‘Pacemaker for the brain’ helps treatment of anorexia

Scientists in Canada claim to have treated severe anorexia using an electronic implant that acts like a ‘pacemaker for the brain’.

In research published in The Lancet medical journal, anorexia patients who had not responded to other therapies were treated with a technique called deep brain stimulation (DBS), which involves delivering electric pulses to the brain via electrode implants.

The pilot study was primarily intended to show the technique, which is already used to treat neurological disorders such as Parkinson’s disease, was safe, but at least half of the six participating patients showed improvements in mood and body mass index (BMI).

Researchers based at the Krembil Neuroscience Centre and University Health Network in Canada used magnetic resonance imaging (MRI) to identify a specific area of the brain that has previously been used for DBS in patients with depression. 

Electrodes were then implanted into this area and connected to a pulse generator implanted under the skin.

The device was activated ten days later and the researchers measured changes in the patients’ mood and anxiety levels to determine the correct level of stimulation.

The researchers expected the treatment to take several months to take effect, as is also the case for depression patients undergoing DBS.

So before the trial they gave the subjects inpatient treatment that caused them to gain weight, which they then began to lose again at the start of the DBS treatment.

However, two months after the electrodes were implanted, this pattern began to reverse and five of the six patients’ weight stabilised or increased.

After nine months, three patients were maintaining a higher weight than before the treatment started – the longest period of sustained increase in weight that any of them had achieved since the onset of illness.

Around half of the patients also experienced improvements in their mood or reduced obsessive-compulsive behaviour. 

Dr Andres Lozano, one of the lead researchers, said the results were particularly encouraging because they seemed to point to treat the anorexia itself rather than acting as a placebo or just increasing the patients’ hunger.

‘The initial weight loss argues against a primary effect of DBS on hunger, appetite, or metabolic rate. It also suggests that there is little in the way of a placebo-related benefit to the surgery.

‘The finding of improvements in mood and anxiety in patients who were still underweight is especially striking, in view of the well known poor response of underweight patients to conventional pharmacotherapies or psychotherapies.’

Anorexia is among the most likely psychiatric disorders to result in death and is among the most common psychiatric disorders in young women aged 15 – 19 years.

Treatment usually focuses on behavioural change but up to 20 per cent of patients derive no benefit from the available treatment and are at risk of dying prematurely from the disease.

The researchers said the DBS treatment appeared to be relatively safe, with just one patient of the six experiencing serious a problem following the treatment, a seizure that took place about two weeks after the initial operation, which was related to a metabolic disorder the patient was suffering as a result of her anorexia.