Published: 20 November 2024
Deep brain stimulation has revealed that a specific type of brain wave activity is associated with levels of anxiety in people living with Parkinson’s disease, according to research led by scientists at City St George’s and University of California San Francisco.
The results, published in Brain, “opens the door” to use deep brain stimulation to relieve symptoms of anxiety in people with the progressive neurological condition.
One in three people living with Parkinson’s disease have troublesome anxiety that effects their daily life. Yet despite this, there has been a major gap in the understanding of the underlying biological causes and ways neurologists can accurately measure symptoms of anxiety, with often ineffective treatment options.
Deep brain stimulation (DBS) is already being used to treat physical symptoms – such as tremors – in people living with Parkinson’s. But, until now, its potential to help relieve non-movement symptoms such as anxiety has not been established.
Thirty-three people with severe Parkinson’s who underwent DBS surgery to help regulate their movement symptoms were recruited to the study. Neurosurgeons implanted fine electrodes into a part of the brain called the basal ganglia, which is linked to movement patterns and functions abnormally in Parkinson’s.
Tracking brain wave activity
The researchers used the electrodes to track the activity of different types of brain waves in three different settings with different devices. At City St George’s, University of London, the brain activity of twelve patients was measured whilst they rested after the operation using external electrodes from the head connected to a computer. At the University of California San Francisco, using permanently implanted neurostimulators, activity was measured in thirteen people at home whilst resting and in eight people while they were engaging in behavioural tasks at home. Levels of anxiety was measured in all patients at the time of measuring brain wave activity using clinical scales.
In all participants across the three settings, the researchers identified that a specific type of brain wave activity, called theta wave activity, was associated with ‘trait’ anxiety - an individual’s general level of anxiety over a long period of time.#
Offering hope for people with Parkinson's
“Anxiety has been recognised as a major unmet therapeutic need in Parkinson’s disease, and our results now offer hope. Now that we have established a link between anxiety and levels of theta brain waves, we plan to use theta wave activity as a marker to track how it changes over the course of the disease. We show that deep brain stimulation has the potential to have wider-reaching benefits for people living with Parkinson’s than we previously thought. It opens the door for us to explore new and advanced neuromodulation treatments tailored to individual patient’s needs to relieve anxiety and a range of other symptoms.”
- Dr Lucia Ricciardi, Senior Lecturer in Neurology and study co-lead author at City St George’s Neuroscience and Cell Biology Research Institute -
Route to personalised therapies
Dr Simon Little, Associate Professor in Neurology at the University of California San Francisco, who co-led the study, said: “Anxiety is very common but particularly frequent and disabling in people with Parkinson’s disease. Understanding the circuits and brain signals of anxiety is important for developing new personalized therapies for this disabling symptom. We hope that this will help people with Parkinson’s disease but may also provide insight and ways to track anxiety across other conditions”.
Jonathan Lovett, 73, from Surbiton was diagnosed with Parkinson’s in January 2016 and was part of the study. He says “I had deep brain stimulation surgery in 2019 and had the chance, between two parts of the surgery, to join in the study with my brain hooked up directly to a laptop via cables protruding from my head. I wanted to give something back to the amazing DBS team.”
“Parkinson’s is a complex disease, almost impossibly so, and advances in technology that allow sophisticated and intelligent control of the devices set to work on brain behaviour, gathering data, remote monitoring, fine tuning medication, trends and pinch points could be life-changing. DBS is a miraculous, transformative intervention to me, but it’s constantly on the same setting. It’s like buying a new car with windscreen wipers on maximum all the time, rain or shine, and no way to turn them off or adjust them. I have 20-25 symptoms, so if this research leads to DBS being more tailored to different symptoms that would undoubtedly improve the daily quality of life for me and others living with Parkinson’s.”
This research was supported by the Medical Research Council (MRC) and the National Institute of Health (NIH, USA).
Learn more about our research impact