Analysis of Clinical Characteristics, Background, and Paroxysmal Activity in EEG of Patients with Juvenile Myoclonic Epilepsy

Juvenile myoclonic epilepsy (JME) appears in adolescence with myoclonic, absence, and generalized tonic clonic (GTC) seizures with paroxysmal activity of polyspike and slow wave (PSW), or spike and wave (SW) complexes in EEG. Our aim was to analyze the clinical characteristics, background EEG activity, and paroxysmal events in 41 patients with JME. Background EEG activity was analyzed with visual, quantitative (QEEG), and neurometric parameters. Our JME patients started with absence seizures at 11.4 ± 1.5 years old, myoclonic seizures at 13.6 ± 2.5 years, and GTC seizures at 15.1 ± 0.8 years. The seizures presented in awakening at 7:39 h with sleep deprivation, alcoholic beverage intake, and stress as the most frequent precipitant factors. Paroxysmal activity was of PSW and fast SW complexes with 40.5 ± 62.6 events/hour and a duration of 1.7 s. Right asymmetric paroxysmal activity was present in 68.3% of patients. Background EEG activity was abnormal in 31.7% of patients with visual analysis. With QEEG beta AP (absolute power) increase and AP delta decrease were the most frequent abnormalities found. Spectral analysis showed that 48.7% of patients had normal results, and 26.83% and 24.4% had higher and lower frequencies than 10.156 Hz, respectively. We concluded that, with visual analysis, background EEG activity was abnormal in a few patients and the abnormalities increased when QEEG was used.

Theta and gamma hippocampal-neocortical oscillations during the episodic-like memory test: impairment in epileptogenic rats

Cortical oscillations in different frequency bands have been shown to be intimately involved in exploration of environment and cognition. Here, the local field potentials in the hippocampus, the medial prefrontal cortex (mPFC), and the medial entorhinal cortex (mEC) were recorded simultaneously in rats during the execution of the episodic-like memory task. The power of hippocampal theta (~4-10 Hz), slow gamma (~25-50 Hz), and fast gamma oscillations (~55-100 Hz) was analyzed in all structures examined. Particular attention was paid to the theta coherence between three mentioned structures. The modulation of the power of gamma rhythms by the phase of theta cycle during the execution of the episodic-like memory test by rats was also closely studied. Healthy rats and rats one month after kainate-induced status epilepticus (SE) were examined. Paroxysmal activity in the hippocampus (high amplitude interictal spikes), excessive excitability of animals, and the death of hippocampal and dentate granular cells in rats with kainate-evoked SE were observed, which indicated the development of seizure focus in the hippocampus (epileptogenesis). One month after SE, the rats exhibited a specific impairment of episodic memory for the what-where-when triad: unlike healthy rats, epileptogenic SE animals did not identify the objects during the test. This impairment was associated with the changes in the characteristics of theta and gamma rhythms and specific violation of theta coherence and theta/gamma coupling in these structures in comparison with the healthy animals. We believe that these disturbances in the cortical areas play a role in episodic memory dysfunction in kainate-treated animals. These findings can shed light on the mechanisms of cognitive deficit during epileptogenesis.

Ping-pong gaze in a refractory focal status epilepticus

An 83-year-old woman presented to emergency department with fever, low level of consciousness and right deviation in the conjugate gaze. Neurological examination revealed a spontaneous, slow, horizontal and continuous conjugate eye deviation alternating every 2 to 3 seconds. An electroencephalogram revealed periodic paroxysmal activity with a frequency of 2-3 Hz in left frontal hemispheric. Neuroimaging didn’t show pathological findings. Polymorphonuclear leukocytes were observed in CSF without evidence of microorganisms. Antiepileptic therapy was started without improvement. Finally, the patient died because of refractory focal status. Ping Pong Gaze (PPG) is a slow and rhythmical horizontal abnormal eye movement with a fixed frequency that is observed in comatose states and indicates diffuse structural brain lesions with preserved brainstem functions. PPG presence is an indicator of bad prognosis. We describe a PPG case with a synchronous eye movement with the electroencephalogram activity. Keywords: Ping-pong gaze; status epilepticus; electroencephalography; epilepsy; seizure.

Effect of the compound GIZH -290 and levetiracetam on epileptic activity in rat brain structures on EEG models of bemegrid-induced seizures

The effect of levetiracetam (a derivative of 4-phenylpyrrolidone) and its original analog, the compound GIZH-290, on primary generalized epileptic activity (EpA) in rat brain structures (sensorimotor cortex, dorsal hippocampus-CA3 field and lateral hypothalamus field) on EEG models of bemegridinduced seizures was studied. It was found that EpA, after the introduction of bemegrid, appears in 1–2 minutes in the form of prolonged generalized high-amplitude discharges and is registered within 3 hours. GIZH-290 (5 mg/kg, intraperitoneal, 15 minutes after bemegrid) causes a significant (p < 0.05) decrease in the number of epileptic discharges in the cortex and at the level of the trend in the hippocampus, which is accompanied by a decrease in the amplitude of the Epi-discharges. Levetiracetam at a dose of 200 mg / kg does not significantly change the severity of paroxysmal activity (the number of convulsive discharges and their duration) caused by bemegrid.

Examples of Multi-Sensor Determination of Eruptive Source Parameters of Explosive Events at Mount Etna

Multi-sensor strategies are key to the real-time determination of eruptive source parameters (ESPs) of explosive eruptions necessary to forecast accurately both tephra dispersal and deposition. To explore the capacity of these strategies in various eruptive conditions, we analyze data acquired by two Doppler radars, ground- and satellite-based infrared sensors, one infrasound array, visible video-monitoring cameras as well as data from tephra-fallout deposits associated with a weak and a strong paroxysmal event at Mount Etna (Italy). We find that the different sensors provide complementary observations that should be critically analyzed and combined to provide comprehensive estimates of ESPs. First, all measurements of plume height agree during the strong paroxysmal activity considered, whereas some discrepancies are found for the weak paroxysm due to rapid plume and cloud dilution. Second, the event duration, key to convert the total erupted mass (TEM) in the mass eruption rate (MER) and vice versa, varies depending on the sensor used, providing information on different phases of the paroxysm (i.e., unsteady lava fountaining, lava fountain-fed tephra plume, waning phase associated with plume and cloud expansion in the atmosphere). As a result, TEM and MER derived from different sensors also correspond to the different phases of the paroxysms. Finally, satellite retrievals for grain-size can be combined with radar data to provide a first approximation of total grain-size distribution (TGSD) in near real-time. Such a TGSD shows a promising agreement with the TGSD derived from the combination of satellite data and whole deposit grain-size distribution (WDGSD).

The Monitoring of CO2 Soil Degassing as Indicator of Increasing Volcanic Activity: The Paroxysmal Activity at Stromboli Volcano in 2019–2021

Since 2016, Stromboli volcano has shown an increase of both frequency and energy of the volcanic activity; two strong paroxysms occurred on 3 July and 28 August 2019. The paroxysms were followed by a series of major explosions, which culminated on January 2021 with magma overflows and lava flows along the Sciara del Fuoco. This activity was monitored by the soil CO2 flux network of Istituto Nazionale di Geofisica e Vulcanologia (INGV), which highlighted significant changes before the paroxysmal activity. The CO2 flux started to increase in 2006, following a long-lasting positive trend, interrupted by short-lived high amplitude transients in 2016–2018 and 2018–2019. This increasing trend was recorded both in the summit and peripheral degassing areas of Stromboli, indicating that the magmatic gas release affected the whole volcanic edifice. These results suggest that Stromboli volcano is in a new critical phase, characterized by a great amount of volatiles exsolved by the shallow plumbing system, which could generate other energetic paroxysms in the future.

Intravenous immunoglobulin response in new-onset refractory status epilepticus (NORSE) COVID-19 adult patients

Neurological manifestations may be common in COVID-19 patients. They may include several syndromes, such as a suggested autoimmune abnormal response, which may result in encephalitis and new-onset refractory status epilepticus (NORSE). Quickly recognizing such cases and starting the most appropriate therapy is mandatory due to the related rapid worsening and bad outcomes. This case series describes two adult patients admitted to the university hospital and positive to novel coronavirus 2019 (SARS-CoV-2) infection who developed drug-resistant status epilepticus. Both patients underwent early electroencephalography (EEG) assessment, which showed a pathological EEG pattern characterized by general slowing, rhythmic activity and continuous epileptic paroxysmal activity. A suspected autoimmune etiology, potentially triggered by SARS-CoV-2 infection, encouraged a rapid work-up for a possible autoimmune encephalitis diagnosis. Therapeutic approach included the administration of 0.4 g/kg intravenous immunoglobulin, which resulted in a complete resolution of seizures after 5 and after 10 days, respectively, without adverse effects and followed by a normalization of the EEG patterns.

NEUROPROTECTIVE EFFECT OF SODIUM NITROPRUSSIDE INTRANASAL ADMINISTRATION ON FUNCTIONAL ACTIVITY OF THE BRAIN AND ANXIETY OF RATS WITH ALCOHOL DEPENDENCE

Introduction. Disturbances of the molecular nitrosergic mechanisms of brain activity regulation underlie the reduction of brain protective functions under alcohol dependence. However, development of pathogenetically substantiated approaches to the correction of nitrogen oxide (NO) imbalance in the structures of the limbico-neocortical system of the brain (LNCSB) remains insufficient. Objective. To study the effect of intranasal sodium nitroprusside (SNP) administration on anxiety, electrical activity of the LNCSB and NO content in the hippocampus, hypothalamus and septum + nucleus аccumbens of rats with alcohol dependence. Materials and methods. The studies were carried out on 50 nonlinear white adult male rats in a chronic experiment in 3 groups: intact rats; rats with alcohol dependence; rats with alcohol dependence and intranasal SNP administration. The model of alcohol dependence was created by voluntary alcohol intake at a dose of 1.25 g/kg body weight of rat for 35 days. SNP was administered intranasal at a dose of 8 μg/kg body weight of the animal. The level of anxiety was determined by means of neuroethological tests: multi-parameter comprehensive assessment of anxiety, «open field» and «tail suspension test». The electrical activity of LNCSB was registered by the stereotactic introduction of electrodes. The concentration of NO was investigated in the hippocampus, hypothalamus, septum + nucleus аccumbens Results. Intranasal administration of SNP to rats with alcohol dependence led to suppression of convulsive and paroxysmal activity, caused by alcoholization and withdrawal of alcohol, on the electroencephalogram of the structures of the LNCSB and increased the absolute power of biopotentials of the delta and theta ranges on the spectrogram of the hippocampus. Reduction of anxiety was found in rats with a high baseline level of anxiety accompanied by recovery of NO level, which was depleted by chronic alcoholization, in the hypothalamus and hippocampus. Conclusions. Intranasal administration of SNP as a NO donor causes anxiolytic effects in the state of alcohol withdrawal depending on the baseline level of anxiety: in rats with the high baseline level of anxiety – reduces this level; in rats with the low baseline level – restrains it at the level of anxiety after alcohol intake. Intranasal administration of SNP to the rats with alcohol withdrawal causes positive changes in the electroencephalogram of the LNCSB, which are manifested in suppression of convulsive and paroxysmal activity and enhancement of brain biopotentials in alpha and delta ranges on spectrogram of hippocampus with sustaining this effect for whole day. Intranasal administration of SNP is a source of short-term supply of NO to brain cells, which leads to the restoration of NO levels in the hypothalamus, hippocampus, septum and nucleus accumbens – structures that are involved in the regulation of emotional motivational behavior. Key words. limbic-neocortical system of the brain, model of alcohol dependence, anxiety, nitric oxide, sodium nitroprusside