title: Controlling the lungs via the brain:  a novel neurosurgical method to improve lung function in humans.
abstract: BACKGROUND
  Deep brain stimulation (DBS) of subcortical brain areas such as the periaqueductal grey and subthalamic nucleus has been shown to alter cardiovascular autonomic performance. The supramedullary circuitry controlling respiratory airways is not well defined and has not been tested in humans.
  
  
  OBJECTIVE
  To use direct electric stimulation via DBS macroelectrodes to test whether airway resistance could be manipulated by these areas in awake humans.
  
  
  METHODS
  Thirty-seven patients with in-dwelling deep brain electrodes for movement disorders or chronic pain underwent spirometry according to the European Respiratory Society guidelines. Testing was performed randomly 3 times on stimulation and 3 times off stimulation; patients were blinded to the test. Thoracic diameter changes were measured by a circumferential pressure-sensitive thoracic band. Ten periaqueductal grey and 10 subthalamic nucleus patients were tested. To control for confounding pain and movement disorder relief, the sensory thalamus in 7 patients and globus pallidus interna in 10 patients, respectively, were also tested.
  
  
  RESULTS
  Peak expiratory flow rate (PEFR) increased significantly with periaqueductal grey and subthalamic nucleus stimulation by up to 14% (P = .02 and .005, respectively, paired-samples Student t tests). Stimulation of control nuclei produced no significant PEFR change. Similarly, changes in thoracic diameter reflecting skeletal activity rather than airway caliber did not correlate with the improvement in PEFR. Forced expiratory volume in 1 second was unchanged by stimulation.
  
  
  CONCLUSIONS
  DBS can improve PEFR in chronic pain and movement disorder patients. This finding provides insights into the neural modulation of respiratory performance and may explain some of the subjective benefits of DBS.
authors.affiliation: Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom. jhyam25@hotmail.com
authors.forename: Jonathan A
authors.initials: JA
authors.lastname: Hyam
authors.forename: John-Stuart
authors.initials: JS
authors.lastname: Brittain
authors.forename: David J
authors.initials: DJ
authors.lastname: Paterson
authors.forename: Robert J O
authors.initials: RJ
authors.lastname: Davies
authors.forename: Tipu Z
authors.initials: TZ
authors.lastname: Aziz
authors.forename: Alexander L
authors.initials: AL
authors.lastname: Green
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D046690:Deep Brain Stimulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010487:Periaqueductal Gray / Q000502:physiology*; D012129:Respiratory Function Tests; D012143:Respiratory Physiological Phenomena; D016037:Single-Blind Method; D020531:Subthalamic Nucleus / Q000502:physiology*; D055815:Young Adult