title: Key clinical milestones 15 years and onwards after DBS-STN surgery-A retrospective analysis of patients that underwent surgery between 1993 and 2001.
abstract: OBJECTIVE
  Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for motor fluctuations in Parkinson's disease (PD), but does not halt disease progression. The long-term deterioration of key functions such as cognition, speech, ability to swallow, gait, urinary bladder control, orientation and reality perception is decisive for patients' independency in daily life. In this paper we investigated patients with advanced PD operated at our center with STN-DBS for at least 15 years ago, in respect to key clinical milestones reflecting their overall function in daily living.
  
  
  METHODS
  Retrospective analysis of clinical data concerning key clinical milestones including death in PD-patients, 15 years or more after they underwent STN-DBS surgery. All PD-patients implanted with STN-DBS at Sahlgrenska Hospital before January 1, 2001, were regularly assessed until death, drop-out, or January 11, 2016.
  
  
  RESULTS
  Sixteen men and seven women with a median (range) disease duration of 18 (10-28) years were operated with STN-DBS. The median (range) follow-up time post-surgery was 12 (2-18) years and 692 person-years of disease duration were observed. In January 2016, nine PD-patients (39%) were still alive (eight with active STN-DBS). Initially, motor symptoms improved in all patients. Sustained benefit (implying active stimulation at the last follow up) was maintained in 19 of them (83%) but STN-DBS was inactivated in four (17%) due to inefficacy. Over time, all patients deteriorated slowly, and a majority developed severe non-motor and axial symptoms such as dementia, inability to talk, swallow and walk, urinary incontinence, psychosis, and need for nursing home care. At the last follow up, 16/23 (70%) patients were treated with antidepressants.
  
  
  CONCLUSIONS
  A majority of PD-patients experience sustained motor benefit with continuous STN-DBS. However, over time, non-motor and axial symptoms slowly and severely restrict PD-patients' function in their daily living.
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden. Electronic address: Radu.Constantinescu@vgregion.se.
authors.forename: Radu
authors.initials: R
authors.lastname: Constantinescu
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden.
authors.forename: Barbro
authors.initials: B
authors.lastname: Eriksson
authors.affiliation: Department of Neurology, Norra Älvsborgs Länssjukhus, Sjukhuskansliet, 461 85 Trollhättan, Sweden.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Jansson
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden.
authors.forename: Bo
authors.initials: B
authors.lastname: Johnels
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden.
authors.forename: Björn
authors.initials: B
authors.lastname: Holmberg
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden.
authors.forename: Thordis
authors.initials: T
authors.lastname: Gudmundsdottir
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden.
authors.forename: Annika
authors.initials: A
authors.lastname: Renck
authors.affiliation: Department of Neuropsychiatry, Minnesmottagningen, Wallinsgatan 6, 431 41 Mölndal, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Berglund
authors.affiliation: Department of Neurology, Institute of Neuroscience and Physiology at Sahlgrenska Academy, University of Gothenburg, Sahlgrenska University Hospital, 413 45 Göteborg, Sweden.
authors.forename: Filip
authors.initials: F
authors.lastname: Bergquist
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D046690:Deep Brain Stimulation / Q000379:methods*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D010300:Parkinson Disease / Q000503:physiopathology* / Q000601:surgery / Q000628:therapy*; D012189:Retrospective Studies; D020531:Subthalamic Nucleus / Q000601:surgery
keywords: Advanced Parkinson’s disease; Daily living; Key clinical milestones; Non-motor symptoms; STN-DBS; Subthalamic nucleus deep brain stimulation