title: Phrenic nerve stimulation for diaphragm pacing with a spinal cord stimulator: technical note.
abstract: BACKGROUND
  Diaphragm pacing with electrical stimulation of the phrenic nerve is an established treatment for central hypoventilation syndrome. The device, however, is not readily available, at least in Japan. We used the spinal cord stimulator for pain control for phrenic nerve stimulation. The purpose of this study is to evaluate the efficacy and feasibility of phrenic pacing with the compromise method.
  
  
  METHODS
  We implanted a stimulator for spinal cord stimulation (Itrel 3 or X-trel, Medtronic, MN) in 4 patients with chronic hypoventilation because of brainstem dysfunction of various origins. The stimulation electrode was placed along the right phrenic nerve in the neck, and the device was implanted in the anterior chest. We used the cyclic mode, and set the parameters at 1 second ramp up, 2 seconds on, 3 seconds off. The pulse width and the frequency were set at 150 microsec and 21 Hz, respectively. The amplitude of the output was adjusted to obtain sufficient tidal volume and to maintain PaCO(2) at around 40 mm Hg.
  
  
  RESULTS
  During the follow-up period from 6 to 19 months (mean 8.3 months), stable and sufficient ventilation were observed in all patients without complications. One patient with sleep apnea syndrome used the device only at night and became free from a respirator. Three patients who were completely respirator-dependent became ambulatory during the daytime.
  
  
  CONCLUSIONS
  Though longer follow-up is necessary, diaphragm pacing by stimulation of the phrenic nerve with the spinal cord stimulator is feasible for a treatment of central hypoventilation syndrome.
authors.affiliation: Department of Neurosurgery, Neurological Institute, Tokyo Women's Medical University, Tokyo, Japan.
authors.forename: Takaomi
authors.initials: T
authors.lastname: Taira
authors.forename: Naoto
authors.initials: N
authors.lastname: Takeda
authors.forename: Kaname
authors.initials: K
authors.lastname: Itoh
authors.forename: Akihiro
authors.initials: A
authors.lastname: Oikawa
authors.forename: Tomokatsu
authors.initials: T
authors.lastname: Hori
mesh_terms: D001933:Brain Stem / Q000503:physiopathology; D002908:Chronic Disease; D003964:Diaphragm / Q000502:physiology*; D004558:Electric Stimulation / Q000295:instrumentation / Q000379:methods*; D004567:Electrodes, Implanted; D004867:Equipment Design; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007040:Hypoventilation / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010791:Phrenic Nerve / Q000502:physiology*; D013116:Spinal Cord / Q000502:physiology*