Source Analysis of Triphasic Waves Using Quantitative Neuroimaging Alex Tiburtino Meira, Karen Fernanda Alves, Thais O. P. Rezende, Arthur Oscar Schelp, Luiz Eduardo Betting Journal of Clinical Neurophysiology, 2022 Purpose: Triphasic waves (TWs), a common EEG pattern, are considered a subtype of generalized periodic discharges. Most patients with TWs present with an altered level of consciousness, and the TW pattern is believed to represent thalamocortical dysfunction. However, the exact meaning and mechanism of TWs remain unclear. The objective of the current study was to evaluate the source of TWs using EEG source imaging and computerized tomography. Methods: Twenty-eight patients with TWs were investigated. Source analysis was performed on the averaged TWs for each individual, and source maps were extracted. Normalization and automatic segmentation of gray matter were performed on computerized tomography scans before analysis. Finally, voxelwise correlation analyses were conducted between EEG source maps and gray matter volumes. Results: Source analyses showed that the anterior cingulate cortex was mainly involved in TWs (16/28 patients, 57%). Correlation analyses showed moderate positive and negative correlations between source location and gray matter volumes for the posterior cingulate (T = 2.85; volume = 6,533 mm3; r = 0.53; P = 0.002) and the superior frontal gyrus (T = 2.54; volume = 18,167 mm3; r = −0.48; P < 0.0001), respectively. Conclusions: The results suggest that the anterior cingulate is involved in the origin of TWs. Furthermore, the volumes of posterior brain regions were positively correlated with TWs, indicating a possible preservation of these structures. Conversely, the volumes of anterior regions were negatively correlated with TWs. These findings may indicate a structural pattern necessary for the generation of the abnormal network responsible for TWs.
Aging-related episodic-like memory decline in dogs Felipe Jacques Sanches, Jéssica Cardia de Melo, Sabrina Palha Ferreira, Luzia Aparecida Trinca, Omar Gurrola Arambula, et al. Behavioural Brain Research, 2022
Screen-Printed Electrodes on Tyvek Substrate as Low-Cost Device to Applications in Alzheimer's Disease Detection Bianca Fortes Palley, Julio Cesar Artur, Milena Nakagawa de Arruda, Gustavo Freitas de Souza, David Alexandro Graves, et al. Journal of the Electrochemical Society, 2022 Alzheimer’s disease (AD) is a progressive neurodegenerative disease characterized by impairment of cognitive functions and memory deterioration, which requires an early diagnosis for effective treatment. The use of immunosensors to detect Alzheimer’s disease biomarkers stand out as a quick and cheap alternative for early detection of the disease. The development of Screen-Printed Electrodes (SPEs) meets a growing demand in the market for applications such as signal transducers in biosensor devices. In this work was development a method for fabrication of low cost SPE for application in the detection of Alzheimer’s disease through autoantibodies. It was produced microelectrodes on polyvinyl chloride (PVC), polyvinylidene fluoride (PVDF) and high-density polyethylene (HDPE) manufactured by DuPont Tyvek® substrates. SPEs produced on Tyvek ® substrates have shown promising results for low-cost, disposable and flexible sensors. The carbon paste showed excellent adhesion to Tyvek ® substrate and the electrodes produced showed an electrochemical performance comparable to commercial electrodes, besides reproducible. The detection results showed that it is possible to detect anti-A β 40 autoantibodies in real samples of serum and cerebrospinal fluid using the electrode modified with two bilayers of (PEI/(DDPG + A β 40)) since the capacitance increased more in positive sample with the presence of autoantibody than in negative samples.
Applicability of tactile memory examination as an option to visual-and verbal-based batteries Omar Gurrola Arambula, Flavia Helena Pereira Padovani, Jose Eduardo Corrente, Andreas Batista Schelp, Felipe Jacques Sanches, et al. Dementia E Neuropsychologia, 2021 The validity and applicability of tactile battery tests for the diagnosis and medical follow-up of patients with Alzheimer’s disease and other dementia syndromes do not have their usefulness well understood in clinical practice. While haptic abilities in older individuals receive less attention, in earlier stages of human life they are well focused on. There are even fewer studies on tactile memory, including episodic memory of demented individuals with or without sensorial limitations. The applicability of a new haptic memory battery was evaluated in patients with Alzheimer’s disease with mild or moderate commitment. Objective: The aim of this study is to apply a battery based on tactile perception, recognition, and recollection of everyday objects in patients with Alzheimer’s disease, testing tactile delayed recall memory discrimination and late recognition to compare validated visual and verbal tests. Methods: Tactile-, visual-, and verbal-based memory performance was registered in 21 patients diagnosed with Alzheimer’s disease. Results: Except for tactile identification, it showed that there was a close relationship between the three sensory modalities of memory, with an apparent better performance of tactile incidental memory and recognition compared with the test with pictures. Conclusions: The haptic evaluation of memory demonstrated applicability in the evaluation of memory dysfunction in patients with Alzheimer’s disease. Further studies are needed to establish the sensibility and specificity of the proposed test that had a small sample size and many limitations.
Stroke Chameleons Manifesting as Distinct Radial Neuropathies: Expertise Can Hasten the Diagnosis Fabrício Diniz de Lima, Gustavo José Luvizutto, Arthur Oscar Schelp, Gabriel Pereira Braga, Rodrigo Bazan Case Reports in Neurology, 2017 <b><i>Objective:</i></b> Stroke chameleons encompass an atypical group of syndromes that do not initially appear to be cerebrovascular accidents. The objective of this study was to report patients with different lesions of central origin clinically presenting as wrist drop and with a semiology similar to that produced by peripheral lesions of the radial nerve at different topographical levels. <b><i>Methods:</i></b> This is a case series study of patients presenting with wrist drop during the acute phase of stroke who were assessed by clinical examination and CT and MRI brain scans. <b><i>Results:</i></b> Three cases presenting as monoparesis were evaluated. In all patients, the MRI revealed restricted diffusion in the pre- and post-central gyrus. Electromyography showed that the functionality of the radial, median, and ulnar nerves were intact in all three cases. The monoparesis resolved completely within 1 month of rehabilitation therapy, and no evidence of recurrent or new events was reported during the 6-month follow-up after stenting. <b><i>Conclusion:</i></b> The central message of this study is that when acute onset symptoms are present in a relatively old patient with vascular risk factors, stroke should be considered as the possible aetiology until proven otherwise, and the appropriate steps should be taken to avoid a delay in the treatment and to improve outcomes.
Delayed recall memory impairment in patients with Parkinson’s disease Arthur Oscar Schelp, Cristiane Lara Mendes-Chiloff, Vanessa Cristina Paduan, José Eduardo Corrente, Fabrício Diniz de Lima, et al. Dementia E Neuropsychologia, 2016 Age is one of the risk factors for dementia in patients with Parkinson's disease (PDD). Distinct cognitive syndromes of Parkinson's disease (PD) have been identified in previous studies. Questions about the role of such cognitive disorders in PD outcomes, especially memory dysfunction, in patients with PD remain unanswered. Objective: To establish possible correlations between delayed recall memory (episodic memory), age, and other demographic variables in patients with PD. Methods: A two-stage protocol was applied. Patients with delayed recall memory compromise, selected based on a brief battery of tests (BBRC-Edu), were classified as dementia cases and submitted to the Mattis Dementia Rating Scale (MDRS). Data from patients with memory disturbances were compared against individuals without episodic memory impairment, and correlated with age and demographic variables. Results: Except for identification and naming, all subtests in the screening battery showed a significant difference (p≤0.0001) between the memory-compromised group (case) and the group without memory impairment (no case). The results also correlated negatively with age (p≤0.0001) and positively with level of education (p=0.0874) in patients with PD. Conclusion: The analysis showed a significant relationship between age and dementia characterized by impaired episodic memory. The findings support reports of a wide spectrum of neuropsychological performance impairment in PD with age, particularly dementia associated with memory deterioration. No correlations between disease duration and cognitive dysfunction were evident.
Swallowing quantitative analysis software André Augusto Spadotto, Ana Rita Gatto, Paula Cristina Cola, Arlindo Neto Montagnoli, Arthur Oscar Schelp, et al. Radiologia Brasileira, 2008
Comparison of the effects of barbiturate, benzodiazepine and ketamine on visual evoked potentials in rabbits Electromyography and Clinical Neurophysiology, 2005
Evoked potentials in neurocysticercosis Luiz Antonio de Lima Resende, Svetlana Agapejev, Renata Rodrigues, Arthur Oscar Schelp Arquivos De Neuro Psiquiatria, 1997
Failure of hypertonic glucose supplementation to improve whole-body protein metabolism in fed trauma patients FASEB Journal, 1996
