Glenda Saade suffered her first epileptic fit at 23. For the next 30 years, seizures major and minor were a frequent and disturbing part of her life. Worse, almost, than the physical pain they caused was the anxiety about when the next one might strike, and how serious it would be.
In January, Glenda had surgery guided by a revolutionary technique being developed at Swinburne University of Technology. Eight months on she is seizure-free, has cut her medication, travels independently and is looking forward to getting her driver’s licence back.
The still-mysterious realms of the human brain that cause the physical and emotional distress of an epileptic seizure are being laid bare and the condition surgically arrested, thanks to painstaking application of a novel imaging technique by Swinburne scientists.
The technique uses magnetoencephalography, or MEG, a non-invasive way of reading and measuring the magnetic signals generated by brain activity, and locating their source. It was discovered in the 1960s, but recent advances have turned it into one of the safest and most powerful tools for interpreting brain function. Used in combination with electroencephalography (EEG), MEG is opening a new window into the processes and the precise location of the electrical storms that trigger an epileptic event.
In collaboration with neurologists Dr Chris Plummer and Professor Mark Cook, neurosurgeon Associate Professor Michael Murphy and imaging specialist Simon Vogrin of Melbourne’s St Vincent’s Hospital, Professor David Liley of Swinburne’s Brain and Psychological Sciences Research Centre is using MEG/EEG to locate and help plan surgical treatment for patients with focal epilepsy. The condition affects about 40 per cent of all epilepsy sufferers, about 100,000 Australians, and is caused by an electrical storm that emanates from a single point in the brain.
So far the team has successfully pinpointed and surgically removed the source of the trouble – usually a bundle of nerve cells less than five millimetres across, buried deep within the brain – in five patients.
“Each of these patients had suffered long-standing epilepsy, with seizures every week or so,” Professor Liley says. “None of them has experienced an event since the operation. It’s a major improvement in their quality of life.” It’s also now the world gold standard in focal epilepsy treatment, thanks to Swinburne’s decision to invest millions of dollars in a MEG machine and magnetically-shielded chamber several years ago.
For the patients, the treatment is life-changing. “It’s incredible. I can’t tell you how good it feels not to have to worry about the next seizure,” says Ms Saade, who once burned her hand painfully on the gas stove when she collapsed while cooking dinner for her family. “I’d put off the operation for a long time, because my husband was unwell and I had to care for him – but my family talked me round. I am so happy I did. To anyone else who suffers focal epilepsy I’d say, ‘go and get the operation done’.”
For fellow epilepsy sufferer Ian Atkinson, the change has also been transformational. It eliminated seizures that had afflicted him for 25 years. “The doctor said I had probably been epileptic since birth, but the condition was mild until my 30s: I experienced déjà vu and other strange mental sensations,” he says. Then, at a time of intense emotional stress, he experienced his first grand mal event – a major seizure. It was followed by many others. Even when these were reduced with medication, Mr Atkinson still had strange sensations and blackouts.
“My body would keep functioning normally, but my mind just went blank. I work as a medical technician in a hospital, and I’d come round with absolutely no idea how I got there. I was really sweating just trying to do my job properly,” he says.
Mr Atkinson, who has been seizure-free since May, is planning his first independent trip in decades and contemplating getting a motorbike. “It’s amazing. It’s turned my life around. I’m finding my confidence again,” he says. “Since the operation, there have been no symptoms of epilepsy. Nothing at all. No strange sensations, no funny little feelings. All the concerns I had about the next event are being lifted.”
The advance offered by MEG/EEG is groundbreaking in two ways. Before it, the only way a surgeon could locate the source of the problem was to open a patient’s skull and insert long, delicate needles into their brain. Now the MEG helmet – which resembles a large hairdryer – sits on the patient’s scalp, without any need to open the cranium. This halves the need for surgery, reducing time, cost, and stress on patients.
MEG measures brain magnetic activity in femto-tesla, signals so faint they are a mere fraction of the power of a normal household magnet, requiring the subject and equipment to be shielded in a special chamber to avoid interference from ambient magnetic fields.
No other imaging method can match its precision. It enables the surgeon to delicately excise abnormal cells without risking damage to surrounding brain tissues vital to functions such as walking, sight, speech or hearing.
“We brush their hair vigorously to clean it, and gel up each electrode in the EEG cap, which contains 72 sensors, and then place it in the MEG helmet, which has 306 magnetic sensors,” Professor Liley says. “The patient is sleep-deprived and their medication withheld, to bring on the conditions for an epileptic seizure. Ideally, one actually takes place while the cap is on and we can observe exactly what goes on in the brain, and where,” he says.
“The whole procedure takes about an hour and a half. The resulting data is modelled to pinpoint the precise source of the trouble. The surgeon can then go in, with far greater confidence, and remove it.”
A step forward
Because MEG scans the entire brain, the medical team can also be sure it has isolated the cause of the condition and not missed anything.
Despite years of investigation, epilepsy and its causes are still poorly understood, Professor Liley says. “Our scientific knowledge of it is still fairly primitive, I’d say. And in public, the condition still carries a social stigma. So the use of MEG and EEG to pinpoint and remove its source in a significant number of cases represents a really important step forward.”
The team is now using the method to improve recovery prospects for more than 70 patients.
Importantly, it is making surgical treatment for focal epilepsy the go-to solution, redefining world clinical best practice. While improved surgical outcomes are the primary goal, Professor Liley considers that, down the track, MEG/EEG might also open the way to other treatment methods such as targeted radiotherapy or stem-cell therapy.
“Australia has 10,000 to 12,000 new cases of epilepsy diagnosed each year,” he says. “Around 4000 to 5000 of those are focal epilepsy cases, where the condition arises from a single point within the brain. We can now state with some confidence that we have a method that can make a profound improvement in the lives of many of these people.”