A Review of Parameter Settings for Invasive and Non-invasive Vagus Nerve Stimulation (VNS) Applied in Neurological and Psychiatric Disorders.

Vagus nerve stimulation (VNS) is an established form of neuromodulation with a long history of promising applications. Earliest reports of VNS in the literature date to the late 1800's in experiments conducted by Dr. James Corning. Over the past century, both invasive and non-invasive VNS have demonstrated promise in treating a variety of disorders, including epilepsy, depression, and post-stroke motor rehabilitation. As VNS continues to rapidly grow in popularity and application, the field generally lacks a consensus on optimum stimulation parameters. Stimulation parameters have a significant impact on the efficacy of neuromodulation, and here we will describe the longitudinal evolution of VNS parameters in the following categorical progression: (1) animal models, (2) epilepsy, (3) treatment resistant depression, (4) neuroplasticity and rehabilitation, and (5) transcutaneous auricular VNS (taVNS). We additionally offer a historical perspective of the various applications and summarize the range and most commonly used parameters in over 130 implanted and non-invasive VNS studies over five applications.

Evaluation of a Portable Wavefront Aberrometer for Community Screening Refraction in the Elderly.

SIGNIFICANCE: The SVOne may prove useful to quickly and easily assess refractive correction needs in community screenings and low-resource settings, but not all subjects were testable with the device. PURPOSE: This study aimed to compare the SVOne handheld, smartphone-based wavefront aberrometer with a tabletop autorefractor in identifying refractive errors in elderly subjects. METHODS: Participants 50 years or older at community eye screenings with visual acuity worse than 20/40 in either eye underwent autorefraction followed by two SVOne trials. Power vectors of right eye data were analyzed. RESULTS: Of 84 subjects who underwent autorefraction, 67 (79.8%) were successfully autorefracted with the SVOne, of whom 82.1% (55/67) had a successful repeat reading. Mean M (spherical equivalent) values from tabletop and handheld autorefraction were -0.21 D (95% confidence interval [CI], -0.71 to +0.29 D) and -0.29 D (95% CI, -0.79 to +0.21 D), respectively (P > .05). Mean astigmatism values from tabletop and handheld devices were +1.06 D (95% CI, 0.87 to 1.26 D) and +1.21 D (95% CI, 0.99 to 1.43 D), respectively (P > .05). Intraclass correlation coefficients between devices were 0.95 (95% CI, 0.93 to 0.97) for M, 0.78 (95% CI, 0.66 to 0.86) for J0, and 0.45 (95% CI, 0.24 to 0.63) for J45 (P < .05 for all). Excellent test-retest correlation between SVOne measurements was noted for M (Pearson correlation [r] = 0.96; P < .05), but a weaker correlation was noted for J0 and J45 (r = 0.67 and r = 0.63 [P < .05 for both], respectively). CONCLUSIONS: The SVOne provided strong agreement for M, with the majority of readings within ±1.00 D of each other, when compared with the tabletop autorefractor. A weaker but still good correlation was noted for astigmatism. Similar findings were noted when assessing repeatability.

Postoperative complication rates in the "super-obese" hip and knee arthroplasty population.

The effect of obesity on the outcomes of total joint arthroplasties is an ongoing concern. As obesity becomes more endemic, new categories emerge, such as the "super-obese." We conducted a retrospective study to determine the difference in outcomes among the super-obese. When categorized according to body mass index (BMI), the overall rate of complications was higher for patients with BMI of 45 or higher. Super-obese patients had an odds ratio (OR) of 8.44 for developing inhospital complications. Most importantly, each incremental 5-U increase in BMI above 45 was associated with an increased risk of inhospital (OR, 1.69) and outpatient complications (OR, 2.71), and readmission (OR, 2.0), compared with patients with BMI of 45 to 50. Length of stay was increased by 13.8% for each 5-U increase in BMI above 45. There is a significant increased risk for complications in the super-obese population, and this continues to increase with BMI increases above 45. These data are important when counseling super-obese patients and should be accounted for in reporting quality outcome measures in this population.