PARKINSON’S AWARENESS MONTH – HUNT FOR CURE CONTINUES

Parkinson’s Disease affects 80,000 Australians and there is no cure, but the experts at Sydney’s St Vincent’s Hospital are closing in on one.

Until they get there treatments that improve sufferers’ quality of life are key, according to Professor Stephen Tisch, who heads a world-class team at the hospital’s Neurology Department.

April marks Parkinson’s Awareness Month, and Professor Tisch says the message is that Parkinson’s is serious but treatable, can take years to progress, and for those reasons alone early diagnosis and treatment are essential.

Parkinson’s is caused by the degeneration of brain cells in an area of the brain called the substantia nigra. This leads to a lack of dopamine, which leads to dysfunction in motor control and a loss of movement control.

It is a progressive, degenerative condition, with most patients’ initial symptoms related to motor functions such as tremor, stiffness, slowness, difficulty with walking and movement, often affecting one side of the body more than the other.

Professor Tisch says that while tremors are well-known symptoms it is possible to have Parkinson’s without a tremor. There are also non-motor symptoms such as a loss of smell, constipation, active dreams, speech changes, mood disturbance, inability to multitask, and cognitive decline.

These wide symptoms, and the fact that there is no defined test for the disease, means it’s difficult to diagnose.

“It relies on a clinical diagnosis,” he says. “If your GP suspects it you’d be referred to a neurologist for confirmation. There is no test, but investigations are sometimes performed to rule other conditions.”

Whole more common over 65, Prof Tisch says there are some young-onset patients, under 45, “who are a relatively small group and are sometimes forgotten”. Younger patients also have a higher probability of having a genetic form of Parkinson’s.

The good news is that while progressive, Parkinson’s is not fatal in itself. “You can die from Parkinson’s complications, but depending on the age of onset most patients would not expect to be experiencing life-threatening complications for at least 20 years.”

In most cases there are no know causes, although in some cases there are those genetic factors, and there are signs others may have environmental triggers.

“The prevalence of Parkinson’s is increasing, reasons for which are not understood. Prevalence is increasing in regional areas, and that might have some link to things such as environmental exposure to pesticides.”

Prof Tisch says the mainstay of treatment is dopamine medication, which aims to replace missing dopamine in the brain. Levodopa is most widely prescribed but there are a number of drugs that perform a supplementary role.

“The emphasis is on treating motor symptoms – trembling, slowness, stiffness, gait difficulty. Drugs are not a cure but definitely improve the quality of life, improve function, and improve survival.”

Another treatment used by the St Vincent’s team is deep-brain stimulation (DBS), which Prof Tisch says is an excellent treatment for people who have developed unstable responses to medication.

He says DBS surgery involves implanting a pacemaker-like device in the chest, wired to an electrode on each side of the brain, resetting signals in the brain. “We would periodically reprogram the DBS to optimise the improvement and it effectively becomes a lifetime therapy.”

Miracle treatments aside, exercise may still be the best medicine.

“There is increasing recognition of the crucial importance of exercise and targeted physiotherapy. This improves general cardio and muscle strength and helps maintaining balance.

“There are also special types of exercise that engage the brain, for example brain-body training where you are doing exercises but are being given a cognitive challenge, such as getting the patient to walk backwards while throwing and catching a scarf.

“Doing these regularly can have a profound benefit which is sometimes similar to medication.”

The key to successful Parkinson’s management is the involvement of a team of professionals.

“At St Vincent’s this involves a multidisciplinary approach, not just medicine but exercise therapy and the involvement of allied health professionals, movement disorder specialists to identify patients in need of more sophisticated therapy, and DBS and therapeutic pumps.”

And while there is no cure yet, St Vincent’s is involved in three studies, the first two of which Prof Tisch describes as “the holy grail, something to slow the disease, not just treat symptoms”.

• The St Vincent’s team is part of syndicate six sites across Australia repurposing existing medications to try and slow Parkinson’s down.
• There is also a trial of diabetic medication Bydureon in diabetic patients (some have combinations of both Parkinson’s and diabetes, Prof Tisch says) to see if that might slow progression.
• And the team is trialing MRI-guided focused ultrasound – “a brain zapper,” Prof Tisch says – that sends beams through the head to produce a therapeutic lesion in the thalamus to treat tremor.

Neurologist Sam Bolitho is a key part of the St Vincent’s team and has a keen interest in movement disorders.

He says there is a real need for a disease-modifying therapy.

“We don’t have that for Parkinson’s right now, but those trials are under way and we are part of that with three main trials and a lot of small, focused research.”

Dr Bolitho says while a cure is coming, for the moment the focus is on improving treatment for quality of life:

“We are running close to the biggest, most complex Parkinson’s management clinic, with all of the complicated treatments – DBS, focused ultrasound, medicine pumps,” he says. “We have a big movement disorders clinic.

“We offer everything for which there is evidence that improves quality of life.”