IIT Delhi comes up with non-invasive diagnostic tool for epilepsy

It will help neurosurgeons pinpoint where in the brain the seizure is located.

The Indian Institute of Technology in Delhi. | Photo Credit: SHIV KUMAR PUSHPAKAR

EPILEPSY is the fourth most common neurological disorder in the world, affecting millions of people worldwide. It involves brief episodes of involuntary body (partial/entire) movement called seizures, primarily caused by erroneous excessive electrical discharges in the brain, that may be accompanied by loss of consciousness and control of bowel or bladder function.

Epilepsies are often controlled with medicines, though drug therapies sometimes fail owing to drug resistance. Drug-resistant epilepsies are most likely to originate from structural abnormalities of the brain, the cure for which is usually surgery.

A harmonics function plot of a subject having a seizure in the left temporal lobe of the brain. | Photo Credit: IIT Delhi

These structural abnormalities are too subtle to be identified on the basis of MRIs alone and always need to be interpreted along with an electroencephalogram (EEG) evaluation. Neurosurgeons also utilise positron emission tomography (PET) scans and magnetoencephalography (MEG). However, PET scans involve exposure to radioactive substances, and India has a limited number of MEG facilities. Craniotomies (surgical removal of part of the bone from the skull to expose the brain) and robot-assisted surgeries are invasive, involving holes being drilled into the skull to place electrodes directly on the brain. It takes two to eight hours to detect the epileptogenic zone.

Now, a team of researchers at IIT Delhi led by Lalan Kumar of the Department of Electrical Engineering, and which included a scientist from Deenanath Mangeshkar Hospital and Research Centre, Pune, has come up with a non-invasive EEG-based Brain Source Localisation framework for epilepsy focal detection that is time efficient and patient friendly. Given the EEG data with seizure, array-processing algorithms can point the coordinates within minutes. “We have proposed utilisation of spherical harmonics and head harmonics basis functions for seizure localisation. To the best our knowledge, this is the first attempt in non-invasive and time efficient seizure localisation,” Kumar was quoted as saying in an IITD press release.  The study titled “Anatomical harmonics basis based brain source localization with application to epilepsy” was recently published in Nature Portfolio’s Scientific Reports.