Sharp Waves Research Articles

Civil Society and Democracy under Pressure: Does Authoritarian Mobilization and Party Incapacity Diminish the Positive Effect of Civil Society?

ABSTRACT Countries worldwide are experiencing a sharp wave of democratic decline that is cutting away at the gains made toward democracy that had occurred in decades prior. While the majority of scholars demonstrate a robust positive association between civil society and democracy, historical case studies in political sociology have demonstrated that nations with robust civic spheres can become cauldrons of anti-democratic politics under particular circumstances, particularly when the country has weak and ineffective political parties and when the country has autocratic movements working to degrade the democracy. While these case studies illuminate important caveats to leading research on civil society, these findings have not been tested at a cross-national level. In this paper, we ask how weak political parties and autocratic mobilization moderate the extent to which countries with more civic participation have stronger democracies around the world. We examine this research question using the continuous level of electoral democracy. Findings of our statistical analysis reveal support for the conditioning effects of weak political parties and autocratic mobilization on the relationship between civil society and electoral democracy and stability.

The defects of the hippocampal ripples and theta rhythm in depression, and the effects of physical exercise on their amelioration

Adverse environmental stress causes depressive symptoms with the impairments of memory formation, cognition, and motivation, however, their underlying neural bases have not been well understood, especially based on the observation of living animals. In the present study, therefore, the mice model of restraint-induced stress was examined electrophysiologically to investigate the alterations of hippocampal sharp wave ripples (SWRs) and theta rhythms. In addition, the therapeutic effects of physical exercise on the amelioration of those hippocampal impairments were examined in combination with a series of behavioral tests. The data demonstrated that chronic restraint stress caused the reductions of occurrence and amplitude of hippocampal SWRs and the decreases of occurrence, duration, and power of theta rhythms, while physical exercise significantly reverted them to the levels of healthy control. Furthermore, hippocampal adult neurogenesis and microglial activation, previously reported to be involved in the etiology of depression, were histologically examined in the mice. The results showed that the impairment of neurogenesis and alleviation of microglial activation were induced in the depressed mice. On the other hand, physical exercise considerably ameliorated those pathological conditions in the affected brain. Consistently, the data of behavioral tests in mice suggested that physical exercise ameliorated the symptomatic defects of motivation, memory formation, and cognition in the depressed mice. The impairments of hippocampal SWRs and theta rhythms in the affected hippocampus are linked with the symptomatic impairments of cognition and motivation, and the defect of memory formation, respectively, in depression. Taken together, this study demonstrated the implications of impairment of the hippocampal SWRs and theta rhythms in the etiology of depression and their usefulness as diagnostic markers of depression.

A Study of Clinical Profile, Radiological and Electroencephalographic Characteristics of Sporadic Creutzfeldt-Jakob Disease From a Tertiary Care Hospital.

Background Sporadic Creutzfeldt-Jakob disease (CJD), the most common form of human prion disease, is the archetypal diagnosis in this category. However, the spectrum of possible diagnoses is wide, encompassing various treatable conditions. A lack of standardized diagnostic criteria and a tendency to opt for brain biopsies and clinical autopsies can be limiting factors in reaching a conclusive diagnosis. Objective This study aims to retrospectively analyze clinical and investigative findings in patients referred to a specialized neurology clinic exhibiting rapidly progressive dementia. These patients were ultimately diagnosed with Probable sporadic Creutzfeldt-Jakob disease (CJD) based on the 2018 CDC criteria for sporadic CJD. Materials and Methods This study included cases of CJD diagnosed based on clinical, electrophysiological, and imaging parameters at a tertiary care hospital in India from 2016 to 2020. The diagnostic criteria proposed by the CDC (Centers for Disease Control and Prevention) were employed to categorize patients as definite, probable, or possible CJD cases. All patients underwent MRI (magnetic resonance imaging) imaging and EEG ( electroencephalography) recording, while diagnostic brain biopsies were not conducted due to a lack of consent from close relatives. Results This observational descriptive study comprised four patients diagnosed with Probable sporadic CJD (sCJD), all of whom were female. The patients exhibited an age range of 57 to 75 years at the onset of the disease, with a mean age of onset at 67.5 years. Unfortunately, all patients succumbed to the disease within 6 months of its onset. Rapidly progressive dementia was a common symptom in all cases. Additionally, patient one and patient four displayed myoclonus and dystonia, patient two exhibited myoclonus and akinetic mutism, and patient three had myoclonus, chorea, and ataxia. MR brain imaging, including T2 sequence, FLAIR sequence, and DWI/ADC mapping, was performed on all patients, revealing both cortical gray matter and deep gray matter (basal ganglia) T2/FLAIR hyperintensities with DWI restriction. A cortical ribboning pattern was observed in all cases. EEG results indicated generalized delta slow waves with triphasic complexes in three patients, while patient three alone displayed periodic sharp wave complexes at a frequency of 1 per 1 - 1.5 seconds. Conclusion MRI with DWI and ADC brain mapping emerges as the most valuable diagnostic tool for patients with clinical presentations suggesting sCJD. In this study, all patients displayed restricted diffusion, as confirmed by ADC mapping. Regrettably, the characteristic features of sCJD with restricted diffusion in the cortex, thalamus, and basal ganglia may often elude detection by radiologists outside specialized centers, resulting in diagnostic delays. Conversely, when basal ganglia or cortical signal abnormalities are detected in conjunction with parenchymal swelling, alternative diagnoses such as encephalitis or lymphoma should be considered, as parenchymal swelling is not a typical feature of sCJD as revealed by MRI.

Neurotoxic effects of a well known antibiotic!

To the Editor, Cefepime is a fourth-generation cephalosporin with broad-spectrum antimicrobial activity covering a wide range of both gram-negative and gram positive organisms. It is administered parenterally to treat pneumonia, urinary tract infections as well as skin and soft tissue infections. It is generally well tolerated with the most commonly reported side effects being diarrhea and rash. However, cefepime induced neurotoxicity is a rare but life- threatening adverse effect that, despite being described in literature, is often overlooked. According to the literature, about 15% of ICU patients managed with cefepime may develop neurological symptoms, including altered consciousness, aphasia, myoclonus, encephalopathy, seizures and coma. EEG abnormalities such as non-convulsive status epilepticus, myoclonic status epilepticus, triphasic waves and focal sharp waves have also been reported. Risk factors for cefepime neurotoxicity include renal function impairment, overdosing, previous brain injury and elevated serum cefepime concentrations.1 A case study published in 2021 reported a rare case of cefepime induced neurotoxicity where an elderly female suffering from chronic renal transplant rejection was given cefepime. Despite renal dosage adjustment, the patient developed neurotoxicity and presented with acute delirium, inability to tolerate oral intake and non-convulsive status epilepticus on EEG. Discontinuation of cefepime resulted in improvement of symptoms.2 Another case series published in 2017 reported cefepime induced neurotoxicity in 3 patients, one of whom had normal kidney function. These patients presented with asynchronous myoclonus and expressive aphasia.3 Considering the common use of cefepime in hospital settings, it is very important to heed the possible neurological adverse effects of this antibiotic which can be potentially fatal. Cefepime should be used with caution especially in individuals with preexisting renal impairment. Fortunately, cefepime neurotoxicity is reversible and usually resolves with discontinuation of the drug. In a few cases, dialysis may be needed to hasten the elimination of the drug.4 Anticonvulsants may be needed if patient presents with seizures or non-convulsive status epilepticus.5 Since treatment is simple and recovery rates are good, prompt recognition is crucial. Especially in ICU patients, recognition of cefepime induced neurotoxicity is challenging as it may present with neurological symptoms that are common in critically ill patients. Therefore, ICU patients receiving cefepime should be closely monitored. It is of vital importance to raise awareness regarding the neurotoxic effects of cefepime to facilitate early recognition which will help reduce morbidity and mortality associated with this drug.

Prefrontal neuronal ensembles link prior knowledge with novel actions during flexible action selection

We make decisions based on currently perceivable information or an internal model of the environment. The medial prefrontal cortex (mPFC) and its interaction with the hippocampus have been implicated in the latter, model-based decision-making; however, the underlying computational properties remain incompletely understood. We have examined mPFC spiking and hippocampal oscillatory activity while rats flexibly select new actions using a known associative structure of environmental cues and outcomes. During action selection, the mPFC reinstates representations of the associative structure. These awake reactivation events are accompanied by synchronous firings among neurons coding the associative structure and those coding actions. Moreover, their functional coupling is strengthened upon the reactivation events leading to adaptive actions. In contrast, only cue-coding neurons improve functional coupling during hippocampal sharp wave ripples. Thus, the lack of direct experience disconnects the mPFC from the hippocampus to independently form self-organized neuronal ensemble dynamics linking prior knowledge with novel actions.

Optimization of Muscle Selection for Needle Electromyography in Isolated C6 Root Lesion: A Prospective Chart Review Study.

The aim of the study is to evaluate muscles with more prominent needle electromyographic findings to optimize needle electromyography screening of isolated C6 radiculopathy in patients with C6 root lesions. This prospective clinical study was performed on 39 patients with isolated and unilateral cervical radiculopathy selected from all referrals of 1733 patients to the electrodiagnosis unit of the physical medicine and rehabilitation department of a tertiary medical center (from April 2021 to December 2021). The presence of fibrillation potentials, positive sharp waves, and/or neurogenic motor action potentials that occurred in isolation or combination with selected muscles was considered an abnormal finding. Of 1733 referrals, 39 patients (18 males [46.1%] and 21 females [53.8%]), with a mean age of 49.7 ± 9.6 yrs, were found eligible. According to needle electromyography findings, the most involved muscles in C6 root lesion were pronator teres (100%), followed by extensor carpi radialis longus (94.8%), flexor carpi radialis (89.7%), brachioradialis (82%), infraspinatus (82%), supraspinatus (79.4%), deltoid (74.3%), biceps brachii (64.1%), extensor digitorum communis (33.3%), and triceps brachii (15.3%) muscles. The pronator teres is the most involved muscle of patients diagnosed with C6 radiculopathy. It might be considered the key muscle for screening and accurate diagnosis of C6 root involvement.

Delayed radiation-induced motor neuron syndrome: A case report.

Delayed radiation-induced motor neuron syndrome (DRIMNS) is an atypical motor neuron disorder that develops months or years after radiation therapy. In this study we present a case of DRIMNS that developed forty years after radiotherapy and to discuss differential diagnoses. A 56-year-old male patient was admitted to our clinic with complaints of increasing difficulty in walking for the past year. He had a history of operation and radiotherapy due to testicular tumor. Electroneuromyography (ENMG) and thoracic, lumbosacral, plexus and pelvic magnetic resonance imaging (MRI) were performed considering radiculopathy, plexopathy and motor neuron disease in the differential diagnosis. MRIs revealed no abnormality. Needle EMG of lower extremity and lumbar paraspinal muscles revealed fibrillation and positive sharp waves concomitant with fasciculations and reduced recruitment suggesting anterior horn cell/root involvement. DRIMNS was considered rather than motor neuron disease based on the long duration of symptoms with slow progressive course and history of radiotherapy to the pelvic region. DRIMNS is a rare entity that should be considered in the differential diagnosis of lower extremity muscle weakness in a patient with a history of malignancy and radiotherapy. EMG findings are very valuable in making the diagnosis together with the clinical picture.

Myelin abnormalities in merosin-deficient congenital muscular dystrophy.

Merosin is a protein complex located in the basement membrane of skeletal muscles and laminin α2-containing regions of the central and peripheral nervous systems. However, because of the prominence of muscle-related symptoms, peripheral neuropathy associated with merosin-deficient congenital muscular dystrophy type 1A (MDC1A) has received little clinical attention. This study aimed to present pathological changes in intramuscular nerves of three patients with MDC1A and discuss their relationship with electrophysiological findings to provide new evidence of peripheral nerve involvement in MDC1A. MDC1A was confirmed by clinical features, muscle biopsy, and genetic testing for variants in LAMA2. To clarify peripheral nerve involvement, we statistically evaluated electrophysiological and muscle pathology findings of intramuscular nerves. These findings were compared with those of age-matched boys with Duchenne muscular dystrophy (DMD) as controls with normal nerves. Nerve conduction studies (NCS) were performed before biopsy. Biopsied intramuscular nerves were examined with electron microscopy using g-ratio, which is the ratio of axon diameter to myelinated fiber diameter. The myelin sheaths were significantly thinner in MDC1A patients than in age-matched DMD patients, with a mean g-ratio of 0.76 ± 0.07 in MDC1A patients and 0.65 ± 0.14 in DMD patients (p < .0001). No neuropathic changes were identified in muscle pathology. Low compound muscle action potential amplitudes, positive sharp waves and fibrillation potentials, and low-amplitude motor unit potentials with increased polyphasia indicated myopathic changes; no neurogenic changes were seen. We postulate that the thin myelin associated with MDC1A reflects the role of merosin in myelin maturation.

5 Combining Neurophysiology and Behavioral Measures to Identify Biomarkers of Clinical and Preclinical Hippocampus-Dependent Memory Dysfunction

Objective:Memory is a critical piece of the human experience and impairments in neural memory networks can have devastating consequences for the affected person. A subtype of memory, episodic memory generates context for the present based on past experience and allows us to make predictions about the future. Episodic memories become stable fixtures through long-term memory consolidation. It is believed that consolidation of episodic memory requires a dynamic interplay between connected hippocampal-cortical networks, mainly during sleep. Sleep oscillations, slow oscillations and thalamocortical spindles, coupled with hippocampal sharp wave ripples (SWR) is proposed to be mechanistically involved in establishing the crucial cortical-subcortical dialog. The current study aimed to determine alterations in typical sleep oscillations and oscillation coupling in patients with and without structural hippocampal damage and correlate them with neuropsychological measures believed to be sensitive to hippocampal dysfunction, i.e., Rey Auditory Verbal Learning Task (RAVLT) and Verbal Paired Associates (VPA-II).Participants and Methods:We used intracranial electroencephalography (iEEG) in 14 patients with epilepsy to directly record hippocampal and neocortical oscillations and neuropsychological measures obtained prior to implantation. Half of the participants were diagnosed with mesial temporal sclerosis (MTS) in the left hippocampus and healthy tissue in the right hippocampus. The other half did not have MTS and had either mesial temporal epilepsy without MTS or extra-temporal seizures. We analyzed hippocampal SWR output from both hippocampi and characterized neocortical slow oscillations and spindles and their coupling for each participant. We correlated electrophysiological data with behavioral results of neuropsychological testing in order to characterize the clinical relevance.Results:SWR analysis revealed significant differences in the frequency, t(7639) = 15.52, p&gt;.001, p &gt; .001), amplitude, t(7664) = -23.93, p &gt; .001, and waveforms (p &gt; .001) of SWR in the sclerotic versus healthy hippocampi. Patients with a sclerotic hippocampus but relatively preserved verbal memory scores (RAVLT, VPA-II) showed increased SWR amplitudes in the contralateral hippocampus compared to patients with low verbal memory scores. Additionally, we found differences between hemispheres in phase amplitude coupling of SWRs to spindles and SOs (p &gt; 0.001). Results of our correlational analysis were variable and dependent upon additional factors, such as age of onset and diagnosis duration.Conclusions:Results from this work will aid in establishing a criterion for characterizing a relationship between subcortical and cortical oscillations as they relate to memory performance. Besides aiding our understanding of the neural mechanisms underpinning memory consolidation this will ideally help with developing neurophysiological biomarkers that may predict possible memory decline in resective or ablative neurosurgery absent of structural lesion. In addition, this work may potentially provide first evidence of a neurophysiological biomarker directly recorded from the human hippocampus to support possible reorganization of memory functioning in the non-sclerotic hippocampus.

EEG-based epileptic seizure detection using binary dragonfly algorithm and deep neural network

Electroencephalogram (EEG) is one of the most common methods used for seizure detection as it records the electrical activity of the brain. Symmetry and asymmetry of EEG signals can be used as indicators of epileptic seizures. Normally, EEG signals are symmetrical in nature, with similar patterns on both sides of the brain. However, during a seizure, there may be a sudden increase in the electrical activity in one hemisphere of the brain, causing asymmetry in the EEG signal. In patients with epilepsy, interictal EEG may show asymmetric spikes or sharp waves, indicating the presence of epileptic activity. Therefore, the detection of symmetry/asymmetry in EEG signals can be used as a useful tool in the diagnosis and management of epilepsy. However, it should be noted that EEG findings should always be interpreted in conjunction with the patient's clinical history and other diagnostic tests. In this paper, we propose an EEG-based improved automatic seizure detection system using a Deep neural network (DNN) and Binary dragonfly algorithm (BDFA). The DNN model learns the characteristics of the EEG signals through nine different statistical and Hjorth parameters extracted from various levels of decomposed signals obtained by using the Stationary Wavelet Transform. Next, the extracted features were reduced using the BDFA which helps to train DNN faster and improve its performance. The results show that the extracted features help to differentiate the normal, interictal, and ictal signals effectively with 100% accuracy, sensitivity, specificity, and F1 score with a 13% selected feature subset when compared to the existing approaches.

Sensory disturbances in Creutzfeldt-Jakob disease.

Creutzfeldt-Jakob disease (CJD) is a fatal neurodegenerative disease characterized by rapidly progressive dementia, motor impairments, and psychiatric symptoms. Sensory disturbances were occasionally reported as well. The study aims to describe the sensory symptoms of the disease. The CJD Israeli National Database was screened for patients who presented sensory symptoms throughout the disease course. Symptoms, characteristics, and distribution were reviewed and the demographic and clinical data (sex, etiologies of the disease, age of onset, disease duration, neurological exam finding, tau protein level, EEG and MRI findings) were compared with the demographics and clinical data of CJD without sensory symptoms. Then, the patients with sensory symptoms were divided into patients with symptom distribution consistent with peripheral nervous system (PNS) involvement and central nervous system (CNS) involvement. The demographics and clinical data of the 2 groups were compared. Eighty-four CJD patients with sensory symptoms and 645 CJD patients without sensory symptoms were included in the study. Sensory symptoms were more common in genetic E200K CJD patients (14.6% vs. 5.6% respectively, p = 0.0005) (chi-squared test). Numbness and neuropathic pain were the most common symptoms and distribution of symptoms of "stocking gloves" with decreased deep tendon reflexes suggesting peripheral neuropathy in 44% of the patients. In these patients, the classical EEG findings of Periodic Sharp Wave Complexes were less often found (58% vs. 22%, p = 0.02) (chi-squared test). Sensory symptoms are more common in E200K patients and often follow peripheral neuropathy distribution that suggests PNS involvement.

Salinization and Solonetsization of Soils in River Valleys of the Kulunda Plain

The surface of the Kulunda Plain is dissected by a system of ancient wide valleys, former runoff hollows, which have a very small slope (less than 1°). Rivers flow along these weakly expressed valleys, redistributing readily soluble salts throughout the territory. The regime of these rivers is characterized by a sharp and high flood wave and low (up to complete drying) runoff in the summer. The purpose of this work is to study the ion-salt system of soils of ancient runoff troughs of the Kulunda Plain, groundwater and river waters in order to identify modern processes of soil salinization. During floods, river water feeds close-lying groundwater, influencing its chemical composition. Studies of three key sites in the valleys of the Bagan (Novosibirsk region), Burla and Kulunda (Altai Territory) rivers took place in 2021–2022. Ground waters of varying degrees of mineralization (from 3.4 to 63.0 g/l) and lie close to the surface (2–5 m), which causes a wide distribution of saline hydromorphic soils in the study area. Differences in the salt state of soils in different valleys, groundwater and river waters are discussed. The degree of salinization of soils depended on their granulometric composition. The high content of physical clay contributed to the rise of salts with groundwater and their accumulation in the soil profile. A large amount of exchangeable sodium in the soil absorbing complex of the studied soils (more than 3–5 cm (eq)/kg), the predominance of easily soluble sodium salts in the soil solution with its low mineralization, as well as the alkaline reaction of the soil medium indicates the manifestation of the process of soil salinization.

Neuronal ceroid lipofuscinosis: A case report

Neuronal ceroid lipofuscinoses (NCL) represent severe neurodegenerative conditions which is one of the lysosomal storage disorders. There are four main clinical forms of NCL among which late infantile variety is the second most common condition. Here, we discuss a case concerning a boy aged 5 years and 4 months who exhibited a continuous decline in cognitive and motor functions starting from the age of 4. As the disorder advanced, he experienced gradual deterioration of his eyesight, unsteady walking and myoclonic seizures. An electroencephalogram performed on the child demonstrated widespread instances of sharp and slow wave discharges alongside a slowed background activity. Magnetic resonance imaging revealed extensive cerebral and noticeable cerebellar degeneration. A skin biopsy extracted from the armpit area displayed distinctive eosinophilic inclusions within the cells and structures in the eccrine ducts which stained positively for periodic acid-Schiff. These findings indicated a possibility of neuronal ceroid lipofuscinoses. Bangabandhu Sheikh Mujib Medical University Journal 2023;16(3): 174-177

298 An atypical presentation of Creutzfeldt-Jakob Disease as a stroke mimic—experience from an Irish tertiary centre

Abstract Background Sporadic Creutzfeldt-Jakob Disease (sCJD) is a rare neurodegenerative prion disease that presents with symptoms of rapid neuropsychiatric decline including dementia, behavioural abnormalities and loss of higher cortical function. Patients commonly present with rapidly-progressive neuromotor symptoms such as ataxia and myoclonus. Very few cases of CJD have been reported in which the patient initially presents with stroke symptoms such as hemiparesis as their primary presenting symptom. We present a case of a 56 year old male who initially presented to the stroke unit with waxing and waning left sided weakness and a non-corresponding ipsilateral left-sided acute parietal infarct on diffusion-weighted MRI. Over four weeks, his condition progressively worsened with declining cognitive function, motor dysfunction, sphincter dysfunction and eventual death. Methods Methods used to confirm the suspected diagnosis included: (1) Periodic sharp wave complexes are the most classical EEG finding for CJD and are seen in two third of the patients diagnosed with sporadic CJD, (2) The presence of the 14–3-3 protein in CSF has been found to be a sensitive and specific marker for sporadic CJD, (3) Neuroimaging plays a vital role in the diagnosis of CJD including serial MRIs and EEG sufficient to exclude other differential diagnoses. Results MRI brain revealed an acute cortical infarct within left parietal lobe measuring 3 mm.A n EEG demonstrated periodic sharp wave complexes occurring maximally in the left centro-temporal region. EEG finding was suggestive of a diagnosis of a prion disease. CJD Surveillance Unit confirmed the cerebrospinal fluid analysis was positive for RT-QuIC indicating sporadic CJD. Conclusion In cases of patients presenting with clinical signs and symptoms of a stroke with subsequent ipsilateral neurological findings on MRI, CJD should be included as a differential diagnosis. Additionally, a lumbar puncture, not routinely recommended in stroke patients, should be performed early to aid in early detection of CJD in order to confirm diagnosis and optimise the ceiling of care.

MR Neurography and Quantitative Muscle MRI of Parsonage Turner Syndrome Involving the Long Thoracic Nerve.

Parsonage-Turner syndrome (PTS) is characterized by severe, acute upper extremity pain and subsequent paresis and most commonly involves the long thoracic nerve (LTN). While MR neurography (MRN) can detect LTN hourglass-like constrictions (HGCs), quantitative muscle MRI (qMRI) can quantify serratus anterior muscle (SAM) neurogenic changes. 1) To characterize qMRI findings in LTN-involved PTS. 2) To investigate associations between qMRI and clinical assessments of HGCs/electromyography (EMG). Prospective. 30 PTS subjects (25 M/5 F, mean/range age = 39/15-67 years) with LTN involvement who underwent bilateral chest wall qMRI and unilateral brachial plexus MRN. 3.0 Tesla/multiecho spin-echo T2-mapping, diffusion-weighted echo-planar-imaging, multiecho gradient echo. qMRI was performed to obtain T2, muscle diameter fat fraction (FF), and cross-sectional area of the SAM. Clinical reports of MRN and EMG were obtained; from MRN, the number of HGCs; from EMG, SAM measurements of motor unit recruitment levels, fibrillations, and positive sharp waves. qMRI/MRN were performed within 90 days of EMG. EMG was performed on average 185 days from symptom onset (all ≥2 weeks from symptom onset) and 5 days preceding MRI. Paired t-tests were used to compare qMRI measures in the affected SAM versus the contralateral, unaffected side (P < 0.05 deemed statistically significant). Kendall's tau was used to determine associations between qMRI against HGCs and EMG. Relative to the unaffected SAM, the affected SAM had increased T2 (50.42 ± 6.62 vs. 39.09 ± 4.23 msec) and FF (8.45 ± 9.69 vs. 4.03% ± 1.97%), and decreased muscle diameter (74.26 ± 21.54 vs. 88.73 ± 17.61 μm) and cross-sectional area (9.21 ± 3.75 vs. 16.77 ± 6.40 mm2). There were weak to negligible associations (tau = -0.229 to <0.001, P = 0.054-1.00) between individual qMRI biomarkers and clinical assessments of HGCs and EMG. qMRI changes in the SAM were observed in subjects with PTS involving the LTN. 2 TECHNICAL EFFICACY: Stage 1.

Hyperbolic Conduction and Radiation Heat Transfer in Axisymmetric Cylinders with Variable Properties

This work investigates the combined mode of hyperbolic heat conduction and radiation transfer in a one-dimensional axisymmetric cylinder filled with absorbing, emitting, and scattering media. The volumetric radiation is investigated thanks to the semianalytic solution of the matrix formulation of the spherical harmonics equations PN. The governing hyperbolic energy equation is solved using the finite volume method (FVM) with Roe’s correction of interface fluxes in order to enhance the performances of the method, and the lattice Boltzmann method (LBM) has been designed for comparisons. The effects of the parameters such as constant and spatial-dependent scattering albedos, temperature-dependent thermal conductivity, heat-generated sources, extinction, and the conduction–radiation parameter on both the temperature and heat flux distributions for steady and transient states within the medium are examined. The results of the present work are in excellent agreement with those available in the literature. The PN−FVM results are also compared to those obtained with the PN−LBM combination, and excellent agreement is obtained. These results show that the mentioned parameters have a significant effect on both the temperature profiles and the hyperbolic sharp wave front. This study also shows that the proposed layered approach is an efficient, fast, and accurate solution method for radiative analysis in inhomogeneous media, whereas the Roe’s correction of interface fluxes in the FVM is suitable to accommodate a thermal wave front in non-Fourier analysis.

Burst suppression pattern on EEG in West syndrome in an infant with heterozygous variant in the CACNA1A gene

Abstract West syndrome is a severe epilepsy syndrome characterized by the classical triad of infantile spasms, hypsarrhythmia on electroencephalography (EEG) and psychomotor retardation. The classical hypsarrhythmia pattern on EEG consists of a high amplitude, arrhythmic, disorganized background with multifocal spikes and slow and sharp waves. The burst suppression (BS) pattern on EEG is a less commonly described pattern in West syndrome. Among the genetic causes of West syndrome, mutations in the CACNA1A gene are rarely reported. We hereby report a BS pattern on EEG in an infant with West syndrome with heterozygous variant in the CACNA1A gene.

Hourglass-like constrictions on MRI are common in electromyography-confirmed cases of neuralgic amyotrophy (Parsonage-Turner syndrome): A tertiary referral center experience.

Hourglass-like constrictions (HGCs) of involved nerves in neuralgic amyotrophy (NA) (Parsonage-Turner syndrome) have been increasingly recognized with magnetic resonance neurography (MRN). This study sought to determine the sensitivity of HGCs, detected by MRN, among electromyography (EMG)-confirmed NA cases. This study retrospectively reviewed records of patients with the clinical diagnosis of NA, and with EMG confirmation, who underwent 3-Tesla MRN within 90 days of EMG at a single tertiary referral center between 2011 and 2021. "Severe NA" positive cases were defined by a clinical diagnosis and specific EMG criteria: fibrillation potentials or positive sharp waves, along with motor unit recruitment (MUR) grades of "discrete" or "none." On MRN, one or more HGCs, defined as focally decreased nerve caliber or diffusely beaded appearance, was considered "imaging-positive." Post hoc inter-rater reliability for HGCs was measured by comparing the original MRN report against subsequent blinded interpretation by a second radiologist. A total of 123 NA patients with 3-Tesla MRN performed within 90 days of EMG were identified. HGCs were observed in 90.2% of all NA patients. In "severe NA" cases, based on the above EMG criteria, HGC detection resulted in a sensitivity of 91.9%. Nerve-by-nerve analysis (183 nerve-muscle pairs, nerves assessed by MRN, muscles assessed by EMG) showed a sensitivity of 91.0%. The second radiologist largely agreed with the original HGC evaluation, (94.3% by subjects, 91.8% by nerves), with no significant difference between evaluations (subjects: χ2 = 2.27, P = .132, nerves: χ2 = 0.98, P = .323). MRN detection of HGCs is common in NA.

Single closed-loop acoustic stimulation targeting memory consolidation suppressed hippocampal ripple and thalamo-cortical spindle activity in mice.

Brain rhythms of sleep reflect neuronal activity underlying sleep-associated memory consolidation. The modulation of brain rhythms, such as the sleep slow oscillation (SO), is used both to investigate neurophysiological mechanisms as well as to measure the impact of sleep on presumed functional correlates. Previously, closed-loop acoustic stimulation in humans targeted to the SO Up-state successfully enhanced the slow oscillation rhythm and phase-dependent spindle activity, although effects on memory retention have varied. Here, we aim to disclose relations between stimulation-induced hippocampo-thalamo-cortical activity and retention performance on a hippocampus-dependent object-place recognition task in mice by applying acoustic stimulation at four estimated SO phases compared to sham condition. Across the 3-h retention interval at the beginning of the light phase closed-loop stimulation failed to improve retention significantly over sham. However, retention during SO Up-state stimulation was significantly higher than for another SO phase. At all SO phases, acoustic stimulation was accompanied by a sharp increase in ripple activity followed by about a second-long suppression of hippocampal sharp wave ripple and longer maintained suppression of thalamo-cortical spindle activity. Importantly, dynamics of SO-coupled hippocampal ripple activity distinguished SOUp-state stimulation. Non-rapid eye movement (NREM) sleep was not impacted by stimulation, yet preREM sleep duration was effected. Results reveal the complex effect of stimulation on the brain dynamics and support the use of closed-loop acoustic stimulation in mice to investigate the inter-regional mechanisms underlying memory consolidation.

Admission Clinical and EEG Features Associated With Mortality and Long-term Neurologic and Cognitive Outcomes in Pediatric Cerebral Malaria.

For children with cerebral malaria, mortality is high, and in survivors, long-term neurologic and cognitive dysfunctions are common. While specific clinical factors are associated with death or long-term neurocognitive morbidity in cerebral malaria, the association of EEG features with these outcomes, particularly neurocognitive outcomes, is less well characterized. In this prospective cohort study of 149 children age 6 months to 12 years who survived cerebral malaria in Kampala, Uganda, we evaluated whether depth of coma, number of clinical seizures, or EEG features during hospitalization were associated with mortality during hospitalization, short-term and long-term neurologic deficits, or long-term cognitive outcomes (overall cognition, attention, memory) over the 2-year follow-up. Higher Blantyre or Glasgow Coma Scores (BCS and GCS, respectively), higher background voltage, and presence of normal reactivity on EEG were each associated with lower mortality. Among clinical and EEG features, the presence of >4 seizures on admission had the best combination of negative and positive predictive values for neurologic deficits in follow-up. In multivariable modeling of cognitive outcomes, the number of seizures and specific EEG features showed independent association with better outcomes. In children younger than 5 years throughout the study, seizure number and presence of vertex sharp waves were independently associated with better posthospitalization cognitive performance, faster dominant frequency with better attention, and higher average background voltage and faster dominant background frequency with better associative memory. In children younger than 5 years at CM episode but 5 years or older at cognitive testing, seizure number, background dominant frequency, and the presence of vertex sharp waves were each associated with changes in cognition, seizure number and variability with attention, and seizure number with working memory. In children with cerebral malaria, seizure number is strongly associated with the risk of long-term neurologic deficits, while seizure number and specific EEG features (average background voltage, dominant rhythm frequency, presence of vertex sharp waves, presence of variability) are independently associated with cognitive outcomes. Future studies should evaluate the predictive value of these findings.