scholarly journals Analysis of electrooculogram (EOG) signals in studying myasthenia gravis

2021 ◽  
Author(s):  
Timothy Liang
Keyword(s):  
Myasthenia Gravis ◽  
Time Domain ◽  
Early Stage ◽  
Screening Method ◽  
Neuromuscular Disorder ◽  
Severe Form ◽  
Linear Discriminant ◽  
Rise Rate ◽  
Common Precursor ◽  
Average Rise

Myasthenia Gravis (MG) is a neuromuscular disorder that induces muscle weakness and fatigue which can be fatal. A common precursor for severe form of MG is ocular MG. In this thesis, we explored signal processing methodologies for early stage detection of MG using electrooculogram (EOG) signals. An EOG signal database consisting of 62 control and 16 MG (mild to moderate) subjects were analyzed for eye movement characteristics and EOG signal morphologies using time domain and wavelet domain techniques. A linear discriminant analysis (LDA) based classifier was used to quantify the ability of features in separating MG from control samples. Average overall classification accuracy achieved by the proposed method for the best time domain feature (average rise rate) and best wavelet feature (scale band energy) was 82.5% (P<0.01, AUC=0.887) and 83.8% (P<0.01, AUC=0.893), respectively. The obtained results suggest EOG based analysis is a viable, non-invasive alternative MG screening method.

scholarly journals Analysis of electrooculogram (EOG) signals in studying myasthenia gravis

2021 ◽  
Author(s):  
Timothy Liang
Keyword(s):  
Myasthenia Gravis ◽  
Time Domain ◽  
Early Stage ◽  
Screening Method ◽  
Neuromuscular Disorder ◽  
Severe Form ◽  
Linear Discriminant ◽  
Rise Rate ◽  
Common Precursor ◽  
Average Rise

Myasthenia Gravis (MG) is a neuromuscular disorder that induces muscle weakness and fatigue which can be fatal. A common precursor for severe form of MG is ocular MG. In this thesis, we explored signal processing methodologies for early stage detection of MG using electrooculogram (EOG) signals. An EOG signal database consisting of 62 control and 16 MG (mild to moderate) subjects were analyzed for eye movement characteristics and EOG signal morphologies using time domain and wavelet domain techniques. A linear discriminant analysis (LDA) based classifier was used to quantify the ability of features in separating MG from control samples. Average overall classification accuracy achieved by the proposed method for the best time domain feature (average rise rate) and best wavelet feature (scale band energy) was 82.5% (P<0.01, AUC=0.887) and 83.8% (P<0.01, AUC=0.893), respectively. The obtained results suggest EOG based analysis is a viable, non-invasive alternative MG screening method.

The diagnosis and management of ocular myasthenia gravis

2019 ◽  
Vol 5 (1-2) ◽  
pp. 3-8
Author(s):  
Gordon Plant
Keyword(s):  
Myasthenia Gravis ◽  
Severe Form ◽  
Differential Diagnostics ◽  
Diagnosis And Management ◽  
Ocular Myasthenia ◽  
Clinical Presentations ◽  
Ocular Myasthenia Gravis

Ocular myasthenia is not the most severe form of myasthenia but it might cause certain difficulties to diagnose. In this article, we shall discuss the clinical presentations of ocular myasthenia, its differential diagnostics, examinations and management. Keywords: ocular myasthenia gravis, diagnosis, examination, management.

scholarly journals Research on the Time-Domain Dielectric Response of Multiple Impulse Voltage Aging Oil-Film Dielectrics

Energies ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1948
Author(s):  
Chenmeng Zhang ◽  
Kailin Zhao ◽  
Shijun Xie ◽  
Can Hu ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Time Domain ◽  
Dielectric Response ◽  
Early Stage ◽  
Debye Model ◽  
Polarization Current ◽  
Depolarization Current ◽  
Oil Film ◽  
Impulse Voltage ◽  
The Time Domain ◽  
Film Dielectric

Power capacitors suffer multiple impulse voltages during their lifetime. With the multiple impulse voltage aging, the internal insulation, oil-film dielectric may deteriorate and even fail in the early stage, which is called accumulative effect. Hence, the time-domain dielectric response of oil-film dielectric with multiple impulse voltage aging is studied in this paper. At first, the procedure of the preparation of the tested samples were introduced. Secondly, an aging platform, impulse voltage generator was built to test the accumulative effect of capacitor under multiple impulse voltage. Then, a device was used to test the time-domain dielectric response (polarization depolarization current, PDC) of oil-film dielectric in different aging states. And finally, according to the PDC data, extended Debye model and characteristic parameters were obtained by matrix pencil algorithm identification. The results indicated that with the increase of impulse voltage times, the time-domain dielectric response of oil-film dielectric changed accordingly. The polarization current curve moved up gradually, the insulation resistance decreased when subjected to the repeated impulses. In frequency domain, the frequency spectrum of tan δ changed along with the impulse accumulation aging, especially at low frequency. At last, combined with the aging mechanism of oil-film dielectric under multiple impulse voltage, the test results were discussed.

scholarly journals Effective Early Treatment of AChR Antibody-Positive Myasthenia Gravis with Rituximab; the Experience from a Neuroimmunology Clinic in a Developing Country

2021 ◽  
Vol 13 ◽  
pp. 117957352110160
Author(s):  
Thomas Mathew ◽  
Kurian Thomas ◽  
Saji K John ◽  
Shruthi Venkatesh ◽  
Raghunandan Nadig ◽  
...  
Keyword(s):  
Observational Study ◽  
Myasthenia Gravis ◽  
Treatment Option ◽  
Early Treatment ◽  
Early Stage ◽  
Tertiary Care ◽  
Response To Treatment ◽  
Myasthenic Crisis ◽  
Achr Antibody ◽  
Significant Difference

Background: Rituximab is reserved for treating refractory myasthenia gravis (MG) patients. Here we report our experience with rituximab in AChR antibody positive generalized MG (gMG) and impending myasthenic crisis (IMC). Methods: This retrospective, observational study, conducted at a tertiary care, neuroimmunology clinic, analyzed the data of patients with AChR antibody positive gMG, treated with rituximab between 1st January 2016 and 30th October 2018. Results: Eleven patients with AChR antibody positive gMG received rituximab. Mean age of the cohort was 50.54 ± 18.71 years with 9 males. Seven out of 11 patients received rituximab in the early stage (<2 years from onset) and had good response to treatment. Four of the 5 patients with IMC improved with rituximab alone. In the 10 patients who regularly followed up, there was a significant difference between the QMG scores at baseline and at 1, 2, 6, 12, and 18 months ( P < .0001). Conclusion: Rituximab appears to be a potentially effective early treatment option for AChR antibody positive generalized MG and impending myasthenic crisis.

Azathioprine-Induced Pancytopenia and Septic Complications: A Probable Cause of Death

2017 ◽  
Vol 31 (5) ◽  
pp. 510-513 ◽  
Author(s):  
Bijoy K. Panda ◽  
Siddhi Umarje ◽  
Arundhati Diwan
Keyword(s):  
Chronic Kidney Disease ◽  
Septic Shock ◽  
Myasthenia Gravis ◽  
Blood Count ◽  
Neuromuscular Disorder ◽  
Suspected Drug ◽  
Septic Complications ◽  
Clinical Investigations ◽  
Severe Pancytopenia ◽  
Relationship Of

Azathioprine, an immunosuppressant which is widely used in the management of the autoimmune neuromuscular disorder. Myasthenia gravis is known to cause myelotoxicity. A 55-year-old male recently diagnosed with myasthenia gravis and chronic kidney disease was put on azathioprine (100 mg/d) along with pyridostigmine and prednisolone. When the treatment was initiated, the hematological reports revealed normal levels of blood count. However, approximately within 3 weeks of continuing the prescribed drugs, the patient was readmitted for complaints of loose watery stools, weakness, and giddiness. Clinical investigations revealed severe pancytopenia, suspecting to be related to azathioprine. The suspected drug (azathioprine) was withdrawn, and the management for pancytopenia was initiated. However, on the second day of hospitalization, the patient underwent cardiac arrest and septic shock which lead to death. Adverse drug reaction assessment revealed a plausible and causal relationship of azathioprine with pancytopenia and other adverse effects seen in this patient.

scholarly journals Difficult Decisions in Minimally Invasive Surgery of the Thymus

Cancers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 5887
Author(s):  
Ankit Dhamija ◽  
Jahnavi Kakuturu ◽  
J. W. Awori Hayanga ◽  
Alper Toker
Keyword(s):  
Minimally Invasive Surgery ◽  
Minimally Invasive ◽  
Myasthenia Gravis ◽  
Invasive Surgery ◽  
Early Stage ◽  
Disease Process ◽  
Standard Of Care ◽  
Prognostic Importance

A minimally invasive resection of thymomas has been accepted as standard of care in the last decade for early stage thymomas. This is somewhat controversial in terms of higher-staged thymomas and myasthenia gravis patients due to the prognostic importance of complete resections and the indolent characteristics of the disease process. Despite concerted efforts to standardize minimally invasive approaches, there is still controversy as to the extent of excision, approach of surgery, and the platform utilized. In this article, we aim to provide our surgical perspective of thymic resection and a review of the existing literature.

scholarly journals Zytux in Refractory Myasthenia Gravis: A Multicenter, Open-Labeled, Clinical Trial Study of Effectiveness and Safety of a Rituximab Biosimilar

2021 ◽  
Vol 12 ◽  
Author(s):  
Farzad Fatehi ◽  
Kamyar Moradi ◽  
Ali Asghar Okhovat ◽  
Ghazaleh Shojatalab ◽  
Behnaz Sedighi ◽  
...  
Keyword(s):  
Quality Of Life ◽  
Clinical Trial ◽  
Myasthenia Gravis ◽  
Clinical Status ◽  
Neuromuscular Disorder ◽  
Clinical Trial Registration ◽  
Prednisolone Dose ◽  
Immune Mediated ◽  
Post Infusion

Objectives: Myasthenia gravis (MG) is an immune-mediated neuromuscular disorder responsive to immunomodulatory treatments. 10–20% of MGs are not responsive to conventional first-line therapies. Here, we sought to investigate the efficacy and safety of rituximab therapy in the treatment of patients with refractory MG.Methods: In a 48-week, multicenter, open-labeled, prospective cohort setting, 34 participants with refractory MG were assigned to receive infusions of Zytux, which is a rituximab biosimilar, according to a validated protocol. Clinical, functional, and quality of life (QoL) measurements were recorded at baseline, and seven further visits using the Myasthenia Gravis Foundation of America (MGFA), Myasthenia Gravis Composite (MGC), Myasthenia Gravis Activities of Daily Living profile (MG-ADL), and Myasthenia Gravis Quality of Life (MGQoL-15) scales. Besides, the post-infusion side effects were systematically assessed throughout the study.Results: The correlation analysis performed by generalized estimating equations analysis represented a significant reduction of MGC, MG-ADL, and MGQoL-15 scores across the trial period. The subgroup analysis based on the patients' clinical status indicated a significant effect for the interaction between time and MGFA subtypes on MG-ADL score, MGC score, and pyridostigmine prednisolone dose, reflecting that the worse clinical condition was associated with a better response to rituximab. Finally, no serious adverse event was documented.Conclusions: Rituximab therapy could improve clinical, functional, and QoL in patients with refractory MG in a safe setting. Further investigations with larger sample size and a more extended follow-up period are warranted to confirm this finding.Clinical Trial Registration: The study was registered by the Iranian Registry of Clinical Trials (IRCT) (Code No: IRCT20150303021315N18).

Advantages of Using a Time-Domain Approach for Dynamic Positioning (DP) Pipelay Studies

2014 ◽  
Author(s):  
Evren Armaoğlu ◽  
Paolo Monti
Keyword(s):  
Time Domain ◽  
Early Stage ◽  
Large Diameter ◽  
Weather Forecast ◽  
Dynamic Simulations ◽  
Power Generators ◽  
Fully Integrated ◽  
Critical Areas ◽  
Deep Waters ◽  
Slow Drift

Normally, the DP capability of a vessel is calculated through the use of static force equilibrium programs in which the dynamic effects are either not taken into account or taken into account by empirical load amplification factors. However, competitive and safe S-laying of large diameter pipelines in deep waters lead to large and long pipe lay vessels for which DP requirements are demanding. The power/propulsion requirement of the vessel needs to be considered from an early stage especially when accounting for the pipe laying equipment demands. This imposes a need for detailed dynamic analysis of the lay vessel. This analysis needs to include the slow drift oscillations counteracted by DP and the analysis in entirety needs to ensure the pipe string integrity is maintained. To this purpose Saipem developed in-house a time-domain simulator (FIPLA – Fully Integrated Pipe LAying) that employs all environmental forces (i.e. wind, wave, current) as well as the pipe tension on the vessel. It is used to assess the DP performances and laying capabilities of pipe lay vessels in harsh dynamic environments as well as critical areas for operations. The software can also be used to assess the performance of the vessel in case of failure of thrusters, power generators or bus bars, study DP Control System improvements, and assess the interaction between vessel, tensioner and pipe in deep and shallow waters. This paper focuses on the advantages of using dynamic simulations as an enhancement to the static DP capability charts, to produce detailed information for the DP Operator (DPO) in terms of setting of the DP parameters and to analyze critical laying events. This information can be used together with the weather forecast and can help getting the best performance out of the DP system in harsh environments, reducing downtime, improving operability and ensuring a safe operation.

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