Imagine being awake while a neurosurgeon drills a hole in your skull and then inserts a wire deep into the centre of your brain.

Local anaesthetic and the lack of pain receptors on the brain itself mean there is no pain, but instead it is intensely loud inside your head as the vibrations move through the skull to the bones which enable hearing.

"It was fascinating and terrifying at the same time," said Susan O'Sullivan, only the seventh person to undergo this treatment for a condition she had been living with for nearly two decades.

O'Sullivan was in a second group of patients involved in research on the use of deep brain stimulation therapy to treat spasmodic dysphonia, a chronic neurological condition where a person's vocal cords stop working properly as a result of muscle spasms. The first research group saw six people treated with this surgery for the same condition before her. She was the seventh person in the world to undergo this surgical treatment specifically for spasmodic dysphonia.

Dr. Christopher Honey, a leading Canadian neurosurgeon based in Vancouver, performs deep brain stimulation surgeries for Parkinson's patients.

The deep brain stimulation surgery had already been used to give Parkinson's patients back their freedom of movement. Honey saw instances of patients who had Parkinson's and spasmodic dysphonia experience great improvements in both conditions after the surgery. He began to wonder if there was an opportunity to also use deep brain stimulation to treat patients who had only spasmodic dysphonia with the surgical intervention.

While some people may not be able to imagine themselves being interested in taking part in a study involving neurosurgery, O'Sullivan had more than one reason to be willing to take a place on the leading edge of neurosurgical research.

For 17 years, O'Sullivan lived with a hidden disability, managing to overcome the challenges of people making a lot of assumptions based on her inability to speak at times.

She first began experiencing symptoms related to dysphonia in 2006, with her voice cracking and having trouble getting words out.

Initially, she didn't know what was going on, but in 2007, after seeing a specialist, she was diagnosed. Initial treatments involved acupuncture to alleviate some of the symptoms.

But as a negotiator for the province working with First Nations, she struggled sometimes at work.

"There's a lot of talking that has to take place," she said. At the time, she was very involved in the theatre, sang in a choir and was an arts administration volunteer. The condition also impacted her social life, as she wouldn't want to go out to social gatherings where people would try to speak to her and she wouldn't be able to respond or engage much.

"I tried and it's way too frustrating," she said. "I'm a pretty positive person but I can see how people would become quite depressed." 

She found relief in an effective treatment, injections of Botox into her vocal cords. This helped relieve the symptoms temporarily for 17 years, but she had to drive back and forth to Vancouver every two-and-a-half-months. As the treatments wore off, each time she would again lose some of her ability to speak and her voice would become cracked and hoarse.

O'Sullivan was also aware she wouldn't want to be driving back and forth to Vancouver every two-and-a-half-months year-round as she got older. So she signed up to take part in the research study and undergo the deep brain stimulation surgery.

The preparation involved forgoing the Botox treatment for six months leading up to the surgery. She once again lost her ability to speak, only able to communicate in whispers.

She said when the doctor told her it was like a normal Tuesday for the surgical team, it helped reassure her and she felt like she was in good hands, despite some understandable fear leading up to the day of the surgery. 

To prepare her for the surgery, they fit her head with a metal cage to hold her head still and in position.

All of this meant, by the time the surgeon arrived and the drill came out, she was ready to get on with it.

The surgery implants a tiny wire into the basal ganglia of the brain. This is the area of the brain responsible for coordinating the body's movements. The wire is connected to a transmitter on her upper chest, which is turned off and on and up and down by a remote.

It took a bit of time for her body to adjust to having something foreign inside it, and only after two months was the device turned on to begin stimulating the brain.

On Jan. 2, 2024, the device was turned on.

"That was a really nice way to start the year," said O'Sullivan. Slowly, she was able to adjust the power of the device, finding a happy medium between the improvement in her voice and some side effects which impacted her arm and face.

But once she found the "happy medium" O'Sullivan said she considers her voice nearly back to full function.

Each night, she has to remember to turn the device off, to give the nerves a break, and prevent the brain from regressing back to using the other pathways which lead to the spasmodic dysphonia.

With a small bump on her head she has to point out for a person to notice and another small bump on her chest, and a line leading up to her neck, the device is now just a part of her. In five years she will have to have the battery in her chest transmitter replaced.

She said having the surgery has changed her life.

"It's been fantastic."

Post-surgery she did a walking tour in Japan with a friend and said the trip was "hugely liberating" for her as she got used to being able to speak to people normally again.

The journey to get to this place has been long and included a lot of learning for her, both about the power of the voice as well as invisible disabilities. 

Some thought she must have had a "rough weekend" when they heard her speak, but O'Sullivan said she appreciates the great support she did have, including from her partner Harry Jennings and the First Nations communities she worked with through her job. Without the understanding of these communities, who recognized it as a real problem, she said her job would have been much more difficult.

Now, O'Sullivan said many people have been fascinated by her story and the research she is a part of, which she hopes can continue to help even more people with a range of brain disorders.

"I felt very fortunate to have it done."

She said research is also being done to use neurological stimulation treatments for other brain-related disorders like Alzheimer's, dementia, severe depression and drug addiction.

"I think we're on the cusp of understanding the brain a lot more."