Hemodynamic responses to head-up tilt after spinal cord injury support a role for the mid-thoracic spinal cord in cardiovascular regulation

• Published in: Spinal cord Vol. 49; no. 2; pp. 251 - 256
• Main Authors: Bluvshtein, V, Korczyn, A D, Akselrod, S, Pinhas, I, Gelernter, I, Catz, A
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-02-2011; Nature Publishing Group
• Subjects: 631/378/1687/1825; 631/443/592; 692/700/139/1735; Adult; Anatomy; Autonomic Nervous System Diseases - diagnosis; Autonomic Nervous System Diseases - etiology; Autonomic Nervous System Diseases - physiopathology; Biological and medical sciences; Biomedical and Life Sciences; Biomedicine; Cardiovascular Diseases - diagnosis; Cardiovascular Diseases - etiology; Cardiovascular Diseases - physiopathology; Cerebrospinal fluid. Meninges. Spinal cord; Female; Hemodynamics - physiology; Human Physiology; Humans; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Medical sciences; Middle Aged; Nervous system (semeiology, syndromes); Neurochemistry; Neurology; Neuropsychology; Neurosciences; original-article; Paraplegia - complications; Paraplegia - physiopathology; Predictive Value of Tests; Prospective Studies; Quadriplegia - complications; Quadriplegia - physiopathology; Spinal Cord Injuries - complications; Spinal Cord Injuries - diagnosis; Spinal Cord Injuries - physiopathology; Traumas. Diseases due to physical agents; transcranial Doppler ultrasonography; spinal cord injuries; tilt-table test; hemodynamics; power spectrum analysis; Sonography; Doppler ultrasound study; Spinal cord; Nervous system diseases; Vertebral canal; Central nervous system; Tilt table; Spectrum analysis; Spinal cord trauma; Central nervous system disease; Hemodynamics; Patient position; Spinal cord disease; Tilt up method; Power spectrum
• ISSN: 1362-4393; 1476-5624
• DOI: 10.1038/sc.2010.98

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.
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.