Researchers at IIT Delhi have developed a non-invasive EEG-based Brain Source Localization (BSL) framework for epilepsy focal detection that is both time efficient and patient-friendly. Within minutes, the array processing algorithms can point to the coordinates given the EEG data with seizures. The team of researchers, led by Prof Lalan Kumar of IIT Delhi’s Department of Electrical Engineering, has proposed novel head harmonics-based algorithms for seizure localization.
Epilepsy is fourth most common neurological disorder in world
“Epilepsy is the fourth most common neurological disorder in the world and affects millions worldwide. It involves brief episodes of involuntary body (partial/entire) movement called seizures and may be accompanied by loss of consciousness and control of bowel or bladder function, primarily due to erroneous excessive electrical discharges. Quite a lot of epilepsies can be controlled by medicines, however,
when medicines fail to control seizures, it is labeled as drug-resistant epilepsy,” said the IIT.
Drug-resistant epilepsies are most likely caused by structural abnormalities in the brain, and thus brain surgery provides a complete cure for these patients if the exact origin and extent of abnormality are identified by a neurosurgeon. The most difficult and time-consuming task in surgical evaluation is determining the source of an electrical abnormality and correlating it with a structural abnormality of the brain.
Availability of MEG is limited
These structural abnormalities are so subtle that they cannot be identified using MRI alone and must always be interpreted in conjunction with electroencephalogram (EEG) evaluation. Neurosurgeons may also use positron emission tomography (PET) scans and magnetoencephalography (MEG). PET scans require the ingestion of radioactive substances. In India, the availability of MEG is extremely limited. Craniotomy and robot-assisted surgery are invasive procedures in which clinicians drill holes in the skull to implant electrodes on the brain. Epileptogenic Zone Detection takes two to eight hours and is unpleasant for patients.
The researchers have validated the proposed source localization algorithms on clinical EEG data for epileptogenic zone localization. The proposed framework offers an effective solution to clinicians in automated and time-efficient seizure localization. “It is a breakthrough considering the comfort of patients,” Prof Kumar added.
Dr Amita Giri, a Prime Minister’s Research Fellow (PMRF) in the Department of Electrical Engineering at IIT Delhi, has developed the novel epileptic region detection method as a major part of her Ph.D. work. The other members of the research team include Prof. Tapan K. Gandhi, Electrical Engineering Dept., IIT Delhi, and Dr. Nilesh Kurwale, Deenanath Mangeshkar Hospital and Research Center, Pune, Maharashtra, India.
Their study titled ‘Anatomical harmonics basis based brain source localization with application to epilepsy’ was published in Nature’s Scientific Reports. “We have proposed utilization of spherical harmonics and head harmonics basis functions for seizure Localization. To the best of our knowledge, this is the first attempt at non-invasive and time-efficient seizure Localization,” Prof. Lalan Kumar, Department of Electrical Engineering, IIT Delhi, said.
