Since its earliest days, researchers and clinicians at The Neuro have been uncovering the mysteries of epilepsy and improving methods of diagnosing and treating patients. More than 70 years ago, The Neuro’s founder, Dr. Wilder Penfield, introduced a surgical procedure for epilepsy known as the Montreal Procedure, which is still performed throughout the world. The Neuro also pioneered the use in Canada of the electroencephalogram and magnetic resonance imaging for epilepsy research and diagnosis. For Purple Day for Epilepsy, March 26, The Neuro highlights the work of its epilepsy researchers and clinicians past and present who have improved the lives of people suffering from this often debilitating disease.
A distinguished past
Among the distinguished figures in The Neuro’s history was one of the world’s most renowned epileptologists, Dr. Frederick Andermann. He died in 2019 after spending his entire medical career here. In an homage to Dr. Anderman following his death, an international panel of epileptologists gathered at The Neuro to present their latest findings in epilepsy syndromes, research procedures and surgical techniques. Last December, The Neuro named its Clinical Epileptology Unit in honour of Dr. Andermann, who had served for 35 years as the unit’s director. A plaque with his name is placed there in his honour. World recognition of Dr. Andermann’s legacy was shown with the creation of the Fred Andermann Lecture in Clinical Epileptology by the International League Against Epilepsy, an organism that bestowed its Lifetime Achievement Award on Dr. Andermann in 2015.
A far-reaching future
Dr. Birgit Frauscher is a member of a new generation of researchers and clinicians at The Neuro who are continuing the tradition of pathbreaking work in epilepsy begun by the generations of Dr. Penfield and Dr. Andermann.
Dr. Frauscher and her colleagues have shed light, for example, on how epileptic activity during sleep might influence the development of sleep disruptions. Disturbed sleep is common among epilepsy patients, but the direct influence of nocturnal epileptic activity on sleep is still poorly understood.
Thirty-six patients in the Frederick Andermann Clinical Epileptology Unit agreed to undergo tests to determine whether sleep-related epileptic activity is associated with sleep disruption. All the patients had focal drug-resistant epilepsy. The results of the study were published in Annals of Neurology, 2020, 88, pp 907-920 (should hyperlink, “Annals of Neurology’).
The tests used two methods for locating seizures. Stereo-electroencephalography involves placing electrodes in targeted areas of both hemispheres of the brain, which allows monitors to detect the source of seizures deeper in the brain than can be detected by conventional electroencephalography (EEG). Polysomnography uses various sensors attached to the patient’s body overnight. The sensors record brain waves, eye movements and muscle activity.
“The vast majority of previous studies used traditional EEG on the scalp, which detect seizures that reach the surface but not those deep in the brain,” says Dr. Frauscher. “Our innovative approach gave us a precise three-dimensional pattern of the evolution of the seizure and its location. We were able to record not only obvious seizures,but also single epileptic spikes that are extremely brief, less than 70 milliseconds.”
It was already known that many sleeping epilepsy patients either were awakened or were aroused following convulsive seizures.
Dr. Frauscher’s team found evidence that fragmented sleep might also be associated with hardly noticeable epileptic activity in periods between seizures, known as interictal activity. In their study, an increase in interictal activity was recorded before people’s arousal, which suggested that this activity was linked to sleep disruption. There was also an increase in the rate of tiny epileptic seizures during arousal. Dr. Frauscher suspects that this rate increase might be a result of instability at the sleep-wake boundary making the brain more prone to generate seizures.
“Not only obvious seizures but these small signatures of epilepsy might be disturbing sleep,” says Dr. Frauscher. “Until now, medication has been used to stop large seizures, but clinicians have not addressed how to treat these small signatures. Our data could change the way that we treat epilepsy. But first we need to do more studies. We are now undertaking research to find out whether the interictal activity is driving the wake reactions or whether there is a possible third factor.”
On Purple Day for Epilepsy, The Neuro salutes not only Dr. Frauscher and her colleagues, but all those who work in research and clinical institutes worldwide to better understand epilepsy and to provide treatments so that patients can live happier lives.