|Motor symptoms do not|
show expected worsening
after five years when
treatment briefly stopped
FRIDAY, Jan. 28 (HealthDay News) -- In patients with Parkinson's disease (PD) who are effectively treated with deep brain stimulation (DBS), the natural progression of the disease's motor symptoms appears to stabilize over time, according to a study published in the November issue of the International Journal of Neuroscience.
Michele Tagliati, M.D., of the Mount Sinai School of Medicine in New York City, and colleagues investigated the long-term progression of PD motor symptoms in 50 patients treated with subthalamic nucleus deep brain stimulation (STN-DBS). Patients were evaluated preoperatively and at yearly intervals using the Unified Parkinson's Disease Rating Scale: 21 patients at year one, 17 at year two, 14 at year three, 16 at year four, and nine at year five. Four clinical states were assessed: off medication and DBS off, off medication and DBS on, on medication and DBS off, on medication and DBS on.
The researchers found that motor scores measured without medication and with DBS off were virtually unchanged compared to the preoperative scores of patients up to five years after surgery. This result was seen in patients with both shorter (<11 years) and longer duration of PD prior to surgery. There was also no consistent deterioration from untreated baseline in any of the motor subscores, which included tremor, rigidity, bradykinesia, and axial symptoms.
"Untreated PD motor scores did not worsen over time in patients undergoing STN-DBS, suggesting that there is no progression of motor severity. These results could be explained either by a natural stabilization of PD motor symptoms after many years or neuroprotective properties of STN-DBS," the authors write.