Long-term Effect of Low Frequency Stimulation on Aspiration and Freezing of Gait in PD With STN DBS
Condition: Parkinson's Disease
MeSH terms: Parkinson Disease
Study type: Interventional

Summary: 
      Our recent study (Xie et al, Neurology 2015; 84: 415-420) found that bilateral STN DBS of
      60Hz, compared to the traditional 130Hz, decreased the aspiration frequency and swallowing
      difficulty, freezing of gait (FOG), and other axial symptoms and parkinsonism in Parkinson
      patients with FOG refractory to 130Hz and medications. The benefit of 60Hz stimulation
      persisted during the 6-week study period, but with worsening tremor in one patient. However,
      it remains unknown whether the benefit of 60Hz would persist on prolonged stimulation period,
      and whether there is carry-over effect across different conditions. Hence, the investigators
      would like to test the hypothesis that the 60Hz stimulation, compared to 130Hz might have
      persistent benefit over an extended period in reducing the swallowing dysfunction, FOG, and
      other axial symptoms in these PD patients even after correcting the potential carry-over
      effect.
    

Detailed description: 
      The investigators will enroll 14 Parkinson patients with bilateral STN DBS and refractory FOG
      to 130Hz stimulation and dopaminergic medications for two visits of at least 6-month apart.
      The 6 patients remaining on 60Hz stimulation after our previous study consisting of 7
      patients will be assessed once again as visit-2 after previous visit-1 of their last study.
      We anticipate to have 20 patents complete for visit-1 and at least 18 patients complete for
      visit-2 in this randomized double-blind prospective crossover study with their usual
      medication "on" state, with 6-7 patients on each starting condition (60Hz vs 130Hz vs DBS
      off). Swallowing function on modified barium swallowing test and swallowing questionnaire,
      FOG in stand-walk-sit test and questionnaire, and other axial and motor function on UPDRS-III
      will be assessed under each DBS condition. Changes in measurements between 60Hz and 130Hz at
      each visit and under 60Hz between two visits will be analyzed, with swallowing function and
      FOG as primary, and the rest as secondary outcomes, correcting for potential carryover
      effect. Changes between other DBS conditions might also be explored in this 2-year study.

      This would be the first study on the long-term effect of 60Hz stimulation on dysphagia, FOG
      and other axial and motor symptoms in Parkinson patients with bilateral STN DBS and FOG
      refractory to 130Hz stimulation and dopaminergic medications, which will have significant
      impact on the treatment of difficult axial symptoms of high morbidity and mortality.
    

Intervention name(s): Deep Brain Stimulation (DBS) at 60 Hz; Deep Brain Stimulation (DBS) at 130 Hz; Deep Brain Stimulation (DBS) Off (Sham)
Intervention type(s): Device; Device; Device
Intervention description(s): Bilateral subthalamic nucleus deep brain stimulation at 60 Hz; Bilateral subthalamic nucleus deep brain stimulation at 130 Hz; Deep Brain Stimulation (DBS) Off (Sham)
Other intervention name(s): Low Frequency Stimulation (LFS); High Frequency Stimulation (HFS)
Intervention model: Single Group Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: DBS; Low frequency stimulation; Dysphagia; Freezing of gait