title: Effect of propofol anesthesia on resting state brain functional connectivity in Indian population with chronic back pain.
abstract: OBJECTIVE
  Functional magnetic resonance imaging (fMRI) studies in healthy volunteers have shown alterations in brain connectivity following anesthesia as compared to the awake state. It is not known if the anesthesia-induced changes in brain connectivity are different in a pathological state. This study aims to evaluate changes in the resting state functional connectivity in the brain, after propofol anesthesia, in patients with chronic back pain (CBP).
  
  
  METHODS
  Fourteen adults with CBP were included in this prospective study over 6 months. After excluding structural brain pathology, a resting state fMRI was performed in the awake state, and the sequences were repeated after propofol anesthesia. The primary outcome measure was change in resting state connectivity after propofol. Student's t-test was performed between the pre and post-propofol sedation data of all patients with total brain volume as covariates of interest. A repeated measures analysis of variance was used to compare pre- and post-propofol changes in cardiorespiratory parameters.
  
  
  RESULTS
  There were 8 male and 6 female patients in the study, and the mean age of the study population was 46.9 ± 11.3 years. Propofol sedation resulted in an increased strength of functional connectivity between the posterior cingulate cortex (PCC) and thalamus in patients with CBP, whereas there was a generalized decrease in functional integration within the large scale brain networks. The changes in cardiorespiratory parameters before and after propofol administration were not statistically significant.
  
  
  CONCLUSIONS
  Strengthening of functional connectivity was seen between PCC and thalamus with decrease in large scale brain networks following propofol anesthesia in patients with CBP. These changes are similar to those previously described in normal volunteers.
authors.affiliation: Department of Neuroanaesthesia, NIMHANS, Bengaluru, Karnataka, India.
authors.forename: Kamath
authors.initials: K
authors.lastname: Sriganesh
authors.affiliation: Department of Clinical Neurosciences, NIMHANS, Bengaluru, Karnataka, India.
authors.forename: Rakesh
authors.initials: R
authors.lastname: Balachandar
authors.affiliation: Department of Clinical Neurosciences, NIMHANS, Bengaluru, Karnataka; Regional Institute of Occupational Health, ICMR, Bengaluru, Karnataka, India.
authors.forename: Bhavani Shankara
authors.initials: BS
authors.lastname: Bagepally
authors.affiliation: Department of Neuro Imaging and Interventional Radiology, NIMHANS, Bengaluru, Karnataka, India.
authors.forename: Jitender
authors.initials: J
authors.lastname: Saini
authors.affiliation: Department of Neuroanaesthesia, NIMHANS, Bengaluru, Karnataka, India.
authors.forename: G S
authors.initials: GS
authors.lastname: Umamaheswara Rao
mesh_terms: D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D059350:Chronic Pain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D063132:Connectome / Q000379:methods*; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000008:administration & dosage / Q000494:pharmacology*; D007194:India; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009415:Nerve Net / Q000000981:diagnostic imaging / Q000187:drug effects / Q000503:physiopathology; D015742:Propofol / Q000008:administration & dosage / Q000494:pharmacology*; D011446:Prospective Studies
chemical_list: D006993:Hypnotics and Sedatives; D015742:Propofol