Epilepsy is a chronic condition caused by sudden electrical discharges in the brain. These erratic impulses surge through brain regions, causing seizures. Though medications can control seizures, about one-third of the people with epilepsy develop resistance to the drugs, rendering the medication ineffective in the treatment.
Fortunately, emerging technology-enabled medical interventions are providing hopeful solutions that can assist in monitoring and controlling seizures.
A tool for speedy detection
Neurologists use a non-invasive instrument called an electroencephalogram (EEG) to record the differences in electrical signals underlying the cause of a seizure. “A difficult but crucial epilepsy diagnosis is to differentiate between general and focal epilepsy as they have different treatments depending on the region where the seizures occur,” says Dr Latika Mohan from the All India Institute of Medical Science (AIIMS), Rishikesh, in a conversation with Happiest Health. “It’s harder to differentiate when the intensity of seizure is so minute that many people aren’t even aware of their underlying seizures,” she points out.
Addressing this challenging task of accurately reading the complex EEG signals, Dr Hardik J Pandya and his research group from the Indian Institute of Science (IISc), Bengaluru, developed a computer algorithm which assists doctors in interpreting EEGs and determining the epilepsy type.
“Each EEG test takes around 45 minutes. The algorithm makes the doctors’ work easier by automatically identifying, analysing differences in signal, accordingly, determine the epilepsy type,” Dr Pandya says.
“There are other diagnostic methods like magnetoencephalography, but they are expensive and not accessible to many,” says Dr Mohan from AIIMS. “EEG is cheaper, and the software makes it more accessible in rural areas where experts are unavailable.” In addition, she says, reading the EEG recordings is time-intensive and not every clinician follows the required recording protocol of 45 minutes. “This is where the algorithm works in favour of time and efficient diagnosis,” she adds.
Immunotherapy meets medicine
One reason people with epilepsy develop drug resistance is that the medicines cause inflammation in the brain. Researchers are exploring immunotherapies or ways to suppress such inflammation.
These immune therapies are used along with medications to douse or stimulate an immune response that reduces side effects and improves drug action. One study shows that a key cell membrane protein called P-glycoprotein filters all that enters the brain, playing an active role in restricting antiepileptic drugs from passing. By immunotherapy methods, researchers are looking for ways to control P-glycoprotein’s activity.
Although the research is in its nascency, it provides a hope of offering individuals with epilepsy a seizure-free life one day.
Brain implants that control seizures
“In cases of multiple seizures in a day, managing them becomes hard, especially with drug resistance,” says Dr Mohan. However, with advances in technology, some devices electrically stimulate parts of the brain that help to manage seizures in people.
Neurostimulation is a method of electrically suppressing seizures with a pacemaker-like device implanted with electrodes in the brain. “Deep brain stimulation (DBS) provides an external electrical impulse whenever a seizure occurs. It opposes the abrupt brain electric impulse and ends the seizure before it affects the person,” explains Dr Pandya from the IISc.
Researchers are also developing other stimulation devices without the risk of implanted electrodes in the brain. For example, vagus nerve stimulation (VNS) and trigeminal nerve stimulation (TNS) work similarly without the risk of electrodes implanted into the brain. In addition, these methods have fewer side effects.
VNS sends regular mild pulses to the brain through the vagus nerve, which modulates the body’s involuntary activity. Therefore, it does not require deep brain surgery. With minimum incision, the implant is placed near the collar bone and connected to the nerve.
The Food and Drug Administration, USA, has approved the use of VNS for conditional epileptic cases where there is resistance to at least two drugs. However, VNS is used in conjunction with medications, not in their stead.
Dr Pandya adds, “TNS are external devices placed on the forehead, which provide an electrical impulse to the brain regions via the trigeminal nerve – a primary sensory nerve situated on the forehead.” The device has completed the phase 2 clinical trials with promising results.
Risk of tissue damage
“Although these devices help to manage seizures, every intervention comes with a few risks like tissue damage or an infection. Still, in extreme epilepsy cases with multiple seizures daily, the pros of the devices outweigh the side effects,” explains Dr Mohan.
Dr Pandya’s team is currently developing flexible biocompatible microelectrode arrays that can potentially minimise the damage and infection of implantable devices. The microelectrode of 3-5 mm is implanted into the outermost surface of the brain; it records the brain signals from 32 channels.
“This wide range allows researchers to observe and interpret the changes in the brain signals during seizures and analyse the condition based on which part of the brain is affected,” he says. Currently, the team is verifying the efficacy of the device on animal models.
Moreover, the device is also an efficient tool for neurosurgeons to interpret drug effects, and analyse and interpret the exact region of seizures, says Dr Pandya. He estimates that “Ideally, it should take three to five years for the device to come into [actual] treatment.”