16 results on '"Nguyen, Dang K."'
Search Results
2. Epileptic Prodromes: Insights from Surveying 196 Patients and 150 Caregivers
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Gagliano, Laura, Bou Assi, Elie, Herrera-Fortin, Tamara, Lesage, Frédéric, Sawan, Mohamad, and Nguyen, Dang K.
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ABSTRACT:Objective:Uncontrolled epilepsy creates a constant source of worry for patients and puts them at a high risk of injury. Identifying recurrent “premonitory” symptoms of seizures and using them to recalibrate seizure prediction algorithms may improve prediction performances. This study aimed to investigate patients’ ability to predict oncoming seizures based on preictal symptoms.Methods:Through an online survey, demographics and clinical characteristics (e.g., seizure frequency, epilepsy duration, and postictal symptom duration) were collected from people with epilepsy and caregivers across Canada. Respondents were asked to answer questions regarding their ability to predict seizures through warning symptoms. A total of 196 patients and 150 caregivers were included and were separated into three groups: those who reported warning symptoms within the 5 minutes preceding a seizure, prodromes (symptoms earlier than 5 minutes before seizure), and no warning symptoms.Results:Overall, 12.2% of patients and 12.0% of caregivers reported predictive prodromes ranging from 5 minutes to more than 24 hours before the seizures (median of 2 hours). The most common were dizziness/vertigo (28%), mood changes (26%), and cognitive changes (21%). Statistical testing showed that respondents who reported prodromes also reported significantly longer postictal recovery periods compared to those who did not report predictive prodromes (P< 0.05).Conclusion:Findings suggest that patients who present predictive seizure prodromes may be characterized by longer patient-reported postictal recovery periods. Studying the correlation between seizure severity and predictability and investigating the electrical activity underlying prodromes may improve our understanding of preictal mechanisms and ability to predict seizures.
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- 2023
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3. Recognition of Psychogenic Versus Epileptic Seizures Based on Videos
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Birca, Veronica, Keezer, Mark R., Chamelian, Laury, Lortie, Anne, and Nguyen, Dang K.
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ABSTRACTObjective:Ictal semiology interpretation for differentiating psychogenic nonepileptic seizures (PNESs) and epileptic seizures (ESs) is important for the institution of appropriate treatment. Our objective was to assess the ability of different health care professionals (HCPs) or students to distinguish PNES from ES based on video-recorded seizure semiology.Methods:This study was designed following the Standards for Reporting of Diagnostic Accuracy Studies (STARD) guidelines. We showed in a random mix 36 videos of PNES or ES (18 each) and asked 558 participants to classify each seizure. The diagnostic accuracy of various groups of HCPs or students for PNES versus ES was assessed, as well as the effect of patient age and sex. Measures of diagnostic accuracy included sensitivity, specificity, and area under the curve (AUC).Results:The descending order of diagnostic accuracy (AUC) was the following (p ≤ 0.001): (1) neurologists and epileptologists; (2) neurology residents; (3) other specialists and nurses with experience in epilepsy; and (4) undergraduate medical students. Although there was a strong trend toward statistical difference, with AUC 95% confidence intervals (CIs) that were not overlapping, between epileptologists (95% CI 93, 97) compared to neurologists (95% CI 88, 91), and neurologists compared to electroencephalography technicians (95% CI 82, 87), multiple pairwise comparisons with the conservative Tukey–Kramer honest significant difference test revealed no statistical difference (p = 0.25 and 0.1, respectively). Patient age and sex did not have an effect on diagnostic accuracy in neurology specialists.Conclusion:Visual recognition of PNES by HCPs or students varies overall proportionately with the level of expertise in the field of neurology/epilepsy.
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- 2022
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4. Neuroimaging of Epilepsy
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Lapalme-Remis, Samuel and Nguyen, Dang K.
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- 2022
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5. Chemical Constituents, Antioxidant, and Antimicrobial Activities of Ethyl Acetate Fractionated Extract from Rhizomes of Zingiber monophyllumGagnep.: In vitro and in silico Screenings
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Giang, Le D., Tran-Trung, Hieu, Thuy, Phan T., Thi Giang An, Nguyen, Nguyen-Ngoc, Hieu, Nguyen, Trang H.D., Nguyen, Dang K., Nguyen, Anh V., Chen, Tran V., Ha, Nguyen X., and Duc, Dau X.
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Objective/Background:Zingiber monophyllumGagnep., a member of the Zingiberaceae family, is known for its significant biological activities. The current study aimed to determine the volatile components of the ethyl acetate (EtOAc) fractionated extract found in the rhizomes of this species. This is the first report on the chemical composition and bioactivities of Z. monophyllumrhizomes fractionated extract. Methods:The chemical constituents were analyzed and determined using gas chromatography-mass spectrometry (GC-MS). Antioxidant activities were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and ferric reducing antioxidant power (FRAP) assays using ascorbic acid as a positive control. Antibacterial and antifungal properties of the EtOAc fractionated extract of Z. monophyllumrhizomes were assessed against Escherichia coli, Pseudomonas aeruginosa, Salmonella enterica, Enterococcus faecalis, Staphylococcus aureus, Bacillus cereus, and Candida albicans. Density functional theory (DFT) and molecular docking were also employed to illustrate antioxidant and antimicrobial activities. Results:Nine components were identified by GC-MS analysis from the EtOAc fractionated extract of Z. monophyllumrhizomes. (E)-labda-8(17),12-diene-15,16-dial (9), spathulenol (2), and neointermedeol (5) were the major components (21.8%, 16.8%, and 11.9%, respectively). Moderate antioxidant activities of the EtOAc fractionated extract were observed viaboth the DPPH assay and the FRAP assay using ascorbic acid as the standard compound. The extract demonstrated remarkable antimicrobial activity against all examined microbial strains, except for P. aeruginosa. The DFT study analyzed the antioxidant potential of each component in the fractionated extract. Molecular docking study chose E. faecalisDNA gyrase B, E. coliDNA gyrase B, S. aureusbiotin protein ligase, E. faecalisAlanine racemase, and C. albicansN-myristoyltransferase as potential target proteins for antimicrobial activity. Conclusion:In this study, the chemical composition of the EtOAc fractionated extract of Z monophyllumrhizomes was demonstrated through GC-MS analysis for the first time. Nine components, including alloaromadendrene, spathulenol, globulol, τ-cadinol, neointermedeol, aromadendrene oxide-(2), ambrial, (E)-15,16-dinorlabda-8(17),11-dien-13-one, and (E)-lambda-8 (17),12-diene-15,16-dial along with relative content were identified in this fractionated extract. The bioassays revealed that the fractionated extract showed moderate antioxidant activities and significant antimicrobial activities. The antioxidant and antimicrobial potential of each component was also theoretically examined by the DFT study and molecular docking study, respectively.
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- 2024
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6. Eslicarbazepine for focal epilepsy and acute intermittent porphyria∗
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Herrera‐Fortin, Tamara, Pana, Raluca, Wesolowska, Ewa, Bourré‐Tessier, Josiane, and Nguyen, Dang K.
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Porphyrias are rare genetic disorders which cause a deficiency in the enzymes involved in the biosynthesis of heme. The treatment of epilepsy in patients with acute intermittent porphyria can be difficult since many anticonvulsants can increase heme synthesis and trigger porphyric attacks. We report a patient with focal epilepsy successfully treated with eslicarbazepine without exacerbation of porphyria.
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- 2020
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7. Towards accurate prediction of epileptic seizures: A review.
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Bou Assi, Elie, Nguyen, Dang K., Rihana, Sandy, and Sawan, Mohamad
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EPILEPSY ,MATHEMATICAL optimization ,ALGORITHMS ,MACHINE learning ,ARTIFICIAL intelligence - Abstract
Recent research has investigated the possibility of predicting epileptic seizures. Intervention before the onset of seizure manifestations could be envisioned with accurate seizure forecasting. Although efforts for better prediction have been made, the translation of current approaches to clinical applications is still not possible. While early findings have been optimistic, the absence of statistical validation and reproducibility has raised doubts about the existence of a preictal state. Analysis and algorithmic studies are providing evidence that transition to the ictal state is not random, with build-up leading to seizures. We have reviewed the general framework of reliable algorithmic seizure prediction studies, discussing each component of the whole block diagram. We have explored steps along the pathway, from signal acquisition to adequate performance evaluation that should be taken into account in the design of an efficient seizure advisory/intervention system. The present review has established that there is potential for improvement and optimization in the seizure prediction framework. New databases, higher sampling frequencies, adequate preprocessing, electrode selection, and machine-learning considerations are all elements of the prediction scheme that should be assessed to achieve more realistic, better-than-chance performances. [ABSTRACT FROM AUTHOR]
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- 2017
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8. Comparison of source localization techniques in diffuse optical tomography for fNIRS application using a realistic head model
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Tremblay, Julie, Martínez-Montes, Eduardo, Vannasing, Phetsamone, Nguyen, Dang K., Sawan, Mohamad, Lepore, Franco, and Gallagher, Anne
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Functional near-infrared spectroscopy (fNIRS) is a non-invasive imaging technique that elicits growing interest for research and clinical applications. In the last decade, efforts have been made to develop a mathematical framework in order to image the effective sources of hemoglobin variations in brain tissues. Different approaches can be used to impose additional information or constraints when reconstructing the cerebral images of an ill-posed problem. The goal of this study is to compare the performance and limitations of several source localization techniques in the context of fNIRS tomography using individual anatomical magnetic resonance imaging (MRI) to model light propagation. The forward problem is solved using a Monte Carlo simulation of light propagation in the tissues. The inverse problem has been linearized using the Rytov approximation. Then, Tikhonov regularization applied to least squares, truncated singular value decomposition, back-projection, L1-norm regularization, minimum norm estimates, low resolution electromagnetic tomography and Bayesian model averaging techniques are compared using a receiver operating characteristic analysis, blurring and localization error measures. Using realistic simulations (n = 450) and data acquired from a human participant, this study depicts how these source localization techniques behave in a human head fNIRS tomography. When compared to other methods, Bayesian model averaging is proposed as a promising method in DOT and shows great potential to improve specificity, accuracy, as well as to reduce blurring and localization error even in presence of noise and deep sources. Classical reconstruction methods, such as regularized least squares, offer better sensitivity but higher blurring; while more novel L1-based method provides sparse solutions with small blurring and high specificity but lower sensitivity. The application of these methods is also demonstrated experimentally using visual fNIRS experiment with adult participant.
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- 2018
9. Effectiveness of transcranial magnetic stimulation for treatment-resistant depression at a Canadian tertiary referral hospital.
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Massé-Leblanc, Camille, Jodoin, Véronique Desbeaumes, Nguyen, Dang K., Lespérance, Paul, and Miron, Jean-Philippe
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- 2023
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10. Retrospective analysis of phone queries to an epilepsy clinic hotline.
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Laforme, Anny, Jubinville, Suzie, Gravel, Micheline, Cossette, Patrick, and Nguyen, Dang K.
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- 2014
11. The Hybrid Operculo-Insular Electrode.
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Bouthillier, Alain, Surbeck, Werner, Weil, Alexander G., Tayah, Tania, and Nguyen, Dang K.
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- 2012
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12. An Implantable Seizure-Onset Detector Based on a Dual-Path Single-Window Count-Based Technique for Closed-Loop Applications
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Safi-Harb, Mona, Salam, Muhammad Tariqus, Nguyen, Dang K., and Sawan, Mohamad
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- 2011
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13. Near‐infrared spectroscopy as an alternative to the Wada test for language mapping in children, adults and special populations
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Gallagher, Anne, Thériault, Martin, Maclin, Ed, Low, Kathy, Gratton, Gabriele, Fabiani, Monica, Gagnon, Louise, Valois, Katja, Rouleau, Isabelle, Sauerwein, Hannelore C., Carmant, Lionel, Nguyen, Dang K., Lortie, Anne, Lepore, Franco, Béland, Renée, and Lassonde, Maryse
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The intracarotid amobarbital test (IAT) is the most widely used procedure for pre‐surgical evaluation of language lateralization in epileptic patients. However, apart from being invasive, this technique is not applicable in young children or patients who present mental retardation and/or language deficits. Functional magnetic resonance imaging (fMRI) is increasingly employed as a non‐invasive alternative. Again, this method is more difficult to use with young children, especially hyperactive ones, since they have to remain motionless during data acquisition. The aim of this study was to determine whether near‐infrared spectroscopy (NIRS) can be used as an alternative technique to investigate language lateralization in children and special populations. Unlike Wada test, NIRS is non‐invasive, and it is more tolerant to movement artefacts than fMRI. In the present study, NIRS data were acquired in four epileptic children, a 12‐year‐old boy with pervasive developmental disorder and a 3‐year‐old, healthy child, as well as three healthy and two epileptic adults, while they performed a verbal fluency task and a control task. When applicable, the results were compared to the subjects' fMRI and/or IAT findings. Clear laterality of speech was obtained in all participants, including the two non‐epileptic children, and NIRS results matched fMRI and IAT findings. These results, if replicable in larger samples, are encouraging and suggest that NIRS has the potential to become a viable, non‐invasive alternative to IAT and fMRI in the determination of speech lateralization in children and clinical populations that cannot be submitted to more invasive techniques.
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- 2007
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14. Generalized Epilepsy and Classic Spike-Wave Discharges With Unilateral Thalamic Lesions
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Nguyen, Dang K., Podubnaia, Ala B., Carmant, Lionel, Guilbert, François, and Cossette, Patrick
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BACKGROUND Idiopathic generalized epilepsy (IGE) is a heterogeneous condition with a predominantly genetic origin. Clinical hallmarks of IGE syndromes include generalized spike and wave discharges and normal results on brain imaging. OBJECTIVE To describe 2 patients with clinical presentations compatible with IGE but whose imaging studies revealed unilateral thalamic lesions. DESIGN Case reports. SETTING University-affiliated hospitals. PATIENTS Two 21-year-old patients (1 man and 1 woman). MAIN OUTCOME MEASURES Magnetic resonance imaging findings. RESULTS Magnetic resonance imaging unexpectedly revealed unilateral thalamic lesions. CONCLUSIONS We recommend doing magnetic resonance imaging studies in patients with IGE, especially in refractory or atypical cases. In rare cases, clinical features compatible with IGE may be associated with structural thalamic or other lesions.Arch Neurol. 2006;63:1321-1323--
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- 2006
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15. Multimodal imaging platform for surgical guidance during epilepsy surgery
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Dehghani, Hamid, Wabnitz, Heidrun, Laurence, Audrey, Beaulieu, Emile, Nguyen, Dang K., Bouthillier, Alain, Trudel, Dominique, and Leblond, Frederic
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- 2019
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16. Prophylactic anticonvulsants for gliomas: a seven-year retrospective analysis
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Lapointe, Sarah, Florescu, Marie, Nguyen, Dang K., Djeffal, Chanez, and Bélanger, Karl
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Background The American Academy of Neurology (AAN) does not recommend routine use of prophylactic antiepileptic drugs (pAEDs) in patients with newly diagnosed brain tumors. If used in the perioperative setting, discontinuation is suggested after the first postoperative week. It is unclear whether such recommendations are followed. Our objective was to compare our perioperative and long-term pAED use in glioma patients with AAN practice parameters.Methods Retrospective chart review was performed on 578 glioma patients from 2006 to 2013. Seizures and AED use were assessed at surgery, 3 months postoperatively and death, last visit or 16 months postoperatively. Patients were divided into three groups at surgery: seizure-free with pAED, seizure-free without pAED, and seizure patients. Long-term pAED use was defined as continued use at 3 months postsurgery without seizures. pAEDs efficacy, factors influencing its use, and survival were examined.Results Out of 578 patients identified, 330 (57.1%) were seizure-nai&x0308;ve preoperatively. There were no significant differences in age, histology, tumor location or resection status between seizure-free populations with and without prophylaxis. Of 330 seizure-nai&x0308;ve patients, 205 (62.1%) received pAEDs at surgery. Ninety-six (46.9%) of those patients were still on pAEDs 3 months postsurgery (median use = 58 days). Rate of long-term prophylaxis use decreased by 13.5% over 6 years (70.3% in 2006; 56.8% in 2012). Phenytoin was preferred in 2006 (98.2%) with increasing use of levetiracetam over 6 years (44.6% in 2012). The only predictive factor for pAED use was complete resection (P = .0069). First seizure prevalence was similar in both seizure-free populations (P = .91). The seizure population had more men (P = .007), younger patients (P < .0001), lower-grade gliomas (P = .0003) and survived longer (P = .001) compared with seizure-free populations.Conclusions In our center, long-term prophylactic AED use is high, deviating from current AAN Guidelines. Corrective measures are warranted.- Published
- 2015
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