Faculty Collaboration Database

Leg sympathetic response to noxious skin stimuli is similar in high and low level human spinal cord injury. Clin Neurophysiol 2008 Feb;119(2):466-74

Date

12/07/2007

Pubmed ID

18055258

Pubmed Central ID

PMC2267914

DOI

10.1016/j.clinph.2007.10.013

Scopus ID

2-s2.0-37349038578 (requires institutional sign-in at Scopus site)   8 Citations

Abstract

OBJECTIVE: To determine if sympathetically mediated vasoconstriction in the lower extremities is injury level dependent. Although sympathetic responses have been measured in the limbs of people with high and low level SCI using blood flow measurements, including Doppler ultrasound and venous plethysmography, a direct comparison between injury levels has not been made.

METHODS: Volunteers with chronic SCI were grouped according to injury level. Above T6: high level (HL, n=7), and T6 and below: low level (LL, n=6). All subjects had complete motor and sensory loss. Leg arterial flows were recorded by venous occlusion plethysmography, and continuous heart rate and mean arterial pressure (MAP) were measured. The conditioning stimulus consisted of transcutaneous stimulation to the arch of the contralateral foot.

RESULTS: HL and LL subjects demonstrated a significant decrease in arterial conductance during stimulation with no significant difference found between groups. As expected, only group HL demonstrated a significant increase in MAP.

CONCLUSIONS: These results support our hypothesis that local (leg) sympathetic responses are similar for both high and low level SCI.

SIGNIFICANCE: While low level SCI does not typically present with autonomic dysreflexia, bouts of increased reflex sympathetic activity could have ramifications for metabolism as well as renal and motor system function.

Author List

Garrison MK, Ng AV, Schmit BD

Authors

Alexander V. Ng PhD Associate Professor in the Exercise Science department at Marquette University
Brian Schmit PhD Professor in the Biomedical Engineering department at Marquette University

MESH terms used to index this publication - Major topics in bold

Adult
Analysis of Variance
Blood Pressure
Female
Heart Rate
Humans
Lower Extremity
Male
Middle Aged
Neural Conduction
Physical Stimulation
Reaction Time
Skin
Spinal Cord Injuries
Sympathetic Nervous System