REVIEW | doi:10.20944/preprints202104.0043.v1
Subject: Arts & Humanities, Other Keywords: Epilepsy, Theatre, Neurology, Cultural History, Drama, Engagement, Medical Communication
Online: 2 April 2021 (11:12:17 CEST)
The theatre has a tremendous ability to influence public discourse and shape societal opinions. And medical conditions can provide writers with a rich scope for plot development and characters with challenges to overcome. In particular, the neurological condition epilepsy has many possibilities with historical beliefs that people were possessed by gods and devils and the sudden, disabling seizures characteristic of the condition. But used unsympathetically, it can promote misunderstanding within audiences, resulting in discrimination for people with the condition. This review looks back at how epilepsy has been portrayed throughout history. How the Greeks portrayed epilepsy as a punishment from the gods. Then later, how Shakespeare utilised epilepsy to suggest characters as uncontrollable. However, we finish on a message of hope as modern writers look to collaboration to ensure accurate and honest portrayals of epilepsy, improving public understanding and removing many of the stigmas that have dogged the condition.
ARTICLE | doi:10.20944/preprints201612.0151.v1
Online: 30 December 2016 (07:43:42 CET)
Mesial temporal lobe epilepsy (mTLE) is one of the most common and refractory focal epilepsy syndromes. The molecular mechanisms of TLE are not completely understood. The aim of this study was to investigate the expression and potential function of plasma exosomal miRNAs (miR-483-5p, miR-671-5p, and miR-150-3p) in a mouse mode and in temporal lobe epilepsy patients. It was found that exosomal miRNAs were differentially expressed in three phases of the mouse mode, and exosomal miRNAs were down-regulated in mTLE patients compared with healthy controls. A bioinformatics analysis showed that target genes of exosomal miRNAs were significantly involved in the apoptotic process, cell adhesion, nervous system development, neurotrophin signaling pathway, PI3K-Akt signaling pathway, and metabolic pathways. The areas under the curve of miR-483-5p and miR-150-3p were 0.8714 (sensitivity = 75.00%, specificity = 91.65%) and 0.8213 (sensitivity = 67.50%, specificity = 90.00%), respectively. More importantly, the exosomal miRNAs were significantly associated with clinical parameters. Exosomal miRNAs may have the potential to become diagnostic and therapeutic biomarkers.
ARTICLE | doi:10.20944/preprints202109.0316.v1
Subject: Biology, Physiology Keywords: temporal lobe epilepsy; hippocampus; 4-aminopyridine; epilepsy model; long-term potentiation; AMPA receptor.
Online: 17 September 2021 (12:45:31 CEST)
Even brief epileptic seizures can lead to activity-dependent structural remodeling of neural circuitry. Animal models show that the functional plasticity of synapses and changes in the intrinsic excitability of neurons can be crucial for epileptogenesis. However, the exact mechanisms underlying epileptogenesis remain unclear. We induced epileptiform activity in rat hippocampal slices for 15 min using a 4-aminopyridine (4-AP) in vitro model and observed hippocampal hyperexcitability for at least 1 hour. We tested several possible mechanisms of this hyperexcitability, including changes in intrinsic membrane properties of neurons, presynaptic and postsynaptic alterations. Neither input resistance nor other essential biophysical properties of hippocampal CA1 pyramidal neurons were affected by epileptiform activity. The glutamate release probability also remained unchanged, as the frequency of miniature EPSCs and the paired amplitude ratio of evoked responses did not change after epileptiform activity. However, we found an increase in the AMPA/NMDA ratio, suggesting alterations in the properties of postsynaptic glutamatergic receptors. Thus, the increase in excitability of hippocampal neural networks is realized through postsynaptic mechanisms. In contrast, the intrinsic membrane properties of neurons and the probability of glutamate release from presynaptic terminals are not affected in a 4-AP model.
REVIEW | doi:10.20944/preprints202202.0259.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: Epilepsy; Neuroimmunology; Neuroinflammation; Epileptogenesis; Personalized medicine
Online: 21 February 2022 (14:59:18 CET)
Background: Immunologic and neuro-inflammatory pathways have been found to play a major role in the pathogenesis of many neurological disorders such as epilepsy, proposing the use of novel therapeutic strategies. In the era of personalized medicine and in the face of the exhaustion of anti-seizure therapeutic resources it is worth looking at the current or future possibilities that neuroimmunomodulator or anti-inflammatory therapy can offer us in the management of patients with epilepsy. Methods: We performed a narrative review on the recent advances on the basic epileptogenic mechanisms related to the activation of immunity or neuroinflammation with special attention to current and future opportunities for novel treatments in epilepsy. Results: Neuroinflammation can be considered a universal phenomenon and occurs in structural, infectious, post-traumatic, autoimmune, or even genetically based epilepsies. The emerging research developed in recent years has allowed us to identify the main molecular pathways in-volved in these processes. These molecular pathways could constitute future therapeutic targets for epilepsy. Conclusions: Different drugs current or in development have demonstrated their capacity to inhibit or modulate molecular pathways involved in the immunologic or neuroinflammatory mechanisms described in epilepsy. Some of them should be tested in the future as possible antiepileptic drugs.
Online: 7 February 2019 (11:26:29 CET)
Introduction: Epilepsy is one of the most common neurological diseases. Epilepsy poses a significant burden on the quality of life of affected individuals and their families. The aim of this study was to determine the psychiatric disorders in epileptic patients. Methods and Materials: This descriptive-analytical study was conducted in 2017 with a simple random sampling method on patients with epilepsy who admitted to the neurology department. Results: Among the 150 examined patients, 88 (58.7%) were female and 63(42%) had epilepsy more than 10 years. The most common psychiatric disorder among epileptic patients was depression (68 patients = 45.3%) and anxiety (65 patients = 43.3%) patients. Conclusion: Most of patients had more than 10 years history of epilepsy. Also, Anxiety and depression were the most common symptoms in epileptic patients. It need to more study to determine the psychiatric disorders in epileptic patients.
ARTICLE | doi:10.20944/preprints202203.0180.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: seizures; epilepsy; Alzheimer’s disease; antiseizure medications; hyperexcitability
Online: 14 March 2022 (09:36:19 CET)
Epilepsy and Alzheimer's disease (AD) incidence increase with age. There are reciprocal relationships between epilepsy and AD. Epilepsy is a risk factor for AD and, in turn, AD is an independent risk factor for developing epilepsy in old age and abnormal AD biomarkers in PET and or CSF are frequently found in late onset epilepsies of unknown etiology. Accordingly, epilepsy and AD share pathophysiological processes including neuronal hyperexcitability and an early excitatory-inhibitory dysregulation leading to dysfunction in the inhibitory GABAergic and excitatory glutamatergic systems. Moreover, both β-amyloid and tau protein aggregates, the anatomopathological hallmarks of AD, have proepileptic effects. Finally, these aggregates have been found in the resection material of refractory temporal lobe epilepsies suggesting that epilepsy leads to amyloid and tau aggregates. Some epileptic syndromes, such as medial temporal lobe epilepsy share structural and functional neuroimaging findings with AD, leading to overlapping symptomatology such as episodic memory deficits and toxic synergistic effects. In this respect, the existence of epileptiform activity and electroclinical seizures in AD appears to accelerate progression of cognitive decline and the presence of cognitive decline is much more prevalent in epileptic patients than in elderly without epilepsy. Notwithstanding their clinical significance, the diagnosis of clinical seizures in AD is a challenge. Most are focal and manifest with altered level of consciousness without motor symptoms, and are often interpreted as cognitive fluctuations. Finally, despite the frequent association of epilepsy and AD dementia, there is a lack of clinical trials to guide the use of antiseizure medications (ASM). There is also a potential role for ASMs to be used as disease-modifying drugs in AD.
ARTICLE | doi:10.20944/preprints202202.0270.v1
Subject: Medicine & Pharmacology, Other Keywords: Onchocerciasis; Onchocerca volvulus; epilepsy; nodding syndrome; ivermectin
Online: 22 February 2022 (11:10:26 CET)
A two phase survey of epilepsy was conducted in selected villages in Mundri West and East Counties (26 June−8 July, 2021), an onchocerciasis-endemic area in Western Equatoria State in South Sudan. In the first phase, households were visited by a trained research team to identify persons suspected to have epilepsy. In the second phase, persons suspected to have epilepsy were interviewed and examined by a clinician to confirm the diagnosis. A total of 364 households agreed to participate in the survey, amounting to 2,588 individuals. The epilepsy screening questionnaire identified 91 (3.5%) persons suspected to have epilepsy, of whom in 86 (94.5%) the diagnosis of epilepsy was confirmed by a clinician. The overall prevalence of confirmed epilepsy was 3.3% (95% CI: 2.7-4.1%), and of nodding syndrome 0.9% (95% CI: 0.6-1.4%). In 61 (16.8%) households there was at least one person with epilepsy. Only 1,212 (46.9%) of 2,583 people took ivermectin during the last distribution round in 2021. The annual epilepsy incidence was 77.3/100.000 (95% CI: 9.4-278.9/100,000) and the annual epilepsy mortality 251.2/100,000 (95% CI: 133.8-428.7/100,000). In conclusion, a high prevalence and incidence of epilepsy was observed in villages in Mundri. Urgent action is needed to prevent children from developing onchocerciasis-associated epilepsy by strengthening the local onchocerciasis elimination programme.
ARTICLE | doi:10.20944/preprints202110.0415.v1
Subject: Medicine & Pharmacology, Behavioral Neuroscience Keywords: epilepsy; hydrogen sulfide; corneal kindled mice, mitochondrial dysfunction, oxidative stress, LC-MS/MS; temporal lobe epilepsy; neurological disorder; gasotransmitter
Online: 27 October 2021 (13:36:04 CEST)
Epilepsy is a heterogenous neurological disorder characterized by recurrent unprovoked seizures, mitochondrial stress, and neurodegeneration. Hydrogen sulfide (H2S), a gasotransmitter, promotes mitochondrial function and biogenesis, elicits neuromodulation and neuroprotection, and may acutely suppress seizures. A major gap in knowledge remains in understanding the role of mitochondrial dysfunction and progressive changes in H2S levels following acute seizures and during epileptogenesis. We thus sought to quantify changes in H2S and its methylated metabolite (MeSH) via LC-MS/MS subsequent to acute maximal electroshock and 6 Hz 44 mA seizures in mice, as well as in the corneal kindled mouse model of chronic seizures. Plasma H2S was acutely reduced after a maximal electroshock seizure. H2S or MeSH levels in whole brain homogenate and expression of related genes in corneal kindled mice were not altered. However, plasma H2S and MeSH levels were significantly lower during kindling, but not after established kindling. Morever, we demonstrated a time-dependent increase in expression of mitochondrial membrane integrity-related proteins, Opa1, Mfn2, Drp1, and Mff during kindling, which did not correlate with gene expression. Taken together, short-term reductions in plasma H2S could be a novel biomarker for seizures. Future studies should further define the role of H2S and mitochondrial stress in epilepsy.
ARTICLE | doi:10.20944/preprints202107.0706.v1
Subject: Medicine & Pharmacology, Allergology Keywords: epilepsy; glutamatergic transmission; glutamine synthesis; methionine sulfoximine; metabolomics
Online: 30 July 2021 (14:26:35 CEST)
Pretreatment with non-convulsive dose of methionine sulfoximine (MSO) attenuated lithi-um-pilocarpine-induced (Li-Pilo) seizures in young rats . We hypothesized that the effect of MSO results from a) glutamine synthetase block-mediated inhibition of conversion of Glu/Gln precursors to neurotransmitter Glu, and/or from b) altered synaptic Glu release. Pilo was admin-istered 60 min prior to sacrifice, MSO at 75 mg/kg, i.p., 2.5 h earlier. [1,2-13C]acetate and [U-13C]glucose were i.p.-injected either together with Pilo (onset) or 15 min before sacrifice (final phase). Their conversion to Glu and Gln in hippocampus and entorhinal cortex was followed us-ing [13C] gas chromatography-mass spectrometry. Release of in vitro loaded [3H]D-Asp from ex vi-vo brain slices was measured in continuously collected superfusates. Protein and mRNA expres-sion were measured by Western Blot and real-time PCR techniques, respectively. At no time point nor brain region did MSO modify incorporation of [13C] to Glu or Gln in Pilo-treated rats. MSO pretreatment decreased by ~37% high potassium-induced [3H]D-Asp release and reduced by ~50% the synaptic vesicular Glu transporter VGLUT1 protein, but not mRNA content in the hippo-campus. The results indicate that MSO at non-convulsive dose mitigates the initial Pilo-induced seizures by interfering with synaptic Glu-release but not with neurotransmitter Glu recycling.
REVIEW | doi:10.20944/preprints202105.0317.v1
Subject: Medicine & Pharmacology, Behavioral Neuroscience Keywords: Medial septum; Oscillation; Oscillopathy; Deep brain stimulation; Epilepsy
Online: 14 May 2021 (08:44:10 CEST)
The medial septum (MS), as part of the basal forebrain, supports many physiological functions, from sensorimotor integration to cognition. With often reciprocal connections with a broad set of peers at all major divisions of the brain, the MS orchestrates oscillatory neuronal activities throughout the brain. These oscillations are critical in generating sensory and emotional salience, locomotion, maintaining mood, supporting innate anxiety, and governing learning and memory. Accumulating evidence points out that the physiological oscillations under septal influence are frequently disrupted or altered in pathological conditions. Therefore, the MS may be a potential target for treating neurological and psychiatric disorders with abnormal oscillations (oscillopathies) to restore healthy patterns or erase undesired ones. Recent studies have revealed that the patterned stimulation of the MS alleviates symptoms of epilepsy. We discuss here that stimulus timing is a critical determinant of treatment efficacy on multiple time scales. On-demand stimulation may dramatically reduce side effects by not interfering with normal physiological functions. A precise pattern-matched stimulation through adaptive timing governed by the ongoing oscillations is essential to effectively terminate pathological oscillations. The time-targeted strategy for the MS stimulation may provide an effective way of treating multiple disorders including Alzheimer’s disease, anxiety/fear, schizophrenia, and depression, as well as pain.
ARTICLE | doi:10.20944/preprints202104.0135.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Onchocerciasis; Onchocerca volvulus; epilepsy; nodding syndrome; prevalence; ivermectin
Online: 5 April 2021 (12:53:07 CEST)
In June 2020, a door-to-door household survey was conducted in Mvolo County, an onchocerciasis endemic area in South Sudan. A total of 2,357 households containing 15,699 individuals agreed to participate in the study. Of these, 5,046 (32.1%, 95%CI: 31.4-32.9%) had skin itching and 445 (2.8%, 95% CI: 2.6-3.1%) were blind. An epilepsy screening questionnaire identified 813 (5.1%) persons suspected to have epilepsy. Of them, 804 (98.9%) were seen by a medical doctor and in 798 (98.1%) the diagnosis of epilepsy was confirmed. The overall epilepsy prevalence was 50.8/1000 (95% CI: 47.6-54.4/1000) and prevalence of nodding syndrome was 22.4/1000 (95% CI: 20.1-24.9/1000). Younger age, being male, skin itching, blindness and living in a village close to the Naam river were risk factors for epilepsy. The annual incidence of epilepsy was 82.8/100,000 (95% CI: 44.1-141.6/100,000). In conclusion, a high prevalence and incidence of epilepsy was observed in Mvolo, South Sudan. Strengthening the onchocerciasis elimination programme is urgently needed to prevent epilepsy in this region.
CASE REPORT | doi:10.20944/preprints202011.0386.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Precision diagnosis; Personalised interventions; Temporal lobe epilepsy (TLE)
Online: 13 November 2020 (14:15:57 CET)
A 12 year old boy was diagnosed with temporal lobe epilepsy (TLE) along with mesial temporal sclerosis based on MRI (magnetic resonance imaging) results. The diagnosis was further confirmed by genetic analysis. He also had minor psychiatric symptoms of obsessive-compulsive disorders and mood swings. After 4 years of treatment with Sodium Valproate no change in symptoms was observed. Genetic testing along with deep phenotyping revealed altered glutamate pathway and metabolism. Post genetic testing the patient was put on a combination of Sodium Valproate and Valproic acid along with supplementation of N-acetylcysteine (NAC), Cyanocobalamin, Pyridoxine and Cholecalciferol. Within three months of this combined therapy the patient experienced complete elimination of seizures and drastic improvement in mood and social behaviour. The case report highlights the importance of precision diagnosis in understanding the underlying perturbed pathways in structural epilepsy like TLE and demonstrates the importance of non-invasive targeted therapy in such cases.
Subject: Medicine & Pharmacology, Allergology Keywords: cannabinoid receptor 2; epilepsy; cAMP, M-current; anti-inflammatory
Online: 6 July 2021 (17:09:20 CEST)
Epilepsy is characterized by repeated spontaneous reactions caused by hyper-excitability and neurons firing in high synchronization in the central nervous system. It seriously affects the quality of life of epileptic patients and nearly 30% of individuals are refractory to treatment of antiepileptic drugs. Therefore, there is an urgent need to develop new medicines to manage and control the refractory epilepsy. Cannabinoid ligands including selective cannabinoid receptor subtype (CB1 or CB2 receptor) ligands and non-selective cannabinoid (synthetic and endogenous) ligands may serve as the novel candidates for this need. Cannabinoid systems appear to regulating seizure activity in the brain through the activation of CB1 and CB2 cannabinoid receptors (CB1R and CB2R). An abundant series of cannabinoid analogues have been tested in various animal models, including a rat pilocarpine model of acquired epilepsy, in vitro hippocampal neuronal culture models of acquired epilepsy and status epilepticus, a pentylenetetrazole model of myoclonic seizures in mice and a penicillin-induced model of epileptiform activity in the rats. The accumulating lines of evidence show that cannabinoid ligands exhibit significant benefits to control seizure activity in different epileptic models. For this reason, we summarize the relationship between brain CB2 receptors and seizures, and emphasize the potential mechanisms of their therapeutic effects involving affecting neurons, astrocytes, and microglia cells. The unique features of CB2Rs, such as lower expression levels under physiological conditions and high inducibility under epileptic conditions, make it an important target for future research on drug-resistant epilepsy.
Subject: Medicine & Pharmacology, Allergology Keywords: nNOS; Temporal lobe epilepsy; Interneuron; Synaptic transmission; Mouse models
Online: 25 November 2020 (10:19:05 CET)
Excitation-inhibition imbalance of GABAergic interneurons is predisposed to develop chronic temporal lobe epilepsy (TLE). We have previously shown that virtually every neuronal nitric oxide synthase (nNOS)-positive cell is a GABAergic inhibitory interneuron in the denate gyrus. The present study was designed to quantify the number of nNOS-containing hilar interneurons using stereology in pilocapine- and kainic acid (KA)-exposed transgenic adult mice that expressed GFP under the nNOS promoter. In addition, we studied the properties of miniature excitatory postsynaptic current (mEPSC) and paired-pulse response ratio (PPR) of evoked EPSC in nNOS interneurons using whole cell recording techniques. Results showed that there were fewer nNOS-immunoreactive interneurons of chronically epileptic animals. Importantly, patch-clamp recordings revealed reduction in mEPSC frequency, indicating diminished global excitatory input. In contrast, PPR of evoked EPSC following the granule cell layer stimulation was increased in epileptic animals suggesting reduced neurotransmitter release from granule cell input. In summary, we propose that impaired excitatory drive onto hippocampal nNOS interneurons may be implicated in the development of refractory epilepsy.
Subject: Medicine & Pharmacology, Pathology & Pathobiology Keywords: Epilepsy; Brain damage; Golgi determinations; Ramon y Cajal: axons
Online: 27 March 2020 (12:35:20 CET)
As a medical student (Granada University Medical School, Spain), interested in Pediatrics, expended countless hours at the hospital pediatric facilities and got to know many of the children and their medical problems. A particular case, still vivid on my mind, awaken my scientific curiosity. One day, walking and talking with a seven years old child he unexpectedly felt down unconscious with multiple, incontrollable and erratic muscular contractions involving face, body and extremities and salivating. I was overwhelmed thinking it was the child’ last hour. At the time, my knowledge of epilepsy was nil. Following the seizures, the child was up, talking and walking with me as if nothing has happened and without any knowledge of the event. What could have caused the brain motor cortex to suddenly discharge that amount of altered activity causing generalized and erratic muscular contractions remains inexplicable. I migrated to USA, become a Pediatric (Developmental) Pathologist and Director of the Pediatrics Autopsy Service (1962-1999) at the Dartmouth-Hitchcock Medical Center, New Hampshire. I carried out countless postmortem studied of children brains, normal (unaltered) as well as those altered by hemorrhagic, hypoxic-ischemic and/or traumatic damage. With an NIH Fellowship, I spend one year (1967-68) at the Cajal Institute (Madrid, Spain) studying Cajal’ old Golgi preparations and learning about the method. Some of my Golgi studies of children’ brains have been published: The Human Brain. Prenatal Development and Structure, Springer, Heidelberg, Germany, 2012. The present monograph explores the developmental neuropathology of selected perinatal cortical injuries through their acute, subacute and chronic stages. Including: a) how an altered neuronal activity evolves in a damaged cortical region; b) how it moves through the cortex (epileptic auras); and c) how it reaches the motor cortex to be discharged as erratic and incontrollable muscular contractions. Understanding these processes should provide insights into the pathogenesis of epilepsy secondary to perinatal brain damage.
ARTICLE | doi:10.20944/preprints202203.0114.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: epilepsy; Responsive Neurostimulation; wireless transmission; BLE; Delta encoding; low power
Online: 8 March 2022 (02:16:09 CET)
This research refers to the creation of a method of medical technology such as a device that can collect, encode, temporarily store, and transfer electroencephalographic signals from epileptic patients for study and evaluation. For applying the specific apparatus related to neurostimulation technologies such as Deep Brain Stimulation (DBS) and Responsive Neurostimulation (RNS) the approaches followed concern three basic levels. The first level is concerned with initial modelling and creating the template for the following two stages. Further on, the second level is based on developing code for programming integrated circuits and simulation with the appropriate software. The third and final stage is the most substantial, as the transmitter’s construction is attempted at the evaluation level. In particular, more than one software and device are involved in this phase for the most realistic performance of the desired result. However, it is worth noting that the principal goal of this study is to achieve low consumption rates for the device’s complete and smooth operation. As a result, this research aims to evolve this device so that it can send data wirelessly and simultaneously provide energy efficiency.
ARTICLE | doi:10.20944/preprints202107.0416.v1
Subject: Biology, Anatomy & Morphology Keywords: Epilepsy; VOCs; Attention seeking behaviours; Remote Odour Delivery Mechanism (RODM)
Online: 19 July 2021 (14:30:08 CEST)
Abstract Epilepsy is a disorder of the brain and a seriously debilitating condition, which has been associated with injury, social stigmatisation and in some cases, sudden unexpected and premature death. A sense of profound isolation is felt by many individuals with epilepsy, and this community has expressed an urgent desire for an early warning system to allow them time to prepare for seizure onset. Surveys of dog owners with epilepsy have previously reported that some dogs can predict the onset of a seizure. The current study used an experimental design to investigate the alleged propensity of untrained pet dogs to react to human epileptic seizures. We hypothesised that seizures are associated with specific volatile organic compounds resulting in detectable odours which are the biomarker that triggers these reported behavioural changes in the dogs. Here we provide details of the first empirical test to demonstrate that pet dogs display several significant behavioural changes when they are exposed to seizure-related odours that apparently emanate from their owners. Using a repeated measures design experiment, recordings were made of the reactions of 19 untrained pet dogs to odours from sweat samples provided by three people with epilepsy and by two people without epilepsy (controls). The seizure-associated sweat samples were captured pre-seizure, during seizure and post-seizure. All samples were randomly delivered to individual dogs in a test area, using two bespoke pieces of apparatus called Remote Odour Delivery Mechanisms (RODM). One RODM delivered only experimental odours, the other delivered only control odours. Behavioural changes by the dogs on encountering the odour samples were recorded by video for later analysis. Consistent with our hypothesis, seizure-associated odours evoked significant behavioural changes in the dogs which were affiliative in nature and directed at their owners.
REVIEW | doi:10.20944/preprints202102.0478.v2
Subject: Keywords: epilepsy; computational model; seizures; single neurons level; networks; whole brain
Online: 16 June 2021 (12:14:49 CEST)
Dynamical system tools offer a complementary approach to detailed biophysical seizure modeling, with a high potential for clinical applications. This review describes the theoretical framework that provides a basis for theorizing certain properties of seizures and for their classification according to their dynamical properties at onset and offset. We describe various modeling approaches spanning different scales, from single neurons to large-scale networks. This narrative review provides an accessible overview of this field, including non-exhaustive examples of key recent works.
ARTICLE | doi:10.20944/preprints202003.0292.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: temporal lobe epilepsy; antioxidants; oxidative stress; neuroimmune; major depression; schizophrenia
Online: 19 March 2020 (02:11:32 CET)
Background: Temporal lobe epilepsy (TLE) is the most common focal epilepsy subtype in adults and is frequently accompanied by depression, anxiety and psychosis. Aberrations in total paraoxonase (PON)1 status may occur in TLE and those psychiatric conditions. Methods: We examined paraoxonase (PON)1 status, namely Q192R PON1 genotypes and PON1 enzymatic activities, in 40 normal controls and 104 TLE patients, 27 without comorbidities, and 77 with comorbidities including mood disorders (n=25), anxiety disorders (n=27) and psychosis (n=25). Outcomes: CMPAase and arylesterase activities were significantly lower in TLE and mesial temporal sclerosis (MTS) with and without psychiatric comorbidities than in normal controls. The areas under the ROC curve of CMPAase were 0.893 (0.037) for TLE and 0.895 (±0.037) for MTS. Partial Least Squares (PLS) path analysis showed that there were specific indirect effects of PON1 genotype on TLE severity (p<0.0001) and psychopathology (p<0.0001), which were both mediated by lowered CMPAase activity, while arylesterase activity was not significant. The severity of TLE was significantly associated with psychopathology scores. Furthermore, PON1 CMPAase activity was inversely associated with Mini Mental State Examination scores. Interpretation: The severity of TLE and comorbidities are to a large extent explained by lowered PON1 enzyme activities and by effects of the Q192R genotype which are mediated by lowered CMPAase activity. Total PON1 status plays a key role in the pathophysiology of TLE, MTS and psychiatric comorbidities by increasing the risk of oxidative toxicity. PON1 enzyme activities are new drug targets in TLE to treat seizure frequency and psychiatric comorbidities.
ARTICLE | doi:10.20944/preprints201912.0382.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: glioblastoma multiforme; MGMT; IDH1; EGFR; P53; ATRX; Ki67; neurosurgery; oncology; epilepsy
Online: 29 December 2019 (13:04:12 CET)
Glioblastoma is a solid, infiltrating and the most frequent highly malignant primary brain tumor. Our aim was to find the prognostic value of mutations of IDH1, MGMT, EGFR, p53, ATRX, Ki67 genes and the correlation between sex, age, presenting with seizures, number of interventions, extent of resection with Overall Survival (OS), Progression Free Survival (PFS) and Karnofsky performance status (KPS) score. A randomized retrospective analysis of 122 patients treated by a single operator at Sapienza University of Rome, was carried out. After surgery patients followed standard treatment Stupp protocol . Exclusion criteria were: patients with primitive brainstem and spinal cord gliomas and patients who underwent partial resections (resection < 90%) and cases of brain biopsy exclusively for diagnostic purposes. Statistical analysis with a simultaneous regression model was carried on by SPSS 25 ® (IBM) program. Results showed statistically significant survival increase in four groups: 1) patients treated with gross total resection (p< 0.03); 2) patients with methylated MGMT promoter (p<0.005); 3) patients with non EGFR amplification or EGFRvIII mutation (p<0.035); 4) mutated IDH1/IDH2 (p<0.0161). Higher survival rates (but not statistically significant) were observed also in patients with: age < 75 years, Ki 67 <10%, lesions in non eloquent areas, ATRX gene mutation and presentation with seizures.
ARTICLE | doi:10.20944/preprints202207.0366.v1
Subject: Life Sciences, Other Keywords: onchocerciasis; community directed treatment with ivermectin; elimination; epilepsy; focus group discussions; misconceptions
Online: 25 July 2022 (09:27:22 CEST)
Despite of over 20 years of community directed treatment with ivermectin (CDTI), a high prevalence of onchocerciasis and onchocerciasis-associated epilepsy were observed in rural villages in Mahenge, Tanzania. Therefore, we assessed the knowledge, attitude and practice about onchocerciasis in four rural villages in the Mahenge area. This was a qualitative study conducted between June and July 2019. Eleven focus group discussions were organized with persons with epilepsy and their caretakers, community resource persons, and community drug distributors (CDDs), and two in-depth interviews with district programme coordinators of neglected tropical diseases (NTD). Most participants were aware about symptoms of onchocerciasis using local terminologies such as “ukurutu/rough dry skin” and “kuwashwa/itching”. A small proportion of people did not take ivermectin during CDTI for fear of adverse reactions such as itching and swelling. Some men believed that ivermectin may decrease libido. Challenges for high CDTI coverage included, long walking distance by CDDs to deliver drugs to households, persons being away for farming, low awareness of the disease and limited supervision by the NTD coordinators. In conclusion, ivermectin uptake in Mahenge should be optimised by continuous advocacy about the importance of taking ivermectin to prevent onchocerciasis-associated morbidity and by improving supervision during CDTI.
ARTICLE | doi:10.20944/preprints202203.0314.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: metabolomics; antiseizure medication; ¹H Nuclear Magnetic Resonance; focal epilepsy; response to treatment
Online: 23 March 2022 (09:11:52 CET)
A major challenge in the clinical management of patients with mesial temporal lobe epilepsy (MTLE) is identifying those who do not respond to antiseizure medication (ASM), allowing for the timely pursuit of alternative treatments, such as epilepsy surgery. Here, we investigated changes in plasma metabolites as biomarkers of pharmacoresistance in patients with MTLE. Furthermore, we used the metabolomics data to gain insights into the mechanisms underlying MTLE and response to ASM. We performed an untargeted metabolomic method using magnetic resonance spectroscopy and multi- and univariate statistical analyses to compare data obtained from plasma samples of 28 patients with MTLE compared to 28 controls. The patients were further divided according to response to ASM: 20 patients were refractory to treatment, and eight were responsive to ASM. We only included patients using carbamazepine in combination with clobazam. We compared the group of patients with controls and found that the profiles of glucose (p = 0.01), saturated lipids (p = 0.0002), isoleucine (p = 0.0001), β-hydroxybutyrate (p = 0.0003), and proline (p = 0.02) were different in patients compared to controls (p < 0.05). In addition, lipoproteins (p = 0.05), lactate (p = 0.05), glucose (p = 0.05), unsaturated lipids (p = 0.05), isoleucine (p = 0.05), and proline (p = 0.05), could discriminate between the two groups of patients classified according to response to ASM. The identified metabolites were linked to different biological pathways related to cell energy metabolism, and pathways linked to inflammatory processes and the modulation of neurotransmitter release and activity in MTLE. In contrast, we found that pyruvate metabolism may be linked to resistance to ASM. In conclusion, in addition to insights into the mechanisms underlying MTLE and the response to treatment with ASM, our results suggest that plasma metabolites may be used as biomarkers of disease and response to ASM in patients with MTLE. These findings warrant further studies exploring the clinical use of metabolites to assist in decision-making when treating patients with MTLE.
REVIEW | doi:10.20944/preprints202108.0513.v1
Subject: Keywords: liquid biopsy; epilepsy; circulating biomarkers; cfDNA; lncRNA; tRNA; miRNA; diagnosis; prognosis; therapeutics
Online: 26 August 2021 (16:40:54 CEST)
Epilepsy is one of the most common disorders of the central nervous system, impacting nearly 50 million people around the world. Heterogeneous in nature, epilepsy presents in children and adults alike. Currently, surgery is the only treatment that can cure epilepsy. However, not all individuals are eligible or have successful outcomes. Difficulty in accessing samples of human brain tissue along with advances in sequencing technology have driven researchers to investigate sampling liquid biopsies in blood, serum, plasma, and cerebrospinal fluid within the context of epilepsy. Liquid biopsies provide minimal or non-invasive sample collection approaches and can be assayed relatively easily across multiple time points, unlike tissue-based sampling. Various efforts have investigated circulating nucleic acids from these samples including microRNAs, cell-free DNA, transfer RNAs, and long non-coding RNAs. Here, we review nucleic acid-based liquid biopsies in epilepsy to improve understanding of etiology, diagnosis, prediction, and therapeutic monitoring.
CASE REPORT | doi:10.20944/preprints202008.0502.v1
Subject: Medicine & Pharmacology, Other Keywords: KARS gene; aminoacylation; leucodistrophy; epilepsy; hearing loss developmental delay; whole exome sequencing
Online: 24 August 2020 (03:10:45 CEST)
The KARS gene encodes the aminoacyl-tRNA synthetase (aaRS) which activates and joins the lysin with its corresponding transfer RNA (tRNA), through the ATP-dependent aminoacylation of the amino acid. The KARS gene mutations have been linked to diverse neurologic phenotypes such as: neurosensorial hearing loss, leukodistrophy, microcephaly, developmental delay or regression, peripheral neuropathy, cardiomyopathy, impairment of the mitochondrial respiratory chain, hyperlactatemia, among others. This article presents the case of a Colombian pediatric patient with two pathological missense variants in a compound heterozygous state in the KARS gene.
REVIEW | doi:10.20944/preprints202007.0373.v1
Subject: Medicine & Pharmacology, Psychiatry & Mental Health Studies Keywords: autism spectrum disorder; cannabinoids; cannabidiol; cannabidivarin; THC; problem behaviors; sleep; epilepsy; side effects.
Online: 17 July 2020 (09:19:13 CEST)
The etiopathogenesis of autism spectrum disorder (ASD) remains largely unclear. Among other biological hypotheses, researchers have evidenced an imbalance in the endocannabinoid (eCB) system, which regulates some functions typically impaired in ASD, such as emotional responses and social interaction. Also, cannabidiol (CBD), the non-intoxicating component of Cannabis sativa, has been recently approved for treatment-resistant epilepsy. Seizures represent frequent medical comorbidities of ASD and could be responsible for the onset or worsening of behavioral problems. Thus, it has been hypothesized that cannabinoids could be useful in improving some ASD symptoms. Our systematic review was conducted according to the PRISMA guidelines and aimed to summarize the literature regarding the use of cannabinoids in ASD. After searching in Web of KnowledgeTM, PsycINFO, and Embase, we included ten studies (eight papers and two abstracts). Four ongoing trials were retrieved in ClinicalTrials.gov. Findings are promising, as cannabinoids appeared to improve problem behaviors, sleep, hyperactivity, and communication deficits, with limited cardiac and metabolic side effects. Interestingly, they generally allowed to reduce the number of prescribed medications and decreased the frequency of seizures in epileptic patients. Mechanisms of action could be linked to the excitatory/inhibitory imbalance found in people with ASD. However, further trials need to be implemented with better characterization and homogenization of samples, and well-defined outcomes.
REVIEW | doi:10.20944/preprints201912.0179.v1
Subject: Life Sciences, Biophysics Keywords: globular set; category theory; multidimensional; visual recognition; drug-resistant epilepsy; transcranial magnetic stimulation.
Online: 13 December 2019 (10:37:03 CET)
Once a wheat sheaf has been sealed and tied up, its packed down straws display the same orientation and zero-divergence. This observation brings us to the mathematical notion of presheaf, i.e., a topological structure in which diverging functions are locally superimposed. We show how the concepts of presheaves and the correlated globular sets, borrowed from category theory and algebraic topology, allow a well-founded mathematical approach to otherwise elusive activities of the brain. The mathematical assessment of brain functions in terms of presheaves: a) explains why spontaneous random spikes synchronize; b) leads to the counterintuitive intuition of antidromic effects in neuronal spikes: when an entrained oscillation propagates from A to B, changes in B lead to changes in A. We provide testable previsions: a) we suggest the proper locations of transcranial magnetic stimulation’s coils to improve the clinical outcomes of drug-resistant epilepsy; b) we advocate that axonal stimulation by external sources backpropagates and alters the neuronal electric oscillatory frequency. Further, we describe how the hierarchical information transmission inside globular sets provides fresh insights concerning different issues at various coarse-grained scales, such as object persistence, memory reinforcement in spite of random noise, Bayesian inferential circuits.
ARTICLE | doi:10.20944/preprints202010.0616.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: Spike-and-wave; Generalized Gaussian distribution; EEG; Morlet wavelet; k-nearest neighbors classifier; Epilepsy
Online: 29 October 2020 (14:05:54 CET)
Spike-and-wave discharge (SWD) pattern detection in electroencephalography (EEG) signals is a key signal processing problem. It is particularly important for overcoming time-consuming, difficult, and error-prone manual analysis of long-term EEG recordings. This paper presents a new SWD method with a low computational complexity that can be easily trained with data from standard medical protocols. Precisely, EEG signals are divided into time segments for which the Morlet 1-D decomposition is applied. The generalized Gaussian distribution (GGD) statistical model is fitted to the resulting wavelet coefficients. A k-nearest neighbors (k-NN) self-supervised classifier is trained using the GGD parameters to detect the spike-and-wave pattern. Experiments were conducted using 106 spike-and-wave signals and 106 non-spike-and-wave signals for training and another 96 annotated EEG segments from six human subjects for testing. The proposed SWD classification methodology achieved 95 % sensitivity (True positive rate), 87% specificity (True Negative Rate), and 92% accuracy. These results set the path to new research to study causes underlying the so-called absence epilepsy in long-term EEG recordings.
ARTICLE | doi:10.20944/preprints202012.0527.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: epilepsy; seizure detection; electroencephalography; classification with a deferral option; home monitoring; long-term monitoring; wearables
Online: 21 December 2020 (13:40:43 CET)
Wearable technology will become available and allow prolonged electroencephalography (EEG) monitoring in the home environment of patients with epilepsy. Neurologists analyse the EEG visually and annotate all seizures, which patients often under report. Visual analysis of a 24 hour EEG recording typically takes one to two hours. Reliable automated seizure detection algorithms will be crucial to reduce this analysis. We study a dataset of behind-the-ear EEG measurements. Our first aim was to develop a methodology to reduce the EEG dataset by classifying part of the data automatically, while retaining 100% detection sensitivity (DS). Prediction confidences are determined by temperature scaling of the classification model outputs and trust scores. A DS of approximately 90% (99%) can be achieved when automatically classifying around 90% (60%) of the data. Perfect DS can be achieved when automatically classifying 50% of the data. Our second contribution demonstrates that a common modelling strategy, where predictions from several short EEG segments are used to obtain a final prediction, can be improved by filtering out untrustworthy segments with low trust scores. The false detection rate shows a relative decrease between 21% and 43%, and the DS shows a small increase or decrease.
ARTICLE | doi:10.20944/preprints201811.0493.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: recognition of epilepsy EEG; Symlet wavelet; gradient boosting machine; grid search optimizer; multiple-index evaluation
Online: 20 November 2018 (09:31:20 CET)
Automatic recognition methods for non-stationary EEG data collected from EEG sensors play an essential role in neurological detection. The integrative approaches proposed in this study consists of Symlet wavelet processing, a gradient boosting machine, and a grid search optimizer for a three-level classification scheme for normal subjects, intermittent epilepsy, and continuous epilepsy. Fourth-order Symlet wavelets were adopted to decompose the EEG data into five time-frequency sub-bands, whose statistical features were computed and used as classification features. The grid search optimizer was used to automatically find the optimal parameters for training the classifier. The classification accuracy of the gradient boosting machine was compared with that of a support vector machine and a random forest classifier constructed according to previous descriptions. Multiple-index were used to evaluate the Symlet wavelet transform-gradient boosting machine-grid search optimizer classification scheme, which provided better classification accuracy and detection effectiveness than has recently reported in other work on three-level classification of EEG data.
CASE REPORT | doi:10.20944/preprints202107.0661.v1
Subject: Life Sciences, Genetics Keywords: CLN2; epilepsy; Jammu and Kashmir; loss of ambulation; neuronal ceroid lipofuscinoses type 2; neuroregression; seizures; TPP1
Online: 29 July 2021 (14:01:16 CEST)
We report diagnosis of Neuronal Ceroid Lipofuscinosis Type 2 (CLN2), a rare, hereditary neurodegenerative disease of childhood, in a four and a half year old girl, the first child of non-consanguineous parents with no family history. Despite extensive efforts by the parents, her clinical condition remained undiagnosed and without management, until recently. Our published “Bottom-up Approach”, based on comprehensive and multidisciplinary clinical, pathological, radiographical and genetic evaluations, played key role in diagnosis of the disease. Detailed analyses involving Next Generation Sequencing confirmed a missense variation NC_00011.10:g.6616374C>T (NP_000382.3:p.Arg339Gln; rs765380155) in exon 8 of TPP1 gene. In silico analyses predicted it to be highly pathogenic. Further family screening (including her both unaffected parents and asymptomatic, one year old younger sister) of the identified variation through Sanger Sequencing, revealed a perfect autosomal recessive segregation in the family. This study is the first case report on classic CLN2 from Jammu and Kashmir-India. This study is also indicating the effectiveness of our “Bottom-up Approach” in understanding rare disorders in low resource regions and the importance of timely diagnosis. Like in the proband, had diagnosis been established a bit early, the family might have benefitted at least with reference to their second child through counselling programmes.
CASE REPORT | doi:10.20944/preprints202105.0101.v1
Subject: Medicine & Pharmacology, Allergology Keywords: GLUT1 deficiency syndrome, modified Atkins diet, cognition, dystonia, dyskinesia, seizure, epilepsy, ketogenic diet, glucose transporter type 1.
Online: 6 May 2021 (15:12:17 CEST)
Glucose is the primary energy fuel used by the brain and is transported across the blood-brain barrier (BBB) by the glucose transporter type 1 and 2. A GLUT1 genetic defect is responsible for glucose transporter type 1 deficiency syndrome (GLUT1DS). Patients with GLUT1DS may present with pharmaco-resistant epilepsy, developmental delay, microcephaly, and/or abnormal movements, with tremendous phenotypic variability. Diagnosis is made by the presence of specific clinical features, hypoglycorrhachia and an SLC2A1 gene mutation. Treatment with a ketogenic diet therapy (KDT) is the standard of care as it results in production of ketone bodies which can readily cross the BBB and provide an alternate energy source to the brain in the absence of glucose. KDTs have been shown to reduce seizures and abnormal movements in children diagnosed with GLUT1DS. However, little is known about the impact of KDT on cognitive function, seizures and movement disorders in adults newly diagnosed with GLUT1DS and started on a KDT in adulthood, or the appropriate ketogenic diet therapy to administer. This case report demonstrates the potential benefits of using a modified Atkins diet (MAD), a less restrictive ketogenic diet therapy on cognition, seizure control and motor function in an adult with newly-diagnosed GLUT1SD.
REVIEW | doi:10.20944/preprints202204.0189.v1
Subject: Life Sciences, Other Keywords: astrocytes; reactive astrogliosis; TGF-β; traumatic brain injury; stroke; aging; Alzheimer’s disease; Parkinson’s disease; amyotrophic lateral sclerosis; multiple sclerosis; epilepsy
Online: 20 April 2022 (09:06:47 CEST)
Astrocytes are essential for normal brain development and functioning. They respond to brain injury and disease through a process referred to as reactive astrogliosis, where the reactivity is highly heterogenous and context dependent. Reactive astrocytes are active contributors to brain pathology and can exert beneficial, detrimental, or mixed effects following brain insults. Transforming growth factor-β (TGF-β) has been identified as one of the key factors regulating astrocyte reactivity. Genetic and pharmacological manipulation of TGF-β signaling pathway in animal models of CNS injury and disease alters pathological and functional outcomes. This review aims to provide recent understanding regarding astrocyte reactivity and TGF-β signaling in brain injury, aging, and neurodegeneration. Further, it explores how TGF-β signaling modulates astrocyte reactivity and function.