title: Beneficial Effects of Bilateral Subthalamic Stimulation on Non-Motor Symptoms in Parkinson's Disease.
abstract: BACKGROUND
  STN-DBS is well established to improve motor symptoms and quality of life in patients with PD. While non-motor symptoms are crucial for quality of life in these patients, only neuropsychiatric and neuropsychological symptoms have been systematically studied in a longitudinal design so far. However, these are only a part of the non-motor symptoms spectrum.
  
  
  OBJECTIVE
  We hypothesized that STN-DBS is associated with a beneficial effect on a range of non-motor symptoms.
  
  
  METHODS
  In this multicenter, open, prospective, international study (EuroInf-study, UKCRN10084/DRKS00006735) we investigated non-motor effects of STN-DBS in "real-life" use. We evaluated Non-motor Symptom Scale, and Questionnaire, PD Questionnaire-8, Scales for Outcomes of PD motor examination and complications, and activities of daily living preoperatively and at 6 months follow-up in 60 consecutive patients (35 male, mean age: 61.6 ± 7.8 years, mean disease duration: 10.4 ± 4.2 years).
  
  
  RESULTS
  All outcomes improved significantly at 6 months follow-up (PD Questionaire-8, p = 0.006; activities of daily living, p = 0.012; all others, p < 0.001; Wilcoxon signed-rank, respectively paired t-test; Bonferroni-correction). Post-hoc analyses of Non-motor Symptom Scale domains showed a significant reduction of sleep/fatigue and miscellaneous domains (p ≤ 0.001), perceptual problems/hallucinations (p = 0.036), and urinary (p = 0.018) scores. Effect sizes were "moderate" for Non-motor Symptom Scale, and motor complications, "large" for motor examination, and "small" for other outcomes.
  
  
  CONCLUSIONS
  This study provides evidence that bilateral STN-DBS improves non-motor burden in patients with PD and opens the door to a more balanced evaluation of DBS outcomes. Further randomized studies are needed to confirm these findings and compare DBS non-motor effects to other invasive therapies of advanced PD.
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany. Electronic address: haidar.dafsari@uk-koeln.de.
authors.forename: Haidar Salimi
authors.initials: HS
authors.lastname: Dafsari
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College Hospital, London, UK.
authors.forename: Prashanth
authors.initials: P
authors.lastname: Reddy
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany.
authors.forename: Christiane
authors.initials: C
authors.lastname: Herchenbach
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Wawro
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany.
authors.forename: Jan Niklas
authors.initials: JN
authors.lastname: Petry-Schmelzer
authors.affiliation: Department of Stereotaxy and Functional Neurosurgery, University Hospital Cologne, Germany.
authors.forename: Veerle
authors.initials: V
authors.lastname: Visser-Vandewalle
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College Hospital, London, UK.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Rizos
authors.affiliation: Department of Neurology and Neurosurgery, Salford Royal Foundation Trust, Greater Manchester, UK.
authors.forename: Monty
authors.initials: M
authors.lastname: Silverdale
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College Hospital, London, UK.
authors.forename: Keyoumars
authors.initials: K
authors.lastname: Ashkan
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College Hospital, London, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Samuel
authors.affiliation: Department of Neurology and Neurosurgery, Salford Royal Foundation Trust, Greater Manchester, UK.
authors.forename: Julian
authors.initials: J
authors.lastname: Evans
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany.
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Huber
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany.
authors.forename: Gereon R
authors.initials: GR
authors.lastname: Fink
authors.affiliation: Parkinson disease and Movement Disorders Unit, IRCCS Hospital San Camillo, Venice, Italy.
authors.forename: Angelo
authors.initials: A
authors.lastname: Antonini
authors.affiliation: National Parkinson Foundation International Centre of Excellence, King's College Hospital, London, UK.
authors.forename: K Ray
authors.initials: KR
authors.lastname: Chaudhuri
authors.affiliation: National Center of Epidemiology and CIBERNED, Carlos III Institute of Health, Madrid, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Martinez-Martin
authors.affiliation: Department of Neurology, University Hospital Cologne, Cologne, Germany. Electronic address: lars.timmermann@uk-koeln.de.
authors.forename: Lars
authors.initials: L
authors.lastname: Timmermann
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D011788:Quality of Life; D012890:Sleep; D020531:Subthalamic Nucleus / Q000502:physiology*
keywords: Deep brain stimulation; Non-Motor Symptom Scale; Nonmotor symptoms; Quality of life