Article

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. STUDY DESIGN: 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).
SETTING: 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. CONCLUSION:
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.

Langue : ANGLAIS