Predictive factors affecting early deterioration of axial symptoms after subthalamic nucleus stimulation in Parkinson's disease. 
Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment option for medically refractory Parkinson's disease (PD).  However, some patients show deterioration of axial symptoms within a short time after surgery.  We studied 43 patients who underwent bilateral STN-DBS and investigated predictive factors affecting early deterioration of axial symptoms.  Among 43 patients, 16 patients showed obvious deterioration of axial symptoms within three years of surgery.  Multiple logistic regression analysis indicated that the significant independent variables related to early deterioration of axial symptoms were rapidly progressive short duration of the disease and advanced age at surgery.  These results suggest that patients with rapidly progressing PD, who need early surgical intervention, tend to show early deterioration of axial symptoms after STN-DBS.