title: The decade after subthalamic stimulation in advanced Parkinson's disease: A balancing act.
abstract: OBJECTIVE
  The duration of improvement in quality of life after subthalamic nucleus deep brain stimulation (STN DBS) for Parkinson's disease (PD) and the presurgical identification of factors predicting sustained clinical benefits have implications in patient selection and timing of surgery. These aspects were assessed in patients who underwent yearly assessment for at least 7 years after surgery.
  
  
  METHODS
  The quality of life, motor and cognitive outcomes of 25 patients who completed the 7-year assessment, and 12 patients who completed the 10-year assessment, were analyzed.
  
  
  RESULTS
  The improvement in quality of life was sustained only for 5 years, while the severity of motor signs and motor fluctuations remained reduced at 7 and 10 years. Tremor and rigidity showed more enduring reduction than bradykinesia and axial signs. The dose reduction in medications could be maintained until 7 years, by which time, the axial scores were worse than that seen at the pre-DBS levels. At 10 years, a higher levodopa requirement and recurrence of dyskinesias were noted. Patients with greater pre-DBS levodopa-responsive motor signs had greater long-term motor improvement.
  
  
  CONCLUSIONS
  STN DBS performed in patients with advanced motor fluctuations and severe dyskinesias provide only an average of 5 years of quality of life improvement. STN DBS in patients with motor signs that are less responsive to levodopa results in shorter duration of clinical benefits. The improvements in the severity of motor fluctuations, rigidity, and tremor are the most enduring benefits of STN DBS that last a decade . However, these are offset by worsening axial and cognitive functions, bradykinesia, a higher levodopa requirement, and recurrence of dyskinesias by the end of the decade.
authors.forename: Syam
authors.initials: S
authors.lastname: Krishnan
authors.forename: Sreeram
authors.initials: S
authors.lastname: Prasad
authors.forename: Krishnakumar Kesava
authors.initials: KK
authors.lastname: Pisharady
authors.forename: Gangadhara
authors.initials: G
authors.lastname: Sarma
authors.forename: Sankara P
authors.initials: SP
authors.lastname: Sarma
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
authors.forename: Asha
authors.initials: A
authors.lastname: Kishore
mesh_terms: D003071:Cognition; D046690:Deep Brain Stimulation; D005500:Follow-Up Studies; D006801:Humans; D007980:Levodopa; D010300:Parkinson Disease / Q000628:therapy*; D011788:Quality of Life; D012720:Severity of Illness Index; D020531:Subthalamic Nucleus; D016896:Treatment Outcome
chemical_list: D007980:Levodopa