SYDNEY, AUSTRALIA – Many Parkinson’s disease centers performing deep brain stimulation surgery are not using formal, standardized screening for impulse control disorders in pre- or postsurgical patients, according to a large survey of Parkinson Study Group centers.
Deep brain stimulation surgery is known to increase impulsivity, and standard practice is to identify and treat impulse control disorders in patients before surgery, according to lead author Dr. Nawaz Hack, a junior fellow in movement disorders at the University of Florida, Gainesville, and his colleagues.
Dr. Nawaz Hack
"Surgery will improve their motor symptoms, but it may make their impulsivity worse, especially if you don’t screen and appropriately identify it," Dr. Hack said. "But if you catch it early through a standardized screening, you can address it."
The researchers surveyed 48 Parkinson Study Group centers, 97% of which performed deep brain stimulation surgery and 67% of which said they served a population of over 500 patients a year.
The results showed that only 23% of sites employed a formal battery of tests for impulsive and compulsive behavior and that 7% did not report screening for impulse control disorders.
Speaking at a poster session at the international congress of Parkinson’s Disease and Movement Disorders, Dr. Hack said that the majority of sites were employing a more ad-hoc approach to screening for impulse control disorders, using questions that were not necessarily standardized.
The survey found that 80% of responding centers used a neuropsychologist to screen for potential behavioral issues but only 32% used a psychiatrist, suggesting that most are focused on identifying the problem but do not necessarily have the facilities to manage and treat it.
There was also a wide variety of approaches taken to manage impulse control issues in presurgical patients.
Seventy-nine percent of patients with an impulse control disorder were treated with medication reduction, although there were 10 different strategies employed across centers, the survey’s authors reported.
"This is what happens in the centers that understand Parkinson’s disease – these are centers that are knowledgeable – so if we’re deficient there, what’s happening?" Dr. Hack said.
The concern was that patients whose impulsivity becomes exacerbated by surgery were more likely to be lost to follow up because of the potential financial consequences of their behavioral disorder.
"If you’re impulsive before, and you’re not treated or screened, you will be seriously impulsive after, so they’ll leave the operating room, they’ll go home, and they’ll start doing behaviors that are literally destroying their family, their lives, and their finances," Dr. Hack said.
However, he said that identifying patients with impulse control disorders could be difficult because patients were sometimes reluctant to volunteer information on behaviors that might indicate the presence of impulsivity, such as hypersexuality or problem gambling.
Nearly three-quarters of centers (72%) reported observing impulse control disorders among deep brain stimulation surgery patients, and 68% reported it in postoperative patients.
Most centers (79%) did not feel that the choice of brain target, whether subthalamic nucleus or globus pallidus, was influential in behavioral disorders.
Dr. Hack did not declare any financial conflicts of interest with the research.