Predictive Factors of Short/Long-term Outcome and Complications of Bilateral DBS in PD
Condition: Parkinson Disease
MeSH terms: Parkinson Disease
Study type: Observational

Summary: 
      The purpose and main objective of this study is the research of pre-operative and operative
      predictive factors of short-term (1-year) and long-term (15-years) improvement of quality of
      life, motor and non-motor symptoms in Parkinson's disease patients who have undergone to
      bilateral Subthalamic Nucleus Deep Brain Stimulation.

      The hypothesis of the study is that the definition of pre-operative and operative predictive
      factors could be able to improve the pre-operative prognostic accuracy of outcome and
      complications after surgery, allowing also a better selection of the most suitable candidates
      for bilateral Subthalamic Nucleus Deep Brain Stimulation.

      For example, we can suppose that an older age at surgery, elevated axial score, a less
      preoperative dopa-responsiveness, the presence of mild executive dysfunction at surgery or an
      unfavourable social status, could negatively influence the short and long term surgery
      outcome
    

Detailed description: 
      Subthalamic NucleusDeep Brain Stimulation (STN-DBS) represents a short and long-term
      effective treatment in Parkinson's disease (PD) patients. Various randomized controlled
      trials have confirmed the superiority of STN-DBS compared to the best medical treatment in
      patients with advanced Parkinson disease in term of improvement of motor function and quality
      of life. On the other hand, STN- DBS is associated with an increased risk of adverse events
      compared to best medical treatment.

      Data from previous meta-analysis have shown that only pre-operative dopa-responsiveness can
      predict the clinical efficacy and outcome of STN-DBS. In particular the improvement of
      STN-DBS on quality of life mainly concern the physical aspects of functioning with a lower
      improvement on social and cognitive aspects.

      However, not all of PD symptoms respond similarly to STN-DBS. In particular the effects of
      STN-DBS on the so-called levodopa unresponsive symptoms (i.e. gait and balance symptoms,
      autonomic dysfunction, sleep disorders, cognitive decline and speech and swallowing troubles)
      are modest or absent. Furthermore, levodopa unresponsive symptoms are one of the main causes
      of impairment and disability in advanced PD patients. Bearing in mind these informations, the
      clinical phenotyping of candidates for surgery appear crucial for the prediction of DBS
      outcome and selection of better candidates. In the recent years, several papers highlighted
      and expanded the list of possible predictive factors, from a motor point of view to non-motor
      symptoms and psychosocial aspects.

      In this setting, the aim of our study is to determine the pre-operative and operative
      short-term (1-year) and long-term (15-years) predictive factors of improvement of quality of
      life and motor and non-motor symptoms in a large cohort of PD patients who have undergone to
      bilateral STN-DBS. The better definition of short-term and long-term predictive factors and
      its association with the different PD different clinical phenotypes could allow in the future
      a better definition of the effects of STN-DBS on quality of life and motor and non-motor
      symptoms in the different PD clinical phenotypes.

      In the same way, it could be assumed that a better definition of pre-operative predictive
      factors of surgical, hardware and stimulation-induced STN-DBS side effects in the short term,
      could also allow a better definition of the risk-to-benefit ratio and outcome after STN-DBS
      surgery
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Non-Probability Sample
Study population: 
        Patient with Parkinson's disease treated with bilateral Subthalamic Nucleus Deep Brain
        Stimulation
      
Keywords: Parkinson Disease; Deep Brain Stimulation; Subthalamic Nucleus; Predictive factors