title: Electrophysiological assessment in patients with long term hypoxia.
abstract: OBJECTIVE
  To evaluate visual evoked potentials (VEP) patterns in chronic obstructive pulmonary disease (COPD) patients who were compliant with supplemental oxygen treatment relative to non-compliant COPD patients.
  
  
  METHODS
  This prospective study protocol was reviewed and approved by the local ethical committee of Selcuk University and the research was performed in the Department of Neurology, Elbistan State Hospital, Kahramanmaras, Turkey from May to October 2014. Blood gas measurements and pulmonary function tests were carried out in patients with advanced stage COPD. The VEP was assessed in both eyes in both compliant and non-compliant patients.
  
  
  RESULTS
  The study included 43 patients; 24 (55.8%) of the patients were not in compliance with their supplemental oxygen treatment, while 19 patients (44.2%) received adequate oxygen treatment. There was no statistically significant difference between patients with regards to pulmonary function test results and blood gas measurements. The VEP latency was significantly greater in both eyes of the non-compliant patients.
  
  
  CONCLUSIONS
  Previous studies have reported prolonged VEP latencies in inflammatory diseases of the central nervous system. Similar electrophysiological findings were observed in our study and we propose that this may be due to oxidative stress, and inflammation that occurs secondary to chronic ischemia.
authors.affiliation: Department of Neurology, Baskent University, Konya, Turkey. E-mail: faikilik@hotmail.com.
authors.forename: Faik
authors.initials: F
authors.lastname: Ilik
authors.forename: Ahmet C
authors.initials: AC
authors.lastname: Pazarli
authors.forename: Fatih
authors.initials: F
authors.lastname: Kayhan
authors.forename: Harun
authors.initials: H
authors.lastname: Karamanli
authors.forename: Hatice K
authors.initials: HK
authors.lastname: Ozlece
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001784:Blood Gas Analysis; D016022:Case-Control Studies; D005074:Evoked Potentials, Visual / Q000502:physiology*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D000860:Hypoxia / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D010102:Oxygen Inhalation Therapy; D010349:Patient Compliance; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D012129:Respiratory Function Tests; D014421:Turkey; D014797:Vital Capacity
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