COVID-19 diagnosis by routine blood tests using machine learning

Physicians taking care of patients with coronavirus disease (COVID-19) have described different changes in routine blood parameters. However, these changes, hinder them from performing COVID-19 diagnosis. We constructed a machine learning predictive model for COVID-19 diagnosis. The model was based and cross-validated on the routine blood tests of 5,333 patients with various bacterial and viral infections, and 160 COVID-19-positive patients. We selected operational ROC point at a sensitivity of 81.9% and specificity of 97.9%. The cross-validated area under the curve (AUC) was 0.97. The five most useful routine blood parameters for COVID19 diagnosis according to the feature importance scoring of the XGBoost algorithm were MCHC, eosinophil count, albumin, INR, and prothrombin activity percentage. tSNE visualization showed that the blood parameters of the patients with severe COVID-19 course are more like the parameters of bacterial than viral infection. The reported diagnostic accuracy is at least comparable and probably complementary to RT-PCR and chest CT studies. Patients with fever, cough, myalgia, and other symptoms can now have initial routine blood tests assessed by our diagnostic tool. All patients with a positive COVID-19 prediction would then undergo standard RT-PCR studies to confirm the diagnosis. We believe that our results present a significant contribution to improvements in COVID-19 diagnosis.Comment: 11 pages, 4 figures, 2 table

CRITICAL ANALYSIS OF REFERRALS TO ELECTRODIAGNOSTIC EXAMINATION OF THE PERIPHERAL NERVOUS SYSTEM

Background. Clinical neurophysiologists observe a large number of examinees referred to a electromyographic (EMG) laboratory without clinical symptoms or signs of the peripheral nervous system lesion. Such referrals do not improve management of patients, but only unnecessarily burden examinees and laboratory personnel. The aim of the present study was to check appropriateness of referrals to electrodiagnostic examination, look for reasons for problems and suggest possible improvements.Methods. From the database of the Institute of Clinical Neurophysiology in Ljubljana all examinees evaluated by the author in a »general« EMG laboratory in the first 4 months of 2002 were included. From data about examinees, referral doctors, referral diagnoses, clinical symptoms and signs and electrophysiological findings, predictive values for neurological referral diagnoses and electrodiagnostic abnormalities were calculated using descriptive and multivariate statistical analyses.Results. Three hundred examinees (42% men) were included. Neurological diagnosis was provided in 55% of referrals. Electrodiagnostic abnormalities were found in 45% of examinees (carpal tunnel syndrome 50%, radiculopathy 25%, other mononeuropathies 15%, polineuropathy 9%). In 9% of examinees only clinical, and in 47% neither clinical nor electrodiagnostic abnormalities were demonstrated. Using a multivariate analysis positive effect of referral with neurological diagnosis, of paraesthesiae and findings of weakness and sensory loss, and negative effect of pain and referral diagnosis cervicobrachialgia or lumboischialgia on pathological electrodiagnostic findings were found. Isolated pain and paraesthesiae (with carpal tunnel syndrome excluded) were particularly poor predictors of abnormal electrodiagnostic findings (9% and 16%, respectively). With exception of 20 patients with carpal tunnel syndrome, none with normal clinical neurological examination had abnormal electrodiagnostic findings.Conclusions. Our study confirmed inappropriateness of electrodiagnostic examination as a screening tool for the peripheral nervous system lesions. Inappropriate referrals were due to poor evaluation of examinees before referral, and due to use of electrodiagnosis in screening of patients. We propose electrodiagnostic examination only of patients with unequivocal clinical signs of the peripheral nervous system lesion, and of patients with typical symptoms of the carpal tunnel syndrome. Referrals should include neurological diagnostic question and all relevant clinical data. This would reduce waiting time, save money, and improve evaluation of patients with peripheral nervous system lesions.</p

No Major Nerve Regeneration Seems to Occur during Recovery of Ulnar Neuropathy at the Elbow

Introduction: There are three main potential mechanisms of recovery after nerve lesion: (1) resolution of conduction block, (2) collateral reinnervation, and (3) nerve regeneration. Their relative contributions in recovery after focal neuropathies are not well established. Methods: In a group of previously reported prospective cohort of patients with ulnar neuropathy at the elbow (UNE), I performed a post-hoc analysis of their clinical and electrodiagnostic findings. I compared amplitudes of the compound muscle action potential (CMAP) and sensory nerve action potential (SNAP) on ulnar nerve stimulation, as well as qualitative concentric needle electromyography (EMG) findings in the abductor digiti minimi muscle on the initial and follow-up examinations several years later. Results: Altogether, 111 UNE patients (114 arms) were studied. During median follow-up period of 880 days (range: 385–1545 days), CMAP amplitude increased (p = 0.02), and conduction block in the elbow segment recovered (from median 17% to 7%; p p = 0.89). On needle EMG, spontaneous denervation activity diminished (p p p = 0.43). Conclusions: Findings of the present study indicate that nerve function in chronic focal compression/entrapment neuropathies seems to improve mainly due to the resolution of the conduction block and collateral reinnervation. Contribution of nerve regeneration seems to be minor; the majority of axons lost in chronic focal neuropathies probably never recover. Further studies using quantitative methods are needed to validate present findings

Cauda equina lesions as a complication of spinal surgery

Although the most common aetiology of cauda equina lesions is lumbar intervertebral disc herniation, iatrogenic lesions may also be the cause. The aim of this study was to identify and present patients in whom cauda equina lesions occurred after spinal surgery. From the author’s series of patients with cauda equina lesions, those with the appearance of sacral symptoms after spinal surgery were identified. To demonstrate lesions more objectively, electrodiagnostic studies were performed in addition to history and clinical examination. Imaging studies were also reviewed. Of 69 patients from the series, 11 patients in whom a cauda equina lesion developed after spinal surgery were identified. The aetiology comprised surgery for herniated intervertebral disc in 5 (4 performed by a single surgeon), spinal stenosis surgery in 4, and postoperative lumbar epidural haematoma in 2 patients (each performed by a different surgeon). Proportion of spinal surgeries with this complication varied from 0 to 6.6‰ in different centres. Patients with iatrogenic cauda equina lesion were significantly older (p < 0.001), and reported more severe urinary, but similar bowel and sexual symptoms compared to other patients in the series. In conclusion the study identified spinal surgery as the cause of approximately 15% of cauda equina lesions. More than a third of lesions developed after procedures performed by a single surgeon. Most of the remaining lesions could probably be avoided by better surgical technique (e.g. the use of a high-speed drill instead of a Kerrison rongeur in patients with severe spinal stenosis), or prevented by closer postoperative monitoring (e.g. in patients with postoperative lumbar epidural haematoma)

T1-nerve root neuroma presenting with apical mass and Horner's syndrome

<p>Abstract</p> <p>Background</p> <p>The appearance of dumbbell neuroma of the first thoracic root is extremely rare. The extradural component of a T1-dumbbell neuroma may present as an apical mass. The diagnosis of hand weakness is complex and may be delayed in T1-neuroma because of absence of the palpable cervical mass. One-stage removal of a T1-root neuroma and its intrathoracic extension demanded an extended posterior midline approach in the sitting position.</p> <p>Case presentation</p> <p>A 51-year old man had suffered a traumatic partial tendon rupture of his wrist flexor muscles 6 years ago. Since the incident he occasionally felt fullness and tenderness in the affected forearm with some tingling in his fingers bilaterally. During the last two years the hand weakness was continuous and hypotrophy of the medial flexor and intrinsic hand muscles had become apparent. Electrophysiological studies revealed an ulnar neuropathy in addition to mild median and radial nerve dysfunction, including a mild contralateral carpal tunnel syndrome. The diagnostic work-up for multiple mononeuropathy in the upper extremity was negative. Repeated electrophysiological studies revealed fibrillations in the C7 paravertebral muscles on the affected side. Chest x-ray revealed a large round apical mass on the affected side. A Horner's syndrome was noted at this point of diagnostic work-up. MRI of the cervical and thoracic spine revealed a dumbbell T1 neuroma enlarging the intervertebral foramen at T1-2 and a 5 cm large extradural tumor with extension into the apex of the ipsilateral lung. The patient underwent surgery in sitting position using a left dorsal midline approach. Although the T1 root could not be preserved, the patient's neurological condition was unchanged after the surgery.</p> <p>Conclusion</p> <p>Extended posterior midline exposure described here using hemilaminectomy, unilateral facetectomy and costo-transversectomy is efficient and safe for one-stage removal of dumbbell tumors at the T1 level with a predominantly extraforaminal component in the apex of the lung extending up to 6–7 cm laterally. Horner's syndrome, if present and observed, may significantly narrow the differential diagnosis of hand weakness caused by T1-root tumors.</p

Differentiating Viral and Bacterial Infections: A Machine Learning Model Based on Routine Blood Test Values

The growing threat of antibiotic resistance necessitates accurate differentiation between bacterial and viral infections for proper antibiotic administration. In this study, a Virus vs. Bacteria machine learning model was developed to discern between these infection types using 16 routine blood test results, C-reactive protein levels, biological sex, and age. With a dataset of 44,120 cases from a single medical center, the Virus vs. Bacteria model demonstrated remarkable accuracy of 82.2%, a Brier score of 0.129, and an area under the ROC curve of 0.91, surpassing the performance of traditional CRP decision rule models. The model demonstrates substantially improved accuracy within the CRP range of 10 40 mg/L, an interval in which CRP alone offers limited diagnostic value for distinguishing between bacterial and viral infections. These findings underscore the importance of considering multiple blood parameters for diagnostic decision-making and suggest that the Virus vs. Bacteria model could contribute to the creation of innovative diagnostic tools. Such tools would harness machine learning and relevant biomarkers to support enhanced clinical decision-making in managing infections

Expert consensus on the combined investigation of ulnar neuropathy at the elbow using electrodiagnostic tests and nerve ultrasound

The addition of ultrasound (US) to electrodiagnostic (EDX) tests can significantly enhance the accuracy of testing for ulnar neuropathy at the elbow (UNE). We aimed to obtain expert consensus to guide clinicians on the combined use of EDX and US in UNE investigation. Consensus was achieved using the Delphi method. Two consecutive anonymised questionnaires were submitted to 15 experts, who were asked to choose their level of agreement with each statement. Consensus was pre-defined as ≥ 80% rating agreement. The experts concluded that all investigations of UNE should include both nerve conduction studies and US. There was consensus that US should include cross-sectional area measurement and assessment of nerve mobility at the elbow, and that the entire ulnar nerve should be imaged. This study defined expert opinion on the ‘core’ techniques that should be used routinely in the UNE investigation using EDX and US. Areas with lack of consensus highlighted some controversial issues in the current use of these diagnostic modalities and the need for future research. This document is an initial step to guide clinicians on the combined investigation of UNE using EDX and US, to be regularly updated as new research emerges

Expert consensus on the combined investigation of carpal tunnel syndrome with electrodiagnostic tests and neuromuscular ultrasound

Expert consensus was sought to guide clinicians on the use of electrodiagnostic tests (EDX) and neuromuscular ultrasound (NMUS) in the investigation of suspected carpal tunnel syndrome (CTS).Consensus was achieved using the Delphi method via three consecutive anonymised surveys of 15 experts and was defined as rating agreement &gt;= 80%.The panel agreed that combining EDX and NMUS is more informative than using each modality alone. NMUS adds value in patients with clinically suspected CTS with non-localizing or normal EDX, atypical EDX, failed CTS surgery, polyneuropathy, and CTS suspected to be secondary to structural pathology. The median nerve cross-sectional area should be measured at the site of maximal nerve enlargement, and the nerve should be scanned from mid-forearm to the palm. The group also identified those situations where the wrist-to-forearm area ratio and longitudinal scans of the median nerve should also be obtained. EDX should always be performed to quantify CTS severity and in individuals over age 70.This document is an initial step to guide clinicians on the combined investigation of CTS using EDX and NMUS, to be updated regularly with the emergence of new research. (C) 2022 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved

Standards for quantification of EMG and neurography

\u3cp\u3eThis document is an update and extension of ICCN Standards published in 1999. It is the consensus of experts on the current status of EMG and Neurography methods. A panel of authors from different countries with different approach to routines in neurophysiological methods was chosen based on their particular interest and previous publications. Each member of the panel submitted a section on their particular area of interest and these submissions were circulated among the panel members for edits and comments. This process continued until a consensus was reached. The document covers EMG topics such as conventional EMG, Macro EMG, applications of surface EMG and electrical impedance myography. Single Fiber EMG is not included, since it is the topic in a separate IFCN document. A neurography section covers topics such as motor and sensory neurography, F wave recordings, H-reflex, short segment recordings, CMAP scan and motor unit number methods. Other sections cover repetitive nerve stimulation and Pediatric electrodiagnostic testing. Each method includes a description of methodologies, pitfalls, and the use of reference values. Clinical applications accompany some of these sections.\u3c/p\u3