title: Hemodynamic responses to head-up tilt after spinal cord injury support a role for the mid-thoracic spinal cord in cardiovascular regulation.
abstract: BACKGROUND
  Data showing a role for the mid-thoracic spinal cord (SC) in the control of hemodynamic changes is scarce despite existing evidence for its involvement in autonomic regulation.
  
  
  METHODS
  On the basis of the open label prospective series comparing three groups.
  
  
  OBJECTIVE
  To determine whether the mid-thoracic SC has a role in hemodynamic regulation during head-up tilt (HUT).
  
  
  METHODS
  Spinal Research Laboratory, Loewenstein Rehabilitation Hospital.
  
  
  METHODS
  A total of 13 healthy control subjects, 10 patients with T(4)-T(6) paraplegia and 11 with C(4)-C(7) tetraplegia were examined during supine rest and during HUT. Heart rate (HR), blood pressure (BP), HR spectral components (lower frequency fluctuation (LF), higher frequency fluctuations (HF) and LF/HF) and cerebral blood flow velocity (CBFV) were continuously measured or calculated.
  
  
  RESULTS
  BP response to HUT differed among these groups (P<0.02). During HUT, BP decreased markedly in the tetraplegia group (from a mean value of 81.65 to 67.69  mm Hg), and increased in the control groups (from 92.89 to 95.44 mm Hg) and in the T(4)-T(6) paraplegia group (from 96.24 to 97.86 mm Hg). Significant correlation was found in the control and tetraplegia groups between increases in HR LF/HF and HR at HUT (r>0.7; P<0.01). No such correlation was found in the paraplegia group. HUT effect on HR and CBFV was significant in all groups (P<0.001), but group differences were statistically non-significant.
  
  
  CONCLUSIONS
  Findings were generally compatible with those of comparable previously published studies, but they also support a role for the mid-thoracic SC in hemodynamic regulation, which should be considered in clinical setting and in research.
authors: Department of Spinal Rehabiliation, Loewenstein Rehabilitation Hospital, Raanana, Israel.
authors: V
authors: V
authors: Bluvshtein
authors: A D
authors: AD
authors: Korczyn
authors: S
authors: S
authors: Akselrod
authors: I
authors: I
authors: Pinhas
authors: I
authors: I
authors: Gelernter
authors: A
authors: A
authors: Catz
mesh_terms: D000328:Adult; D001342:Autonomic Nervous System Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D002318:Cardiovascular Diseases / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006439:Hemodynamics / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010264:Paraplegia / Q000150:complications / Q000503:physiopathology; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011782:Quadriplegia / Q000150:complications / Q000503:physiopathology; D013119:Spinal Cord Injuries / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology*