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Andrew Brierley was wide awake and watching his own deep-brain surgery on a screen

Tuesday October 30, 2012

Brad Crouch

news.com.au - ANDREW Brierley wants to eat spaghetti. Matt McDonald and Rob Wilcox think it is a good idea, so they take a journey to the centre of Andrew's brain.

And Andrew is awake the whole time, watching what's going on at the back of his head on a wide-screen TV.
Andrew, 54, of Brompton, has had Parkinson's disease for about a decade.

The degenerative brain disease causes such severe stiffness, slowness and tremors that he had to give up his job as a truck owner-driver, go on a disability pension, and face the humiliation of eating junk food because he finds it easier to jam a hamburger in his mouth than cope with the delicate motor skills needed to cook and eat such things as cereal or pasta.

Drugs have come a long way to help cope with the disease where changes in the brain jumble electrical signals controlling movement, but for some people the side effects can range from hoarding to gambling.

Nor do the drugs distinguish between one side of the body, with lots of tremors and the other with few. Enter Deep Brain Stimulation.

Flinders Medical Centre was the first hospital in South Australia to use DBS, in 2007, on people with Parkinson's disease and the team is among the most experienced in Australia.

Now about eight people a year undergo DBS at Flinders in the hope implanted electrodes will hijack and tame wayward brain cells to restore movement control.

Medical staff are quick to stress it's not a cure - the cause of Parkinson's is unknown; it is a progressive disease affecting about 80,000 Australians.

But this technique to curb the symptomatic tremors, stiffness and slowness can restore quality of life.

In Andrew's case, the hand control it returns means he can once again enjoy eating Special K for breakfast and spaghetti for dinner, buttoning his clothes, cleaning his teeth and holding a drink.

People with advanced Parkinson's once destined for care or a nursing home can live independently for longer; people on disability pensions can work again.

Of course it comes at a cost - about $35,000. But that compares with up to $45,000 a year - every year - for medication plus the prospect of taxpaying workers ending up in nursing homes.

Andrew agreed last week to let the Sunday Mail sit through his DBS operation at FMC.

DBS has been used in Europe since 1987 for conditions such as Parkinson's, epilepsy and even Tourette syndrome. In Australia, it is still only used for a limited range of movement disorders.

Neurosurgeon Dr Matt McDonald describes DBS as "the frontier of neurosurgery".

"In the future it could be used for things like depression, obesity, anorexia and obsessive compulsive disorder," he says.

"For medical staff this is feel-good surgery - it is upbeat to see people go from a wheelchair or a nursing home to being able to work again."

It is a fairly early start. Andrew has been off his medication in preparation for the operation so the full symptoms can be assessed as the procedure unfolds.

Not all people with Parkinson's are suitable, and candidates undergo a range of tests, including psychiatric ones, before approval, as well as rehearsals to help them stay calm during the procedure.

By 8am, the team ready to work on Andrew in three separate stages of the procedure are in scrubs and assembling in the FMC's theatres.

At any given stage, up to 16 people will be crowded around Andrew - two neurosurgeons, a neurologist, registrars, three anaesthetists and various nurses.

The first stage involves a CT scan which will be merged with an MRI scan to give the surgical team a precise "road map" of Andrew's brain.

Using this road map, Andrew's neurologist, Associate Professor Rob Wilcox, calculates the precise location to implant the electrodes, going in from the top of Andrew's head about 10cm to the centre of his brain, avoiding major blood vessels and other delicate obstacles.

Millimetre-perfect is not good enough.

In DBS, the surgeons work in fractions of millimetres.

They are aiming for the subthalamic nucleus (STN) which controls movement. In Parkinson's, it is malfunctioning. DBS aims to send battery-powered electrical impulses down a wire to electrodes to block the abnormal firing pattern in the STN and restore control of movement.

Calculations complete, Andrew is wheeled into the operating theatre.

A metal base for a large frame has been bolted into his skull, giving him a slight "Frankenstein" look.

The frame itself allows co-ordinates from the road map to be used to precisely guide the electrodes into place.

The co-ordinates are worked out, the frame is attached to the base and Stage 2 begins with Andrew awake and calm under a local anaesthetic.

"How are you feeling?" I ask Andrew.

"Just fine - looking forward to it," he replies.

They tell me it is like turning on a lightbulb, once they activate the electrodes, the tremors simply stop.

"They told me I would probably not get back to 100 per cent but at the moment I am about 40 per cent; I can't do daily functions like doing up buttons, so the idea of any improvement makes it worth trying. The whole idea is a little mind-boggling."

Andrew is awake this entire stage, and with a TV camera attached to an overhead light, is able to watch the whole procedure on a big-screen TV.

He needs to be awake so the team can get him to move his hands, test his speech and assess if the symptoms of Parkinson's are being controlled, and also to assess if there are any side effects, such as slurred speech or blurred vision.

If the implants are even slightly out of place there could be problems.

At 9.45am a flap of skin about the size of a playing card right on the top of Andrew's head is peeled back exposing his skull.

Then Dr McDonald - assisted by neurosurgeon Dr Simon Sandler - begins drilling the first of two holes - about the width of a pencil - into Andrew's head.

Two implants will be needed - the first on the left side of the brain to control movement on the right side of the body, and vice versa.

The grinding buzz of the drill sounds uncomfortably like a dentist's drill, and it has a fail-safe mechanism to stop it as soon as it is through the skull bone. A second drill cleans up the edges.

Andrew says he cannot feel a thing and the noise doesn't bother him.

"Look, I do have a brain after all," he quips while
watching the TV as the drill is removed leaving the top of his brain exposed and the team prepares to send down a test electrode.

The surgical team have their own repartee but there is an air of precision among the calmness and no room for error, only professional perfection.

Among the 500 pieces of equipment in the room, the test electrode, 0.8mm wide on the end of a gossamer-thin wire, is guided down the frame, into Andrew's brain and along the trajectory so carefully mapped earlier.

Lights are dimmed and a silence comes over the room. It is not just the tenseness of the moment, it is to hear the electricity of the brain cells and to assess brainwaves on monitors as the test electrode is manoeuvred into position.
It is not all smooth sailing - the team is not completely satisfied and a second test wire is used.

Eventually, with some tiny adjustments, they find the ideal spot deep in Andrew's brain and pump in electric currents of up to six volts to check the effects.

Dr Wilcox says the aim is to "kidnap pathways" to restore control of movement.

As the currents flow, he speaks loudly to Andrew, asking him to open and shut his right hand quickly to see if the rigidity has eased and assessing his tremors.

He moves his own fingers in front of Andrew's face, ordering him to follow their movement and to count the number of fingers.

His vision seems unaffected. Next Dr Wilcox repeatedly asks Andrew to repeat after him: "Say `K, K, K, la la la, me, me, me.'

Say 'British Constitution.' Say 'newly laid linoleum'."

Andrew repeats it easily - his speech seems fine.

By 10.35am, the team are satisfied they have reached the ideal spot in the brain, so the test electrode is removed and the permanent brain lead with four electrodes is implanted.

The whole procedure is then repeated after a second hole is drilled on the right side of Andrew's skull, for electrodes to control the left side of his body.

The wires from the two lots of electrodes come out of the holes in Andrew's skull which are then filled in, leaving the wires protruding.

The first two stages of the procedure have taken about four hours and is tiring on the patient as well as the medical staff.

In the third stage of the operation - and with Andrew under a full anaesthetic - the wires are buried under his skin leading to a battery implanted in his chest, much like a heart pacemaker.

The battery has a five-to-six year lifespan and can be adjusted through the skin of the chest using a remote control.

If Andrew's condition deteriorates the battery can be remotely turned up to combat the symptoms.

The two lots of electrode combinations can be adjusted independently, allowing precise control over various levels of symptoms in different parts of the body.

One trap for people with such implants is getting too close to electric motors, for instance bracing an electric drill against their chest - this can switch the battery off, and the tremors return as instantly as flicking a light switch.

"This is not a cure," Dr Wilcox emphasises.

"But it is about restoring quality of life and independence."

The whole procedure takes most of the day, but Andrew's recovery in hospital only takes four days before he is home again.

He is currently on no Parkinson's medication. He is a happy man.

"I'm bulletproof - my tremors are completely gone and I can eat cereal or spaghetti or whatever I want," he says.

"It really is a miracle. My shakes are gone and I am not on medication any more. I've got my life back."
>> brad.crouch@news.com.au
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FYI: The procedure
ABOUT
80,000 Australians have Parkinson's disease - as many as 40 per cent have not yet been diagnosed. It is a degenerative disease with no known cause or cure where abnormal electrical signals patterns in the brain cause symptoms such as slowness, rigidity and tremors in the limbs.

DRUGS can help control symptoms for some people but may have
side effects, and they can be very expensive.

DEEP Brain Stimulation (DBS) involves mapping a patient's brain, drilling a hole in the skull and sending a thin wire with tiny electrodes at the tip deep into the brain to the subthalamic nucleus that helps controls movement.

THE wires are routed from the skull under the skin of the neck to a battery implanted in the chest, like a heart pacemaker.

THE battery sends electrical impulses to the electrodes to override the abnormal activity, giving patients significantly better control of their movements. A remote control can adjust the impulses as the disease progresses.

FLINDERS Medical Centre pioneered the procedure in SA in 2009 and about eight cases are done there each year. It can also be done privately at Wakefield Hospital by the same team.

THE procedure is done in three stages: CT scan merged with an MRI to map the brain, implanting the electrodes in the brain, and implanting and connecting the battery in the chest - involving a team of up to 16 at any one time.