Modulation of sleep interictal epileptiform discharges in partial epilepsy of childhood

OBJECTIVE NREM sleep increases the Interictal Epileptic Discharges (IEDs) in the majority of children affected by partial epilepsy (both symptomatic or cryptogenetic). Experimental data revealed that the normal sleep oscillations, leading to the appearance of spindles and delta waves on the surface EEG during NREM sleep, might develop into paroxysmal synchronization. Spectral analysis enables the quantitative description of the dynamics of delta (slow wave activity, SWA, 0,5-4,5 Hz) and sigma activity (SA, 12.0-16.0 Hz) and can be used to assess the relationship between SA, SWA and IEDs during sleep. DESIGN AND METHODS We have performed overnight continuous EEG-polysomnographic studies in 7 patients (mean age 7.2+/-1.3). The temporal series of SWA and SA were obtained from a spike-free derivation lead. The IEDs count was performed on the most active lead. Relationships between sigma and SWA and time series of IEDs were tested by means of correlation techniques after data normalization. RESULTS Our results revealed a significant higher correlation between IEDs and SA with respect to SWA in all the subjects, in total sleep time. The same analysis limited to NREM sleep highlights the better correlation between SA and IEDs. CONCLUSIONS Our data suggest that the neural mechanisms involved in the generation of sleep spindles facilitate the IEDs production in childhood partial epilepsies at least in those strongly activated by sleep.

[1]  R S Fisher,et al.  Spike-wave rhythms in cat cortex induced by parenteral penicillin. II. Cellular features. , 1977, Electroencephalography and clinical neurophysiology.

[2]  S. Shapiro,et al.  An Analysis of Variance Test for Normality (Complete Samples) , 1965 .

[3]  P. Genton,et al.  Etude de l'EEG de sieste dans les epilepsies partielles idiopathiques et symptomatiques de l'enfant , 1988, Neurophysiologie Clinique/Clinical Neurophysiology.

[4]  P. Gloor,et al.  Pathophysiology of generalized penicillin epilepsy in the cat: the role of cortical and subcortical structures. I. Systemic application of penicillin. , 1977, Electroencephalography and clinical neurophysiology.

[5]  A. Rechtschaffen,et al.  A manual of standardized terminology, technique and scoring system for sleep stages of human subjects , 1968 .

[6]  I Feinberg,et al.  Systematic trends across the night in human sleep cycles. , 1979, Psychophysiology.

[7]  J. Röschke,et al.  Different phase relationships between EEG frequency bands during NREM and REM sleep. , 1997, Sleep.

[8]  D Contreras,et al.  Relations between cortical and thalamic cellular events during transition from sleep patterns to paroxysmal activity , 1995, The Journal of neuroscience : the official journal of the Society for Neuroscience.

[9]  P. Pola,et al.  Interictal epileptic activity during sleep: a stereo-EEG study in patients with partial epilepsy. , 1984, Electroencephalography and clinical neurophysiology.

[10]  Peter Achermann,et al.  A model of human sleep homeostasis based on EEG slow-wave activity: Quantitative comparison of data and simulations , 1993, Brain Research Bulletin.

[11]  J. Gotman,et al.  Interictal spiking during wakefulness and sleep and the localization of foci in temporal lobe epilepsy , 1991, Neurology.

[12]  J. Montplaisir,et al.  Sleep and epilepsy. , 1985, Electroencephalography and clinical neurophysiology. Supplement.

[13]  P. Ktonas,et al.  Delta (0.5-1.5 Hz) and sigma (11.5-15.5 Hz) EEG power dynamics throughout quiet sleep in infants. , 1995, Electroencephalography and clinical neurophysiology.

[14]  L F Quesney,et al.  Pathophysiology of generalized penicillin epilepsy in the cat: the role of cortical and subcortical structures. II. Topical application of penicillin to the cerebral cortex and to subcortical structures. , 1977, Electroencephalography and clinical neurophysiology.

[15]  J. W. Crawley,et al.  The Relationship Between Sleep Spindles and Spike-and-Wave Bursts in Human Epilepsy , 1990 .

[16]  C. Hommet,et al.  Sleep and epilepsy. , 1999, Sleep medicine reviews.

[17]  P. Achermann,et al.  Spindle frequency activity in the sleep EEG: individual differences and topographic distribution. , 1997, Electroencephalography and clinical neurophysiology.

[18]  S. Roux,et al.  Influence of waking and sleep stages on the inter-ictal paroxysmal activity in partial epilepsy with complex seizures. , 1983, Electroencephalography and clinical neurophysiology.

[19]  D. McCormick,et al.  Sleep and arousal: thalamocortical mechanisms. , 1997, Annual review of neuroscience.

[20]  P. Crandall,et al.  Special characteristics of EEG activity accompanying deep spiking in a patient with schizophrenia. , 1970, Electroencephalography and clinical neurophysiology.

[21]  M. Hafez,et al.  HLA Antigens and Idiopathic Epilepsy , 1985, Epilepsia.

[22]  G. Rosadini,et al.  Relationship of sleep interictal epileptiform discharges to sigma activity (12–16 Hz) in benign epilepsy of childhood with rolandic spikes , 1999, Clinical Neurophysiology.

[23]  G. Rosadini,et al.  An EEG computerized system for the evaluation of hypnotic drugs. , 1992, International journal of psychophysiology : official journal of the International Organization of Psychophysiology.

[24]  J. Tukey,et al.  Transformations Related to the Angular and the Square Root , 1950 .

[25]  I. Feinberg,et al.  Sigma (12–15 Hz) and Delta (0.3–3 Hz) EEG oscillate reciprocally within NREM sleep , 1991, Brain Research Bulletin.

[26]  Xihong Lin,et al.  Relationship of interictal epileptiform discharges to sleep depth in partial epilepsy. , 1997, Electroencephalography and clinical neurophysiology.

[27]  P Kellaway,et al.  Sleep and Epilepsy , 1985, Epilepsia.

[28]  T. Gasser,et al.  Transformations towards the normal distribution of broad band spectral parameters of the EEG. , 1982, Electroencephalography and clinical neurophysiology.

[29]  F. Galletti,et al.  Decharges EEG localisees continues pendant le sommeil chez l'enfant , 1989, Neurophysiologie Clinique/Clinical Neurophysiology.

[30]  A. Borbély,et al.  All‐night dynamics of the human sleep EEG , 1993, Journal of sleep research.

[31]  M. Stecker,et al.  Treatment of Refractory Status Epilepticus with Propofol: Clinical and Pharmacokinetic Findings , 1998, Epilepsia.

[32]  P. Gloor,et al.  An assessment of the value of sleep-electroencephalography for the diagnosis of temporal lobe epilepsy. , 1958, Electroencephalography and clinical neurophysiology.

[33]  A. Davies,et al.  Intrinsic programmes of growth and survival in developing vertebrate neurons , 1994, Trends in Neurosciences.

[34]  H. Merica,et al.  A Neuronal Transition Probability Model for the Evolution of Power in the Sigma and Delta Frequency Bands of Sleep EEG , 1997, Physiology & Behavior.