Impact of cognitive stimulation on ripples within human epileptic and non-epileptic hippocampus

Investor logo
Investor logo

Warning

This publication doesn't include Faculty of Medicine. It includes Central European Institute of Technology. Official publication website can be found on muni.cz.

Authors

BRÁZDIL Milan CIMBÁLNÍK Jan ROMAN Robert SHAW Daniel Joel STEAD Matt M. DANIEL Pavel JURÁK Pavel HALÁMEK Josef

Year of publication 2015
Type Article in Periodical
Magazine / Source BMC Neuroscience
MU Faculty or unit

Central European Institute of Technology

Citation
Web http://www.biomedcentral.com/content/pdf/s12868-015-0184-0.pdf
Doi http://dx.doi.org/10.1186/s12868-015-0184-0
Field Neurology, neurosurgery, neurosciences
Keywords High-frequency oscillations; Hippocampal ripples; Epilepsy; Human cognition
Attached files
Description Background: Until now there has been no way of distinguishing between physiological and epileptic hippocampal ripples in intracranial recordings. In the present study we addressed this by investigating the effect of cognitive stimulation on interictal high frequency oscillations in the ripple range (80-250 Hz) within epileptic (EH) and non-epileptic hippocampus (NH). Methods: We analyzed depth EEG recordings in 10 patients with intractable epilepsy, in whom hippocampal activity was recorded initially during quiet wakefulness and subsequently during a simple cognitive task. Using automated detection of ripples based on amplitude of the power envelope, we analyzed ripple rate (RR) in the cognitive and resting period, within EH and NH. Results: Compared to quiet wakefulness we observed a significant reduction of RR during cognitive stimulation in EH, while it remained statistically marginal in NH. Further, we investigated the direct impact of cognitive stimuli on ripples (i.e. immediately post-stimulus), which showed a transient statistically significant suppression of ripples in the first second after stimuli onset in NH only. Conclusion: Our results point to a differential reactivity of ripples within EH and NH to cognitive stimulation.
Related projects:

You are running an old browser version. We recommend updating your browser to its latest version.

More info