Microvascular instability in tetraplegic patients: preliminary observations.

Abstract

Case control. To describe the effect of spinal cord injury on microvascular stability. Veterans Administration Medical Center, West Roxbury, MA, USA. A total of 19 tetraplegic patients, aged 63+/-12 years, were surveyed for microvascular instability. Photoelectric pulse sensors were applied to the skin surface of the neck on both sides and to the distal pads of the left and right fourth fingers of subjects in the sitting position. All pulses during the survey periods were recorded by a polygraph system. The unstable fraction of pulsatile cutaneous blood flow (UFCF) was calculated by the sum of the periods during which pulses at any site were either half or twice the baseline amplitude divided by the survey time. Simultaneous UFCF, which was pulsatile flow change in the same direction at the same time in two leads, was also measured. Flow changes in patients with motor and sensory complete lesions were compared with incomplete lesions. Survey times were 7017+/-670 s. Tetraplegic complete UFCF and simultaneous UFCF were 0.25+/-0.12 and 0.07+/-0.07, respectively. Tetraplegic incomplete UFCF and simultaneous UFCF were 0.0.13+/-0.9 and 0.02+/-0.04, respectively. The differences between the groups were significant for UFCF (P=0.04), but not for simultaneous UFCF (P=0.14). Tetraplegic subjects demonstrate an instability of cutaneous microvascular blood flow that is related to the severity of paralysis.