Continuous spike-and-wave activity during slow-wave sleep in patients with rett syndrome

The article presents a description of a clinical case of a child 3 years 8 months old with Rett syndrome caused by the mutation of p.Val485fs in the MECP2 gene. According to electroencephalography data at the age of 1 year and 6 months, diffuse continued epileptiform activity in the form of high-amplitude (up to 300 μV) acute – slow wave complexes (continuous spike-waves during slow-wave sleep, CSWS) with an index of 90–100 % was revealed. At the control examination at the age of 2 years and 10 months diffuse epileptiform activity was replaced by multifocal activity with an index of up to 70–80 % at certain epochs, in general, not exceeding 50–60 %. During the entire observation period there were no epileptic seizures. It remains unknown whether the presence of CSWS at such an early age is a predictor of a more severe course of Rett syndrome – in our observation the girl did not acquire walking skills and a delay in psychic and speech development was evident already before the 12 month of life. more research is needed on the frequency of the CSWS phenomenon and its role in the development of clinical features in Rett syndrome.

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Expanding the Spectrum of EEG Periodic Discharges in Subacute Sclerosing Panencephalitis: A Case Report

Journal of Child Science ◽

10.1055/s-0041-1735536 ◽

2021 ◽

Vol 11 (01) ◽

pp. e245-e249

Author(s):

Iliyana Aleksandrova ◽

Asya Asenova ◽

Daniela Deneva ◽

Veneta Bojinova

Keyword(s):

Case Report ◽

Slow Wave ◽

Subacute Sclerosing Panencephalitis ◽

Epileptiform Activity ◽

Epileptic Seizures ◽

High Amplitude ◽

The Body ◽

Diagnostic Process ◽

Sharp Waves ◽

Eeg Abnormalities

Abstract Background Atypical electroencephalogram (EEG) abnormalities emerge in patients with subacute sclerosing panencephalitis (SSPE), especially in cases with an atypical clinical presentation that can lead to diagnostic difficulties. Case Report In this article, we presented a case of SSPE with an atypical onset with epileptic seizures and Parkinson's features. The neurological examination during the initial evaluation of the patient showed extrapyramidal syndrome, hyperreflexia, intention tremor, and dysmetria. Cranial magnetic resonance imaging was normal. Video EEGs were performed in wakefulness and sleep. In wakefulness, multiple brief seizures (1–1.5 seconds were recorded, consisting of gradual bending of the body forward and to the right that lacked the sudden characteristic of myoclonia. During those episodes, we recorded generalized epileptiform activity of 4 or 5 sharp waves, with higher amplitude in the anterior regions, in some of the paroxysms superimposed on a slow wave or followed by a high amplitude slow wave. The paroxysms appeared periodically every 15 to 30 seconds. However, 2 months later, the EEG showed typical periodic generalized activity of biphasic/triphasic slow waves (Radermecker complexes), accompanied by myoclonias. Conclusion We reported a peculiar EEG pattern in a patient with SSPE that consists of periodic generalized activity of sharp waves. Atypical EEG patterns can appear when the disease progresses, but initially too, before typical periodic complexes and can complicate the diagnostic process.

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Consciousness among delta waves: a paradox?

Brain ◽

10.1093/brain/awab095 ◽

2021 ◽

Cited By ~ 1

Author(s):

Joel Frohlich ◽

Daniel Toker ◽

Martin M Monti

Keyword(s):

Slow Wave Sleep ◽

Spectral Power ◽

Vegetative State ◽

Mitochondrial Diseases ◽

Epileptic Seizures ◽

High Amplitude ◽

Convincing Evidence ◽

Delta Activity ◽

Parallel Body ◽

Delta Oscillations

Abstract A common observation in EEG research is that consciousness vanishes with the appearance of delta (1 – 4 Hz) waves, particularly when those waves are high amplitude. High amplitude delta oscillations are very frequently observed in states of diminished consciousness, including slow wave sleep, anaesthesia, generalised epileptic seizures, and disorders of consciousness such as coma and vegetative state. This strong correlation between loss of consciousness and high amplitude delta oscillations is thought to stem from the widespread cortical deactivation that occurs during the “down states” or troughs of these slow oscillations. Recently, however, many studies have reported the presence of prominent delta activity during conscious states, which casts doubt on the hypothesis that high amplitude delta oscillations are an indicator of unconsciousness. These studies include work in Angelman syndrome, epilepsy, behavioural responsiveness during propofol anaesthesia, postoperative delirium, and states of dissociation from the environment such as dreaming and powerful psychedelic states. The foregoing studies complement an older, yet largely unacknowledged, body of literature that has documented awake, conscious patients with high amplitude delta oscillations in clinical reports from Rett syndrome, Lennox-Gastaut syndrome, schizophrenia, mitochondrial diseases, hepatic encephalopathy, and nonconvulsive status epilepticus. At the same time, a largely parallel body of recent work has reported convincing evidence that the complexity or entropy of EEG and magnetoencephalogram or MEG signals strongly relates to an individual’s level of consciousness. Having reviewed this literature, we discuss plausible mechanisms that would resolve the seeming contradiction between high amplitude delta oscillations and consciousness. We also consider implications concerning theories of consciousness, such as integrated information theory and the entropic brain hypothesis. Finally, we conclude that false inferences of unconscious states can be best avoided by examining measures of electrophysiological complexity in addition to spectral power.

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Short-Duration Epileptic Discharges Show a Distinct Phase Preference During Ongoing Hippocampal Slow Oscillations

Journal of Neurophysiology ◽

10.1152/jn.00418.2010 ◽

2010 ◽

Vol 104 (4) ◽

pp. 2194-2202 ◽

Cited By ~ 7

Author(s):

Philip H. de Guzman ◽

Farhang Nazer ◽

Clayton T. Dickson

Keyword(s):

Short Duration ◽

Temporal Lobe ◽

Slow Wave ◽

Rem Sleep ◽

Slow Wave Sleep ◽

Epileptiform Activity ◽

Epileptic Activity ◽

Network Synchronization ◽

State Dependent ◽

Oscillatory Pattern

Non-REM (slow-wave) sleep has been shown to facilitate temporal lobe epileptiform events, whereas REM sleep seems more restrictive. This state-dependent modulation may be the result of the enhancement of excitatory synaptic transmission and/or the degree of network synchronization expressed within the hippocampus of the temporal lobe. The slow oscillation (SO), a ∼1 Hz oscillatory pattern expressed during non-REM sleep and urethane anesthesia, has been recently shown to facilitate the generation, maintenance, and propagation of stimulus-evoked epileptiform activity in the hippocampus. To further address the state-dependent modulation of epileptic activity during the SO, we studied the properties of short-duration interictal-like activity generated by focal application of penicillin in the hippocampus of urethane-anesthetized rats. Epileptiform spikes were larger but only slightly more prevalent during the SO as opposed to the theta (REM-like) state. More notably, however, epileptic spikes had a significant tendency to occur just following the peak negativity of ongoing SO cycles. Because of the known phase-dependent changes in 1) synaptic excitability (just following the positive peak of the SO) and 2) network synchronization (during the negative peak of the SO), these results suggest that it is the synchrony and not the changes in synaptic excitability that lead to the facilitation of epileptiform activity during sleep-like slow wave states.

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Heightened Delta Power during Slow-Wave-Sleep in Patients with Rett Syndrome Associated with Poor Sleep Efficiency

PLoS ONE ◽

10.1371/journal.pone.0138113 ◽

2015 ◽

Vol 10 (10) ◽

pp. e0138113 ◽

Cited By ~ 8

Author(s):

Simon Ammanuel ◽

Wesley C. Chan ◽

Daniel A. Adler ◽

Balaji M. Lakshamanan ◽

Siddharth S. Gupta ◽

...

Keyword(s):

Rett Syndrome ◽

Slow Wave ◽

Slow Wave Sleep ◽

Sleep Efficiency ◽

Poor Sleep ◽

Delta Power

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High-voltage, diffuse delta rhythms coincide with wakeful consciousness and complexity in Angelman syndrome

Neuroscience of Consciousness ◽

10.1093/nc/niaa005 ◽

2020 ◽

Vol 2020 (1) ◽

Cited By ~ 1

Author(s):

Joel Frohlich ◽

Lynne M Bird ◽

John Dell’Italia ◽

Micah A Johnson ◽

Joerg F Hipp ◽

...

Keyword(s):

High Voltage ◽

Angelman Syndrome ◽

Cortical Neurons ◽

Slow Wave Sleep ◽

Epileptic Seizures ◽

High Amplitude ◽

Relative Level ◽

Eeg Activity ◽

Cortical Dynamics ◽

Volitional Behavior

Abstract Abundant evidence from slow wave sleep, anesthesia, coma, and epileptic seizures links high-voltage, slow electroencephalogram (EEG) activity to loss of consciousness. This well-established correlation is challenged by the observation that children with Angelman syndrome (AS), while fully awake and displaying volitional behavior, display a hypersynchronous delta (1–4 Hz) frequency EEG phenotype typical of unconsciousness. Because the trough of the delta oscillation is associated with down-states in which cortical neurons are silenced, the presence of volitional behavior and wakefulness in AS amidst diffuse delta rhythms presents a paradox. Moreover, high-voltage, slow EEG activity is generally assumed to lack complexity, yet many theories view functional brain complexity as necessary for consciousness. Here, we use abnormal cortical dynamics in AS to assess whether EEG complexity may scale with the relative level of consciousness despite a background of hypersynchronous delta activity. As characterized by multiscale metrics, EEGs from 35 children with AS feature significantly greater complexity during wakefulness compared with sleep, even when comparing the most pathological segments of wakeful EEG to the segments of sleep EEG least likely to contain conscious mentation and when factoring out delta power differences across states. These findings (i) warn against reverse inferring an absence of consciousness solely on the basis of high-amplitude EEG delta oscillations, (ii) corroborate rare observations of preserved consciousness under hypersynchronization in other conditions, (iii) identify biomarkers of consciousness that have been validated under conditions of abnormal cortical dynamics, and (iv) lend credence to theories linking consciousness with complexity.

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Continuous Spike and Wave in Slow-Wave Sleep in a Patient With Rett Syndrome and in a Patient With Lhermitte-Duclos Syndrome and Neurofibromatosis 1

Journal of Child Neurology ◽

10.1177/0883073813509888 ◽

2013 ◽

Vol 29 (12) ◽

pp. NP176-NP180 ◽

Cited By ~ 4

Author(s):

Sushanth Bhat ◽

Xue Ming ◽

Rony Dekermenjian ◽

Sudhansu Chokroverty

Keyword(s):

Rett Syndrome ◽

Slow Wave ◽

Slow Wave Sleep ◽

Neurofibromatosis 1

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Slow Oscillation State Facilitates Epileptiform Events in the Hippocampus

Journal of Neurophysiology ◽

10.1152/jn.90795.2008 ◽

2009 ◽

Vol 102 (3) ◽

pp. 1880-1889 ◽

Cited By ~ 18

Author(s):

Farhang Nazer ◽

Clayton T. Dickson

Keyword(s):

Slow Wave Sleep ◽

Epileptiform Activity ◽

High Amplitude ◽

Slow Oscillation ◽

Dynamic Coordination ◽

Epileptiform Discharges ◽

Mesial Temporal Lobe ◽

Activity State ◽

Hippocampal Eeg ◽

Epileptiform Events

In mesial temporal lobe (MTL) epilepsy, which typically involves the hippocampus (HPC), epileptiform events are enhanced during slow wave sleep (SWS). It remains unclear how and why the electroencephalographic (EEG) states that constitute SWS might predispose the HPC to this type of pathological activity. Recently our laboratory has described a novel state of deactivated hippocampal EEG activity that occurs during both SWS and urethan anesthesia: the slow oscillation (SO). This activity is characterized by a high-amplitude ∼1-Hz signal, high synchrony within the hippocampus, and a dynamic coordination with neocortical SO. To assess how this activity state might influence epileptiform discharges, we studied the properties of stimulation-evoked and spontaneous epileptiform events elicited in the HPC of urethan-anesthetized rats. We compared those elicited during the SO to those occurring during the theta rhythm. The average duration but not the amplitude of evoked afterdischarges (ADs) was consistently larger during the SO. In addition, spontaneous epileptiform events were more frequent and of higher amplitude during the SO. Last, the bilateral propagation of both ADs and spontaneous events in the hippocampus was enhanced during the SO. These results imply that the threshold for the generation and propagation of epileptiform activity in the hippocampus is lowered during the SO and that this state may be a seed for the initiation, maintenance, and generalization of MTL epilepsy. Further examination of the pathophysiology of sleep-epilepsy interactions in the HPC will be of benefit for an understanding of the mechanisms, prognosis, and therapy for this form of epilepsy.

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Aggravation of symptomatic occipital epilepsy of childhood by carbamazepine

Vojnosanitetski pregled ◽

10.2298/vsp1404404s ◽

2014 ◽

Vol 71 (4) ◽

pp. 404-407 ◽

Cited By ~ 1

Author(s):

Fadil Skrijelj ◽

Mersudin Mulic

Keyword(s):

Slow Wave ◽

Clinical Manifestations ◽

Brain Magnetic Resonance Imaging ◽

Poor Performance ◽

Epileptic Seizures ◽

High Amplitude ◽

Psychomotor Development ◽

Vacuum Extraction ◽

Sharp Waves ◽

Normal Limits

Introduction. Carbamazepine can lead to aggravation of epileptic seizures in generalized epilepsies (primary or secondary) with clinical manifestations of absence (typical or atypical) and/or myoclonic seizures. However, some focal epilepsies can be also aggravated by the introduction of carbamazepine. Case report. We presented a 10-year-old boy born after a complicated and prolonged delivery completed by vacuum extraction, of early psychomotor development within normal limits. At the age of 8 years he had the first epileptic seizure of simple occipital type with generalization and urination. Brain magnetic resonance imaging (MRI) showed focal cortical reductions in the left parietal and occipital regions. Interictal EEG recorded slowed basic activities above the posterior regions of the left hemisphere, with intermittent occurrence of occipital sharp waves and bioccipital sharp and slow-wave complexes. Initially, treatment with valproate was administered; however, the addition of carbamazepine into therapy induced aggravation of seizures and EEG findings, changed behavior and poor performance at school. By withdrawal of carbamazepine the condition improved both clinically and in EEG findings. Conclusion. Childhood occipital epilepsy lesions show deterioration due to carbamazepine, which if administered induces aggravation of seizures, behavior changes, cognition with occurrence of long-term bilateral discharges, and posterior sharp and slow wave high amplitude complexes recorded by EEG.

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