy, Oskam recovered great control of hip flexor movements even when the device was switched-off and could walk short distances with the help of crutches, suggesting recovery of nerve cells (neuronal plasticity) that were not totally damaged after the accident.
A new hope for spinal cord injuries
In spite of the hopeful results, the authors of this work underline in the article, published this week in Nature, that the digital bridge was only validated in a single individual with partial - and not total- damage of the spinal cord and therefore it remains unclear whether this system would work on other tetraplegic patients. In fact, the research team is currently recruiting three patients to test if a similar device can also restore arm movements.
It is likely that next approaches will be focused in developing non-invasive devices and in the use of other interventions like stem cells that could restore (or replace) the activity of injured neurons to achieve a more natural walk for these patients.
Original article
A digital bridge made of wireless implanted devices between the brain and the spinal cord has enabled an individual with chronic tetraplegia to stand and walk naturally in community settings. Moreover, neurorehabilitation mediated neurological improvements that persisted even when the bridge was switched off.
To walk, the brain delivers executive electrical signals to muscles through nerves that emerge from the spinal cord. But when an accident damages the neurons in the spinal cord involved in this connection, the consequence is permanent paralysis. This is the case of Gert-Jan Oskam, who twelve years ago had a cycling accident that damaged the spinal cord in his neck, causing total paralysis of his legs.
Some years ago, a research group from the Ecole Polytechnique Fédérale of Lausanne developed a program that combined epidural electrical stimulation in the spinal cord with neurorehabilitation seasons, enabling Oskam to regain the ability to step with the help of a front-wheel walker. The same group has recently developed an implanted electronic “bridge” connecting his brain activity to a device that delivers electrical pulses in real time to his legs, allowing Oskam to walk with full (mind) control of his pace.
Now for the first time in a decade Oskam is able to stand up and have a beer with his friends at the bar.
A digital system connecting his brain to his legs
The digital “bridge” consists of a three-component system of implanted devices enabling recording and processing of cortical activity and stimulation of the lumbosacral spinal cord wirelessly and in real time.
The first component of the bridge is based on a couple of implants made of 64 electrodes embedded in the skull that record the brain activity of the sensorimotor cortex, the part of the brain that controls voluntary movements.
These implants transmit ultrahigh frequency (402-405 mHz) signals in real time to the second component, a portable base station in a backpack worn by the patient, which generates online predictions of motor intentions on the basis of these signals.
Then the decoded motor intentions are converted into stimulation commands that are transferred into an implantable pulse generator, similar to those used by Parkinson’s patients to deliver deep brain stimulation. The authors upgraded this last component with wireless communication modules and implanted it into the targeted dorsal root zones to specifically stimulate the lower limb muscles.
The result of this integrated and wireless chain of hardware and software is a brain-spine interface that converts brain activity into analogue electrical stimulation enabling the self-controlled activity of the legs through mind. In the words of Oskam: “The stimulation before (with the old system) was controlling me and now I am controlling stimulation by my thought”.
Towards recovery of natural walking
One of the reasons that prompted Oskam to use this digital bridge was that, after three years of regular neurorehabilitation with stimulation only, his motor skills stopped improving. With this new system, now he is not only able to voluntarily move his legs and feet, he can also walk in complex terrains like steep surfaces and climb stairs, which require adaptive modulation of the amplitude of muscle activity.
Moreover, after 40 seasons of neurorehabilitation combining stimulation with physiotherapy, Oskam recovered great control of hip flexor movements even when the device was switched-off and could walk short distances with the help of crutches, suggesting recovery of nerve cells (neuronal plasticity) that were not totally damaged after the accident.
A new hope for spinal cord injuries
In spite of the hopeful results, the authors of this work underline in the article, published this week in Nature, that the digital bridge was only validated in a single individual with partial - and not total- damage of the spinal cord and therefore it remains unclear whether this system would work on other tetraplegic patients. In fact, the research team is currently recruiting three patients to test if a similar device can also restore arm movements.
It is likely that next approaches will be focused in developing non-invasive devices and in the use of other interventions like stem cells that could restore (or replace) the activity of injured neurons to achieve a more natural walk for these patients.
Original article