ABSTRACT
Recently several authors have reported that diffusion tensor imaging (DTI) might provide a new understanding of sciatica. The purpose of this study was to investigate the clinical feasibility of DTI for the evaluation of lumbar spinal nerve of patients with sciatica associated with lumbar degenerative disorders. Thirty-four patients (25men, mean age63. 3years) with degenerated lumbar disease, 14 patients with lumbar spinal stenosis with foraminal stenosis, 12 with lumbar spinal stenosis without foraminal stenosis, five with lumbar disc herniation, two with discogenic low back pain, and one with spondylolysis who underwent 3.0T magnetic resonance (MR) imaging and surgical treatment were included in the present study. Fractional anisotropy (FA) was calculated from an FA map, and tractography was investigated. In asymptomatic nerves, tractography showed all L3-S1 spinal nerve roots clearly. Abnormalities of tractography were classified into three types by shape; "Disrupted", "Narrowing", and "Tapering". More abnormalities of tractography were found in patients with lumbar spinal stenosis, and especially in patients with foraminal stenosis. The disrupted type was the most common. The mean FA of entrapped symptomatic nerves was less than seen on the intact side. This study demonstrates that tractography shows abnormal findings for nerve roots in lumbar spinal degeneration and that FA decreases in symptomatic roots. DTI may offer not only morphological evaluation, but also quantitative evaluation. We believe that DTI can be used as a tool for the diagnosis of lumbar spinal degenerative disease.
Subject(s)
Diffusion Tensor Imaging/methods , Intervertebral Disc Degeneration/pathology , Lumbar Vertebrae/pathology , Sciatica/pathology , Spinal Nerves/pathology , Spinal Stenosis/pathology , Adult , Feasibility Studies , Female , Humans , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Intervertebral Disc Degeneration/complications , Lumbar Vertebrae/innervation , Male , Middle Aged , Reproducibility of Results , Sciatica/etiology , Sensitivity and Specificity , Spinal Stenosis/complicationsABSTRACT
STUDY DESIGN: Assessment of pain-related behavior and immunohistology of the dorsal root ganglion in a rat model. OBJECTIVE: To investigate pain-related behavior in a rat model of nerve crush plus inflammation using the CatWalk system. SUMMARY OF BACKGROUND DATA: A definitive method for evaluating animal models of lumbar disease has not been established. Von Frey testing has often been used in this type of study, but the reliability remains in question. The CatWalk system is a computer-assisted apparatus for analyzing gait that provides an automated way to assess gait function during pain. However, there have been few reports using this system for models of lumbar disease. METHODS: Fourteen rats were divided into 2 groups: a treatment group and a sham group. For the treatment group, nucleus pulposus was applied to the sciatic nerve and the sciatic nerve was pinched. Two different methods for assessment of pain-related behavior, von Frey testing and CatWalk analysis, were used before surgery and at 4 and 7 days after surgery. Immunohistochemistry was used to examine calcitonin gene-related peptide expression in L4 to L6 dorsal root ganglia. RESULTS: No significant differences were found between the treatment and sham control groups using von Frey testing. However, significant differences in 4 parameters were found between the 2 groups using the CatWalk system (P < 0.05). The proportion of calcitonin gene-related peptide-immunoreactive neurons was higher in the treatment group than in the control group (P < 0.05). CONCLUSION: Our results demonstrate that the CatWalk system is useful for the measurement of pain-related behavioral change in our rat model in which nociception was indicated at a cellular level. Although further studies are needed, we think that this system is a valid alternative method for the evaluation of models of lumbar disease in rodents.
