With no known causes nor cures, both obsessive-compulsive disorder (OCD) and Parkinson's disease afflict millions of sufferers worldwide.
The right therapies, however, can significantly ease the discomfort of living with OCD and Parkinson's. Now Stevens is pitching in with timely research that may lead to better treatment options.
"This is a serious health concern," says George McConnell, a Stevens Institute of Technology assistant professor of biomedical engineering, an expert on an emerging non-pharmacological therapy for OCD, Parkinson's and related neurological and psychiatric disorders.
Electrical pulses that improve symptoms
Parkinson's afflicts 1 million patients in the U.S. and at least 7 to 10 million worldwide (possibly many more), progressively attacking neurons, motor functions, muscular movements and eventually emotions and behavior. Although quality of life for individuals with Parkinson's can be improved with medications or surgery, symptoms worsen with progression of the disease.
Obsessive-compulsive disorder (OCD) is estimated to affect 2 to 5 million in the U.S. and tens of millions worldwide. It can cause irrational thinking, anxiety, depression and self-harming behaviors; treatment is usually through a combination of antidepressant medicines and psychotherapy.
Half of OCD patients do not respond to medications, but a promising newer treatment for the disorder was approved by the FDA in 2009, after more than a decade of use as an alternate Parkinson's treatment: deep-brain stimulation (DBS).
In DBS, very brief pulses of electricity are delivered to the brain by implanted electrodes. These disrupt the abnormal firing of the neurons — "like a sort of brain pacemaker," explains McConnell — in the region of the electrodes, often immediately: some Parkinson’s tremors have been shown to dissipate within a few seconds of the treatment. OCD relief can take longer, on the order of weeks or months, yet DBS also appears to be effective in treating this disorder.
The reason these microsecond-long bursts of energy to the deep brain alleviate Parkinson's and OCD, however, remains unclear.
"Researchers still don't know the precise mechanism of why DBS works in motor diseases, much less for psychiatric diseases," explains McConnell. "With no clear rationale for why DBS works, programming the optimal frequency, spacing, duration or strength of pulses is a time-consuming trial-and-error process.
"A better understanding of the mechanisms of synaptic plasticity underlying DBS treatment could revolutionize the way clinicians program these devices, and that's what we're searching for here at Stevens."
To help support the work, McConnell has received a prestigious NARSAD Young Investigator Grant from the Brain & Behavior Research Foundation to learn more about how and why DBS therapy is so effective.
Fewer side effects, longer battery life, more targeted surgery
McConnell is studying the use of different types of DBS on genetically modified mice predisposed to OCD in Stevens' Laboratory for NeuroInnovation.
He performs the research by implanting additional electrodes in mice brains that will monitor and report aberrations and changes in neural activity, even down to the single-neuron level, during the experimental DBS sessions.
McConnell will collaborate with Duke University researchers on the work, exploring the concept of synaptic plasticity — a mechanism for human and animal memory and learning that works by strengthening or weakening connections between neurons.
"The NARSAD grant will enable me to extend my translational research from the neural basis of DBS for Parkinson’s to the neural basis of DBS for psychiatric diseases, starting with OCD," he notes.
That could one day mean quicker, less expensive relief for severe-OCD sufferers; fewer side effects of the therapy; longer battery life in implanted devices; and additional basic research to inform more effective surgical treatments for Parkinson's symptoms such as gait and postural instability.
"Dr. McConnell's approach for studying the mechanism by which DBS elicits therapeutic effects for neurodegenerative diseases like Parkinson’s," concludes Peter Tolias, director of Stevens' university-wide Center for Healthcare Innovation (CHI), "provides a platform technology that can be applied to psychiatric disorders."