title: Effect of Age and Disease Duration on the Levodopa Response in Patients with Advanced Parkinson's Disease for Deep Brain Stimulation of the Subthalamic Nucleus.
abstract: BACKGROUND
  Deep brain stimulation (DBS) has become a preferred option for the treatment of motor symptoms in patients with advanced Parkinson's disease (PD). A good levodopa response (LR) is considered the most important criterion in determining the suitability of a patient for DBS. However, the effect of age and disease duration (DD) on the LR is still a subject of discussion.
  
  
  OBJECTIVE
  Here, we investigated the effect of age and DD on the preoperative LR in PD patients to be selected for DBS.
  
  
  METHODS
  From August 2011 to May 2015, 54 consecutive patients (29 men and 25 women) with advanced PD were evaluated for DBS of the STN and included in this retrospective study.
  
  
  RESULTS
  Thirty-seven patients were found suitable for DBS of the STN and 29 of them underwent bilateral surgery. We found no significant correlation between DD and the LR. However, there was a significant negative correlation between the patients' age and the LR.
  
  
  CONCLUSIONS
  The results indicate that the patients' age, rather than DD, has a negative effect on the LR. The study, therefore, indicates that PD patients with an advanced age and with a poor LR are not good candidates for DBS of the STN.
authors.affiliation: Department of Neurology, Ondokuz Mayis University , Samsun , Turkey.
authors.forename: Dursun
authors.initials: D
authors.lastname: Aygun
authors.affiliation: Department of Neurosurgery, Ondokuz Mayis University, Samsun, Turkey; Department of Neurosurgery, Maastricht Medical Center, Maastricht, Netherlands; Department of Translational Neuroscience, Maastricht Medical Center, Maastricht, Netherlands.
authors.forename: Ersoy
authors.initials: E
authors.lastname: Kocabicak
authors.affiliation: Department of Neurology, Ondokuz Mayis University , Samsun , Turkey.
authors.forename: Mustafa Onur
authors.initials: MO
authors.lastname: Yildiz
authors.affiliation: Department of Neurosurgery, Maastricht Medical Center, Maastricht, Netherlands; Department of Translational Neuroscience, Maastricht Medical Center, Maastricht, Netherlands.
authors.forename: Yasin
authors.initials: Y
authors.lastname: Temel
keywords: Parkinson’s disease; age; deep brain stimulation; disease duration; levodopa response; subthalamic nucleus