Polysaccharide/Lipid Nanoconjugates as Alternative Building Blocks for Highly Biocompatible Microcapsules.

Saccharide/lipid nanoconjugates are attractive building blocks for the construction of micro- and nanosized structures because of the roles of glycolipids in human body, courtesy of their intrinsic and functional properties. Herein, nanoconjugates based on dextran and oleic acid (Dex-OA) were synthesized via facile amide-linkage chemistry. The resultant Dex-OA micelles could self-assemble into spherical water-filled microcapsules via a water-in-oil emulsification process. By cross-linking, the microcapsules could be transferred to aqueous media, forming a stable microcapsule dispersion. According to optical and fluorescence microscopy, the microcapsules displayed a spherical morphology, and their synthesis is dependent on the concentration of Dex-OA nanoconjugates. Furthermore, the microcapsules could easily encapsulate and retain fluorescently labeled dextran. This strategy offers a robust and efficient method for the construction of microcapsules from fully natural amphiphilic building blocks with the potential for application in diverse fields such as biomedicine, protocell research, and microreactors.

Endonasal clipping of unruptured right paraclinoid aneurysm. Case report in a third level center in Mexico City.

Paraclinoid aneurysms take importance due to the technical difficulty due to anatomical relationships, which is why different approaches have been sought for their proper management. This is a female patient with a finding of a paraclinoid aneurysm and treatment using an endonasal approach with adequate angiographic support. Knowledge of the anatomy and surgical skill are required for the management of these lesions, assisted by angiographic controls for successful treatment. The endoscopic endonasal approach is adequate if the anatomy allows it and the basic hospital infrastructure is available to obtain high success rates.

Los aneurismas paraclinoideos cobran importancia debido a la dificultad técnica por sus relaciones anatómicas, por lo que se han buscado diferentes abordajes para su adecuado manejo. Se presenta el caso de una paciente con un aneurisma paraclinoideo y tratamiento mediante abordaje endonasal con apoyo angiográfico adecuado. Se requieren conocimientos de la anatomía y habilidad quirúrgica para el manejo de estas lesiones, así como asistencia de controles angiográficos para el éxito del tratamiento. El abordaje endonasal endoscópico es adecuado en caso de que la anatomía lo permita y se tenga la infraestructura hospitalaria básica para obtener un alto índice de éxitos.

Biofabrication of Gold Nanotriangles Using Liposomes as a Dual Functional Reductant and Stabilizer.

Negatively charged liposomes accomplished both functions as a reducing and stabilizing agent in the synthesis of gold nanotriangles (GNTs). Liposomes are based on a mixture of phospholipids phosphatidylcholine/phosphoglycerol, and they were used as a template phase to perform the GNTs. The method was evaluated under different conditions such as temperature, reaction time, phosphoglycerol chain length, and precursor concentration. Isotropic and anisotropic gold nanoparticles are formed simultaneously during the synthesis. Therefore, by combining centrifugation and depletion flocculation strategies, the sample was concentrated in terms of GNTs from 15% crude to 80% by using sodium dodecyl sulfate (SDS). As a result, a green colored dispersion was obtained containing highly purified, well-defined, negatively charged GNTs, where the edge length of most particles is centered in the range of 60-80 nm with an average thickness of 7.8 ± 0.1 nm. By this purification process, it was possible to highly increase the yield in terms of GNTs. Other surfactants [cetyltrimethylammonium chloride (CTAC), hexadecyltrimethylammonium bromide (CTAB), Tween 20, and dodecyldimethylammonium bromide] were evaluated during the purification stage, and both CTAB and CTAC show similar results to those obtained by using SDS. These GNTs are potential candidates for future applications in molecular imaging, photothermal therapy, drug delivery, biosensing, and photodynamic therapy.

Spinal drop of atypical choroid plexus papilloma in an adult patient: A case report and literature review.

BACKGROUND: Choroid plexus papillomas (CPPs) are benign extra-axial tumors that originate from the choroid plexus; these tumors rarely have metastases, being at the spinal level the location with few reported cases. CASE DESCRIPTION: We report the case of a 48-year-old man with a history of atypical fourth ventricular CPP and gross total resection (GTR) in 2008. In 2015, he presented with radicular pain, decreased strength, and paresthesia in the left leg. Magnetic resonance imaging revealed a well-defined intradural ovoid lesion in the vertebral canal at the level of the L3-L4 intersomatic space. Subtotal resection of the tumor was performed. The patient recovered well, with relief of pain and no neurological deficit. A literature research few cases of CPP metastasis in adults. We describe here a fifth-decade male patient with a lumbar neoplasm, which according to the histopathologic characteristics and location is the first case of an atypical papilloma implant of the choroid plexus at this spinal level. CONCLUSION: GTR of primary lesions and associated implants remains the gold standard for surgical treatment of CPP. Radiotherapy, stereotactic radiosurgery, and chemotherapy are adjuvant therapies for CPP but there is no definitive protocol for the management of implants. Proper follow-up of these patients is essential since spinal drop can appear many years after the initial presentation of CPP.

Ventriculopleural shunt dysfunction as the first sign of a hidden aneurysmal Subarachnoid Hemorrhage: A case report.

INTRODUCTION: Subarachnoid Hemorrhage (SAH) is caused by an aneurysmatic origin in 80% of cases. In the adult population, the risk of shunt dysfunction is about 16% in the first year, with proximal mechanical obstruction being the most frequent cause. CASE REPORT: An 81-year-old man with a history of shunt system placement presented among clinical data of shunt dysfunction. The brain Computed Tomography (CT) showed dilation of the ventricular system, with no other associated injury. The cause of the dysfunction was a SAH determined by a lumbar puncture (LP) study. We performed an angiography reporting 3 aneurysms. DISCUSSION: The risk of shunt dysfunction at one year is 40% and at two years, the risk ups to 53% with obstruction of the system and infection being the two principal causes. The usefulness of a lumbar puncture for late detection of SAH lies in the red cells in the Cerebrospinal Fluid (CSF). When the CT is negative and the clinical suspicion remains, the lumbar puncture (LP) continues with higher sensitivity despite is over 12 hours of the onset clinic symptoms. CONCLUSION: This case encourages to follow a rigorous protocol study for patients with multiple shunt dysfunction and chronic hydrocephalus. Also, this case invites to consider a hidden SAH secondary to a vascular pathology as a differential diagnosis for a multiple shunt dysfunction.

Automated Measurement of Lumbar Lordosis on Radiographs Using Machine Learning and Computer Vision.

STUDY DESIGN: Cross sectional database study. OBJECTIVE: To develop a fully automated artificial intelligence and computer vision pipeline for assisted evaluation of lumbar lordosis. METHODS: Lateral lumbar radiographs were used to develop a segmentation neural network (n = 629). After synthetic augmentation, 70% of these radiographs were used for network training, while the remaining 30% were used for hyperparameter optimization. A computer vision algorithm was deployed on the segmented radiographs to calculate lumbar lordosis angles. A test set of radiographs was used to evaluate the validity of the entire pipeline (n = 151). RESULTS: The U-Net segmentation achieved a test dataset dice score of 0.821, an area under the receiver operating curve of 0.914, and an accuracy of 0.862. The computer vision algorithm identified the L1 and S1 vertebrae on 84.1% of the test set with an average speed of 0.14 seconds/radiograph. From the 151 test set radiographs, 50 were randomly chosen for surgeon measurement. When compared with those measurements, our algorithm achieved a mean absolute error of 8.055° and a median absolute error of 6.965° (not statistically significant, P > .05). CONCLUSION: This study is the first to use artificial intelligence and computer vision in a combined pipeline to rapidly measure a sagittal spinopelvic parameter without prior manual surgeon input. The pipeline measures angles with no statistically significant differences from manual measurements by surgeons. This pipeline offers clinical utility in an assistive capacity, and future work should focus on improving segmentation network performance.

Evaluación del trofismo del músculo temporal posquirúrgico en relación con el tiempo de manipulación y la infiltración transoperatoria de bupivacaína isobárica al 0.5% en pacientes sometidos a craneotomía pterional / Evaluation of temporal muscle trophism in relation to the manipulation time and infiltration of 0.5% isobaric bupivacaine through a pterional approach

Introducción: Existen diferentes técnicas para reconstrucción del músculo temporal (MT) en el abordaje pterional (AP) con el objetivo de evitar y disminuir la atrofia, hasta el momento ninguna ha logrado evitarla en su totalidad. La administración de bupivacaína genera regeneración de fibras musculares. Aún no existe en la literatura médica estudios que evalúen el tiempo de manipulación del MT y que den uso a la bupivacaína para el tratamiento de la atrofia después de un abordaje pterional, el presente estudio pretende describir los efectos de estas variables. Pacientes y métodos: Estudio longitudinal, incluyendo pacientes de 18-80 años y sometidos a abordaje pterional en los años 2016-2017. Evaluamos los efectos de la manipulación del MT y la administración de bupivacaína al 0,5% sobre el trofismo y la función del MT. Resultados: Veintinueve pacientes fueron sometidos a AP; 16(55,17%) contaron con criterios para infiltración con bupivacina al 0,5%. Se encontró una correlación negativa entre los tiempos de manipulación y el trofismo, no estadísticamente significativo (p>0,05). Se evalúo los índices de disfunción de Helkimo y Fonseca prequirúrgicos y posquirúrgicos encontrándose un incremento estadísticamente significativo en la disfunción (p<0,05). En pacientes infiltrados con bupivacaína al 0,5% se observó una diferencia media del espesor de MT de 0,275±1,18mm, en contraste con los no infiltrados de 2,39±1,30mm (t[27] = -5,118, p=0,0001). Conclusiones: La manipulación del MT durante el abordaje pterional, condiciona un impacto sobre la calidad de vida de acuerdo con los índices de disfunción, debido a la atrofia. Esta investigación presenta que la administración de bupivacaína al 0,5% durante la cirugía ofrece una disminución en la atrofia del MT

Introduction: There are different techniques for the reconstruction of the temporal muscle (TM) in the pterional approach (PA) in order to avoid and reduce atrophy, it has not been able to avoid it in its entirety. The administration of bupivacaine generates regeneration of muscle fibres. There are no studies in the medical literature that evaluate the time of TM manipulation and the use of bupivacaine for the treatment of atrophy after pterional approach, the present investigation aim is to describe the effects of these variables. Patient and methods: Longitudinal study, including patients from 18-80 years old with pterional approach at 2016-2017. We evaluated the effects of the TM manipulation times and the administration of 0.5% bupivacaine on the trophism and function of TM. Results: Twenty-nine patients underwent a PA; 16(55.17%) count with criteria for 0.5% bupivacain infiltration. We found a negative correlation between manipulation times and trophism, with no statistically significance (p>.05). We evaluated presurgical and postsurgical index of Helkimo and Fonseca's index, finding an increase of disfunction with statistically significance (p<.05). In patients who were infiltrated with 0.5% bupivacaine we observed a mean difference in the TM's trophism of 0.275±1.18mm, in contrast with no infiltrated which was 2.39±1.30mm (t[27] = -5.118, p=.0001). Conclusions: The manipulation of the TM during a pterional approach conditioned an impact on the quality of life according to the disfunction indexes, due to atrophy. This investigation exhibits that de administration of 0.5% bupivacaine during surgery offers a decrease in the TM atrophy

The Effects of Preoperative Steroid Therapy on Perioperative Morbidity and Mortality After Adult Spinal Deformity Surgery.

STUDY DESIGN: Retrospective cohort analysis. OBJECTIVES: To identify the effects of preoperative steroid therapy on 30-day perioperative complications after adult spinal deformity (ASD) surgery. SUMMARY OF BACKGROUND DATA: Chronic steroid therapy has demonstrated therapeutic effects in the treatment of various medical conditions but is also known to be associated with surgical complications. There remains a gap in the literature regarding the impact of chronic steroid therapy in predisposing patients to perioperative complications after elective surgery for ASD. METHODS: We performed a retrospective analysis of data from the 2008-2015 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Patients were divided into two groups based on preoperative steroid therapy. Differences in baseline patient characteristics, comorbidities, and operative variables were assessed. Univariate analysis was performed to compare the incidence of perioperative complications. Multivariate stepwise logistic regression models were then used to adjust for baseline patient and operative variables in order to identify perioperative complications that were associated with preoperative steroid therapy. RESULTS: We identified 7,936 patients who underwent surgery for ASD, of which 418 (5.3%) were on preoperative steroid therapy. Preoperative steroid therapy was an independent risk factor for four perioperative complications, including mortality (odds ratio [OR] 2.42, 95% confidence interval [CI] 1.30, 4.51; p = .005), wound dehiscence (OR 3.12, 95% CI 1.45, 6.70; p = .004), deep vein thrombosis (DVT) (OR 2.10, 95% CI 1.24, 3.55; p = .006), and blood transfusion (OR 1.34, 95% CI 1.08, 1.66; p < .007). CONCLUSIONS: Patients on preoperative steroid therapy are at increased risk of 30-day mortality, wound dehiscence, DVT, and blood transfusion after surgery for ASD. An interdisciplinary approach to the perioperative management of steroid regimens is critical. LEVEL OF EVIDENCE: Level III.

The influence of the shape of Au nanoparticles on the catalytic current of fructose dehydrogenase.

Graphite electrodes were modified with triangular (AuNTrs) or spherical (AuNPs) nanoparticles and further modified with fructose dehydrogenase (FDH). The present study reports the effect of the shape of these nanoparticles (NPs) on the catalytic current of immobilized FDH pointing out the different contributions on the mass transfer-limited and kinetically limited currents. The influence of the shape of the NPs on the mass transfer-limited and the kinetically limited current has been proved by using two different methods: a rotating disk electrode (RDE) and an electrode mounted in a wall jet flow-through electrochemical cell attached to a flow system. The advantages of using the wall jet flow system compared with the RDE system for kinetic investigations are as follows: no need to account for substrate consumption, especially in the case of desorption of enzyme, and studies of product-inhibited enzymes. The comparison reveals that virtually identical results can be obtained using either of the two techniques. The heterogeneous electron transfer (ET) rate constants (kS) were found to be 3.8 ± 0.3 s-1 and 0.9 ± 0.1 s-1, for triangular and spherical NPs, respectively. The improvement observed for the electrode modified with AuNTrs suggests a more effective enzyme-NP interaction, which can allocate a higher number of enzyme molecules on the electrode surface. Graphical abstract The shape of gold nanoparticles has a crucial effect on the catalytic current related to the oxidation of D-(-)-fructose to 5-keto-D-(-)-fructose occurring at the FDH-modified electrode surface. In particular, AuNTrs have a higher effect compared with the spherical one.

Evaluation of temporal muscle trophism in relation to the manipulation time and infiltration of 0.5% isobaric bupivacaine through a pterional approach. / Evaluación del trofismo del músculo temporal posquirúrgico en relación con el tiempo de manipulación y la infiltración transoperatoria de bupivacaína isobárica al 0,5% en pacientes sometidos a craneotomía pterional.

INTRODUCTION: There are different techniques for the reconstruction of the temporal muscle (TM) in the pterional approach (PA) in order to avoid and reduce atrophy, it has not been able to avoid it in its entirety. The administration of bupivacaine generates regeneration of muscle fibres. There are no studies in the medical literature that evaluate the time of TM manipulation and the use of bupivacaine for the treatment of atrophy after pterional approach, the present investigation aim is to describe the effects of these variables. PATIENT AND METHODS: Longitudinal study, including patients from 18-80 years old with pterional approach at 2016-2017. We evaluated the effects of the TM manipulation times and the administration of 0.5% bupivacaine on the trophism and function of TM. RESULTS: Twenty-nine patients underwent a PA; 16(55.17%) count with criteria for 0.5% bupivacain infiltration. We found a negative correlation between manipulation times and trophism, with no statistically significance (p>.05). We evaluated presurgical and postsurgical index of Helkimo and Fonseca's index, finding an increase of disfunction with statistically significance (p<.05). In patients who were infiltrated with 0.5% bupivacaine we observed a mean difference in the TM's trophism of 0.275±1.18mm, in contrast with no infiltrated which was 2.39±1.30mm (t[27] = -5.118, p=.0001). CONCLUSIONS: The manipulation of the TM during a pterional approach conditioned an impact on the quality of life according to the disfunction indexes, due to atrophy. This investigation exhibits that de administration of 0.5% bupivacaine during surgery offers a decrease in the TM atrophy.

The Effects of Preoperative Steroid Therapy on Perioperative Complications After Elective Anterior Lumbar Fusion.

OBJECTIVE: To examine the effects of chronic preoperative steroid therapy on 30-day perioperative complications after anterior lumbar fusion (ALF). METHODS: We retrospectively analyzed data from the American College of Surgeons National Surgical Quality Improvement Program between 2008 and 2015. Adult patients who underwent ALF were included and divided into 2 groups: steroids and no steroids. We compared baseline patient demographics, comorbidities, and operative variables between these 2 groups and then performed a multivariate regression analysis to determine complications that were independently associated with chronic steroid therapy. We also performed a subgroup analysis of the steroid group to identify additional risk factors that further predispose these patients to postoperative complications. RESULTS: A total of 9483 patients were included, of whom 289 (3.0%) were on chronic steroid therapy. Univariate analysis showed that chronic steroid use was independently associated with 4 perioperative complications, including deep surgical site infection (odds ratio [OR], 2.78; confidence interval [CI], 1.09-7.10; P = 0.033), pulmonary complications (OR, 1.98; CI, 1.02-3.86; P = 0.044), blood transfusion (OR, 1.60; CI, 1.15-2.23; P = 0.005), and extended length of stay (OR, 1.58; CI, 1.17-2.16; P = 0.003). In patients on chronic steroid therapy, pulmonary comorbidity and extended operative time were additional risk factors that further predisposed to perioperative complications, including deep surgical site infection, blood transfusion, and extended length of stay. CONCLUSIONS: Chronic preoperative steroid therapy is associated with perioperative complications after ALF. Decisions about the discontinuing or holding steroid therapy preoperatively should be determined through an interdisciplinary approach between the medical and surgical teams.

Neural network analysis of sleep stages enables efficient diagnosis of narcolepsy.

Analysis of sleep for the diagnosis of sleep disorders such as Type-1 Narcolepsy (T1N) currently requires visual inspection of polysomnography records by trained scoring technicians. Here, we used neural networks in approximately 3,000 normal and abnormal sleep recordings to automate sleep stage scoring, producing a hypnodensity graph-a probability distribution conveying more information than classical hypnograms. Accuracy of sleep stage scoring was validated in 70 subjects assessed by six scorers. The best model performed better than any individual scorer (87% versus consensus). It also reliably scores sleep down to 5 s instead of 30 s scoring epochs. A T1N marker based on unusual sleep stage overlaps achieved a specificity of 96% and a sensitivity of 91%, validated in independent datasets. Addition of HLA-DQB1*06:02 typing increased specificity to 99%. Our method can reduce time spent in sleep clinics and automates T1N diagnosis. It also opens the possibility of diagnosing T1N using home sleep studies.

Brown tumor of the cervical spine in a patient with secondary hyperparathyroidism: A case report.

INTRODUCTION: Brown tumors are non-neoplastic, expansive bone lesions that occur only in the setting of hyperparathyroidism. The most usual localization of brown tumors is in mandible, ribs and large bones. In cervical spine, to date, there are only 11 cases reported. The aim of this work is to report the case of a patient with Wegener´s granulomatosis with secondary end stage renal failure who developed a brown tumor in C4 vertebra. PRESENTATION OF CASE: A 25-year-old woman with an history of 2 months of worsening cervicalgia without history of trauma. She complained about progressive neck pain with irradiation to both shoulders and right arm paresthesias, spontaneous fracture or brown spinal cord tumor were suspected. She presented cervical spine instability, was managed with corpectomy of C4 and biopsy. DISCUSSION: The initial suspicion of this disease must be since the first clinician contact of the patient and with the past medical history of end stage renal failure plus recent neurologic manifestations. The aim of neurosurgical management of these patients is to promote spinal stability and release spinal cord and nerve roots to eliminate risk of neurological deficits. CONCLUSION: The importance of the prompt diagnosis of the brown tumor is to establish a multidisciplinary management to prevent progression, neurologic complications and sequelae despite its benign behavior.

A cellular mechanism for inverse effectiveness in multisensory integration.

To build a coherent view of the external world, an organism needs to integrate multiple types of sensory information from different sources, a process known as multisensory integration (MSI). Previously, we showed that the temporal dependence of MSI in the optic tectum of Xenopus laevis tadpoles is mediated by the network dynamics of the recruitment of local inhibition by sensory input (Felch et al., 2016). This was one of the first cellular-level mechanisms described for MSI. Here, we expand this cellular level view of MSI by focusing on the principle of inverse effectiveness, another central feature of MSI stating that the amount of multisensory enhancement observed inversely depends on the size of unisensory responses. We show that non-linear summation of crossmodal synaptic responses, mediated by NMDA-type glutamate receptor (NMDARs) activation, form the cellular basis for inverse effectiveness, both at the cellular and behavioral levels.

Correction: Design and Validation of a Periodic Leg Movement Detector.

[This corrects the article DOI: 10.1371/journal.pone.0114565.].

Sleep-stage transitions during polysomnographic recordings as diagnostic features of type 1 narcolepsy.

OBJECTIVE: Type 1 narcolepsy/hypocretin deficiency is characterized by excessive daytime sleepiness, sleep fragmentation, and cataplexy. Short rapid eye movement (REM) latency (≤15 min) during nocturnal polysomnography (PSG) or during naps of the multiple sleep latency test (MSLT) defines a sleep-onset REM sleep period (SOREMP), a diagnostic hallmark. We hypothesized that abnormal sleep transitions other than SOREMPs can be identified in type 1 narcolepsy. METHODS: Sleep-stage transitions (one to 10 epochs to one to five epochs of any other stage) and bout length features (one to 10 epochs) were extracted from PSGs. The first 15 min of sleep were excluded when a nocturnal SOREMP was recorded. F(0.1) measures and receiver operating characteristic curves were used to identify specific (≥98%) features. A data set of 136 patients and 510 sex- and age-matched controls was used for the training. A data set of 19 cases and 708 sleep-clinic patients was used for the validation. RESULTS: (1) ≥5 transitions from ≥5 epochs of stage N1 or W to ≥2 epochs of REM sleep, (2) ≥22 transitions from ≥3 epochs of stage N2 or N3 to ≥2 epochs of N1 or W, and (3) ≥16 bouts of ≥6 epochs of N1 or W were found to be highly specific (≥98%). Sensitivity ranged from 16% to 30%, and it did not vary substantially with and without medication or a nocturnal SOREMP. In patients taking antidepressants, nocturnal SOREMPs occurred much less frequently (16% vs. 36%, p < 0.001). CONCLUSIONS: Increased sleep-stage transitions notably from ≥2.5 min of W/N1 into REM are specifically diagnostic for narcolepsy independent of a nocturnal SOREMP.

Design and validation of a periodic leg movement detector.

Periodic Limb Movements (PLMs) are episodic, involuntary movements caused by fairly specific muscle contractions that occur during sleep and can be scored during nocturnal polysomnography (NPSG). Because leg movements (LM) may be accompanied by an arousal or sleep fragmentation, a high PLM index (i.e. average number of PLMs per hour) may have an effect on an individual's overall health and wellbeing. This study presents the design and validation of the Stanford PLM automatic detector (S-PLMAD), a robust, automated leg movement detector to score PLM. NPSG studies from adult participants of the Wisconsin Sleep Cohort (WSC, n = 1,073, 2000-2004) and successive Stanford Sleep Cohort (SSC) patients (n = 760, 1999-2007) undergoing baseline NPSG were used in the design and validation of this study. The scoring algorithm of the S-PLMAD was initially based on the 2007 American Association of Sleep Medicine clinical scoring rules. It was first tested against other published algorithms using manually scored LM in the WSC. Rules were then modified to accommodate baseline noise and electrocardiography interference and to better exclude LM adjacent to respiratory events. The S-PLMAD incorporates adaptive noise cancelling of cardiac interference and noise-floor adjustable detection thresholds, removes LM secondary to sleep disordered breathing within 5 sec of respiratory events, and is robust to transient artifacts. Furthermore, it provides PLM indices for sleep (PLMS) and wake plus periodicity index and other metrics. To validate the final S-PLMAD, experts visually scored 78 studies in normal sleepers and patients with restless legs syndrome, sleep disordered breathing, rapid eye movement sleep behavior disorder, narcolepsy-cataplexy, insomnia, and delayed sleep phase syndrome. PLM indices were highly correlated between expert, visually scored PLMS and automatic scorings (r²â€Š= 0.94 in WSC and r²â€Š= 0.94 in SSC). In conclusion, The S-PLMAD is a robust and high throughput PLM detector that functions well in controls and sleep disorder patients.

Sleep-spindle detection: crowdsourcing and evaluating performance of experts, non-experts and automated methods.

Sleep spindles are discrete, intermittent patterns of brain activity observed in human electroencephalographic data. Increasingly, these oscillations are of biological and clinical interest because of their role in development, learning and neurological disorders. We used an Internet interface to crowdsource spindle identification by human experts and non-experts, and we compared their performance with that of automated detection algorithms in data from middle- to older-aged subjects from the general population. We also refined methods for forming group consensus and evaluating the performance of event detectors in physiological data such as electroencephalographic recordings from polysomnography. Compared to the expert group consensus gold standard, the highest performance was by individual experts and the non-expert group consensus, followed by automated spindle detectors. This analysis showed that crowdsourcing the scoring of sleep data is an efficient method to collect large data sets, even for difficult tasks such as spindle identification. Further refinements to spindle detection algorithms are needed for middle- to older-aged subjects.

Exploring the electrocardiogram as a potential tool to screen for premotor Parkinson's disease.

The aim of this study was to test the hypothesis that patients with REM sleep behavior disorder, many of whom will develop Parkinson's disease (PD) or a related synucleinopathy, will demonstrate decreased heart rate variability (HRV) compared with a group of age-matched controls as measured by an electrocardiogram during wakefulness. We compared HRV in 11 untreated idiopathic REM sleep behavior disorder patients (9 men and 2 women; mean age, 63.3 years; SD, 7.5 years) and 11 control subjects with idiopathic insomnia without REM sleep behavior disorder (7 men and 4 women; mean age, 59.5 years; SD, 8.7 years). Subjects with other causes of reduced HRV were excluded. HRV was determined from 5-minute presleep segments of a single channel electrocardiogram recorded during polysomnographic evaluations, using R-R intervals during wakefulness. Time domain, geometric measures, and spectral analysis of the R-R intervals were significantly different between cases and controls. A discriminant function analysis correctly classified 95.5% of subjects (overall model fit, P = 0.016). Leave-one-out cross-validation correctly classified 77.3% of subjects. HRV during wakefulness is significantly decreased in patients with idiopathic REM sleep behavior disorder compared with control subjects, suggesting abnormalities of both sympathetic and parasympathetic function. Patients with RBD may later develop motor and cognitive features of a Lewy body disorder, such as PD. Cardiac autonomic dysfunction is also impaired in PD, suggesting that impaired HRV may be an early sign of PD. HRV measured by routine electrocardiograms could be used to screen for Lewy body disorders such as PD.