Using deep brain stimulation to treat severe obsessive compulsive disorder

Obsessive compulsive disorder (OCD) can be a life-crippling affliction. Professor David Castle, St Vincent’s Professor of Psychiatry, clearly recalls one of his first OCD patients.

Untitled-1 copy“Her symptoms were so severe that she didn’t eat or drink anything besides Lucozade for two years to avoid using the toilet, because of the cleaning rituals she needed to do afterwards. She also hadn’t had a shower in two years.”

In the field of mental disorders there are many disabling conditions but Professor

Castle believes severe OCD is possibly the most disabling of all. “Most severe OCD patients have no lives beyond the confines and tyranny of their illness.”

In Australia, the treatment for patients with severe OCD is quite limited – essentially, it’s either behavioural or drug therapy.

Sometimes patients simply aren’t well enough to undertake these treatments or they may find them ineffective. Anti-anxiety medications are available but can have considerable side effects, greatly affecting the patient’s general health.

In 2010, Professor Castle and Associate Professor Peter Bosanac, Clinical Director of St Vincent’s Mental Health, became aware of the work of Professor Damian Denys in Amsterdam, who was looking at deep brain stimulation of patients with severe OCD.

Serendipitously, St Vincent’s Director of Clinical Neurosciences, Professor Mark Cook, was trialling a brain implant device to predict epilepsy seizures. The trio joined forces with the Bionics Institute and, in an Australian-first study, this multidisciplinary team developed a deep brain stimulation treatment for people with OCD.

Neurostimulation leads are inserted into the target area of a patient’s brain. A wafer-thin wire connects the leads to a pulse generator which is implanted just near the collarbone.

The pulse generator sends out targeted electrical signals to help modify the brain’s activity and neurocircuitry at or near sites implicated in OCD, without any significant damage to brain tissue. Importantly, the procedure can be “reversed” if necessary.

The ethical issues surrounding any psychosurgery are highly complex, and the team spent two and a half years working on protocols and determining the first patient to trial the device.

Some of the most important and unique work in this study was discovering how to better map the pre- and post-intervention pathways.

The team performed MEG imaging, PET scans and neuropsychological tests on the patient  to measure cognitive brain processes and the physiological function of the brain – both before and after the device was implanted.

The team included St Vincent’s Mental Health, St Vincent’s neurosurgeon Mr Peter McNeill, the Bionics Institute led by Professor Hugh McDermott, Swinburne Neuroimaging, the Austin Hospital, and several allied health professionals.

“We understood the importance of taking extreme care – making the right choice of patient was critical. We were also mindful of what happens next – how to support patients if it doesn’t work and, just as importantly, how to help them adjust if it does work,” Professor Castle says.

The patient chosen for the trial had been diagnosed with OCD as a teenager, many years earlier, and was severely restricted in having a life outside the home because of their OCD rituals. The patient had been on multiple, high doses of anti-obsessional medications, with limited benefit, and had also undergone many trials of cognitive behavioural therapy, including as an inpatient, again with limited improvement.

Professor Castle said the team included an occupational therapist, who worked with the patient in their home in the lead up to the operation and afterwards. ‘If it works, it takes a long time for patients to re-adjust and rebuild their lives, and come to terms with the lost opportunities that have resulted from their illness. There is also a lot of work to do in skills remediation because they have missed out on large chunks of their life.’

Six months since the deep brain stimulation implantation, the patient has responded very well to the treatment – the team has been able to substantially decrease the use of prescribed medications.

“The patient reports that OCD is no longer an issue,” a delighted Professor Castle says.

“They have gone from staying at home all day to now holding down a job. It has also liberated the family’s time, because they were the patient’s primary carers.”

The approach shows great promise but it is not yet a cure.”

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