Recent comments in /f/science

baggier t1_j9caxny wrote

Probably wrong, though cant get the original article due to paywall. This has been suggested before and is not needed, any autocatalytic process with a negative feedback loop (e.g. one enantiomer inhibiting production of the other or using the other as feedstock) will end up with just one enantiomer surviving.

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shiruken t1_j9c0seq wrote

Direct link to the peer-reviewed study: M. P. Powell, et al., Epidural stimulation of the cervical spinal cord for post-stroke upper-limb paresis, Nature Medicine (2023).

>Abstract: Cerebral strokes can disrupt descending commands from motor cortical areas to the spinal cord, which can result in permanent motor deficits of the arm and hand. However, below the lesion, the spinal circuits that control movement remain intact and could be targeted by neurotechnologies to restore movement. Here we report results from two participants in a first-in-human study using electrical stimulation of cervical spinal circuits to facilitate arm and hand motor control in chronic post-stroke hemiparesis (NCT04512690). Participants were implanted for 29 d with two linear leads in the dorsolateral epidural space targeting spinal roots C3 to T1 to increase excitation of arm and hand motoneurons. We found that continuous stimulation through selected contacts improved strength (for example, grip force +40% SCS01; +108% SCS02), kinematics (for example, +30% to +40% speed) and functional movements, thereby enabling participants to perform movements that they could not perform without spinal cord stimulation. Both participants retained some of these improvements even without stimulation and no serious adverse events were reported. While we cannot conclusively evaluate safety and efficacy from two participants, our data provide promising, albeit preliminary, evidence that spinal cord stimulation could be an assistive as well as a restorative approach for upper-limb recovery after stroke.

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drkgodess t1_j9bz6zw wrote

Shared access of Nature journal article in pdf: here

Key excerpts from Telegraph article:

> Scientists recruited Ms Rendulic, now 33, and one other stroke survivor, a 47-year-old woman, to be the first people to try out electrical stimulation of the spinal cord with the aim of improving arm and hand motor movements...

>Scientists created a device that inserts two electrodes into the spinal cord in between vertebrae in the neck area.

>The electrodes stayed in place for 29 days. When these were activated, the patients - the first ever to experience this technology - had 40 per cent more grip force and 40 per cent more speed in their injured hands...

> “We discovered that electrical stimulation of specific spinal cord regions enables patients to move their arm in ways that they are not able to do without the stimulation.”

> ...The researchers said the stimulation procedure, known as epidural electrical stimulation of the cervical spinal cord, does not require invasive surgery and appears to have no negative side effects.

That it worked after such a long time and it was minimally invasive seem to be the major breakthroughs in this case study.

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