Patterns and utility of myelin oligodendrocyte glycoprotein (MOG) antibody testing in cerebrospinal fluid

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is an idiopathic central nervous system (CNS) demyelinating disease gaining recognition with wider availability of cell-based assay (CBA) testing and recently published diagnostic criteria. However, uncertainty remains regarding the interpretation of antibody titers, particularly cerebrospinal fluid (CSF) MOG antibody titers.

METHODS

All MOG IgG CBA results performed by the provincial MitogenDx laboratory in Alberta from July 2017 to July 2023 were retrieved. Chart review was performed in patients with both serum and CSF testing and ≥ 1 positive MOG antibody result. Demographics, antibody titers, clinical and imaging features, treatment, and diagnosis were analyzed based on serum/CSF status.

RESULTS

Among 4494 MOG CBA assays, there were 413 CSF samples in 402 patients, and 268 patients had at least one associated serum sample. Mean time between CSF and serum testing was 20.9 days (range 0-870 days), most with testing within 30 days. Five of the 268 patients had serum positive/CSF positive MOG antibodies, 4 with acute disseminated encephalomyelitis and 1 with longitudinally extensive transverse myelitis. Twenty-three patients had serum positive/CSF negative MOG and 13/23 with optic neuritis. CSF MOG antibody positive patients were younger, and more likely to remain MOG seropositive versus CSF negative patients. No seronegative patient had MOG antibodies in CSF.

CONCLUSIONS

In province-wide testing, CSF MOG antibodies were rare, only in MOG seropositive patients and none with optic neuritis. Our study does not support a clear role for CSF MOG antibody testing in the majority of patients, although further study is required.

Five-Year Outcomes of Graft-Free Tube Shunts and Risk Factors for Tube Exposures in Glaucoma

PRCIS

Use of a scleral tunnel technique instead of a patch graft can be considered in most cases of tube shunt implantation. Grafts may still be considered in younger (<65 y old) East Asians.

PURPOSE

(1) To assess the risk factors for tube exposure with a graft-free implantation technique and (2) to examine 5-year outcomes of graft-free tube shunt insertion.

METHODS

This was a retrospective case series of 204 consecutive eyes undergoing a glaucoma tube shunt implantation with a scleral tunnel technique in lieu of a graft. Preoperative and postoperative best-corrected visual acuity, intraocular pressure, and number of glaucoma medications were compared. Failure was defined as the following: (1) intraocular pressure >21 mm Hg or ≤5 mm Hg on 2 consecutive visits after 3 mo; (2) required additional glaucoma surgery; (3) loss of light perception. Univariable and multivariable regression analyses were conducted to identify risk factors of tube exposures.

RESULTS

Intraocular pressure and the number of glaucoma medications were significantly decreased at all postoperative time points ( P <0.001). Success rates were 91% at year 1, 75% at year 3, and 67% at year 5. The most common early (<3 mo) complication was tube malpositioning. The most common late (>3 mo to 5 y) complications were corneal complications and uncontrolled intraocular pressure. By year 5, 6.9% of tubes were exposed. Multivariable regression showed that age less than 65 years old (odds ratio: 3.66, P =0.04) and East Asian ethnicity (odds ratio: 3.36, P =0.04) were associated with significantly increased risk of tube exposure.

CONCLUSIONS

Graft-free glaucoma tube implantation has comparable long-term outcomes and complication rates to shunts with a graft. Younger (<65 y old) East Asians are at greater risk of tube exposure without a graft.

Utility of online GCA risk models in predicting the result of temporal artery biopsy within a clinical setting: study of diagnostic and screening tests

BACKGROUND

Temporal artery biopsy (TAB) is the gold standard for the diagnosis of giant cell arteritis (GCA) but has many limitations. The Ing model, González-López model, and Weis model are tools to estimate a patient's likelihood of GCA. This study investigates the utility of these prediction models in triaging patients referred for TAB.

METHODS

This study is a retrospective examination of patients who underwent TAB by a neuro-ophthalmologist over a 5-year period. Data collected through chart review were inputted into prediction models to evaluate GCA risk and compared with TAB results and clinical diagnosis. Cut-off values for 100% sensitivity and specificity for TAB result were used to determine whether TAB could be avoided where there was preoperative certainty of the result.

RESULTS

Among 155 eligible patients, mean age was 73 years, and 78.1% were female. TAB was negative in 103 patients (66.5%) and positive in 42 patients (27.1%). Twenty-three patients (22.3%) were diagnosed clinically and treated for biopsy-negative GCA. The Ing model had no positive biopsies below 10.59% and no negative biopsies above 68.44%. The González-López model had no positive biopsies below 0.27% and no negative biopsies above 98.08%. The Weis model had no positive biopsies with a score less than zero.

CONCLUSION

Forty-one biopsies (28.9%) could have been avoided using the Ing model, 9 (6.34%) using the González-López model, and 28 (19.7%) using the Weis model. The findings suggest that the Ing and Weis models are useful screening tools for GCA with the potential to improve the effective use of health care resources.

Leveraging the Full Continuum of Care to Prevent Opioid Use Disorder

Substance use disorder prevention programs are most effective when matched appropriately to the baseline risk of the population. Individuals who misuse opioids often have unique risk profiles different from those who use other substances such as alcohol or cannabis. However, most substance use prevention programs are geared toward universal audiences, neglecting key inflection points along the continuum of care. The HEAL Prevention Cooperative (HPC) is a unique cohort of research projects that represents a continuum of care, from community-level universal prevention to indicated prevention among older adolescents and young adults who are currently misusing opioids or other substances. This paper describes the theoretical basis for addressing opioid misuse and opioid use disorder across the prevention continuum, using examples from research projects in the HPC.

Accelerating Solutions for the Overdose Crisis: an Effectiveness-Implementation Hybrid Protocol for the HEAL Prevention Cooperative

Given increasing opioid overdose mortality rates in the USA over the past 20 years, accelerating the implementation of prevention interventions found to be effective is critical. The Helping End Addiction Long-Term (HEAL) Prevention Cooperative (HPC) is a consortium of research projects funded to implement and test interventions designed to prevent the onset or escalation of opioid misuse among youth and young adults. The HPC offers a unique opportunity to synthesize and share lessons learned from participating research projects' varied implementation experiences, which can facilitate quicker integration of effective prevention interventions into practice. This protocol paper describes our hybrid approach to collecting and analyzing information about the implementation experiences of nine of the HPC research projects while they maintain their focus on assessing the effectiveness and cost-effectiveness of prevention interventions. To better understand implementation within this context, we will address five research questions: (1) What were the context and approach for implementing the prevention interventions, and how was the overall implementation experience? (2) How representative of the target population are the participants who were enrolled and retained in the research projects' effectiveness trials? (3) For what purposes and how were stakeholders engaged by the research projects? (4) What are the adaptable components of the prevention interventions? And finally, (5) how might implementation of the prevention interventions vary for non-trial implementation? This work will result in intervention-specific and general practical dissemination resources that can help potential adopters and deliverers of opioid misuse prevention make adoption decisions and prepare for successful implementation.

A Comparison of Diagnostic Accuracy of Imaging Modalities to Detect Optic Disc Drusen: The Age of Enhanced Depth Imaging Optical Coherence Tomography

PURPOSE

To identify the most accurate diagnostic imaging modality to detect optic disc drusen (ODD) between B-scan ultrasonography (US), fundus photography, fundus autofluorescence (FAF), and enhanced depth imaging optical coherence tomography (EDI-OCT).

DESIGN

Comparative diagnostic analysis.

METHODS

Two hundred five eyes of 105 patients referred to 2 tertiary care neuro-ophthalmology clinics for suspected ODD were recruited: 108 eyes had ODD and 97 did not have ODD. All eyes received a full in-person ophthalmic exam with 3D view of the optic nerve and all 4 imaging modalities. Images were independently reviewed by 3 masked neuro-ophthalmologists to determine the presence or absence of ODD. Final interpretation was made through consensus. The reference standard was defined as the attending ophthalmologist's clinical judgement based on open chart review, with access to all image modalities and clinical information, including disease course. Main outcome measures were sensitivity, specificity, accuracy, and precision for each imaging modality. Examiner confidence was quantified as the proportion of eyes in which the reviewers were certain of their decision.

RESULTS

The EDI-OCT had the highest sensitivity and accuracy (95%, 97%) to detect ODD, compared with FAF (84%, 92%), US (74%, 86%), and fundus photography (38%, 66%), respectively. All image modalities had high specificity (> 97%) and precision (> 93%). The EDI-OCT also had highest examiner confidence (96%) compared with all others (88%).

CONCLUSIONS

Among all modalities, EDI-OCT was the imaging modality with the highest diagnostic utility for the detection of ODD and should be considered as the preferred initial diagnostic modality.

Deep Ensemble Learning for Retinal Image Classification

Purpose

Vision impairment affects 2.2 billion people worldwide, half of which is preventable with early detection and treatment. Currently, automatic screening of ocular pathologies using convolutional neural networks (CNNs) on retinal fundus photographs is limited to a few pathologies. Simultaneous detection of multiple ophthalmic pathologies would increase clinical usability and uptake.

Methods

Two thousand five hundred sixty images were used from the Retinal Fundus Multi-Disease Image Dataset (RFMiD). Models were trained (n = 1920) and validated (n = 640). Five selected CNN architectures were trained to predict the presence of any pathology and categorize the 28 pathologies. All models were trained to minimize asymmetric loss, a modified form of binary cross-entropy. Individual model predictions were averaged to obtain a final ensembled model and assessed for mean area under the receiver-operator characteristic curve (AUROC) for disease screening (healthy versus pathologic image) and classification (AUROC for each class).

Results

The ensemble network achieved a disease screening (healthy versus pathologic) AUROC score of 0.9613. The highest single network score was 0.9586 using the SE-ResNeXt architecture. For individual disease classification, the average AUROC score for each class was 0.9295.

Conclusions

Retinal fundus images analyzed by an ensemble of CNNs trained to minimize asymmetric loss were effective in detection and classification of ocular pathologies than individual models. External validation is needed to translate machine learning models to diverse clinical contexts.

Translational Relevance

This study demonstrates the potential benefit of ensemble-based deep learning methods on improving automatic screening and diagnosis of multiple ocular pathologies from fundoscopy imaging.

Search for Dark Matter Axions with CAST-CAPP

The CAST-CAPP axion haloscope, operating at CERN inside the CAST dipole magnet, has searched for axions in the 19.74 μeV to 22.47 μeV mass range. The detection concept follows the Sikivie haloscope principle, where Dark Matter axions convert into photons within a resonator immersed in a magnetic field. The CAST-CAPP resonator is an array of four individual rectangular cavities inserted in a strong dipole magnet, phase-matched to maximize the detection sensitivity. Here we report on the data acquired for 4124 h from 2019 to 2021. Each cavity is equipped with a fast frequency tuning mechanism of 10 MHz/ min between 4.774 GHz and 5.434 GHz. In the present work, we exclude axion-photon couplings for virialized galactic axions down to g_aγγ = 8 × 10⁻¹⁴ GeV⁻¹ at the 90% confidence level. The here implemented phase-matching technique also allows for future large-scale upgrades.

Haloscopes aim at detecting axions by converting them into photons using high-quality resonant cavities, where the cavity resonance should be tuned with the unknown axion mass. Here, the authors improve exclusion limits using four phase-matched resonant cavities and a fast frequency scanning technique.

Bias estimation in study design: a meta-epidemiological analysis of transcatheter versus surgical aortic valve replacement

BACKGROUND

Paucity of RCTs of non-drug technologies lead to widespread dependence on non-randomized studies. Relationship between nonrandomized study design attributes and biased estimates of treatment effects are poorly understood. Our purpose was to estimate the bias associated with specific nonrandomized study attributes among studies comparing transcatheter aortic valve implantation with surgical aortic valve replacement for the treatment of severe aortic stenosis.

RESULTS

We included 6 RCTs and 87 nonrandomized studies. Surgical risk scores were similar for comparison groups in RCTs, but were higher for patients having transcatheter aortic valve implantation in nonrandomized studies. Nonrandomized studies underestimated the benefit of transcatheter aortic valve implantation compared with RCTs. For example, nonrandomized studies without adjustment estimated a higher risk of postoperative mortality for transcatheter aortic valve implantation compared with surgical aortic valve replacement (OR 1.43 [95% CI 1.26 to 1.62]) than high quality RCTs (OR 0.78 [95% CI 0.54 to 1.11). Nonrandomized studies using propensity score matching (OR 1.13 [95% CI 0.85 to 1.52]) and regression modelling (OR 0.68 [95% CI 0.57 to 0.81]) to adjust results estimated treatment effects closer to high quality RCTs. Nonrandomized studies describing losses to follow-up estimated treatment effects that were significantly closer to high quality RCT than nonrandomized studies that did not.

CONCLUSION

Studies with different attributes produce different estimates of treatment effects. Study design attributes related to the completeness of follow-up may explain biased treatment estimates in nonrandomized studies, as in the case of aortic valve replacement where high-risk patients were preferentially selected for the newer (transcatheter) procedure.

Basic symptoms in young people at ultra-high risk of psychosis: Association with clinical characteristics and outcomes

There has been limited research into the predictive value of basic symptoms and their relationship with other psychopathology in patients identified using the 'ultra high risk' (UHR) for psychosis approach. The current study investigated whether basic symptoms, specifically cognitive disturbances (COGDIS), were associated with a greater risk of transition to psychotic disorder and persistent attenuated psychotic symptoms (APS) at medium term follow-up (mean = 3.4 years) in UHR patients, as well as with general psychopathology at baseline. The sample included 304 UHR participants (mean age = 19.12 years) involved in an international multicenter trial of omega-3 fatty acids. UHR individuals who also met the COGDIS criteria (basic symptoms risk criteria) did not have a greater risk of transition than those who met the UHR criteria alone. However, meeting COGDIS risk criteria was associated with a greater likelihood of meeting the UHR attenuated psychotic symptoms risk group (i.e., having persistent attenuated psychotic symptoms) at 12-month follow-up (odds ratio = 1.85; 95% CI = 1.03, 3.32). Greater severity of cognitive basic symptoms was also independently associated with more severe general psychopathology at study entry. The findings do not support the notion that combined risk identification approaches (UHR and basic symptoms) aid in the identification of individuals at greatest risk of psychosis, although this interpretation is limited by the modest transition to psychosis rate (13%) and the time of follow up. However, the findings indicate that basic symptoms may be a clinically useful marker of more severe general psychopathology in UHR groups and risk for persistent attenuated psychotic symptoms.

Observation of sub-Poissonian light in traveling-wave second-harmonic generation

We report the generation of sub-Poissonian pulses of light by means of traveling-wave second-harmonic generation (SHG) in a type II phase-matched nonlinear crystal. On direct detection, the quantum noise on the output light, which is polarized orthogonally to the input fundamental field, is measured to be below the shotnoise limit by as much as 0.3 +/- 0.2 dB (6 +/- 4%). We show that the input fundamental-power dependence of the measured Fano factor, direct-detection noise as a fraction of the shot-noise limit, is in qualitative agreement with the quantum theory of SHG.

Head-up tilt test with isoproterenol provocation in syncope of unknown origin

OBJECTIVES

Head-up tilt test (HUT) has been reported to be useful in the evaluation of syncope of unknown origin (SUO). However, the sensitivity of HUT with no pharmacologic provocation was relatively low and variable, ranging 32 approximately 70%. Therefore, several protocols of HUT with different degrees and durations of the tilt and modes of provocation were proposed. The purpose of this study was to determine the value of the multi-stage head-up tilt test with isoproterenol provocation (HUT-isp) in the evaluation of SUO and drug efficacy.

METHODS

Sixty-seven patients presenting with SUO and 30 control subjects with no history of syncope underwent the HUT-isp. Blood pressure (BP) was measured every 2 min and whenever the patient complained of any symptom, and cardiac rhythm was continuously monitored. The HUT-isp consisted of 3 stages: first for 20 min with no provocation, second and third stages with infusion of isoproterenol for 10 min each at a rate of 2 micrograms/min and 5 micrograms/min, respectively. A positive HUT-isp was defined when syncope or presyncope was reproduced, accompanied by hypotension (< 80 mmHg) or bradycardia (< 40/min) or both, and positive responses were classified into vasodepressive, cardioinhibitory and mixed type.

RESULTS

The HUT-isp was positive in 56 (83.6%) of 67 patients with SUO and 10 (33.3%) of 30 control subjects. The type of positive responses was vasodepressive in 41 (73.2%), cardioinhibitory in 4 (7.1%) and mixed in 11 (19.6%). The sensitivity of the HUT-isp in diagnosing vasovagal syncope was 83.6%, specificity 66.7% and positive predictive value 84.8%. Positive responses were developed most frequently in the 3rd stage: 76.8% in patients, 70% in controls. The effect of 3 drugs (carteolol, aminophylline and disopyramide) was evaluated in 27 patients with a repeat HUT-isp. Carteolol was effective in 12 (85.7%) of 14 patients, disopyramide in 7 (58. 3%) of 12 and aminophylline in 1 (14.3%) of 7. During the follow-up period of 175 +/- 212 days (26 approximately 623 days), none of the 20 patients with a negative repeat HUT-isp developed a recurrent syncope.

CONCLUSION

The HUT-isp is thought safe and useful to evaluate syncope of unknown origin and to guide effective drug therapy.

Ankle-arm blood pressure index as a predictor of mortality in hemodialysis patients

The ankle-arm blood pressure index (AAI, ratio of ankle to arm systolic blood pressure), a simple, noninvasive, and inexpensive screening test, has recently been found to be highly predictive of subsequent mortality in several populations. The purpose of this study was to evaluate the relationship of the AAI to cardiovascular and all-cause mortality in hemodialysis patients. A cohort of 132 patients was followed for 1 year. The primary outcome measures were cardiovascular and all-cause mortality. An AAI of <0.9 was associated with a relative risk (RR) of cardiovascular mortality of 7.5, (95% CI, 2.3 to 24.8). Other predictive variables included diabetes mellitus RR 3.0, (95% CI, 1.2 to 7.3), and a history of any vascular disease RR 2.6 (95% CI, 1.0 to 7.0). An AAI of <0.9 was also predictive of all-cause mortality, RR 2.4 (95% CI, 1.2 to 4.7). Other predictive variables for all-cause mortality included older age, RR 1.4 per 10 years (95% CI, 1.0 to 2.1), decreased serum albumin RR 0.9 per 0.1 mg/dL (95% CI, 0.8 to 1.0), and diabetes mellitus RR 2.0 (95% CI, 1.0 to 3.7). Multivariate analysis showed an AAI of <0.9 and diabetes mellitus to be the only independent predictors of cardiovascular mortality, and an AAI of <0.9, older age, and a decreased serum albumin were independent predictors of all-cause mortality. In conclusion, we have found an AAI of <0.9 to be a powerful, independent predictor of mortality in hemodialysis patients.

Ankle-arm blood pressure index as a marker for atherosclerotic vascular diseases in hemodialysis patients

The ankle to arm blood pressure index (AABI) has been recently found to be a strong predictor of cardiovascular and overall mortality in several populations. The test, which is a noninvasive marker for lower extremity vascular disease (when the index is < 0.9), is an office procedure that is simple to perform. The purpose of this study was to evaluate the AABI in hemodialysis patients. One hundred seventy-seven hemodialysis patients were studied, of which the AABI could be measured in 142. The AABI was then compared in patients with and without coronary artery disease, cerebrovascular disease, and peripheral vascular disease. In patients with or without coronary artery disease, the AABI was, respectively, 0.87 +/- 0.03 and 1.03 +/- 0.02 (P < 0.0001). For cerebrovascular disease, the mean AABI for patients with or without disease was, respectively, 0.82 +/- 0.04 and 1.00 +/- 0.02 (P < 0.0004). In patients with or without peripheral vascular disease, the mean AABI was, respectively, 0.75 +/- 0.04 and 1.02 +/- 0.02 (P < 0.0001). The mean AABI was 0.86 +/- 0.03 in patients with any of the three diseases compared with 1.07 +/- 0.02 in patients without any vascular disease (P < 0.0001). Thirty-eight percent of patients had an AABI of less than 0.9; 24% were less than 0.8 and 11% were less than 0.7.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of training and performance IQ on the psychomotor skill of Down syndrome persons

Training effects on the psychomotor performance of Down syndrome individuals were assessed. 32 boys and 25 girls (6 to 16 years old) were divided randomly into trained or untrained groups and into either severely or moderately mentally retarded using their WISC-R Performance IQs. Analysis showed that the group who had pretest training opportunities to manipulate experimental materials performed significantly better than those without that training while the moderately retarded children did significantly better than the severely retarded ones. It appears that the performance of persons with Down syndrome could be developed through training.