DTI can provide valuable structural information that may become an innovative tool in evaluating lumbar foraminal nerve root entrapment. The purpose of this study was to visualize the lumbar nerve ...roots and to measure their FA in healthy volunteers and patients with lumbar foraminal stenosis by using DTI and tractography with 3T MR imaging.
Eight patients with lumbar foraminal stenosis and 8 healthy volunteers underwent 3T MR imaging. In all subjects, DTI was performed with echo-planar imaging at a b-value of 800 s/mm(2) and the lumbar nerve roots were visualized with tractography. Mean FA values in the lumbar nerve roots were quantified on DTI images.
In all subjects, the lumbar nerve roots were clearly visualized with tractography. In all patients, tractography also showed abnormalities such as tract disruption, nerve narrowing, and indentation in their course through the foramen. Mean FA values were significantly lower in entrapped roots than in intact roots.
We demonstrated that DTI and tractography of human lumbar nerves can visualize and quantitatively evaluate lumbar nerve entrapment with foraminal stenosis. We believe that DWI is a potential tool for the diagnosis of lumbar nerve entrapment.
A large electronically reconfigurable reflectarray antenna that has 160 × 160 reflecting elements was designed, fabricated, and evaluated so that it could be applied to a millimeter-wave imaging ...system operating in the 60-GHz band. To make it feasible to construct such a large reflectarray, the reflecting element structure had to be simple and easily controlled; therefore, a reflecting element consisting of a microstrip patch and a single-bit digital phase shifter using a p-i-n diode was employed. A large reflectarray antenna was fabricated using the reflecting elements. The measured radiation patterns and antenna gain were in good agreement with those that were calculated. Furthermore, the near-field beam focusing capabilities, which was required to image near-field objects, were also verified through an experiment. Finally, the response time for beamforming was measured, which was far less than the system requirements.
It has been reported that rat L5/6 lumbar discs are innervated mainly by L2 dorsal root ganglion neurons. We previously reported that L2 spinal nerve infiltration was effective for discogenic low ...back pain (DLBP) patients, although the diagnosis was based only on the results of physical examination, plain films, and magnetic resonance imaging (MRI). The purpose of the current study was to evaluate L2 spinal nerve block for DLBP patients retrospectively based on MRI findings and surgical results.
A total of 62 patients with only LBP and no accompanying radicular pain were investigated. Patients had only one level of disc degeneration on MRI. When pain was provoked during discography, we performed surgery at the next stage (40 patients). In all, 22 patients were excluded owing to negative discography results. Of the 40 patients, we evaluated 25 strictly selected patients suffering from DLBP. DLBP was diagnosed when the patient experienced pain relief at least 2 years after anterior lumbar interbody fusion. Fifteen patients who did not show pain relief after surgery were used for the non-DLBP group. L2 spinal nerve infiltration using 1.5 ml of lidocaine was performed in all 40 patients before surgery. The visual analogue scale (VAS) score after L2 spinal nerve infiltration was recorded, and an association of L2 spinal nerve infiltration and DLBP was explored.
Low back pain scores assessed using the VAS score, the Japanese Orthopedic Association score, and the Oswestry Disability Index score in the two groups were not significantly different. L 2 spinal nerve infiltration was effective for 27 patients but not effective for 13 patients; the VAS score after 15 min and 2 h improved in the DLBP group compared with that of the non-DLBP group (P < 0. 05). L2 spinal nerve infiltration was more effective in DLBP patients (21 patients, 84%) than in the non-DLBP group (6 patients, 40%) (P < 0.05).
In the current study, L2 spinal nerve infiltration was effective in 84% of selected DLBP patients and is thought to be a useful tool for diagnosing DLBP. However, we should take into consideration that the L2 spinal nerve infiltration was effective in 40% of non-DLBP patients as well.
Platelet-rich plasma (PRP) contains several growth factors, including platelet-derived growth factor (PDGF), transforming growth factor-β1 (TGF-β1), insulin-like growth factor-1 (IGF-1), and vascular ...endothelial growth factor (VEGF), that are associated with repair processes after central nervous system injury. Although PRP have been applied to some regenerative therapies, the regeneration effects of PRP on spinal cord injury have not been reported. This study applied a rat organ coculture system to examine the ability of PRP to enhance axonal growth in spinal cord tissues and to identify the growth factors in PRP that contribute to the regulation of axon growth. PRP from human peripheral blood was added to organ cocultures. Furthermore, neutralizing antibodies against PDGF-AB, TGF-β1, IGF-1, or VEGF were added to the cocultures with PRP. Axon growth from the brain cortex into the spinal cord was assessed quantitatively using anterograde axon tracing with DiI. Addition of PRP to the cocultures promoted axon growth, and the axon growth was significantly suppressed by the addition of neutralizing antibodies against IGF-1 and VEGF, but not PDGF-AB. In contrast, axon growth was promoted significantly by the addition of neutralizing antibodies against TGF-β1. These findings indicate that PRP promotes axon growth in spinal cord tissues through mechanisms associated with IGF-1 and VEGF, and that TGF-β1 in PRP exerts negative effects on axon growth.
Osteoarthritic (OA) pain is largely considered to be inflammatory pain. However, during the last stage of knee OA, sensory nerve fibers in the knee are shown to be significantly damaged when the ...subchondral bone junction is destroyed, and this can induce neuropathic pain. Several authors have reported that tumor necrosis factor-α (TNFα) in a knee joint plays a crucial role in pain modulation. The purpose of the current study was to evaluate the efficacy of etanercept, a TNFα inhibitor, for pain in knee OA.
Thirty-nine patients with knee OA and a 2-4 Kellgren-Lawrence grading were evaluated in this prospective study. Patients were divided into two groups; hyaluronic acid (HA) and etanercept injection. All patients received a single injection into the knee. Pain scores were evaluated before and 4 weeks after injection using a visual analogue scale (VAS) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and they were compared between the groups.
Before injection, VAS and WOMAC scores were not significantly different between the groups (p>0.05). Significant pain relief was found in the etanercept group at 1 and 2 weeks by VAS, and at 4 weeks by WOMAC score, compared with the HA group (p<0.05). No adverse events were observed in either group.
Direct injection of etanercept into OA knee joints was an effective treatment for pain in moderate and severe OA patients. Furthermore, this finding suggests that TNFα is one factor that induces OA pain.
A microwave variable delay line using a membrane impregnated with liquid crystal was newly fabricated. By employing this device configuration, the phase-shift response becomes fast independently of ...the liquid crystal thickness. Experimental results show that the phase-shift response time of 33 ms is obtained, which is two orders of magnitude faster than that of a conventional delay line. The new delay line also exhibits a 270-degree phase-shift and non-dispersive delay characteristics over a wide microwave-frequency range. Moreover, it is clarified that the phase-shift characteristics to a control voltage depend on the pore size of the membrane.
Introduction
Interleukin-6 (IL-6) is considered to play a crucial role in the radicular pain caused by lumbar spinal stenosis (LSS). However, efficacy of inhibition of IL-6 for sciatica in patients ...with LSS has not been clarified. The purpose of the current study was to examine the effect of the anti-IL-6 receptor monoclonal antibody, tocilizumab, on radicular pain by its epidural administration onto spinal nerves in patients with LSS.
Materials and Methods
A total of 60 patients with low back and radicular leg pain caused by spinal stenosis were investigated. In 30 patients, we infiltrated 2.0 mL of lidocaine and 80 mg of tocilizumab onto the affected spinal nerve, and 2.0 mL of lidocaine and 3.3 mg of dexamethasone were used in 30 patients. Low back pain (LBP), leg pain, and leg numbness were evaluated during 1 month after spinal nerve infiltration.
Results
Infiltration of tocilizumab was more effective than dexamethasone for leg pain (3 days, 1, 2, and 4 weeks), LBP (3 days, 1, 2, and 4 weeks), and leg numbness (3 days, 1 and 2 weeks). No adverse event was observed in either group.
Conclusion
Our results indicate that epidural administration of an anti-IL-6 receptor monoclonal antibody and, tocilizumab, onto the spinal nerve produced reduction of radicular leg pain, numbness, and LBP without adverse event. IL-6 may be one of the inducers of pain caused by spinal stenosis in humans.
I confirm having declared any potential conflict of interest for all authors listed on this abstract Yes
Disclosure of Interest None declared
We investigated the efficacy of pregabalin (PGB) for neuropathic leg pain in lumbar spinal stenosis (LSS) patients with disturbed activities of daily living (ADL)/quality of life (QOL) in a ...prospective observational study. Subjects were a total of 104 LSS patients with neuropathic pain (NeP) in leg and neurological intermittent claudication (IMC) refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) for at least a month. NeP was identified using screening tool, Pain DETECT questionnaire. Visual analog scale (VAS) scores and responses to the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were assessed before and 6 weeks after PGB treatment initiation. Changes in IMC distance and adverse events were also recorded. PGB significantly improved their VAS scores for pain and sleep quality ( P < 0.001 ). With respect to JOABPEQ, significant improvements were observed with regard to the following dimensions: pain-related disorders ( P < 0.01 ), lumbar spine dysfunction ( P = 0.031 ), gait disturbance ( P = 0.028 ), and psychological disorders ( P = 0.014 ). The IMC distance showed an improvement tendency after PGB treatment, albeit with no significance ( P = 0.063 ). Minor adverse events such as dizziness were observed. PGB can be effective for neuropathic leg pain refractory to NSAIDs in LSS patients, resulting in not only pain control but also improving lower back pain-related ADL/QOL scores.
STUDY DESIGN.Animal study.
OBJECTIVE.To evaluate pain behavior and neuropeptide changes in the spinal dorsal horn after sciatic nerve compression and application of nucleus pulposus (NP) in rats.
...SUMMARY OF BACKGROUND DATA.The pathomechanisms of lumbar disc herniation pain have not been fully elucidated. Pain-associated neuropeptides, including substance P and calcitonin gene-related peptide (CGRP), are produced in dorsal root ganglion neurons and transported to spinal dorsal horn nerve terminals where they function in pain transmission. However, changes in CGRP-immunoreactive (IR) sensory nerve terminals have not been reported in models of disc herniation. This study evaluated pain-related behavior and changes in CGRP-IR terminals in the spinal dorsal horn after combined sciatic nerve compression and NP application.
METHODS.Five groups of rats underwent either sciatic nerve compression with NP (n = 20), application of NP only (n = 20), nerve compression only (n = 20), and sham operation with neither compression nor NP (n = 20) or no operation (controls, n = 20). Mechanical hyperalgesia was measured every second day for 3 weeks. CGRP-IR terminals in each spinal dorsal horn lamina were examined 7 and 14 days postsurgery. Pain behavior and CGRP immunoreactivity were compared among the 5 groups.
RESULTS.Mechanical hyperalgesia was found in the NP only, nerve compression only, and the NP with nerve compression groups (P ≤ 0.05). CGRP-IR nerve terminals in the superficial laminae (I and II) and the deep laminae (III–VI) significantly increased in the NP only, nerve compression only, and NP with nerve compression groups compared with control and sham groups (P ≤ 0.05). Significant mechanical hyperalgesia and increased CGRP-IR nerve terminals were found in the NP with nerve compression group compared with the NP only and nerve compression only groups (P ≤ 0.05).
CONCLUSION.Our results indicate that nerve compression plus NP application produces the most pain-related behavior. CGRP-IR nerve terminals increased in laminae I and II that transmit pain and in laminae III to VI that transmit proprioception. Findings suggest that nerve compression plus NP application induces changes in CGRP expression in the superficial and deep laminae, and these changes are partly responsible for disc herniation pain.Level of EvidenceN/A
Transient receptor potential vanilloid 1 (TRPV1) is a ligand-gated nonselective cation channel, which can be activated by capsaicin and other noxious stimuli. Recently, an association between bone ...pain and TRPV1 has been reported. However, the influence of osteoporosis on TRPV1 in the sensory system innervating the femur has not been reported.
TRPV1-immunoreactive (ir) in dorsal root ganglia (DRG) neurons labeled with neurotracer Fluoro-Gold (FG) innervating the femurs of Sprague Dawley rats were examined in control, sham, and ovariectomized (OVX) rats. We evaluated osteoporosis in the femurs and compared the proportion of TRPV1-ir DRG neurons innervating femur between the 3 groups of rats.
OVX rats showed osteoporotic cancellous bone in the femur. FG labeled neurons were distributed from L1 to L6 DRG, but there was no significant difference in the proportion of labeled neurons between the 3 groups (p>0.05). The proportions of FG labeled TRPV1-ir DRG neurons were 1.7%, 1.7%, and 2.8% of DRG neurons innervating the femur, in control, sham-operated, and OVX rats, respectively. The proportion of TRPV1-ir neurons in DRG innervating the femur in OVX rats was significantly higher than that in control and sham-operated rats (p<0.05).
Under physiological conditions, DRG neurons innervating femurs in rats contain TRPV1. Osteoporosis increases the numbers of TRPV1-ir neurons in DRG innervating osteoporotic femurs in rats. These findings suggest that TRPV1 may have a role in sensory perception of osteoporotic femurs.
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