Background: Close relationship exists between sleep slow wave (SSW) and the generation of spike wave in NREM-sleep. SSW are cortically generated oscillations alternating between excitatory depolarization ("Up-phase" of the SSW) and inhibitory hyperpolarization ("Down-phase" of the SSW). It has been shown experimentally that with increasing synchrony of slow neuronal oscillations SSW turn into spike waves. Acoustic pulses applied in correspondence to the SSW "Up-phase" enhance the amplitude of the subsequent SSW. Conversely, tones delivered at the SSW "Downphase" have a disruptive effect on the following SSW. Participants: Patients with epilepsy and spike waves in NREM-sleep. Objective: Modification of spike wave frequency, amplitude and spreading during NREM sleep by acoustic pulses applied at the "Up-" or "Down-phase" of SSW.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
6
Acoustic pulses applied during NREM sleep slow waves "Up-phase" or "Down-phase". The acoustic stimulus will be delivered by speakers with a volume of about 50 dB.
Div. of Clinical Neurophysiology/Epilepsy, University Children's Hospital Zurich
Zurich, Switzerland
Spike wave index
Change of spike wave index during acoustic pulses applied at the "Up-" or "Down-phase" of sleep slow waves. Spike wave index given in percent and calculated by number of seconds within 10 second windows with spike waves over the whole 15 minutes of the block design part.
Time frame: Change baseline (without) and with acoustic pulses in the same NREM period: 45 minutes
Spike wave amplitude
Change of spike wave amplitude (in microvolts) during acoustic pulses applied at the "Up-" or "Down-phase" of sleep slow waves. Amplitudes of maximum spike will be analyzed in 10 seconds periods of the first and the last 100 seconds of every part of the block design. EEG source derivation will be used for the analysis. The mean of the 3 highest amplitudes of each 10 seconds period will be determined and the mean of the 10 periods will presented in mean and SD.
Time frame: Change baseline (without) and with acoustic pulses in the same NREM period: 45 minutes
Spike wave spreading
Change of spike wave spreading during acoustic pulses applied at the "Up-" or "Down-phase" of sleep slow waves. Spreading will be analyzed in 10 seconds periods of the first and the last 100 seconds of every part of the block design. EEG source derivation will be used for the analysis. Maximum spike wave spreading (number of electrodes involved) visible in 3 spike waves of each 10 second period will be determined and the mean of the 10 periods will presented in mean and SD.
Time frame: Change baseline (without) and with acoustic pulses in the same NREM period: 45 minutes
Spike wave index in the NREM (2) period following the NREM (1) period with acoustic pulses
Change of spike wave index in the NREM period following the NREM period with acoustic pulses applied at the "Up-" or "Down-phase" of sleep slow waves. Over the first 15 minutes of the following NREM period: Spike wave index given in percent and calculated by number of seconds within 10 second windows with spike waves .
Time frame: Change baseline (NREM 1) and NREM 2: expected average of 1 hour
Spike wave amplitude in the NREM (2) period following the NREM (1) period with acoustic pulses
Change of spike wave amplitude (in microvolts) in the NREM period following the NREM period with acoustic pulses applied at the "Up-" or "Down-phase" of sleep slow waves. Amplitudes of maximum spike will be analyzed in 10 seconds periods of the first and the last 100 seconds of the following NREM period. EEG source derivation will be used for the analysis. The mean of the 3 highest amplitudes of each 10 seconds period will be determined and the mean of the 10 periods will presented in mean and SD.
Time frame: Change baseline (NREM 1) and NREM 2: expected average of 1 hour
Spike wave spreading in the NREM (2) period following the NREM (1) period with acoustic pulses
Change of spike wave spreading in the NREM period following the NREM period with acoustic pulses applied at the "Up-" or "Down-phase" of sleep slow waves. Spreading will be analyzed in 10 seconds periods of the first and the last 100 seconds of the following NREM period. EEG source derivation will be used for the analysis. Maximum spike wave spreading (number of electrodes involved) visible in 3 spike waves of each 10 second period will be determined and the mean of the 10 periods will presented in mean and SD.
Time frame: Change baseline (NREM 1) and NREM 2: expected average of 1 hour
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