bluuebunny/crossref_metadata_2025 huggingface dataset:
Intracranial EEG Monitoring and Electrocorticography
Authors: Feyissa Anteneh M.
Published: October 2022

In patients with drug-resistant focal epilepsy, precise localization of the “epileptogenic zone” (EZ) is crucial for optimal surgical outcomes. For “skip candidates,” this can be achieved by performing scalp video-EEG (electroencephalographic) monitoring and brain imaging studies. Unfortunately, 25%–50% of cases also require intracranial EEG (iEEG) recording, using primarily subdural grid (SDE) or stereotactic EEG (SEEG) electrodes. The decision about which method to use is mainly dependent on the specific question and suspected location of the EZ. While the precise localization of the EZ within the neocortex is best achieved using SDE, SEEG is preferred when the EZ is in the deep neocortex. Although the two methods differ in their indication, they complement each other and, in some cases, could be employed simultaneously. This chapter discusses the indications, techniques, interpretation, and complications of iEEG. Direct cortical stimulation for functional mapping and tailoring margins of resection is also briefly discussed.
Motor Nerve Conduction Studies
Authors: Jones Lyell K. , Watson James C. , Rubin Devon I.
Published: October 2022

Electrodiagnostic testing is an important part of the evaluation of patients with focal or diffuse neuromuscular disorders. Assessment of compound muscle action potentials (CMAPs) is an essential nerve conduction study (NCS) technique that permits quantitative measurement of peripheral motor function. Since disease of the axons, neuromuscular junctions, or muscle fibers can alter the CMAP, motor NCS can be used to assess disease at each of these locations. This chapter outlines the general physiological and technical principles that practitioners should understand to obtain high-quality CMAPs. It describes how to interpret CMAP changes in the appropriate clinical setting and in the context of a comprehensive electrodiagnostic evaluation. CMAPs are useful diagnostic tools in many neuromuscular disorders, and several common clinical scenarios are presented here.
Cranial Reflexes and Related Techniques
Authors: Smith Benn E.
Published: October 2022

The trigeminal and facial nerves and their central connections may be involved in a number of neurological disorders. Electrophysiological study of the reflex activity mediated by the fifth and seventh cranial nerves have been useful in particular for assessing cranial neuropathies (e.g., Bell palsy) or peripheral facial movement disorders, such as hemifacial spasm or facial synkinesis. In addition, these techniques can provide useful information in some cases of peripheral neuropathy, polyradiculoneuropathy, brainstem lesions, motor neuron disease, progressive supranuclear palsy, and corticobasal syndrome. The reflexes discussed in this chapter are the electrically evoked blink reflex, the jaw jerk (or masseter reflex), the masseter inhibitory reflex, and less commonly used electrophysiologic techniques for studying cranial nerves IX and X. Also, two additional techniques are also discussed: one to assess a sensory nerve in the head that is not a cranial nerve of branchial arch origin, the great auricular sensory nerve, and the other to interrogate trigeminal sensory pathways from the sensory receptor level to the parietal cortex, contact heat-evoked potentials.
Quantitative Motor Unit Number Estimates
Authors: Sorenson Eric J. , Daube Jasper R.
Published: October 2022

Quantitative motor unit number estimates (MUNE) are neurophysiological techniques designed to quantitate the number of viable motor axons that innervate a muscle or muscle group. A variety of techniques have been developed to accomplish this, each with its own advantages and disadvantages. Traditionally, the MUNE is calculated from the supramaximal compound muscle action potential (CMAP) by dividing the CMAP by the mean size of the motor unit potentials. The resulting unitless number represents the number of motor units within a muscle or muscle group. These techniques vary by how this mean motor unit potential size is calculated. These methods have been applied most widely to disorders of the motor neuron, such as amyotrophic lateral sclerosis (ALS), spinal muscular atrophy, and polio. MUNE has been used as a research measure in animal and human studies. Additionally, it has been used as an outcome measure in clinical trials for ALS and spinal muscular atrophy. More recently, two techniques have been developed that rely on statistical calculations from the CMAP and are fundamentally unique from the traditional methods. These have been called the MUNIX and MScanFit methods. These newer methods are faster to apply and can be performed with less patient discomfort. This chapter reviews the traditional and newer technique of motor unit number estimation.
Technical Issues and Potential Complications of Nerve Conduction Studies
Authors: Rubin Devon I.
Published: October 2022

Nerve conduction studies (NCSs) are an important component of a routine electrodiagnostic study and provide valuable information about the function of peripheral nerves, neuromuscular junctions, and muscle. While NCS techniques are standardized and often straightforward in experienced hands, they are fraught with a variety of potential technical problems that may interfere with reliable acquisition of data. Recognition, identification, and correction of technical problems are critical to the accurate interpretation of any electrodiagnostic study. NCSs are safe to perform, but they involve the administration of electric current to the patient and may pose some potential risks in certain clinical circumstances. This chapter reviews technical problems that may occur during the performance of NCSs as well as the potential risks of NCSs.
Single-Fiber Electromyography
Authors: Crum Brian A. , Harper C. Michael
Published: October 2022

Single-fiber EMG (SFEMG) is a specialized electrophysiological technique used to assess for neuromuscular junction diseases. The selectivity of SFEMG depends on the use of a low-frequency filter of 500 Hz and a small electrode size. Voluntary activation or electrical stimulation is used to activate the muscle fibers in SFEMG. SFEMG assesses the relationship in the generation of the action potentials between two time-locked muscle fibers. The primary measurements that are used to determine the adequacy of neuromuscular transmission are jitter and blocking. Unique aspects of SFEMG relate to equipment, software, and technique, which must be understood fully in order to perform high-quality studies. Abnormalities on SFEMG testing need to be taken into consideration with the clinical history, examination, and other electrophysiological tests.
Electrodiagnostic Assessment of Motor Neuron Diseases
Authors: Staff Nathan P.
Published: October 2022

The importance of electrodiagnostic testing in a patient with painless progressive weakness cannot be understated as it may distinguish between neuromuscular diseases with widely disparate prognoses and treatment options. It is particularly useful to determine the neuroanatomical extent of motor neuron dysfunction and its acuity. This can help the clinician refine their differential diagnosis and provide prognostic information for the patient. Diseases of the motor neuron with this clinical presentation may include amyotrophic lateral sclerosis, multifocal motor neuropathy, or spinobulbar muscular atrophy. In this chapter, the electrodiagnostic approach to this clinical problem is discussed. Subsequently, specific diseases of the motor neuron and their electrodiagnostic testing are described.
Assessment of Neuromuscular Junction Diseases
Authors: Naddaf Elie
Published: October 2022

Neuromuscular junction diseases are characterized by fluctuating muscle weakness in various distributions. Patients with similar symptoms are commonly referred for electrodiagnostic testing to confirm or exclude a neuromuscular transmission defect. This chapter details the role of electrodiagnostic testing in the approach to such patients. Routine nerve conduction studies and needle electromyography help to evaluate for alternative causes. Repetitive nerve stimulation and single fiber EMG remain the cornerstone of the electrodiagnostic workup of neuromuscular junction disorders. The chapter describes the utility of these advanced techniques, underscoring their technical intricacies. Finally, it provides a practical electrodiagnostic approach to specific neuromuscular junction diseases.
Neuromuscular Electrodiagnostic Testing in the Intensive Care Unit
Authors: Goodman Brent P.
Published: October 2022

The electrodiagnostic (EDX) evaluation of suspected neuromuscular conditions in the intensive care unit (ICU) requires a thoughtful approach, with particular attention to technical factors that can impact testing in this setting and knowledge of how the various neuromuscular conditions translate into EDX findings for these patients. Electrodiagnostic testing is typically performed in the ICU in order to identify a neuromuscular cause for respiratory failure and weakness. An approach to EDX testing and typical findings in ICU- acquired weakness and primary neuromuscular conditions such as Guillain-Barré syndrome, myasthenic crisis, West Nile poliomyelitis, amyotrophic lateral sclerosis, and other neuromuscular conditions encountered in ICU patients are discussed.
Neuromuscular Ultrasound in the EMG Laboratory
Authors: Boon Andrea J.
Published: October 2022

Neuromuscular ultrasound is a rapidly evolving imaging field that is an ideal diagnostic adjunct to clinical neurophysiology. Where electromyography (EMG) and nerve conduction studies (NCSs) can demonstrate the pathophysiology of a lesion, ultrasound can often determine the underlying cause. Ultrasound is noninvasive, safe, portable, and relatively inexpensive compared to magnetic resonance imaging. High-definition imaging of nerves and muscles allows the electrodiagnostician to identify causes of entrapment, such as cysts, fascial bands, tumors, sites of multifocal or uniform nerve enlargement in more generalized polyneuropathies, and changes in muscle echotexture associated with fibrous or fatty replacement of muscle fibers seen in dystrophies, inflammatory myopathies, and denervation. Ultrasound guidance can enhance the accuracy and safety of NCSs and needle EMG in certain situations, such as obesity, altered anatomy, anticoagulation, or when testing in close proximity to vital structures such as the lung or large blood vessels.
Visual Evoked Potentials
Authors: Carter Jonathan L.
Published: October 2022

Visual evoked potentials (VEPs) are used to evaluate the functional integrity of the anterior visual pathways. Reliable recording of VEPs requires an alert patient with a visual acuity of 20/200 or better who is able to fixate on the target screen. The P100 waveform is easily recorded over the occipital cortex in normal individuals. Abnormalities may include reduced amplitude or absent P100 waveforms and/or slowing of latencies between the retina and cortex. Abnormalities are not specific for pathology in the visual pathways, but demyelinating lesions of the optic nerve or chiasm typically produce prolonged latencies with normal or slightly reduced amplitudes. Latency is considered more reliable than amplitude. Unilateral prolongation of P100 latency, either absolute or relative to the companion eye, suggests unilateral anterior visual pathway involvement. Bilateral P100 latency prolongation is nonlocalizing as it could reflect either bilateral anterior visual pathway involvement or a retrochiasmatic lesion. Clinical utility of VEPS is greatest for detecting abnormalities in patients with suspected inflammatory optic neuritis and for determining asymptomatic lesions in multiple sclerosis and other demyelinating diseases to establish dissemination of lesions in space. VEPs may have higher sensitivity for detecting optic nerve lesions than magnetic resonance of the orbits. Technical factors are important to obtain reliable, reproducible results. False-positive results can occur due to poor patient cooperation. The results should be interpreted within the clinical context presented by the patient and should not by themselves be used to establish a diagnosis of multiple sclerosis or other demyelinating disease.
Motor Evoked Potentials
Authors: Mauricio Elizabeth A.
Published: October 2022

Motor evoked potentials can be generated by either electrical or magnetic stimulation of the corticospinal pathways. Direct activation of pyramidal cells and indirect activation of cortical interneurons generate impulses that propagate down the spinal cord as D-waves and I-waves, ultimately stimulating anterior horn cells and resulting in M-waves recorded over the targeted muscle. Transcranial electrical stimulation is most commonly employed in the operating room for intraoperative neurophysiologic monitoring, ensuring that the integrity of the motor pathways are preserved during brain or spine surgeries. The utility of transcranial magnetic stimulation has been explored in many neurologic diseases, where alterations in central motor conduction time and cortical excitability may provide important clues in diagnosis, prognosis, and monitoring response to treatment.
Evaluation of Adrenergic Function
Authors: Low Phillip A. , Singer Wolfgang
Published: October 2022

The purpose and role of adrenergic function testing in the clinical setting is to assess for autonomic disorders that involve maintenance and regulation of blood pressure and heart rate; it furthermore adds to the assessment of other domains of autonomic function in order to define the distribution of autonomic deficits. Simple, accurate, and reproducible tests of adrenergic function are now routinely used in clinical autonomic laboratories. This chapter focuses on the most widely used tests to evaluate adrenergic function in an autonomic laboratory, namely, beat-to-beat blood pressure and heart rate responses to the Valsalva maneuver and head-up tilt. It is possible to separately evaluate the vagal and adrenergic components of baroreflex sensitivity.
Cardiovagal Reflexes
Authors: Coon Elizabeth A. , Cheshire William P.
Published: October 2022

Assessment of cardiovagal function can be reliably and reproducibly performed using noninvasive tests of cardiovascular function. Measurement of heart rate responses to deep breathing assesses the integrity of afferent and efferent vagal pathways. Measuring heart rate response to Valsalva assesses the vagal component of the baroreflex and should be done with simultaneous recording of arterial pressure. Using heart rate recordings from the Valsalva maneuver, the Valsalva ratio can be computed from the maximal heart rate response to phase II and the minimal heart rate response during phase IV, while baroreflex sensitivity can be measured by plotting each heart interval against the preceding systolic blood pressure value, leading to the slope of the simple linear regression. Quantitative grading of cardiovagal function can be performed using the composite autonomic severity scale. The following chapter describes the physiology, methodology, clinical utility, and shortcomings of the most clinically used tests of cardiovagal function.
Electrophysiology Testing of Movement Disorders
Authors: Klassen Bryan T. , Caviness John N. , Bower James H.
Published: October 2022

The gold standard for diagnosis of most movement disorders remains a careful neurologic examination; however, neurophysiologic evaluation can often complement the clinical examination. Rather than focus on specific electromyographic (EMG) spike morphologies, as is done in neuromuscular EMG, movement disorder neurophysiology studies focus on the pattern of discharges over time and in relation to patterns in other muscles. Thus, surface EMG polygraphy is the main method used, at times in conjunction with simultaneous EEG. Tremor, dystonia, and myoclonus can all be evaluated in this manner. Evoked responses are also useful, particularly to evaluate some types of myoclonus and startle disorders. In order to fully integrate movement neurophysiology into the comprehensive care of patients with movement disorders, a good understanding of both the neurophysiologic techniques and the underlying disease states is necessary; this chapter provides an overview of both.
Assessment of Sleep and Sleep Disorders: Polysomnography and Other Tests
Authors: Silber Michael H. , Harris Cameron D.
Published: October 2022

Soon after the human electroencephalogram was discovered in 1929, researchers began recording brain electrical activity during sleep. In 1937, Loomis described and classified non–rapid eye movement sleep, and in 1953, rapid eye movement sleep was discovered by Aserinsky and Kleitman. In the 1960s, seminal discoveries were made delineating the disturbances in sleep physiology in narcolepsy and obstructive sleep apnea. The clinical evaluation of sleep and its disorders began in the early 1970s, eventually leading to the development of the medical specialty of sleep medicine. The number of clinical sleep laboratories, most within comprehensive sleep centers, has steadily grown. New methodologies have been developed, including the use of various techniques for monitoring sleep and its disturbances in the home environment. The goal of this chapter is to review the techniques used to study sleep and to discuss the physiological parameters recorded.
Peripheral Nervous System Monitoring
Authors: Muzyka Iryna M. , Strommen Jeffrey A. , Harper C. Michel
Published: October 2022

Patients with peripheral nerve injury or trauma often undergo surgical procedures to repair injured nerves. Although the preoperative clinical examination, electrophysiological testing, and imaging studies are used to localize the site(s) of injury for the surgical planning, these studies do not always fully identify the precise site(s) of involvement and often will not be sufficient to determine continuity of a nerve. Intraoperative monitoring (IOM) at the time of surgical exploration or intervention may be critical for surgical decision-making by providing enhanced localization and more accurate information about nerve integrity. Intraoperative monitoring protocols use multiple modalities, including nerve conduction studies, electromyography, sensory and motor evoked potentials, which are individualized based on the preoperative diagnosis and the anticipated surgical procedure. This multimodal intraoperative monitoring provides the surgeon additional diagnostic, localization, mapping, and monitoring feedback to immediately assist with surgical decisions and optimize surgical planning accordingly. Application of IOM in peripheral nerve surgeries include nerve entrapment, repair of traumatic nerve injury, peripheral nerve tumor resection, targeted fascicular nerve biopsy, and prevention of further nerve injury during surgical procedures. Surgical planning and the preservation of the functional integrity of the peripheral nerves can be better achieved with optimal intraoperative monitoring methods, potentially leading to better surgical outcomes and the avoidance of unnecessary surgical interventions or complications.
Digital Signal Processing
Authors: Lagerlund Terrence D.
Published: October 2022

Digital Signal Processing reviews technical considerations for digital signal processing applied to clinical neurophysiologic studies. Digital instruments are replacing analog systems because of convenient storage, retrieval, and review of studies and improved reliability of interpretation. Digitization involves quantization and sampling. Quantization is characterized by quantum size, number of bits, and input range. Sampling is characterized by sampling interval and sampling frequency. The sampling theorem specifies the minimum sampling frequency necessary to adequately represent igher frequency components of a signal. Sampling at less than this frequency produces aliasing. Signal averaging is used for evoked potential and nerve conduction studies, repetitive transient waveforms, and movement-associated potentials. Digital filtering removes unwanted frequency components from a signal by means of software algorithms. In contrast, analog filtering uses electrical circuit components like resisters, capacitors, and coils to remove unwanted frequency components. Both types of filters can be classified as low-pass, high-pass, bandpass, or notch filters. Interval analysis, autocorrelation analysis, and spectral analysis are ways to quantify the frequency content of a signal. Pattern recognition is used to detect waveforms with characteristic features.
Fundamental effective temperature measurements for eclipsing binary stars – II. The detached F-type eclipsing binary CPD-54 810
Authors: Miller N J , Maxted P F L , Graczyk D , Tan T G , Southworth J
Published: October 2022

CPD-54 810 is a double-lined detached eclipsing binary containing two mid-F type dwarfs on an eccentric 26-d orbit. We perform a combined analysis of the extensive photometry obtained by the TESS space mission along with previously published observations to obtain a full orbital and physical solution for the system. We measure the following model-independent masses and radii: $M_1=1.3094\pm 0.0051\, {M_\odot }$, $M_2=1.0896\pm 0.0034\, {M_\odot }$, $R_1=1.9288\pm 0.0030\, {R_\odot }$, and $R_2=1.1815\pm 0.0037\, {R_\odot }$. We employ a Bayesian approach to obtain the bolometric flux for both stars from observed magnitudes, colours, and flux ratios. These bolometric fluxes combined with the stars’ angular diameters (from R1, R2 and the parallax from Gaia EDR3) lead directly to the stars’ effective temperatures: Teff, 1 = 6462 ± 43 K, and Teff, 2 = 6331 ± 43 K, with an additional systematic error of 0.8 per cent (13 K) from the uncertainty in the zero-point of the flux scale. Our results are robust against the choice of model spectra and other details of the analysis. CPD-54 810 is an ideal benchmark system that can be used to test stellar parameters measured by large spectroscopic surveys or derived from asteroseismology, and calibrate stellar models by providing robust constraints on the measured parameters. The methods presented here can be applied to many other detached eclipsing binary systems to build a catalogue of well–measured benchmark stars.
Exploring short-term optical variability of blazars using TESS
Authors: Pininti Vivek Reddy , Bhatta Gopal , Paul Sagarika , Kumar Aman , Rajgor Aayushi , Barnwal Rahul , Gharat Sarvesh
Published: October 2022

We present a first systematic time series study of a sample of blazars observed by the Transiting Exoplanet Survey Satellite (TESS). By cross matching the positions of the sources in the TESS observations with those from Roma-BZCAT, 29 blazars including both BL Lacerate objects and flat-spectrum radio quasars were identified. The observation lengths of the 79 light curves of the sources, across all sectors on which the targets of interest have been observed by TESS, range between 21.25 and 28.2 d. The light curves were analysed using various methods of time series analysis. The results show that the sources exhibit significant variability with fractional variability spanning between 1.41 per cent and 53.84 per cent. The blazar flux distributions were studied by applying normal and log-normal probability density function models. The results indicate that optical flux histogram of the sources are consistent with normal probability density function with most of them following bimodal distribution as opposed to unimodal distribution. This suggests that the days-time-scale optical variability is contributed either by two different emission zones or two distinct states of short-term activity in blazars. Power spectral density analysis was performed by using the power spectral response method and the true power spectra of unevenly sampled light curves were estimated. The power spectral slopes of the light curves ranged from 1.7 to 3.2.
Chronic disseminated intravascular coagulation in a patient with Takayasu arteritis
Authors: Yilmaz Neslihan , Goksoy Hasan Sami , Sever Ibrahim Halil , Yavuz Sule
Published: October 2022

Takayasu arteritis (TA) is a large-vessel vasculitis that predominantly affects the aorta and although it usually causes stenosis, aneurysms have been reported in ∼10–25% of the patients. Here, we present a male TA patient with chronic disseminated intravascular coagulation (DIC) as a rare complication of endovascular grafted aortic aneurysm (AA). Chronic DIC usually presents as mild or even hidden clinical symptoms, and early diagnosis of this condition can only be possible with laboratory tests. Due to the silent clinical scenario, this complication should be kept in mind among AA patients with unexplained thrombocytopenia or coagulation abnormalities.
A Pilot Trial for Prevention of Hepatitis C Virus Transmission From Donor to Organ Transplant Recipient With Short-Course Glecaprevir/Pibrentasvir
Authors: Ramirez-Sanchez Claudia , Kozuch Jade , Shah Mita M , Berumen Jennifer , Mekeel Kristin , Schnickel Gabriel , Taremi Mahnaz , Golts Eugene , Afshar Kamyar , Adler Eric , Pretorius Victor , Aslam Saima
Published: October 2022

A 7-day course of glecaprevir/pibrentasvir started in the preoperative period prevented transmission of hepatitis C virus (HCV) from viremic donors to 10 HCV-negative recipients (2 heart, 1 lung, 6 kidney, 1 heart/kidney) with 100% sustained virological response at 12 weeks.
Daily reactivity to stress and sleep disturbances: unique risk factors for insomnia
Authors: Yoo Jiah , Slavish Danica , Dietch Jessica R , Kelly Kimberly , Ruggero Camilo , Taylor Daniel J
Published: October 2022

Study Objectives

To naturalistically measure sleep disturbances following stress exposure (i.e. sleep reactivity) and stress responses following sleep disturbances (i.e. stress reactivity) at the daily level and prospectively examine these reactivity measures as individual risk factors for insomnia.

Methods

The study assessed 392 nurses’ sleep and stress for 14 days using daily diaries and actigraphy. Self-reported insomnia symptoms were assessed at the end of the 14 days, as well as 6 and 11 months later.

Results

In multilevel modeling, while negative fixed effects indicated that shorter total sleep time (TST) and lower sleep efficiency led to greater stress and vice versa, significant random effects indicated individual variability in sleep reactivity and stress reactivity. In latent score change modeling, greater sleep reactivity (lower diary-determined sleep efficiency following greater stress) and greater stress reactivity (greater stress following shorter diary-determined TST) at baseline were associated with greater insomnia symptoms at 11 months (b = 10.34, p = .026; b = 7.83, p = .03). Sleep reactivity and stress reactivity also interacted to predict insomnia symptoms, such that sleep reactivity was significantly associated with insomnia symptoms for those with high (+1 SD) stress reactivity (b = 17.23, p = .001), but not for those with low (−1 SD) stress reactivity (b = 5.16, p = .315).

Conclusions

Baseline stress reactivity and sleep reactivity independently as well as jointly predict greater insomnia symptoms 11 months later. The findings delineate processes underlying the stress-diathesis model of insomnia and highlight the utility of longitudinal and naturalistic measures of sleep and stress reactivity.
Obesity and Gynecological Cancers: A Toxic Relationship
Authors: Wichmann Ignacio A. , Cuello Mauricio A.
Published: October 2022

(Abstracted from Int J Gynecol Obstet 2021;155(suppl 1):123–134)

The World Health Organization classifies obesity as a noncommunicable pandemic, with approximately 650 million people affected globally in 2016 and 4.7 million people dying prematurely in 2017 because of obesity-related diseases. Among these obesity-related diseases are breast, uterine, cervical, and ovarian cancers in women.
Effect of Self-Monitoring of Blood Pressure on Diagnosis of Hypertension During Higher-Risk Pregnancy: The BUMP 1 Randomized Clinical Trial
Authors: Tucker Katherine L. , Mort Sam , Yu Ly-Mee , Campbell Helen , Rivero-Arias Oliver , Wilson Hannah M. , Allen Julie , Band Rebecca , Chisholm Alison , Crawford Carole , Dougall Greig , Engonidou Lazarina , Franssen Marloes , Green Marcus , Greenfield Sheila , Hinton Lisa , Hodgkinson James , Lavallee Layla , Leeson Paul , McCourt Christine , Mackillop Lucy , Sandall Jane , Santos Mauro , Tarassenko Lionel , Velardo Carmelo , Yardley Lucy , Chappell Lucy C. , McManus Richard J. ,   for the BUMP Investigators
Published: October 2022

(Abstracted from JAMA 2022;327:1656–1665

It is estimated that approximately 10% of pregnancies worldwide in 2019 were affected by elevated blood pressure (BP). The United Kingdom has previously reported inadequate monitoring of elevated BP as a significant contributing factor to maternal death.
Preeclampsia
Authors: Magee Laura A. , Nicolaides Kypros H. , von Dadelszen Peter
Published: October 2022

(Abstracted from N Engl J Med 2022;386:1817–1832)

Preeclampsia complicates 2% to 4% of all pregnancies globally and is a leading cause of maternal morbidity and mortality. As many as 46,000 maternal and 500,000 fetal deaths occur due to this condition, most in low- and middle-income countries.
Coronavirus Disease 2019 (COVID-19) Perinatal Outcomes Across the Pandemic at an Academic Medical Center in New York City
Authors: Seaton Christine Leinbach , Cohen Alexa , Henninger Erin M. , Gendlina Inessa , Hou Wei , Bernstein Peter S. , Duong Tim Q.
Published: October 2022

OBJECTIVE:

To investigate perinatal complications associated with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection during pregnancy in the four major waves of the coronavirus disease 2019 (COVID-19) pandemic in the Bronx, New York.

METHODS:

This retrospective cohort study included all patients who delivered at a single academic medical center between March 1, 2020, and February 13, 2022. SARS-CoV-2 positivity was defined as a positive SARS-CoV-2 test result during pregnancy. Primary outcomes were preterm birth, low birth weight, stillbirth, cesarean delivery, and preeclampsia associated with SARS-CoV-2 infection. Secondary analyses examined outcomes by predominant variant at the time of infection. Group differences in categorical variables were tested using χ2 tests.

RESULTS:

Of the 8,983 patients who delivered, 638 (7.1%) tested positive for SARS-CoV-2 infection during pregnancy. Age, race, ethnicity, and major comorbidities did not differ significantly between the SARS-CoV-2–positive and SARS-CoV-2–negative cohorts (P>.05). Primary outcomes did not differ between the SARS-CoV-2–positive and SARS-CoV-2–negative cohorts (P>.05). There was a marked increase in positive SARS-CoV-2 test results in individuals who gave birth during the Omicron wave (140/449, 31.2%). However, among patients who tested positive for SARS-CoV-2 infection, the preterm birth rate during the Omicron wave (9.9%) was significantly lower than during the original wave (20.3%) and the Alpha (18.4%) wave (P<.05). Vaccination rates were low before the Omicron wave and rose to 47.2% during the Omicron wave among individuals hospitalized with SARS-CoV-2 infection. Finally, second-trimester infection was significantly associated with worse perinatal outcomes compared with third-trimester infection (P<.05).

CONCLUSION:

There was a general trend toward improvement in preterm birth rates across the pandemic among pregnant patients with SARS-CoV-2 infection. The Omicron variant was more infectious, but the preterm birth rate during the Omicron wave was low compared with that during the original wave and the Alpha wave.
Predictors of Deep Infection After Distal Femur Fracture: A Multicenter Study
Authors: Brodke Dane , O'Hara Nathan , Devana Sai , Hernandez Adolfo , Burke Cynthia , Gupta Jayesh , McKibben Natasha , O'Toole Robert , Morellato John , Gillon Hunter , Walters Murphy , Barber Colby , Perdue Paul , Dekeyser Graham , Steffenson Lillia , Marchand Lucas , Fairres Marshall James , Black Loren , Working Zachary , Roddy Erika , El Naga Ashraf , Hogue Matthew , Gulbrandsen Trevor , Atassi Omar , Mitchell Thomas , Shymon Stephen , Lee Christopher
Published: October 2022

Objectives:

To identify potentially modifiable risk factors for deep surgical site infection after distal femur fracture.

Design:

Multicenter retrospective cohort study.

Setting:

Ten Level-I trauma centers.

Patients/Participants:

Patients with OTA/AO 33A or C distal femur fractures (n = 1107).

Intervention:

Surgical fixation of distal femur fracture.

Main Outcome Measurement:

The outcome of interest was deep surgical site infection.

Results:

There was a 7% rate (79/1107) of deep surgical site infection. In the multivariate analysis, predictive factors included alcohol abuse [odds ratio (OR) = 2.36; 95% confidence interval (CI), 1.17–4.46; P = 0.01], intra-articular injury (OR = 1.73; 95% CI, 1.01–3.00; P = 0.05), vascular injury (OR = 3.90; 95% CI, 1.63–8.61; P < 0.01), the use of topical antibiotics (OR = 0.50; 95% CI, 0.25–0.92; P = 0.03), and the duration of the surgery (OR = 1.15 per hour; 95% CI, 1.01–1.30; P = 0.04). There was a nonsignificant trend toward an association between infection and type III open fracture (OR = 1.73; 95% CI, 0.94–3.13; P = 0.07) and lateral approach (OR = 1.60; 95% CI, 0.95–2.69; P = 0.07). The most frequently cultured organisms were methicillin-resistant Staphylococcus aureus (22%), methicillin-sensitive Staphylococcus aureus (20%), and Enterobacter cloacae (11%).

Conclusions:

Seven percent of distal femur fractures developed deep surgical site infections. Alcohol abuse, intra-articular fracture, vascular injury, and increased surgical duration were risk factors, while the use of topical antibiotics was protective.

Level of Evidence:

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.
Cervical Disk Arthroplasty
Authors: Shafi Karim , Kim Andrew G. , Qureshi Sheeraz
Published: October 2022

Purpose:

Cervical disk arthroplasty (CDA) has emerged as a promising alternative to anterior cervical discectomy and fusion for the management of cervical disk degeneration causing neurological symptoms. This manuscript and accompanying digital content demonstrate the senior author’s preferred surgical technique for a single-level CDA.

Methods:

CDA is performed using a standard, left-sided Smith Robinson approach. A complete discectomy is performed, with resection of the posterior longitudinal ligament and decompression of the neuroforamina bilaterally. Careful endplate preparation and trial is performed, and the final implant is impacted under a combination of direct visualization and fluoroscopy. Postoperatively, a soft collar is worn for comfort, and the patient is discharged on postoperative day 1 or 2.

Results:

This video, Supplemental Digital Content 1, http://links.lww.com/CLINSPINE/A254 presents the case of a 43-year old woman with mild cervical spondylosis with a paracentral disk herniation causing left C6 radiculopathy refractory to conservative measures. A C5-6 cervical disk arthroplasty was performed.

Conclusions:

CDA presents a motion-sparing alternative to anterior cervical discectomy and fusion and has the potential to reduce adjacent segment disease, though further studies are needed to fully determine its benefits and expanding indications. Careful patient selection and proper surgical technique, as demonstrated here, remain crucial in optimizing outcomes.
Preliminary Analysis of Cervical Cancer Immunotherapy
Authors: Ma Zhen , Zou Xinxin , Yan Zhaohua , Chen Caiyun , Chen Yumei , Fu Aizhen
Published: October 2022

Cervical cancer is one of the most common gynecologically malignancies worldwide. Although vaccine and cervical cancer screening including human papillomavirus testing, cytology testing, and colposcopy have developed rapidly in recent years, effectively reducing cervical cancer mortality, cervical cancer remains a malignancy with higher female fatality rates worldwide and has a high risk for socioeconomically disadvantaged groups. The combination of platinum-paclitaxel and chemotherapy, possibly with the addition of bevacizumab, is currently the treatment of choice for advanced cervical cancer, but it only has remission purposes. Therefore, new therapeutic strategies are needed for both locally advanced and metastatic cervical cancer. Here, we make a preliminary analysis of cervical cancer immunotherapy.
Sleep Disorders and Coronary Artery Disease
Authors: Dey Subo , Sun Eric , Frishman William H. , Aronow Wilbert S.
Published: October 2022

A sufficient amount and quality sleep is vital components for maintaining optimal physical wellbeing, cognition, and cardiovascular health. Normal sleep provides us with a low physiological stress that promotes overall cardiovascular health. Sleep disorders are common, and often goes undiagnosed. Patients with sleep disorders, commonly suffer from poor quality of life due to the poor quality of their sleep. They are associated with adverse effects on cardiovascular health, such as coronary artery disease. Sleep disorders discussed in this review article include sleep-disordered breathing (obstructive sleep apnea and central sleep apnea), insomnia and restless leg syndrome. Sleep disorders primarily have four acute adverse cardiovascular consequences. First, intermittent hypoxemia-reoxygenation in arterial blood along with PCO2 fluctuation; second is excessive arousals; third, decreased parasympathetic and increased sympathetic tone; fourth being the large pressure swings in the intrathoracic cavity. This review focuses on classifications, and prevalence of the three major classes of sleep disorders, and the evidence to date on the association between these sleep disorders and coronary artery disease.
Validation of Conversion Factors for Therapeutic Drug Monitoring of Lacosamide, Lamotrigine, and Levetiracetam in Dried Capillary Blood
Authors: Hagemann Anne , Klimpel Dennis , Schmitter Elisabeth , Bien Christian G. , Dufaux Bertin , May Theodor W , Brandt Christian
Published: October 2022

Background:

Estimation of serum concentrations of antiseizure medications (ASMs) based on dried capillary blood is an alternative method for therapeutic drug monitoring of epilepsy. The aim of this study was to validate the conversion factors for lacosamide (LCM), lamotrigine (LTG), and levetiracetam (LEV), which were determined in an independent patient sample in a previous study, and identify the most accurate conversion method (simple ratio and regression).

Methods:

Venous and capillary blood samples were collected from adult inpatients with epilepsy treated with LCM (n = 25), LTG (n = 27), and/or LEV (n = 29) before the morning dose (T1) and approximately 2 hours after (T2). Capillary blood was collected using volumetric absorptive microsampling, and the ASM concentrations were measured using a validated liquid chromatography–mass spectrometry method for dried blood samples. Serum concentrations were estimated using conversion factors and compared with those measured using routine laboratory methods.

Results:

For all 3 ASMs, the simple ratio approach performed better than the regression approach. Intraclass correlation coefficients revealed a high agreement between the estimated and measured serum concentrations (LCM T1: 0.93, T2: 0.90; LTG T1: 0.91, T2: 0.91; and LEV T1: 0.97, T2: 0.94). The criteria of the European Medicines Agency for cross-validation were fulfilled for LCM (T1: 72%; T2: 75%) and LEV (T1: 86%; T2: 75%), whereas for LTG, this was only true for capillary blood concentrations ≤11 µg/mL [42.9 µmol/L; T1: 72% (vs. 63% for total range), T2: 67% (vs. 62%)].

Conclusions:

Estimating serum concentrations using capillary blood concentrations is feasible and accurate for LCM and LEV over a wide concentration range, as found in clinical practice. The applicability of this mehod for LTG is limited by its greater variability at higher concentrations; however, acceptable results were achieved for the large proportion of patients with low and medium LTG concentrations.
Evaluating the hearing screening effectiveness of active noise cancellation technology among young adults: A pilot study
Authors: Cheng Hsiu-Lien , Han Ji-Yan , Chu Yuan-Chia , Cheng Yen-Fu , Lin Chia-Mei , Chiang Ming-Chang , Wu Shang-Liang , Lai Ying-Hui , Liao Wen-Huei
Published: October 2022

Background:

The population of young adults who are hearing impaired increases yearly, and a device that enables convenient hearing screening could help monitor their hearing. However, background noise is a critical issue that limits the capabilities of such a device. Therefore, this study evaluated the effectiveness of commercial active noise cancellation (ANC) headphones for hearing screening applications in the presence of background noise. In particular, six confounders were used for a comprehensive evaluation.

Methods:

We enrolled 12 young adults (a total of 23 ears with normal hearing) to participate in this study. A cross-sectional self-controlled study was conducted to explore the effectiveness of hearing screening in the presence of background noise, with a total of 240 test conditions (=3 ANC models × 2 ANC function statuses × 2 noise types × 5 noise levels × 4 frequencies) for each test ear. Subsequently, a linear regression model was used to prove the effectiveness of ANC headphones for hearing screening applications in the presence of background noise with six confounders.

Results:

The experimental results showed that, on average, the ANC function of headphones can improve the effectiveness of hearing screening tasks in the presence of background noise. Specifically, the statistical analysis showed that the ANC function enabled a significant 10% improvement (p < 0.001) compared with no ANC function.

Conclusion:

This study confirmed the effectiveness of ANC headphones for young adult hearing screening applications in the presence of background noise. Furthermore, the statistical results confirmed that as confounding variables, noise type, noise level, hearing screening frequency, ANC headphone model, and sex all affect the effectiveness of the ANC function. These findings suggest that ANC is a potential means of helping users obtain high-accuracy hearing screening results in the presence of background noise. Moreover, we present possible directions of development for ANC headphones in future studies.
Competency-Based Education in Physical Therapy: Developing a Framework for Education Research
Authors: Jensen Gail M. , Jette Diane U. , Timmerberg Jean Fitzpatrick , Chesbro Steven B. , Dole Robin L. , Kapasi Zoher , Lotshaw Ana
Published: October 2022

Background and Purpose.

The physical therapy education community is actively engaged in planning and developing an approach to competency-based education in physical therapy (CBEPT). The creation of an underlying framework for education research in CBEPT can provide guidance in identifying key areas of needed study, give direction for future research, and provide opportunities for collaboration. The purpose of this article is to 1) describe the critical concepts of CBEPT as both an educational philosophy and design and 2) identify a working education research framework, examples of potential research questions, and associated methodological considerations.

Position and Rationale.

As the movement in CBEPT evolves, we have the opportunity to propose a working framework and potential research questions for our education community. An initial step in the development of a research framework was review of a model paper from medical education that proposed a research agenda for competency-based medical education. We developed a draft of categories and related research questions and then used an iterative group process that included members of the Education Leadership Partnership Education Research Network to review and provide feedback. Core areas for investigation include learners, the learning environment, learning progression, and faculty development needs along with examples of potential research questions in each area.

Discussion and Conclusion.

The development of a research framework for CBEPT that can guide much needed education research is critical and timely for the profession. Evidence is vital to widespread adoption, informed and refined processes, understanding, and infrastructure development all linked with the ultimate aim of CBEPT—learner development and meeting societal needs.
Lung transplantation in patients with lung disease secondary to coronavirus disease 2019 infection
Authors: Avella Diego , Bharat Ankit
Published: October 2022

Purpose of review

In this article, we describe preoperative patient selection and outcomes of patients with lung disease secondary to infection from COVID-19 who receive lung transplantation.

Recent findings

Lung transplants for patients with lung disease secondary to infection from COVID-19 have been performed successfully in over 200 patients in the United States. The preoperative course of these patients is somewhat atypical in comparison with patients who have had lung transplants related to chronic lung diseases, where there are more traditional indications for lung transplants. COVID-19 patients have more severe pulmonary disease often requiring mechanical ventilation and extracorporeal mechanical ventilation (ECMO), frequent nosocomial infections, and renal and cardiac dysfunction. The intraoperative course of these COVID-19 patients is often longer and requires increased transfusions of blood products in comparison with non-COVID-19 patients. Additionally, in the postoperative period, COVID-19 patients more frequently require mechanical ventilation and ECMO support. However, the survival rate of such patients at 6 months is greater than 90%.

Patients with respiratory failure secondary to COVID-19 infection that require a lung transplant generally have a complicated preoperative course and the operations are more complex, but the long-term outcomes are excellent.
Neurotrauma
Authors: Niziolek Grace , Sandsmark Danielle K. , Pascual Jose L.
Published: October 2022

Purpose of review

This review will highlight the latest research relevant to the clinical care of traumatic brain injury (TBI) patients over the last 2 years while underscoring the implications of these advances in the understanding of diagnosis, treatment, and prognosis of TBI.

Recent findings

Brain tissue oxygenation monitoring can identify hypoperfusion as an adjunct to intracerebral pressure monitoring. Multiple biomarker assays are now available to help clinicians screen for mild TBI and biomarker elevations correlate with the size of intracranial injury. Beta-blocker exposure following TBI has demonstrated a survival benefit in those with TBI though the mechanism for this remains unknown. The optimal timing for venous thromboembolism prophylaxis for TBI patients is still uncertain.

The current characterization of TBI as mild, moderate, or severe fails to capture the complexity of the disease process and helps little with prognostication. Molecular biomarkers and invasive monitoring devices including brain tissue oxygenation and measures of cerebral autoregulation are being utilized more commonly and can help guide therapy. Extracranial complications following TBI are common and include infection, respiratory failure, coagulopathy, hypercoagulability, and paroxysmal sympathetic hyperactivity.