Limaprost alfadex, a prostaglandin E1 derivative, prevents deterioration of forced exercise capability in rats with chronic compression of the spinal cord

Nonsurgical therapy for lumbar spinal stenosis caused by ligamentum flavum hypertrophy: A review

Lumbar spinal stenosis (LSS) can cause a range of cauda equina symptoms, including lower back and leg pain, numbness, and intermittent claudication. This disease affects approximately 103 million people worldwide, particularly the elderly, and can seriously compromise their health and well-being. Ligamentum flavum hypertrophy (LFH) is one of the main contributing factors to this disease. Surgical treatment is currently recommended for LSS caused by LFH. For patients who do not meet the criteria for surgery, symptom relief can be achieved by using oral nonsteroidal anti-inflammatory drugs (NSAIDs) and epidural steroid injections. Exercise therapy and needle knife can also help to reduce the effects of mechanical stress. However, the effectiveness of these methods varies, and targeting the delay in LF hypertrophy is challenging. Therefore, further research and development of new drugs is necessary to address this issue. Several new drugs, including cyclopamine and N-acetyl-l-cysteine, are currently undergoing testing and may serve as new treatments for LSS caused by LFH.

Pharmacological Treatment of Degenerative Cervical Myelopathy: A Critical Review of Current Evidence

Degenerative cervical myelopathy (DCM) is the leading cause of spinal cord dysfunction in adults, representing substantial morbidity and significant financial and resource burdens. Typically, patients with progressive DCM will eventually receive surgical treatment. Nonetheless, despite advancements in pharmacotherapeutics, evidence for pharmacological therapy remains limited. Health professionals from various fields would find interest in pharmacological agents that could benefit patients with mild DCM or enhance surgical outcomes. This review aims to consolidate all clinical and experimental evidence on the pharmacological treatment of DCM. We conducted a comprehensive narrative review that presents all pharmacological agents that have been investigated for DCM treatment in both humans and animal models. Riluzole exhibits effectiveness solely in rat models, but not in treating mild DCM in humans. Cerebrolysin emerges as a potential neuroprotective agent for myelopathy in animals but had contradictory results in clinical trials. Limaprost alfadex demonstrates motor function improvement in animal models and exhibits promising outcomes in a small clinical trial. Glucocorticoids not only fail to provide clinical benefits but may also lead to adverse events. Cilostazol, anti-Fas ligand antibody, and Jingshu Keli display promise in animal studies, while erythropoietin, granulocyte colony-stimulating factor and limaprost alfadex exhibit potential in both animal and human research. Existing evidence mainly rests on weak clinical data and animal experimentation. Current pharmacological efforts target ion channels, stem cell differentiation, inflammatory, vascular, and apoptotic pathways. The inherent nature and pathogenesis of DCM offer substantial prospects for developing neurodegenerative or neuroprotective therapies capable of altering disease progression, potentially delaying surgical intervention, and optimizing outcomes for those undergoing surgical decompression.

Comparative Study on the Efficacy of Pregabalin Versus Limaprost in Patients With Lumbar Spinal Stenosis: A Prospective, Randomized Controlled Trial

BACKGROUND

Patients with Lumbar Spinal Stenosis (LSS) typically complain of back pain and leg pain. These symptoms reduce the quality of life (QoL) and also cause sleep disturbances. This study compares pregabalin and limaprost's efficacy in LSS for pain, disability, QoL, and sleep, aiming to offer insights for medication selection.

METHODS

This study was designed as a prospective, randomized, single-center, single-blinded, clinical superiority trial targeting patients with LSS. For 6 weeks, 111 patients per group were administered medication following a standard regimen, after which patient-reported outcomes were measured. The primary outcome was the Visual Analogue Scale (VAS) for back and leg pain, and the secondary outcomes included the Oswestry Disability Index (ODI), European Quality of Life 5 Dimensions (EQ-5D), and sleep quality.

RESULTS

After 6 weeks of medication, there were significant improvements over time in the primary outcome, VAS for back pain and leg pain, in both groups, but no significant difference between the 2 groups. Similarly, for the secondary outcomes, ODI and EQ-5D, both groups showed significant improvements, yet there was no significant difference between them. In the subgroup analysis targeting poor sleepers (Pittsburgh sleep quality index, PSQI >5), both groups also exhibited significant improvements in sleep quality, but again, there was no significant difference between the groups.

CONCLUSIONS

Efficacy of pregabalin, limaprost in back and leg pain, ODI, EQ-5D, and sleep quality, but there was no significant difference between the 2 groups. Thus, it is advisable to prescribe based on individual drug responses and potential complications.

Clinical Effectiveness of Conservative Treatments on Lumbar Spinal Stenosis: A Network Meta-Analysis

Objective: To systematically evaluate the clinical effectiveness of conservative treatments including pharmacological treatments and nonpharmacological treatments on patients with lumbar spinal stenosis.

Methods: We searched six electronic databases systematically for randomized clinical trials published between January 2000 and July 2021, including the China National Knowledge Infrastructure, WanFang Data, PubMed, MEDLINE, Embase, and the Cochrane library. The studies focused on the therapeutic effects of pharmacological treatments including calcitonin, antiepileptics, neurotrophic drugs, nonsteroidal anti-inflammatory drugs, Chinese Traditional Medicine, limaprost, and nonpharmacological treatments like physiotherapy for treating lumbar spinal stenosis were included. The outcome was measured using the visual analog scale, Oswestry Dysfunction Index, Japanese Orthopaedic Association Score, and EuroQol Five Dimensions Questionnaire. The quality of eligible studies was assessed by using the Cochrane recommended bias risk assessment tool. Stata was used to conduct the network meta-analysis.

Results: A total of 12 randomized control trials with 1,194 patients were included. The network meta-analysis showed that for the visual analog scale, a better therapeutic effect was noted while using Chinese Traditional Medicine and physiotherapy, followed by analgesics drugs and limaprost. Limaprost and calcitonin were better in decreasing the Oswestry Dysfunction Index. In terms of the Japanese Orthopaedic Association Score, the use of traditional Chinese Medicine and limaprost were associated with a better improvement than other treatments. Meanwhile, limaprost combined with analgesics drugs was found to be effective to improve the EuroQol Five Dimensions Questionnaire.

Conclusion: Among the commonly used conservative treatments for the treatment of lumbar spinal stenosis, limaprost may have better efficacy in improving the Japanese Orthopaedic Association Score and decreasing the Oswestry Dysfunction Index, with a beneficial effect on decreasing the visual analog scale and improving the EuroQol Five Dimensions Questionnaire.

Systematic Review Registration: website, identifier registration number.

Muscone suppresses inflammatory responses and neuronal damage in a rat model of cervical spondylotic myelopathy by regulating Drp1-dependent mitochondrial fission

Cervical spondylotic myelopathy (CSM) is a common cause of disability with few treatments. Aberrant mitochondrial dynamics play a crucial role in the pathogenesis of various neurodegenerative diseases. Thus, regulation of mitochondrial dynamics may offer therapeutic benefit for the treatment of CSM. Muscone, the active ingredient of an odoriferous animal product, exhibits anti-inflammatory and neuroprotective effects for which the underlying mechanisms remain obscure. We hypothesized that muscone might ameliorate inflammatory responses and neuronal damage by regulating mitochondrial dynamics. To this end, the effects of muscone on a rat model of chronic cervical cord compression, as well as activated BV2 cells and injured neurons, were assessed. The results showed that muscone intervention improved motor function compared with vehicle-treated rats. Indeed, muscone attenuated pro-inflammatory cytokine expression, neuronal-apoptosis indicators in the lesion area, and activation of the nod-like receptor family pyrin domain-containing 3 inflammasome, nuclear transcription factor-κB, and dynamin-related protein 1 in Iba1- and βIII-tubulin-labeled cells. Compared with vehicle-treated rats, compression sites of muscone-treated animals exhibited elongated mitochondrial morphologies in individual cell types and reduced reactive oxygen species. In vitro results indicated that muscone suppressed microglial activation and neuronal damage by regulating related-inflammatory or apoptotic molecules. Moreover, muscone inhibited dynamin-related protein 1 activation in activated BV2 cells and injured neurons, whereby it rescued mitochondrial fragmentation and reactive oxygen species production, which regulate a wide range of inflammatory and apoptotic molecules. Our findings reveal that muscone attenuates neuroinflammation and neuronal damage in rats with chronic cervical cord compression by regulating mitochondrial fission events, suggesting its promise for CSM therapy.

Human recombinant erythropoietin improves motor function in rats with spinal cord compression-induced cervical myelopathy

Objective

Erythropoietin (EPO) is a clinically available hematopoietic cytokine. EPO has shown beneficial effects in the context of spinal cord injury and other neurological conditions. The aim of this study was to evaluate the effect of EPO on a rat model of spinal cord compression-induced cervical myelopathy and to explore the possibility of its use as a pharmacological treatment.

Methods

To develop the compression-induced cervical myelopathy model, an expandable polymer was implanted under the C5-C6 laminae of rats. EPO administration was started 8 weeks after implantation of a polymer. Motor function of rotarod performance and grip strength was measured after surgery, and motor neurons were evaluated with H-E, NeuN and choline acetyltransferase staining. Apoptotic cell death was assessed with TUNEL and Caspase-3 staining. The 5HT, GAP-43 and synaptophysin were evaluated to investigate the protection and plasticity of axons. Amyloid beta precursor protein (APP) was assessed to evaluate axonal injury.

To assess transfer of EPO into spinal cord tissue, the EPO levels in spinal cord tissue were measured with an ELISA for each group after subcutaneous injection of EPO.

Results

High-dose EPO maintained motor function in the compression groups. EPO significantly prevented the loss of motor neurons and significantly decreased neuronal apoptotic cells. Expression of 5HT and synaptophysin was significantly preserved in the EPO group. APP expression was partly reduced in the EPO group. The EPO levels in spinal cord tissue were significantly higher in the high-dose EPO group than other groups.

Conclusion

EPO improved motor function in rats with compression-induced cervical myelopathy. EPO suppressed neuronal cell apoptosis, protected motor neurons, and induced axonal protection and plasticity. The neuroprotective effects were produced following transfer of EPO into the spinal cord tissue. These findings suggest that EPO has high potential as a treatment for degenerative cervical myelopathy.

Experimental rat model for cervical compressive myelopathy

Previously, a rat model of chronic compressive myelopathy that uses a water-absorbing polymer inserted under a spinal lamina was reported. However, the best size and coefficient of expansion of the polymer sheet have not yet been established. The aim of the present study was to optimize these properties in an ideal rat model of cervical compressive myelopathy. Thirty rats were used in this study. A sheet of water-absorbing polymer was inserted under the cervical laminae. Rats were divided randomly into five experimental groups by the expansion rate (350 or 200%) and thickness (0.5 or 0.7 mm) and the control. After the surgery, the severity of paralysis was evaluated for 12 weeks. At 12 weeks after the surgery, cresyl violet staining was performed to assess the number of motor neurons in the anterior horn at the C4/C5 segment and Luxol Fast Blue staining was performed to assess demyelination in the corticospinal tract at the C7 segment. 'Slow-progressive' paralysis appeared at 4-8 weeks postoperatively in rat models using sheets with 200% expansion. By contrast, only temporary paralysis was observed in rat models using sheets with 350% expansion. A loss of motor neurons in the anterior horn was observed in all groups, except for the control. Demyelination in the corticospinal tract was observed in rat models using sheets with 200% expansion, but not rat models using sheets with 350% expansion. A polymer sheet that expands its volume by 200% is an ideal material for rat models of cervical compressive myelopathy.

Granulocyte Colony-Stimulating Factor Improves Motor Function in Rats Developing Compression Myelopathy

STUDY DESIGN

Basic animal research.

OBJECTIVE

The effects of granulocyte colony-stimulating factor (G-CSF) were assessed in a rat chronic spinal cord compression model to explore the potential of G-CSF as a pharmacological treatment for cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

G-CSF is a hematopoietic cytokine used clinically to treat neutropenia. Recently, neuroprotective effects of G-CSF have been reported in spinal cord disorders.

METHODS

To introduce the chronic cervical cord compression, thin polyurethane sheets were implanted under C5-C6 laminae of rats and gradually expanded by absorbing water. This model reproduces delayed compressive myelopathy of the cervical spine. In sham operations, the sheets were immediately removed. G-CSF (15 μg/kg) or normal saline (NS) was administered subcutaneously 5 days a week. Experimental groups were sham operation given NS; cord compression given NS; and cord compression given G-CSF. To assess motor functions, rotarod performance, and grip strength were measured. Twenty-six weeks after surgery, cervical spinal cords were examined histopathologically. In the prevention experiment, G-CSF or NS administration was started immediately after surgery. In the treatment experiment, their administration was started 8 weeks after surgery. In another experiment, in three groups in the prevention experiment, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling staining was performed to assess apoptotic cell death at 8 weeks after surgery.

RESULTS

In the prevention experiment, administration of G-CSF preserved the motor functions and motor neurons throughout the 26 weeks, and significantly decreased the number of apoptotic cells at 8 weeks. In the treatment experiment, G-CSF administration from 8 weeks after surgery markedly restored the motor function temporarily to a level equal to the sham group.

CONCLUSION

G-CSF prevents the decline in motor functions and preserves motor neurons in the rat chronic cord compression model. G-CSF also improves motor function in the progressive phase of compression myelopathy.

LEVEL OF EVIDENCE

N/A.

Comparative study of the efficacy of limaprost and pregabalin as single agents and in combination for the treatment of lumbar spinal stenosis: a prospective, double-blind, randomized controlled non-inferiority trial

BACKGROUND CONTEXT

Although the simultaneous management of neuronal ischemia-related pain and compression-demyelination-related neuropathic pain is considered optimal in treating lumbar spinal stenosis (LSS), the effect of combination therapy with pregabalin and limaprost has not been elucidated.

PURPOSE

This study aimed to compare the effects of limaprost and pregabalin individually and in combination for the treatment of LSS.

STUDY DESIGN

This is a prospective, double-blind, double-dummy, randomized controlled trial.

PATIENT SAMPLE

The sample consists of patients with LSS.

OUTCOME MEASURES

The baseline-adjusted Oswestry Disability Index (ODI) score, visual analog scale (VAS) scores for leg pain, the European Quality of Life-5 dimensions (EQ-5D), and initial claudication distance (ICD).

METHODS

The present study (ClinicalTrials.gov, number NCT01888536) was a prospective, double-blind, double-dummy, randomized controlled trial designed to determine the efficacy of limaprost in alleviating leg pain, improving disability, and increasing walking distance in persons with degenerative LSS in three different treatment groups: limaprost alone, pregabalin alone, and combined limaprost and pregabalin through 1:1:1 allocation. The primary outcome was the baseline-adjusted ODI score at 8 weeks after treatment. The non-inferior margin of the ODI was set at δ=10 points.

RESULTS

The baseline-adjusted ODI score (primary outcome) at 8 weeks after treatment in the limaprost group was not inferior to those in the pregabalin and limaprost+pregabalin groups. The overall changes of the baseline-adjusted ODI scores, VAS scores for leg pain, the EQ-5D, and ICD during the follow-up assessments over an 8-week period (secondary end point) were not different among the three groups. The baseline-adjusted ODI scores and VAS scores for leg pain decreasedsignificantly over time after treatment in all three groups. The baseline-adjusted EQ-5D score and ICD also increased significantly over time after treatment in all three groups.

CONCLUSIONS

The efficacy of limaprost for lumbar spinal stenosis was not inferior compared with that of pregabalin or the combination of limaprost and pregabalin in terms of disability. Therefore, combined treatment with limaprost and pregabalin does not provide additional relief in symptoms in patients with LSS compared with monotherapy with limaprost or pregabalin.