title: Early Use of 60 Hz Frequency Subthalamic Stimulation in Parkinson's Disease: A Case Series and Review.
abstract: BACKGROUND
  Deep brain stimulation (DBS) is effective in treating the segmental symptoms of Parkinson's disease (PD) as well as axial symptoms that are levodopa responsive. PD patients on chronic DBS who develop axial symptoms and gait disturbances several years later oftentimes are refractory to high frequency stimulation (HFS). Several studies report benefit produced by low frequency subthalamic nucleus (STN) stimulation in such patients, though the sustainability of the effects has been mixed.
  
  
  OBJECTIVE
  To report the clinical outcomes of a series of patients with Parkinson's disease and levodopa responsive axial and gait disturbances who were switched to 60 Hz stimulation within one year of their DBS surgery.
  
  
  METHODS
  A retrospective review of 5 patients, whose severe pre-DBS, levodopa responsive gait disorders worsened on HFS STN-DBS and were subsequently switched to 60 Hz stimulation within 1 year of their surgery.
  
  
  RESULTS
  The median age of this cohort was 66 years with median disease duration of 14 years. Four of 5 patients' experienced acute worsening of their axial and gait UPDRS III scores on HFS. All patients' gait disorder improved with 60 Hz along with amelioration of their segmental symptoms and reduction of their levodopa induced dyskinesia. The median time on HFS prior to switching to 60 Hz was two months. Stimulation through the ventral contacts was utilized in all patients with relatively modest changes achieved in levodopa equivalent daily dose.
  
  
  CONCLUSIONS
  This case series demonstrates the clinical efficacy of utilizing low frequency (60 Hz) STN stimulation early in the DBS programming course in more advanced PD patients with levodopa responsive gait disturbance and freezing of gait. Activation of a broader stimulation field likely contributed to both axial and segmental symptom improvement while possibly aiding in the reduction of dyskinesia.
authors.affiliation: Department of Neurology, Division of Movement Disorders, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Ritesh A
authors.initials: RA
authors.lastname: Ramdhani
authors.affiliation: Department of Neurology, Division of Movement Disorders, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Amar
authors.initials: A
authors.lastname: Patel
authors.affiliation: Department of Neurology, Division of Movement Disorders, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: David
authors.initials: D
authors.lastname: Swope
authors.affiliation: Department of Neurology, Division of Movement Disorders, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Neurosurgery, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Psychiatry, Icahn School of Medicine at Mount Sinai, New York, NY, USA.|Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
authors.forename: Brian H
authors.initials: BH
authors.lastname: Kopell
mesh_terms: D000368:Aged; D015331:Cohort Studies; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000628:therapy*; D020531:Subthalamic Nucleus / Q000502:physiology*; D016896:Treatment Outcome
keywords: Low frequency stimulation; Parkinson's disease; subthalamic nucleus