Diagnosing and studying epilepsy and migraines is currently being done by placing electrodes directly on the surface of the brain. The electrodes are used to detect cortical spreading depression (CSD), which is a low frequency brainwave linked to these diseases.
Better treatment and diagnosis of these conditions is on the horizon with the discovery that amplified EEGs (electroencephalograms) can achieve the same results. This procedure is not invasive as the current standard is.
In a joint study carried out by researchers from Germany, UBC and Iran, the team has discovered that by using a specially designed amplifier in tandem with EEGs, equally reliable data can be obtained. EEGs make use of electrodes placed on the skull rather than directly on the surface of the brain.
Zoya Bastany, a master’s student in the faculty of applied science at UBC and lead researcher of the study, noted that the electrical signals acquired from the surface of the brain are very similar to those acquired from the skin of the scalp when this method is used.
Using electrical signals obtained from scalp electrodes applied to anesthetized rats, Bastany managed to design an AC/DC amplifier that picks up signals in a much wider frequency range than what a standard clinical EEG system does.
The amplifier CSD was induced in the rats. Recordings from electrodes placed on the rats’ brains were then compared to recordings taken from scalp electrodes.
Guy Dumont, an electrical and computer engineering professor at UCB and Bastany’s supervisor and study co-author, explains that cortical spreading depression has never been accurately measured using EEGs. This new method has made it possible for the first time. Cortical spreading depression can now be studied in a non-invasive manner. The diagnostic cost increase compared to a standard EEG is negligible.
Study co-author, Ali Gorji, a professor of neuroscience at the University of Münster in Germany, hopes the new technique will contribute to the development of migraine drugs that target CSD. Other neurological disorders may also in future be better understood by using this new method.
The clinical relevance of CSD is not yet fully understood, but having this noninvasive way of studying this brainwave is likely to lead to a better understanding, diagnosis and treatment of migraine, as well as other neurological conditions such as stroke, epilepsy and traumatic brain injury.
Study has been published in the journal Neuroscience.