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Peripheral nerve injury afflicts individuals from all walks of life. Despite the peripheral nervous system's intrinsic ability to regenerate, many patients experience incomplete functional recovery. Surgical repair aims to expedite this recovery process in the most thorough manner possible. However, full recovery is still rarely seen especially when nerve injury is compounded with polytrauma where surgical repair is delayed. Pharmaceutical strategies supplementary to nerve microsurgery have been investigated but surgery remains the only viable option. Brief low-frequency electrical stimulation of the proximal nerve stump after primary repair has been widely investigated. This article aims to review the currently known biological basis for the regenerative effects of acute brief low-frequency electrical stimulation on axonal regeneration and outline the recent clinical applications of the electrical stimulation protocol to demonstrate the significant translational potential of this modality for repairing peripheral nerve injuries. The review concludes with a discussion of emerging new advancements in this exciting area of research. The current literature indicates the imminent clinical applicability of acute brief low-frequency electrical stimulation after surgical repair to effectively promote axonal regeneration as the stimulation has yielded promising evidence to maximize functional recovery in diverse types of peripheral nerve injuries.

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AimTo report clinical outcomes and evidence of corneal innervation in patients with neurotrophic keratopathy (NK) treated with minimally invasive corneal neurotisation (MICN) using a sural nerve graft and donor sensory nerves from the face.MethodsPatients undergoing MICN at The Hospital for Sick Children, Toronto, Canada were prospectively recruited. Data on central corneal sensation (CCS, measured with Cochet-Bonnet aesthesiometer), best-corrected visual acuity (BCVA) and corneal epithelial integrity were collected. In four patients who subsequently underwent keratoplasty, immunohistochemical analysis was performed on the corneal explants. One patient underwent magnetoencephalography (MEG) after MICN to characterise the neurophysiological pathways involved.ResultsBetween November 2012 and February 2017, 19 eyes of 16 patients underwent MICN. Mean follow-up was 24.0±16.1 months (range, 6–53). Mean CCS significantly improved from 0.8±2.5 mm to 49.7±15.5 mm at final follow-up (p<0.001). Mean BCVA remained stable, and the number of episodes of corneal epithelial defects after MICN was significantly reduced compared with the year leading up to the procedure (21% vs 89%, respectively; p<0.0001). In the four eyes that underwent keratoplasties after MICN, all transplants fully re-epithelialised and regained sensation subsequently. Immunohistochemistry of the corneal explants demonstrated evidence of corneal reinnervation. In one patient who was 8 months after MICN, novel neuroactivity was detected on MEG in the ipsilateral somatosensory cortex on mechanical stimulation of the reinnervated cornea.ConclusionsBy providing an alternative source of innervation, MICN improves corneal sensation and stabilises the corneal epithelium, permitting optical keratoplasty for patients with NK-related corneal opacity.

BACKGROUND: Unprecedented demand for N95 respirators during the coronavirus disease 2019 (COVID-19) pandemic has led to a global shortage of these masks. We validated a rapidly applicable, lowcost decontamination protocol in compliance with regulatory standards to enable the safe reuse of N95 respirators. METHODS:We inoculated 4 common models of N95 respirators with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and evaluated viral inacti vation after disinfection for 60 minutes at 70°C and 0% relative humidity. Similarly, we evaluated thermal disinfection at 0% to 70% relative humidity for masks inoculated with Escherichia coli. We assessed masks subjected to multiple cycles of thermal disinfection for structural integrity using scanning electron microscopy and for protective functions using standards of the United States National Institute for Occupational Safety and Health for particle filtration efficiency, breathing resistance and respirator fit. RESULTS:A single heat treatment rendered SARS-CoV-2 undetectable in all mask samples. Compared with untreated inoculated control masks, E. coli cultures at 24 hours were virtually undetectable from masks treated at 70°C and 50% relative humidity (optical density at 600 nm wavelength, 0.02 ± 0.02 v. 2.77 ± 0.09, p < 0.001), but contamination persisted for masks treated at lower relative humidity. After 10 disinfection cycles, masks maintained fibre diameters similar to untreated masks and continued to meet standards for fit, filtration efficiency and breathing resistance. INTERPRETATION:Thermal disinfection successfully decontaminated N95 respirators without impairing structural integrity or function. This process could be used in hospitals and long-term care facilities with commonly available equipment to mitigate the depletion of N95 masks.Early release, published at www.cmaj.ca on July 30, 2020. Subject to revision.

The pattern of pediatric hand fracture in different age groups is highlighted in this article. The observations from this study will hopefully encourage further review with a larger cohort and a focus on preventative measures for pediatric hand fractures.

Therapeutic, III.

Corneal anesthesia is a debilitating condition which can ultimately lead to blindness from repetitive corneal injury and scarring. We have developed a minimally invasive technique for corneal re-innervation that we have used with excellent results in ten eyes. This article and accompanying video describes the relevant anatomy and demonstrates the technique in detail.