Parkinson's disease and Deep Brain Stimulation: tailoring treatment for a better outcome

Studying genetic variation into the surgical treatment of deep brain stimulation, Dr Thomas Foltynie investigates why some patients with Parkinson’s diseases respond better than others.

A neuroscientist at the Sobell Department of Motor Neuroscience and Movement Disorders at UCL Institute of Neurology, Dr Foltynie’s team hope to develop treatments that will work for all individuals who live with Parkinson’s disease.

“One patient of mine, a chartered surveyor, developed the characteristic tremor, stiffness and slowness of Parkinson’s disease at the age of 54. Friends, colleagues and the patient himself had all suspected the diagnosis and his biggest concern was that he may no longer be able to work.

He was therefore started on medication straightaway and initially responded very well, was able to continue working effectively and even described that taking the tablets made him feel like he had taken off a lead coat.

However within six months of starting treatment he had developed wild involuntary movements which occurred about 40 minutes after taking each dose of medication. He was then stuck between feeling like he had the lead coat back on when without his tablets, or being unable to keep still or even writhing uncontrollably following each dose.

These involuntary movements can be seen among many patients with Parkinson’s disease after they have had many years of medication but it is unclear why some people develop them so quickly and severely whereas other patients tolerate the same medications without trouble even after 20 years of the same therapy.

As a result of these problems, he was offered deep brain stimulation surgery. While the prospect of having electrodes inserted into his brain was daunting, he had the reassurance of speaking to fellow patients who had previously undergone the surgery. The result was a great success, even more so than some of his fellow patients, and while he still needed to take his medication, he could now do so without experiencing any involuntary movements and remains working full time.

Every patient with Parkinson’s can tell a different story regarding their experience of drug treatments and a growing number can report their individual feelings and variable levels of satisfaction having had deep brain stimulation surgery.

There is mounting evidence to suggest that the reason we all respond differently to medical and surgical treatments, particularly treatments for Parkinson’s disease, relates to common variations in our genes. We already know that genetic variations can alter the chemistry of the brain in subtle ways, so it makes sense that when we use treatments to compensate for the disturbances in brain chemistry that occurs in Parkinson’s disease, different people respond in different ways.

By discovering the extent to which naturally occurring genetic variations can influence and predict response to treatments, I hope to develop ways in which treatments can be tailored to the individual patient with Parkinson’s disease.”

Brain Research Trust has supplied funding to the Sobell department for many years.