The distribution of acquired peripheral nerve injuries associated with severe COVID-19 implicate a mechanism of entrapment neuropathy: a multicenter case series and clinical feasibility study of a wearable, wireless pressure sensor.

We diagnosed 66 peripheral nerve injuries in 34 patients who survived severe coronavirus disease 2019 (COVID-19). We combine this new data with published case series re-analyzed here (117 nerve injuries; 58 patients) to provide a comprehensive accounting of lesion sites. The most common are ulnar (25.1%), common fibular (15.8%), sciatic (13.1%), median (9.8%), brachial plexus (8.7%) and radial (8.2%) nerves at sites known to be vulnerable to mechanical loading. Protection of peripheral nerves should be prioritized in the care of COVID-19 patients. To this end, we report proof of concept data of the feasibility for a wearable, wireless pressure sensor to provide real time monitoring in the intensive care unit setting.

Advanced Materials in Wireless, Implantable Electrical Stimulators That Offer Rapid Rates of Bioresorption for Peripheral Axon Regeneration.

Injured peripheral nerves typically exhibit unsatisfactory and incomplete functional outcomes, and there are no clinically approved therapies for improving regeneration. Post-operative electrical stimulation (ES) increases axon regrowth, but practical challenges from the cost of extended operating room time to the risks and pitfalls associated with transcutaneous wire placement have prevented broad clinical adoption. This study presents a possible solution in the form of advanced bioresorbable materials for thin, flexible, wireless implant that provides precisely controlled ES of the injured nerve for a brief time in the immediate post-operative period. Afterward, rapid, complete and safe modes of bioresorption naturally and quickly eliminate all of the constituent materials in their entirety, without the need for surgical extraction. The unusually high rate of bioresorption follows from the use of a unique, bilayer enclosure that combines two distinct formulations of a biocompatible form of polyanhydride as an encapsulating structure, to accelerate the resorption of active components and confine fragments until complete resorption. Results from mouse models of tibial nerve transection with re-anastomosis indicate that this system offers levels of performance and efficacy that match those of conventional wired stimulators, but without the need to extend the operative period or to extract the device hardware.

Implantation and Control of Wireless, Battery-free Systems for Peripheral Nerve Interfacing.

Peripheral nerve interfaces are frequently used in experimental neuroscience and regenerative medicine for a wide variety of applications. Such interfaces can be sensors, actuators, or both. Traditional methods of peripheral nerve interfacing must either tether to an external system or rely on battery power that limits the time frame for operation. With recent developments of wireless, battery-free, and fully implantable peripheral nerve interfaces, a new class of devices can offer capabilities that match or exceed those of their wired or battery-powered precursors. This paper describes methods to (i) surgically implant and (ii) wirelessly power and control this system in adult rats. The sciatic and phrenic nerve models were selected as examples to highlight the versatility of this approach. The paper shows how the peripheral nerve interface can evoke compound muscle action potentials (CMAPs), deliver a therapeutic electrical stimulation protocol, and incorporate a conduit for the repair of peripheral nerve injury. Such devices offer expanded treatment options for single-dose or repeated dose therapeutic stimulation and can be adapted to a variety of nerve locations.

Phrenic Nerve Involvement in Neuralgic Amyotrophy (Parsonage-Turner Syndrome).

Neuralgic amyotrophy is a poorly understood neuromuscular disorder affecting peripheral nerves mostly within the brachial plexus distribution but can also involve other sites including the phrenic nerve. In the classic form of the syndrome it causes proximal upper limb and neck pain on the affected side with subsequent muscle weakness that can be highly heterogeneous. Nocturnal noninvasive ventilation support is a first-line treatment after phrenic mononeuropathy. The regular monitoring of diaphragm function with spirometry and diaphragm ultrasound can help determine prognosis and inform decision-making.