Elevated Concentration of Hyaluronan in the Cerebrospinal Fluid is a Secondary Marker of Spinal Disorders

Comparison of the effects of corticosteroid and hyaluronic acid-carboxymethylcellulose solution on selective nerve root block for lumbar radiculopathy: A prospective, double-blind, randomized controlled clinical trial

BACKGROUND

Selective nerve root block (SNRB) was shown to effectively control radiating pain and reduce the need for surgical intervention. However, repetitive injections may trigger corticosteroid-induced side effects (hypercorticism, hyperglycemia, or fluid retention). This study aims to compare the potency of hyaluronic acid-carboxymethylcellulose (HA-CMC) solution versus that of corticosteroids regarding lower leg radiating pain (LLRP) improvement and functional outcome.

METHODS

Among 128 patients, 44 patients who complain about having LLRP due to lumbar spinal stenosis and do not have neurological symptoms requiring surgery were enrolled for this study. Group A with 22 patients injected with cocktail A (local anesthetics and corticosteroid) and group B with 22 patients injected with cocktail B (local anesthetics and HA-CMC). Outcome measures were the visual analog scale (VAS), Oswestry Disability Index (ODI), and short form-36 (SF-36). All patients were asked to fill in the questionnaires during the follow-up assessment period at 3 days, 7 days, 2 weeks, 6 weeks, and 12 weeks.

RESULTS

In all time periods, there were no statistical differences between the two groups for VAS scores and VAS improvement over time, ODI scores and ODI improvement over time, and SF-36 PCS scores and SF-36 mental component score scores. Additionally, the 95% confidence interval of the difference in VAS score improvement between the 2 groups in all time periods was within VAS 5.0, which is the minimum clinically relevant difference.

CONCLUSIONS

Considering the adverse effects of corticosteroids, and the similar LLRP improvements, functional outcome, and quality of life, the HA-CMC solution may be an alternative option to corticosteroid in SNRB.

Therapeutic effect of epidural hyaluronic acid in a rat model of foraminal stenosis

PURPOSE

Since receiving a warning from the US Food and Drug Administration (FDA) about injection of corticosteroids into the epidural space having serious adverse events, we have sought alternative medications for injection at this site. Hyaluronic acid (HA) has anti-adhesive, anti-inflammatory, and lubricating properties, so could potentially be useful for spinal pain. The exact mechanism by which spinal stenosis develops is not fully understood, but is likely to involve inflammation. Therefore, we hypothesized that HA could have a therapeutic effect in spinal stenosis. This study evaluated the effects of epidural administration of HA on alleviation of pain in a rat model of foraminal stenosis.

MATERIALS AND METHODS

After creating the animal model, HA (HA group) or saline solution (S group) was administered via an epidural catheter. The paw-withdrawal threshold to mechanical stimulation and motor dysfunction were monitored for up to 21 days. Tissue was collected to evaluate the degree of adhesion, inflammation in the perineural area, and chromatolysis in the dorsal root ganglion (DRG).

RESULTS

The mechanical withdrawal threshold was restored in the HA group but not in the S group (P < 0.001). The HA group also showed less fibrosis (P = 0.026) and less chromatolysis (P = 0.002) than the S group.

CONCLUSION

HA administered epidurally had a therapeutic effect on the allodynia and hyperalgesia induced by chronic compression of the DRG.

The CD44 ligand hyaluronic acid is elevated in the cerebrospinal fluid of suicide attempters and is associated with increased blood-brain barrier permeability

BACKGROUND

The glycosaminoglycan hyaluronic acid (HA) is an important component of the extracellular matrix (ECM) in the brain. CD44 is a cell adhesion molecule that binds to HA in the ECM and is present on astrocytes, microglia and certain neurons. Cell adhesion molecules have been reported to be involved in anxiety and mood disorders. CD44 levels are decreased in the cerebrospinal fluid (CSF) of depressed individuals, and the CD44 gene has been identified in brain GWAS studies as a possible risk gene for suicidal behavior.

METHOD

We measured the CSF levels of HA and the soluble CD44 (sCD44) in suicide attempters (n=94) and in healthy controls (n=45) using ELISA and electrochemiluminescence assays. We also investigated other proteins known to interact with CD44, such as osteopontin and the matrix metalloproteinases MMP1, MMP3 and MMP9.

RESULTS

The suicide attempters had higher CSF levels of HA (p=.003) and MMP9 (p=.004). The CSF levels of HA correlated with BBB-permeability (rho=0.410, p<.001) and MMP9 correlated with sCD44 levels (rho=0.260, p=.005).

LIMITATIONS

Other relevant biological contributors to suicidal behavior is not addressed in parallel to the specific role of CD44-HA signaling. The gender distribution of the patients from whom CSF was analyzed was uneven.

CONCLUSIONS

Increased BBB-permeability and HA levels might be a results of increased neuroinflammation and can play a role in the pathobiology of suicidal behavior. The CD44 signaling pathway might be considered a novel target for intervention in mood disorders.

Hyaluronan tetrasaccharide in the cerebrospinal fluid is associated with self-repair of rats after chronic spinal cord compression

The objective of this study was to explore changes in hyaluronan levels in the cerebrospinal fluid (CSF) in a spinal cord compression model, to investigate whether hyaluronan tetrasaccharide was involved in this process, and to test the effects of hyaluronan tetrasaccharide on neuron and oligodendrocyte repair. We developed a chronic spinal cord compression model with various sizes of polymer sheets (1.5×0.7×0.3 mm(3); 5×1.5×0.7 mm(3)) that were implanted microsurgically underneath the C(5-6) laminae. The rats were divided into three groups: a sham group, a mildly compressed (MC) group, and a widely compressed (WC) group. Locomotor functional evaluations revealed that the behavioral function of the MC and WC groups dropped to their lowest level from the fourth to fifth week and gradually recovered thereafter. The hyaluronan levels in the CSF gradually increased after spinal cord compression. Furthermore, hyaluronan tetrasaccharide was involved in the hyaluronan change. In addition, we found that nuclear factor kappa B (NF-κB) and cellular inhibitor-of-apoptosis protein 2 (c-IAP(2)) were co-expressed in neurons and oligodendrocytes, and caspase-3 expression gradually decreased in the compression model. The brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) expression was upregulated in astrocytes at the fourth week post-compression. Hyaluronan tetrasaccharide (HA(4)) induced NF-κB and c-IAP(2) to suppress the H(2)O(2)-induced apoptosis in primary neuronal cultures and increased BDNF and VEGF expression in astrocytic cultures in vitro. These findings suggest that HA(4) in the CSF may associate with behavioral recovery by increasing the levels of NF-κB, c-IAP(2), and neurotrophic factors after chronic spinal cord compression.