Colin Croxon (centre) has struggled with seizures for nearly a decade. Thanks to deep brain stimulation technology and an expert team at the Krembil Brain Institute, he can now enjoy life again.
"I want to go out and finally enjoy the world."
— Colin Croxon
Kim Croxon has had many difficult days over the years, but one stands out. While at her job coaching gymnastics, she got a panicked call from her daughters, who told her to come home right away. She sped down the highway but could barely reach her house, as several ambulances, fire trucks and police cars were blocking her street. They were there to help her then-teenaged son, Colin, who'd had a severe seizure. He'd fallen down the stairs and had no vital signs until, thankfully, the paramedics revived him.
Now 22, Colin was perfectly healthy until the age of 13, when he started developing seizures. He was diagnosed with epilepsy, and the whole family has been affected by his seizures – he's had up to 22 a day – resulting in regular calls to 911 and trips to the nearby hospital in Bowmanville, Ont. "All of us in this house have severe PTSD. We hear something drop, and we all run," says Croxon.
To deal with Colin's debilitating epilepsy, the Croxon family went to the Krembil Brain Institute (KBI), where they met with a multidisciplinary team of leading epilepsy experts, who determined that a vagus nerve stimulation device may be the best option for Colin. The device, which delivers electrical impulses to the vagus nerve, located in the neck, and can reduce seizures, was surgically implanted in 2017 by Dr. Taufik Valiante.
While that helped for a while, the seizures eventually restarted and the epilepsy team suggested deep brain stimulation (DBS). In November 2020, Dr. Suneil Kalia placed electrodes from a DBS device into Colin's brain, and a controller device was put in his chest.
The result of the surgery was "mind-blowing," says Croxon. Colin's seizures reduced in frequency by 90 per cent. After five weeks, he was able to taper off and then stop taking one of his strongest epilepsy medications. He now wants to train to become a mechanic. "I want to go out and finally enjoy the world," he often says to his family.
That's the potential impact of neuromodulation, a technology that uses electrical stimulation to alter circuit activity and reduce seizures in the brain. The KBI is already a global leader in this area, with teams working hard to push this approach to treating nerve-related conditions – especially brain conditions. "The whole field of neuromodulation is exploding," says Dr. Valiante, Director of the Surgical Epilepsy Program at the KBI, who is also part of the Sprott Department of Surgery at University Health Network (UHN) and Co-Director of the CenteR for Advancing Neurotechnological Innovation to Application (CRANIA), which seeks to develop new neuromodulation technologies.
Stimulating nerves
"The entire body is basically run by nerves, and neuromodulation is anything that alters cell and circuit activity through a device," explains Dr. Valiante. Often, that entails using electrodes, sometimes surgically implanted, or working from the surface of the skin to deliver an electrical impulse.
With modulation, electricity either wakes up a nerve or stops it from doing something. "When you add stimulation or electricity, especially to the brain, you either enhance electrical circuits or you short-circuit them," explains Dr. Lorraine Kalia, a neurologist and senior scientist in the Edmond J. Safra Program in Parkinson's Disease and the Morton and Gloria Shulman Movement Disorders Clinic at the KBI.
DBS is one of the oldest and most widely used forms of neuromodulation, pioneered in part by work done by KBI neurosurgeon Dr. Andres Lozano, but there's also peripheral nerve stimulation, applied to areas such as the vagus nerve, plus the use of stimulation along the spinal cord. Clinicians target abnormal brain circuits, spinal cord and peripheral nerves, often with electrodes, to reduce the tremors and stiffness of Parkinson's disease and to help other movement disorders, mood disorders, pain, spinal cord dysfunction and urological conditions.
Neuromodulation can have life-changing impacts on a range of diseases, often alleviating symptoms and allowing patients to reduce their medications. As well, Dr. Valiante says children with epilepsy are often more alert and engaged, a benefit of reduced medications but also a possible positive side effect of neuromodulation therapy. "There's been arguments that brain stimulation may have some pro-cognitive effects," he says.
Currently, half of all DBS implants in Canada are performed at the KBI, but that represents just one aspect of its wide-ranging neuromodulation work. Its clinicians and researchers are reimagining the field to offer more effective treatments and invent game-changing devices – all of which are helping doctors treat nerve-related health conditions and symptoms.
