title: Treatment of Allodynia by Occipital Nerve Stimulation in Chronic Migraine Rodent.
abstract: BACKGROUND
  Occipital nerve stimulation (ONS) is a therapy that benefits one-third of medically refractory chronic migraine (CM) patients. How ONS affects sensory thresholds and whether modulation of thresholds could predict which patients respond to the therapy remains unclear.
  
  
  OBJECTIVE
  To examine the effects of ONS on mechanical and thermal thresholds in a rodent CM model to better elucidate its mechanism of action.
  
  
  METHODS
  Male Sprague-Dawley rats were implanted bilaterally with electrodes to produce ONS. The CM cohort was infused with inflammatory media epidurally based on a validated model, whereas shams were not. Thresholds were evaluated with von Frey filaments and hot plate and thermode tests.
  
  
  RESULTS
  No baseline differences in sensory thresholds were found between the sham (n = 16) and CM (n = 16) groups. After headache induction, CM animals demonstrated mechanical allodynia in the occiput, periorbital region, forepaws, and hind paws (P < .05). In CM animals, ONS increased mechanical thresholds in all regions (P < .001), whereas in shams, it did not. ONS did not affect thermal thresholds in either group.
  
  
  CONCLUSIONS
  We show that ONS improves mechanical thresholds in a rodent CM model, but not in shams. Our finding that mechanical but not thermal thresholds are altered with ONS suggests a more significant modulation of A-α/β fibers than of C fibers. Assessing the ability of ONS to reduce mechanical thresholds during a trial period could potentially be used to predict which patients respond.
authors.affiliation: *Center for Neuroscience and Neuropharmacology, Albany Medical College, Albany, New York; ‡Department of Neurosurgery, Albany Medical Center, Albany, New York.
authors.forename: Priscilla
authors.initials: P
authors.lastname: De La Cruz
authors.forename: Lucy
authors.initials: L
authors.lastname: Gee
authors.forename: Ian
authors.initials: I
authors.lastname: Walling
authors.forename: Brian
authors.initials: B
authors.lastname: Morris
authors.forename: Nita
authors.initials: N
authors.lastname: Chen
authors.forename: Vignessh
authors.initials: V
authors.lastname: Kumar
authors.forename: Paul
authors.initials: P
authors.lastname: Feustel
authors.forename: Damian S
authors.initials: DS
authors.lastname: Shin
authors.forename: Julie G
authors.initials: JG
authors.lastname: Pilitsis
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D004599:Electric Stimulation Therapy / Q000009:adverse effects; D006930:Hyperalgesia / Q000628:therapy*; D008297:Male; D008881:Migraine Disorders / Q000628:therapy*; D010525:Peripheral Nerves / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley