Association between abnormal sensation and increased microneurographic muscle sympathetic nerve activity of the peroneal nerve in patients with lumbar spinal problems

Abstract

Nine patients with lumbar spinal problems (patient group) and four healthy volunteers as a control group were examined by the microneurographic technique. A tungsten microelectrode (impedance 2 approximately 5 M omega) was introduced into the peroneal nerve in the affected limb in the patient group. Muscle sympathetic nerve activities were rectified and integrated every 0.1 sec. Muscle sympathetic nerve activity was expressed as the burst number of integrated muscle sympathetic nerve activities per minute (burst rate) and the burst number per 100 heart beats (burst incidence). Statistical analyses were performed by ANOVA. The mean burst rate was 22.5 +/- 5.3 burst/min in the patient group, and 11.9 +/- 1.9 burst/min in the control group. The mean burst incidence was 31.7 +/- 8.2 burst/100 HB in the patient group and 17.1 +/- 4.3 burst/100 HB in the control group. Both the mean burst rate and mean burst incidence were higher in the patient group than in the control group (mean burst rate: p < 0.005, mean burst incidence: p < 0.01). In 62.5% of the patients with increased muscle sympathetic nerve activity, dysesthesia (tingling, and pin prick sensations) was complained of. There was a positive correlation between dysesthesia and increased basic activity of the muscle sympathetic nerve. This suggests the sympathetic nervous system may be involved in inducing abnormal sensations.