85 research outputs found
Quantitative EEG and neuromodulation for the treatment of central neuropathic pain in paraplegic patients
Approximately, 2/3 of patients with a spinal cord injury (SCI) suffer from chronic pain, leading to a reduction in quality of life. The prevalence of chronic central neuropathic pain (CNP) in the SCI population is 40%. Recent neuroimaging studies provided evidence that CNP is accompanied by modified brain activity at surface and deep cortical levels and that CNP is resistant to different pharmacological and non-pharmacological treatments.
Our current knowledge on how CNP affects the brain activity of SCI patients is mainly based on fMRI studies. Although these studies provide precise spatial localisation of brain regions most affected by CNP, they indirectly measure brain activity through measuring blood oxygenation. Therefore they lack information specific to neuronal activity such as dynamic, time and frequency dependant oscillatory activity of cortical structures. Therefore, in Phase 1 of this study, electroencephalogram (EEG) activity of paraplegic patients with CNP (PWP) is compared with the EEG activity of able-bodied (AB) participants and paraplegic patients without CNP (PNP). It was found that CNP leads to frequency dependant EEG signatures both in the relaxed state and during motor tasks that are not restricted to the cortical representation of the body part perceived as being painful.
The pharmacological treatment of CNP has a number of side effects and does not provide significant pain relief. The effect of non-pharmacological treatments is inconsistent. Neurofedback (NF) is a non-pharmacological treatment, based on the voluntarily modulation of brain activity to control pain intensity. Using NF training the patient can learn and apply a mental strategy to control pain, without the need for an external device. However, NF requires a large number of training sessions to learn the necessary mental strategy. Therefore, in Phase 2 of this study, the effect on pain intensity of a large number of NF sessions, using different NF training protocols, was assessed. The clinically and statistically significant reduction of pain observed in this study demonstrates that NF training has the potential to manage chronic CNP in paraplegic patients. This study also provides evidence that the reduction of pain achieved using NF training may not be due to a placebo effect. Furthermore, the study demonstrates the immediate global effect of NF training on power and coherence.
To date, no neuroimaging studies that have applied NF training with patients with CNP have shown changes in brain activity before the first and after the last training session. Therefore, in phase 3 of this study, the long-term neurological effect of NF training was assessed using EEG. This study provides evidence that NF training does not only induce an effect on spontaneous EEG activity, but also induces changes on evoked EEG activity.
In conclusion, this study compared the EEG activity of three groups (AB, PWP, and PNP) and found that CNP (PWP group) leads to frequency dependant dynamic oscillatory signatures. The study also reported that NF training has a potential to reduce pain and this reduction of pain might not be an effect of placebo. Furthermore, it was found that NF training induce long-term changes in the EEG activity recorded in relaxed state and during motor tasks. This long-term change in EEG activity was noticed at the surface and deep cortical structures
Central neuropathic pain in paraplegia alters movement related potentials
Objectives:
Spinal Cord Injured (SCI) persons with and without Central Neuropathic Pain (CNP) show different oscillatory brain activities during imagination of movement. This study investigates whether they also show differences in movement related cortical potentials (MRCP).
Methods:
SCI paraplegic patients with no CNP (n = 8), with CNP in their lower limbs (n = 8), and healthy control subjects (n = 10) took part in the study. EEG clustering involved independent component analysis, equivalent current dipole fitting, and Measure Projection to define cortical domains that have functional modularity during the motor imagery task.
Results:
Three domains were identified: limbic system, sensory-motor cortex and visual cortex. The MRCP difference between the groups of SCI with and without CNP was reflected in a domain located in the limbic system, while the difference between SCI patients and control subjects was in the sensorimotor domain. Differences in MRCP morphology between patients and healthy controls were visible for both paralysed and non paralysed limbs.
Conclusion:
SCI but not CNP affects the movement preparation, and both SCI and CNP affect sensory processes.
Significance:
Rehabilitation strategies of SCI patients based on MRCP should take into account the presence of CNP
Reversed cortical over-activity during movement imagination following neurofeedback treatment for central neuropathic pain
Objective:
One of the brain signatures of the central neuropathic pain (CNP) is the theta band over-activity of wider cortical structures, during imagination of movement. The objective of the study was to investigate whether this over-activity is reversible following the neurofeedback treatment of CNP.
Methods:
Five paraplegic patients with pain in their legs underwent from twenty to forty neurofeedback sessions that significantly reduced their pain. In order to assess their dynamic cortical activity they were asked to imagine movements of all limbs a week before the first and a week after the last neurofeedback session. Using time–frequency analysis we compared EEG activity during imagination of movement before and after the therapy and further compared it with EEG signals of ten paraplegic patients with no pain and a control group of ten able-bodied people.
Results:
Neurofeedback treatment resulted in reduced CNP and a wide spread reduction of cortical activity during imagination of movement. The reduction was significant in the alpha and beta band but was largest in the theta band. As a result cortical activity became similar to the activity of other two groups with no pain.
Conclusions:
Reduction of CNP is accompanied by reduced cortical over-activity during movement imagination.
Significance:
Understanding causes and consequences mechanism through which CNP affects cortical activity
Temperature effect and battery charging characteristics analysis based on charging C-rate
Developing fast charging proprieties for LiFePo4 battery is a key issue for a wider deployment of EV. The main drawback of LiFePo4 battery charging is overcharge, overcurrent and high temperature which affects longevity, efficiency, and battery life cycle. In this research, lithium iron phosphate (LiFePo4) battery is investigated for fast, and rapid charging with CC-CV principle. MATLAB/Simulink based custom-designed tool was developed. A dynamic model of lithium-ion phosphate battery is proposed in this research by considering the significant temperature and capacity fading effects. Results have shown that the LiFePo4 battery can be used for fast charging up to 100% and rapid charging up to 85% by maintaining the condition for lifespan of the battery and to shorten the charging time. The simulation results have been showed that, the constructed model can really represent the dynamic performance feature of the lithium-ion battery. The modified model can assess the efficiency of battery execution based on charging C-rate conditions. © BEIESP
Frequency of different groove patterns seen on the occlusal surface of mandibular second premolars
Background: The Mandibular second premolar has commonly three different type traits depending on the occlusal groove patterns. In addition to that they are also recognized on the basis of number of cusps. The objectives of the study were to determine the frequency of different occlusal groove patterns of mandibular second premolars and to acquire base line data for future studies in this population and field of research.Material and Methods: This study was conducted in Islamabad Dental Hospital (IDH), from September 2017 to December 2017. A total of 600 patients (1200 teeth) with fully erupted mandibular second premolars of normal occlusal morphology, in age group of 15 years and above were screened in the Out Patient Department (OPD). Groove patterns on occlusal surfaces and their anatomical variations on both sides i.e. right and left, were observed and noted in a proforma. Data was analyzed using SPSS version 22.Results: Three different patterns of occlusal grooves (Y, U and H) were found in our study population. Y groove pattern was observed in 364 teeth (30.33%), U pattern in 447 teeth (37.25%) and H pattern was noted in 389 (32.41%) teeth. Among males, U pattern was predominant (43.84%) followed by H and then Y pattern. In females, H pattern grooves was found mostly (34.41%), followed by Y and U pattern.Conclusion: The most frequent occlusal groove pattern observed in our population was U followed by H and Y type
MEDIC: A Multi-Task Learning Dataset for Disaster Image Classification
Recent research in disaster informatics demonstrates a practical and
important use case of artificial intelligence to save human lives and suffering
during natural disasters based on social media contents (text and images).
While notable progress has been made using texts, research on exploiting the
images remains relatively under-explored. To advance image-based approaches, we
propose MEDIC (Available at: https://crisisnlp.qcri.org/medic/index.html),
which is the largest social media image classification dataset for humanitarian
response consisting of 71,198 images to address four different tasks in a
multi-task learning setup. This is the first dataset of its kind: social media
images, disaster response, and multi-task learning research. An important
property of this dataset is its high potential to facilitate research on
multi-task learning, which recently receives much interest from the machine
learning community and has shown remarkable results in terms of memory,
inference speed, performance, and generalization capability. Therefore, the
proposed dataset is an important resource for advancing image-based disaster
management and multi-task machine learning research. We experiment with
different deep learning architectures and report promising results, which are
above the majority baselines for all tasks. Along with the dataset, we also
release all relevant scripts (https://github.com/firojalam/medic).Comment: Multi-task Learning, Social media images, Image Classification,
Natural disasters, Crisis Informatics, Deep learning, Datase
Interleukin-1 receptor antagonist attenuates the severity of spinal cord ischemic injury in rabbits
ObjectiveThoracic and thoracoabdominal aortic surgery is sometimes complicated by subacute or delayed paraplegia. Pro-inflammatory cytokine interleukin-1 (IL-1) β has been implicated in extensive inflammation and progressive neurodegeneration after ischemia. Using a rabbit model, we investigated the neuroprotective effects of IL-1 receptor antagonist (IL-1ra) in a temporal fashion.MethodsSpinal cord ischemia was induced by aortic cross-clamping in New Zealand White rabbits. The animals were assigned to three groups. Group C (n = 20) received saline (0.2-mL) and Group I (n = 20) received IL-1ra (200-μg/0.2-mL) intrathecally just after reperfusion. Group S (n = 3) underwent sham operation without aortic occlusion. We assessed the neuroprotective effects of IL-1ra by evaluating neurological function, histopathological changes, and in-situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL staining). We also measured the levels of Nitric Oxide (NO) and S100β in cerebrospinal fluid (CSF). Each evaluation was performed sequentially within 120 hours after reperfusion.ResultsGroup C showed progressive deterioration of motor function which became statistically significant from 48 hours after the onset of reperfusion (P < .05, P < .01, P < .001, P < .001 at 48, 72, 96, and 120 hours, respectively). Compared to Group C, a higher number of viable neurons was observed with less severe spinal cord injury in Group I (P < .01, .05 and .05 at 24, 72, and 120 hours, respectively). TUNEL-positive neurons were also significantly reduced by the administration of IL-1ra (P <.01 and .05 at 24, and 120 hours, respectively). The difference between Group C and Group I with regard to NO was significant at 72 and 120 hours (P < .05), while that in terms of S100β was significant only at 24 hours (P < .05).ConclusionsAdministration of IL-1ra attenuates spinal cord ischemic-reperfusion injury as evidenced by reducing both neuronal necrosis and apoptosis.Clinical RelevanceThe present study explores the possibility of reducing subacute or delayed paraplegia after thoracoabdominal aortic surgery using a pharmacological agent that is already available for clinical use. IL-1 mediated inflammatory reaction after ischemic insult can be thought as one of the mechanisms responsible for delayed infarct expansion leading to subacute or delayed paraplegia. IL-1ra has known anti-inflammatory properties and was therefore expected to suppress such post-ischemic inflammatory reaction, if given at an appropriate time. The results of the present study indicate that IL-1-targetted anti-cytokine therapy can be a potentially useful strategy for the attenuation of neurological injury after spinal cord ischemia
Analysis on Preparation, Application, and Recycling of Activated Carbon to Aid in COVID-19 Protection
Activated carbon (AC) is an extremely porous carbonaceous adsorptive substance which has a rigid carbon matrix with high surface area and broad functional groups. The structure is connected by chemical bonds; arranged irregularly, generating a highly porous arrangement of corners, crevices, claps, and cracks between the carbon layers. Activated carbons are produced high-temperature and chemical activation of waste biomass. The pores in the lattice network of activated carbon permit the removal of impurities from gaseous and liquid medium through adsorption. At present, the COVID-19 disease is the prime concern around the whole world because of its exponential infections and death rate. There is no medicine for this virus, and protection is the only remedy to survive from this contagious disease. Using a face mask is one of the best methods to get rid of COVID-19. The mask combined with activated carbon can be beneficial for adsorbing and disinfecting the virus as it is the versatile adsorbent for the elimination of the organic, inorganic, and pathogenic contaminants
Comparative Neurological and Behavioral Assessment of Central and Peripheral Stimulation Technologies for Induced Pain and Cognitive Tasks
Pain is a multifaceted, multisystem disorder that adversely affects neuro-psychological processes. This study compares the effectiveness of central stimulation (transcranial direct current stimulation—tDCS over F3/F4) and peripheral stimulation (transcutaneous electrical nerve stimulation—TENS over the median nerve) in pain inhibition during a cognitive task in healthy volunteers and to observe potential neuro-cognitive improvements. Eighty healthy participants underwent a comprehensive experimental protocol, including cognitive assessments, the Cold Pressor Test (CPT) for pain induction, and tDCS/TENS administration. EEG recordings were conducted pre- and post-intervention across all conditions. The protocol for this study was categorized into four groups: G1 (control), G2 (TENS), G3 (anodal-tDCS), and G4 (cathodal-tDCS). Paired t-tests (p < 0.05) were conducted to compare Pre-Stage, Post-Stage, and neuromodulation conditions, with t-values providing insights into effect magnitudes. The result showed a reduction in pain intensity with TENS (p = 0.002, t-value = −5.34) and cathodal-tDCS (p = 0.023, t-value = −5.08) and increased pain tolerance with TENS (p = 0.009, t-value = 4.98) and cathodal-tDCS (p = 0.001, t-value = 5.78). Anodal-tDCS (p = 0.041, t-value = 4.86) improved cognitive performance. The EEG analysis revealed distinct neural oscillatory patterns across the groups. Specifically, G2 and G4 showed delta-power reductions, while G3 observed an increase. Moreover, G2 exhibited increased theta-power in the occipital region during CPT and Post-Stages. In the alpha-band, G2, G3, and G4 had reductions Post-Stage, while G1 and G3 increased. Additionally, beta-power increased in the frontal region for G2 and G3, contrasting with a reduction in G4. Furthermore, gamma-power globally increased during CPT1, with G1, G2, and G3 showing reductions Post-Stage, while G4 displayed a global decrease. The findings confirm the efficacy of TENS and tDCS as possible non-drug therapeutic alternatives for cognition with alleviation from pain
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