New research reveals further benefits of deep brain stimulation

Deep brain stimulation (DBS) is the main type of surgery used to treat Parkinson’s. It can give people with the condition better control of movement symptoms including tremor, speed of movements and involuntary movements (dyskinesia).

The surgery involves having fine wires inserted into specific areas of the brain. These are connected to a pulse generator (a device like a heart pacemaker) which is placed under the skin around the chest or stomach area. When the pulse generator is switched on, the electrodes deliver high frequency stimulation to the targeted area. This stimulation changes some of the electrical signals in the brain that cause the symptoms of Parkinson’s.

Find out more about deep brain stimulation.

Although DBS has been available as a treatment for Parkinson’s for some time, we still have a lot to learn about how it works and how to maximise the benefits for people with Parkinson’s.

In this blog we’ll explore 2 new research studies which reveal that DBS may have the potential to:

• slow the progression of Parkinson’s if given at an early stage
• significantly reduce some of the non-motor symptoms of the condition.

Early deep brain stimulation may slow progression

DBS is usually only considered when people have had Parkinson’s for some time and their symptoms are no longer controlled well by medication.

However, recent studies in earlier stage patients have indicated that giving DBS sooner may bring additional benefits.

In a US study, researchers recruited 30 patients with early stage Parkinson’s (within 4 years of onset). All participants received medication to help manage their Parkinson’s and half were randomly selected to also receive DBS.

After 5 years, when the researchers compared the 2 groups they found that those who received medication alone:

• were 5 times more likely to experience worsening tremor
• were 15 times more likely to need multiple Parkinson’s medications
• may be more likely to have worse motor symptoms.

These results provide encouraging signs that giving DBS at an early stage may slow the progression of motor symptoms and reduce the need for medication.

However, this was a small study so these findings need to be explored further and proven in a much larger trial before DBS will become a recommended option for early stage Parkinson’s.

Read more about the research findings on the Neurology website.

Evidence that DBS improves non-motor symptoms

Most people with Parkinson’s will experience non-motor symptoms, which can include issues related to mental health, memory problems and pain. Research has shown that for many, non-motor symptoms can have a greater impact on quality of life than the more obvious movement symptoms.

In a recent international trial, researchers compared 38 people with Parkinson’s who chose to have DBS to 38 who chose to continue on medication alone to explore the impact of the therapy on non-motor symptoms.

After 3 years, participants who had DBS had better outcomes on the non-motor symptoms assessment scale than those who remained on medication alone.

When the researchers looked in more detail, they found that certain non-motor symptoms improved in the DBS group, while others were unaffected by the therapy.

Non-motor symptoms that improved with DBS:

• sleep and fatigue
• urinary (bladder symptoms)
• pain
• sexual function
• inability to smell and taste.

Non-motor symptoms that saw no change after DBS:

• mood and apathy
• perceptual problems and hallucinations
• attention and memory
• gastrointestinal symptoms.

By contrast, for the group who received medication alone non-motor symptoms either stayed the same or worsened over the 3-year study.

Only cardiovascular symptoms, such as dizziness on standing due to blood pressure changes, were found to get worse in those who received DBS. The researchers call for more studies to investigate this further.

Alongside these improvements in non-motor symptoms, those who received DBS also reported a significant improvement in quality of life.

Read the full research paper on the BMJ Journals website.

Getting the best from deep brain stimulation

The 2 studies discussed in this blog post have produced important findings which now need to be explored further in larger trials.

There are also exciting advances being made in developing smarter and more tailored ways to deliver DBS. We reported on some promising results from a trial of adaptive DBS on the blog earlier this year.

Ultimately, this research will help make sure that deep brain stimulation is offered to the right patients at the right time so that people with Parkinson’s get the maximum possible benefit from this vital treatment.