Movement Disorders Center Researches Early Diagnosis Technique and Measures Deep Brain Stimulation Efficacy in Parkinson’s

Penn State Hershey Movement Disorders Center is home to a research study focused on the early diagnosis of Parkinson’s Disease (PD) and a program for measuring the efficacy of deep brain stimulation (DBS) treatment in advanced cases of the disease.

Professor of Neurosurgery James McInerney, MD, states, because PD symptoms can be mistaken for other disorders, an accurate PD diagnosis often does not occur until up to 80 percent of dopamine neurons have died. His colleague, Vice Chair for Research and Professor of Neurosurgery Xuemei Huang, MD, PhD, leads a team that studies the dynamics of arm swing coordination during walking in both PD patients and controls, to identify any marked differences.¹

To date, the majority of comprehensive assessments of walking in PD have focused on the lower extremities noting reduced gait velocity, stride length, and cadence.¹ Although decreased arm swing has been shown to be the most commonly reported motor dysfunction in individuals with PD, there have been very few studies evaluating motion changes of the upper extremities of PD patients during walking.¹ Preliminary results demonstrate that significant differences between the two populations are evident.¹ Control subjects had forearm angular acceleration time series that tended to be symmetrically distributed along a forty-five-degree line (Fig. 1B) as compared with PD patients.¹ PD patients displayed less symmetry with respect to the forty-five-degree line, with time series that featured a more disordered appearance (Fig. 1C).¹

Huang states, “It is our hope that we can develop a simple, non-invasive, inexpensive screening tool to identify people with high risk for developing Parkinson’s disease.”

While the arm swing research study focuses on early PD diagnosis, other initiatives examine treatment options. The Movement Disorders Center measures DBS patients’ performance in balance, cognition, and other areas, both with the device on and off, to provide an accurate assessment of its efficacy. This ability to pinpoint functional improvements that are a direct result of the DBS device will help enhance quality of life for PD patients for whom medications no longer provide sufficient efficacy. The ongoing data review from the DBS efficacy measurement studies reveals improvements in overall PD treatment. Concludes Huang, “During the past year, we have established a new kinesiology lab— one of only a handful nationwide— to measure PD patients’ motor functions and disability from different angles. We plan to collect better and more objective data through this new lab to monitor the outcomes of our treatments (both drug and DBS). We hope that our research can also lead to better insight into falling, a primary risk associated with later-stage PD.”

References

1. Huang X, Mahoney J, Lewis M, Du G, Piazza S, and Cusumano J. Both coordination and symmetry of arm swing are reduced in Parkinson’s disease. Gait & Posture. 35(2012): 373-377.