title: Refined assessment of blood pressure instability after spinal cord injury.
abstract: BACKGROUND
  This study determined whether the Autonomic Dysfunction Following Spinal Cord Injury (ADFSCI) questionnaire, a measure of self-reported frequency and severity of symptoms during hypo- and hypertensive episodes, correlates with blood pressure (BP) instability. In addition, test-retest reliability of the ADFSCI questionnaire was assessed.
  
  
  METHODS
  Thirty individuals with spinal cord injury (SCI) (aged 42±12 years; level of lesion = C3-L1; American Spinal Injury Association Impairment Scale = A-C; lesion duration = 1 month to 30 years after injury) participated in this study. Twenty-four-hour ambulatory BP monitoring (ABPM) was used to assess BP instability. ABPM recorded systolic BP (SBP), diastolic BP (DBP), and heart rate at 15-minute intervals during the daytime and 1-hour intervals during the nighttime. Test-retest reliability was performed by completion of the ADFSCI questionnaire on 2 occasions (i.e., 9±4 days in between).
  
  
  RESULTS
  Individuals with SCI who self-reported autonomic dysreflexia (AD) episodes showed significantly higher SBP coefficient of variation (CV) (14%) and more AD events (n = 11) than individuals who reported never having AD symptoms (CV = 9%; AD events = 1). Both the number of AD events over the 24-hour period and the BP variability (SBP CV) were significantly related to the patients' self-reported total AD score (rho = 0.522, P = 0.005; rho = 0.584, P = 0.001, respectively) and daily AD frequency (rho = 0.553, P = 0.003; rho = 0.586, P = 0.001, respectively). Conversely, no significant correlations existed between the number of hypotensive events over the 24-hour period and self-reported frequency and severity in the ADFSCI questionnaire.
  
  
  CONCLUSIONS
  This study provides evidence that ABPM offers a strong clinical basis for documenting and understanding BP instability, such as AD, and related symptoms in individuals with SCI.
authors.affiliation: International Collaboration on Repair Discoveries, Department of Medicine, University of British Columbia, Vancouver, BC, Canada;
authors.forename: Michèle
authors.initials: M
authors.lastname: Hubli
authors.affiliation: International Collaboration on Repair Discoveries, Department of Medicine, University of British Columbia, Vancouver, BC, Canada;
authors.forename: Cameron M
authors.initials: CM
authors.lastname: Gee
authors.affiliation: International Collaboration on Repair Discoveries, Department of Medicine, University of British Columbia, Vancouver, BC, Canada; Division of Physical Medicine and Rehabilitation, Department of Medicine, University of British Columbia, Vancouver, BC, Canada; G. F. Strong Rehabilitation Centre, Vancouver, BC, Canada. krassioukov@icord.org.
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Krassioukov
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020211:Autonomic Dysreflexia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D018660:Blood Pressure Monitoring, Ambulatory; D005260:Female; D006339:Heart Rate; D006801:Humans; D006973:Hypertension / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D007022:Hypotension / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D013119:Spinal Cord Injuries / Q000150:complications / Q000503:physiopathology*; D011795:Surveys and Questionnaires; D055815:Young Adult
keywords: ambulatory blood pressure monitoring; autonomic dysreflexia; autonomic nervous system; blood pressure; hypertension; hypotension; spinal cord injury.