Pioneering brain surgery gives B.C. woman her voice back
Susan O'Sullivan 'does not regret' signing up for the trial
Twenty years ago, Susan O'Sullivan was working full-time with the Ministry of Forests and volunteering as a singer at her local art centre when her voice began to crack.
"There was some crack that started happening in my voice randomly, and I couldn't understand what it was . . . you sort of put it down to, well, maybe it's stress," said O'Sullivan during an interview with CBC's Daybreak Kamloops.
When her voice started cracking 100 per cent of the time, she received an expert referral to see Dr. Murray Morrison. Unable to get words out by then, she was diagnosed with spasmodic dysphonia.
Spasmodic dysphonia is a disorder in the brain that causes the vocal cords to spasm, interrupting people's speech and their ability to speak.
Thanks to a pioneering study in deep brain stimulation (DBS) — in which a surgeon drills into a patient's brain — O'Sullivan is able to speak freely again.
"It's made a huge difference. I talk to people. My husband says I talk a lot more, and I'm a lot louder. You just feel like you're empowered now because I think we don't realize how important our voice is until it's gone."
Current and innovative treatment
The current treatment for patients with spasmodic dysphonia is a specialized form of botox. Patients get botox injected into their vocal cords to stop the spasms.
According to Dr. Christopher Honey, patients need the injections every three months, and their bodies can eventually develop antibodies to Botox, which can make the drug less effective or stop it from working altogether.
Dr. Murray Morrison and Dr. Christopher Honey piloted a brain stimulation trial with patients who had spasmodic dysphonia in 2018. All patients showed a significant improvement in their voice. When O'Sullivan was offered a seat in the trial, she signed up.
"I was the only one doing deep brain stimulation in British Columbia for over 20 years. I have personally operated on over 1,000 patients with Parkinson's disease, tremors and a variety of conditions. There aren't very many people in the world who've done 1,000," said Dr. Honey.
Deep brain stimulation surgery is done in two parts. The first part is completed with patients awake where an electrode — a platinum wire that carries an electrical current — is put inside the brain. If patients have no side effects, the electrode is locked in while patients are asleep.
A pacemaker is inserted under the skin connected to the electrode by a wire. A remote provides a wireless connection to the pacemaker, which provides the stimulation.
Patients then revisit the clinic to slowly dial up the pacemaker using the remote. Dr. Honey says the pacemakers are specialized to meet each patient's needs.
WATCH | How deep brain stimulation works:
Unexpected discovery
The discovery of the effects of deep brain stimulation on voice came about as a result of its use in treating patients experiencing tremors.
Two patients receiving the treatment reported something unexpected, Dr. Honey said.
The patients, who also had spasmodic dysphonia, told the doctor their voices had improved.
Further research into a third patient, with both tremors and spasmodic dysphonia, proved that deep brain stimulation had a positive effect on the patient's voice as well. This data was used to justify the trial that O'Sullivan took part in.
"We're the only one in the world doing this prospective trial for spasmodic dysphonia," said Dr. Honey.
Research is being done to see if deep brain stimulation can treat pain that is hard to treat with medication. Nerve damage from dental procedures, dental neuralgia, and neuropathic pain from amputation are two types of pain that Dr. Honey is studying the effects of.
Since getting deep brain stimulation surgery, O'Sullivan has travelled to Japan, where she went on a walking tour. She said that being able to speak with people improved the quality of her trip.
"I'm so appreciative to be talking. A year and a half ago, I would have never thought I would be doing an interview," said O'Sullivan.
"I was nervous about it , but I wanted to carry it through, and I'm glad I did. I don't regret anything," said O'Sullivan.
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