Evaluation of the changes in the muscle sympathetic nerve activity and anterior tibial muscle blood flow caused by the Valsalva maneuver in patients with lumbago and healthy subjects.

Clinical symptoms affecting the lower extremities are common among lumber spinal disorder patients. Pain, numbness and sensory disturbance are major signs of these symptoms, and have been suggested to be related to sympathetic nerve disturbance. This study was designed to examine whether these patients experience a difference in sympathetic nerve flow in terms of muscle sympathetic nerve activity (MSA) compared to healthy subjects. Five patients with lumbar intervertebral disc herniation of the spine (LIDH) and four patients with lumbar spinal canal stenosis (LSCS) were examined along with six healthy volunteers. Basic MSAs for IDH and SCS patients that were introduced from a common peroneal nerve were found to be statistically higher than those of the control subjects. MSA behavior and muscle blood flow introduced from the tibialis anterior muscle over 30 seconds while performing the Valsalva maneuver, a well-known technique used to artificially facilitate MSA, were examined for all subjects, and showed relatively slower changes for LIDH and LSCS patients compared to the normal subjects. Muscle blood flow was inversely proportional to MSA for the normal subjects, and this relationship was observed for IDH patients as well as SCS patients. However, MSA and the muscle blood flow of patients gradually changed while performing the Valsalva maneuver relative to the control subjects. This suggests that the systemic physiological response to the maneuver is maintained, but that, some local modification mechanisms exist.