title: Non-invasive monitoring of spreading depression.
abstract: Spreading depression (SD), a slow propagating depolarization wave, plays an important role in pathophysiology of different neurological disorders. Yet, research into SD-related disorders has been hampered by the lack of non-invasive recording techniques of SD. Here we compared the manifestations of SD in continuous non-invasive electroencephalogram (EEG) recordings to invasive electrocorticographic (ECoG) recordings in order to obtain further insights into generator structures and electrogenic mechanisms of surface recording of SD. SD was induced by KCl application and simultaneous SD recordings were performed by scalp EEG as well as ECoG electrodes of somatosensory neocortex of rats using a novel homemade EEG amplifier, AgCl recording electrodes, and high chloride conductive gel. Different methods were used to analyze the data; including the spectrogram, bi-spectrogram, pattern distribution, relative spectrum power, and multivariable Gaussian fit analysis. The negative direct current (DC) shifts recorded by scalp electrodes exhibited a high homogeneity to those recorded by ECoG electrodes. Furthermore, this novel method of recording and analysis was able to separate SD recorded by scalp electrodes from non-neuronal DC shifts induced by other potential generators, such as the skin, muscles, arteries, dura, etc. These data suggest a novel application for continuous non-invasive monitoring of DC potential changes, such as SD. Non-invasive monitoring of SD would allow early intervention and improve outcome in SD-related neurological disorders.
authors.affiliation: The Electrical and Computer Engineering Department, University of British Columbia, Vancouver, Canada.
authors.forename: Zoya J R
authors.initials: ZJ
authors.lastname: Bastany
authors.affiliation: The Electrical and Computer Engineering Department, University of British Columbia, Vancouver, Canada.
authors.forename: Shahbaz
authors.initials: S
authors.lastname: Askari
authors.affiliation: The Electrical and Computer Engineering Department, University of British Columbia, Vancouver, Canada; Child and Family Research Institute, University of British Columbia, Vancouver, Canada.
authors.forename: Guy A
authors.initials: GA
authors.lastname: Dumont
authors.affiliation: Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Germany.
authors.forename: Erwin-Josef
authors.initials: EJ
authors.lastname: Speckmann
authors.affiliation: Epilepsy Research Center, Westfälische Wilhelms-Universität Münster, Germany; Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran, Iran; Mashhad Neuroscience Department, MUMS, Mashhad, Iran; Department of Neurosurgery, Westfälische Wilhelms-Universität Münster, Germany; Department of Neurology, Westfälische Wilhelms-Universität Münster, Germany. Electronic address: gorjial@uni-muenster.de.
authors.forename: Ali
authors.initials: A
authors.lastname: Gorji
mesh_terms: D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D002491:Central Nervous System Agents / Q000494:pharmacology; D013181:Cortical Spreading Depression / Q000187:drug effects / Q000502:physiology*; D004567:Electrodes, Implanted; D004569:Electroencephalography / Q000295:instrumentation / Q000379:methods; D005583:Fourier Analysis; D023421:Models, Animal; D064926:Neurophysiological Monitoring / Q000295:instrumentation / Q000379:methods; D011189:Potassium Chloride / Q000494:pharmacology; D017208:Rats, Wistar; D012815:Signal Processing, Computer-Assisted
chemical_list: D002491:Central Nervous System Agents; D011189:Potassium Chloride
keywords: brain waves; epilepsy; migraine; slow wave; stroke; ultraslow wave