Analysis of blood degradation products and ferritin in the cerebrospinal fluid of dogs with acute thoracolumbar intervertebral disk extrusion, a prospective pilot study.

BACKGROUND: Hemorrhage in the spinal canal leads to further damage of the spinal cord influencing outcome in dogs with intervertebral disk (IVD) extrusion. The aim of the study was to evaluate blood degradation products and ferritin in the cerebrospinal fluid (CSF) of dogs with thoracolumbar IVD extrusion, and their association to clinical parameters and MRI findings. RESULTS: In the CSF of dogs with IVD extrusion, both net oxyhemoglobin absorption (NOA) and net bilirubin absorption (NBA) were significantly higher compared to the control groups of dogs with steroid responsive meningitis arteritis (SRMA) and idiopathic epilepsy (IE) (P < 0.001), but NOA compared to the idiopathic epilepsy group contaminated artificially with blood (IEc) was not (P = 0.890). Ferritin concentration was significantly higher in dogs with IVD extrusion compared to dogs with IE (P = 0.034), but not to dogs with SRMA (P = 0.526). There was no association between NOA, NBA or ferritin concentration and severity or duration of clinical signs. In dogs with a higher ferritin concentration the outcome was better (P = 0.018). In dogs with evidence of hemorrhage on MRI, NOA and NBA were significantly higher (P = 0.016, P = 0.009), but not ferritin (P = 0.0628). CONCLUSION AND CLINICAL IMPORTANCE: Quantification of blood degradation products and ferritin in the CSF of dogs to assess subarachnoidal hemorrhage is feasible; however, larger case numbers are needed to evaluate the relevance of NBA and ferritin as prognostic indicators.

Unraveling the neuroimmune interface in chronic pain-the association between cytokines in the cerebrospinal fluid and pain in patients with lumbar disk herniation or degenerative disk disease.

ABSTRACT: Recent evidence highlights the importance of the neuroimmune interface, including periphery-to-central nervous system (CNS) neuroimmune crosstalk, in chronic pain. Although neuroinflammatory processes have been implicated in central sensitization for a long time, their potential neuroprotective and analgesic effects remain relatively elusive. We have explored the relationships between cytokine expression and symptom severity, and candidates for periphery-to-CNS crosstalk. Patients with degenerative disk disease (DDD) (nociceptive pain) or patients with lumbar disk herniation (LDH) with radiculopathy (predominantly neuropathic pain) completed questionnaires regarding pain and functional disability, underwent quantitative sensory testing, and provided blood and cerebrospinal fluid (CSF) samples. Proximity extension assay (PEA) was used to measure the levels of 92 inflammatory proteins in the CSF and serum from a total of 160 patients and controls, and CSF/serum albumin quotients was calculated for patients with DDD and patients with LDH. We found signs of neuroimmune activation, in the absence of systemic inflammation. Regarding periphery-to-CNS neuroimmune crosstalk, there were significant associations between several cytokines and albumin quotient, despite the latter being primarily at subclinical levels. The cytokines CCL11, CD5, IL8, and MMP-10 were elevated in the CSF, had positive correlations between CSF and serum levels, and associated in a nonlinear manner with back, but not leg, pain intensity in the LDH, but not the DDD, group. In conclusion, we found evidence for neuroimmune activation in the CNS of both patient groups in the absence of systemic inflammation and signs of a communication between CSF and serum. Complex and disease-specific associations were found between cytokines in CSF and back pain intensity.

Clinical significance of cerebrospinal fluid nitric oxide concentrations in degenerative cervical and lumbar diseases.

In animal models of degenerative lumbar disease, inducible nitric oxide synthase (iNOS) is expressed in macrophages and Schwann cells following compression of the cauda equina. We previously reported that NO metabolites (nitrite plus nitrate: [NOx]) in the cerebrospinal fluid (CSF) correlate with postoperative pain relief in patients with degenerative lumbar disease and with neurologic recovery rate postoperatively or after conservative treatment in patients with spinal cord injury. The objective of the present study was to examine the relationship between [NOx] and neurologic severity, and recovery in degenerative cervical and lumbar diseases. Two hundred fifty-seven cases, including 85 patients with cervical compression myelopathy (CCM), 25 with cervical disc herniation (CDH), 70 with lumbar canal stenosis (LCS), and 77 with lumbar disc herniation (LDH), were examined. The CSF [NOx] was measured using the Griess method. Severity of neurologic impairment and clinical recovery was assessed using the Japanese Orthopedic Association score and Hirabayashi's method. [NOx] in CCM and LCS, but not CDH and LDH groups, was significantly higher than that in controls, and correlated with postoperative recovery rates, but not with preoperative neurologic severity. [NOx] significantly correlated with neurologic recovery following surgery for CCM and LCS.

Epidural Fluid Collection After Percutaneous Endoscopic Lumbar Discectomy.

OBJECTIVE: The frequency and extent of epidural fluid collection after percutaneous endoscopic lumbar discectomy (PELD) have not been previously described. The purpose of this study was to evaluate the significance of epidural fluid collection after PELD. METHODS: From March 2008 to November 2015, immediate postoperative magnetic resonance imaging (MRI) of 464 consecutive patients, comprising 284 men and 180 women, were obtained after PELD. The mean age of the patients at the time of admission was 43.1 years (range, 18-81 years). We also performed 24-hour follow-up MRIs after PELD in 35 patients to evaluate the morphologic changes on epidural fluid collection and to identify whether the collection was due to saline accumulation or cerebrospinal fluid leak. RESULTS: The level of disc herniation was at L4-5, L5-S1, L3-4, and L2-3 in 245 (52.8%), 173 (37.3%), 37 (8.0%), and 9 (1.9%) patients, respectively. Of 464 patients, 418 (90.1%) had abnormal epidural fluid collection, 404 (87.1%) patients had ventral epidural fluid collection, 393 (84.7%) patients had dorsal epidural fluid collection, and 10 patients had epidural hematoma as per immediate postoperative MRI. According to the 24-hour follow-up MRI findings, 30 patients had epidural fluid collection; the epidural fluid collection in 28 patients (93.3%) resolved with time, and a minimal amount of fluid remained in 2 patients, but the lesion size decreased compared with that on the previous day. CONCLUSIONS: Epidural fluid collection usually occurs after percutaneous endoscopic discectomy, which is mainly due to saline accumulation and typically resolves with time, without treatment or complications.

Evidence for a Role of Nerve Injury in Painful Intervertebral Disc Degeneration: A Cross-Sectional Proteomic Analysis of Human Cerebrospinal Fluid.

Intervertebral disc degeneration (DD) is a cause of low back pain (LBP) in some individuals. However, although >30% of adults have DD, LBP only develops in a subset of individuals. To gain insight into the mechanisms underlying nonpainful versus painful DD, human cerebrospinal fluid (CSF) was examined using differential expression shotgun proteomic techniques comparing healthy control participants, subjects with nonpainful DD, and patients with painful DD scheduled for spinal fusion surgery. Eighty-eight proteins were detected, 27 of which were differentially expressed. Proteins associated with DD tended to be related to inflammation (eg, cystatin C) regardless of pain status. In contrast, most differentially expressed proteins in DD-associated chronic LBP patients were linked to nerve injury (eg, hemopexin). Cystatin C and hemopexin were selected for further examination using enzyme-linked immunosorbent assay in a larger cohort. While cystatin C correlated with DD severity but not pain or disability, hemopexin correlated with pain intensity, physical disability, and DD severity. This study shows that CSF can be used to study mechanisms underlying painful DD in humans, and suggests that while painful DD is associated with nerve injury, inflammation itself is not sufficient to develop LBP. PERSPECTIVE: CSF was examined for differential protein expression in healthy control participants, pain-free adults with asymptomatic intervertebral DD, and LBP patients with painful intervertebral DD. While DD was related to inflammation regardless of pain status, painful degeneration was associated with markers linked to nerve injury.

The prognostic value of cerebrospinal fluid characteristics in dogs without deep pain perception due to thoracolumbar disc herniation.

Providing a pre-operative prognosis for dogs presented with absent deep pain perception (DPP) is extremely challenging, as the overall recovery rates widely vary. This study assesses the possible correlation between the severity of spinal cord injury and CSF cytology in 31 paraplegic dogs presented with absent DPP due to acute thoracolumbar intervertebral disc herniation (TL-IVDH). All dogs underwent surgical decompression immediately following diagnosis. CSF TNCC, macrophage percentage and macrophage to monocyte (MΦ:M) ratio were significantly higher in dogs that failed to regain DPP within 10 days post-operatively and in dogs that failed to regain ambulation at the end of the study period (P< 0.05). MΦ:M of 0.73 and higher corresponded to a sensitivity of 54% and specificity of 100% for prediction of a negative long-term outcome. CSF TNCC, macrophage percentage and MΦ:M ratio effectively predicted regaining DPP and the long-term outcome in dogs that lost DPP due to acute TL-IVDH.

Dominance of chemokine ligand 2 and matrix metalloproteinase-2 and -9 and suppression of pro-inflammatory cytokines in the epidural compartment after intervertebral disc extrusion in a canine model.

BACKGROUND CONTEXT: In canine intervertebral disc (IVD) disease, a useful animal model, only little is known about the inflammatory response in the epidural space. PURPOSE: To determine messenger RNA (mRNA) expressions of selected cytokines, chemokines, and matrix metalloproteinases (MMPs) qualitatively and semiquantitatively over the course of the disease and to correlate results to neurologic status and outcome. STUDY DESIGN/SETTING: Prospective study using extruded IVD material of dogs with thoracolumbar IVD extrusion. PATIENT SAMPLE: Seventy affected and 13 control (24 samples) dogs. OUTCOME MEASURES: Duration of neurologic signs, pretreatment, neurologic grade, severity of pain, and outcome were recorded. After diagnostic imaging, decompressive surgery was performed. METHODS: Messenger RNA expressions of interleukin (IL)-1ß, IL-2, IL-4, IL-6, IL-8, IL-10, tumor necrosis factor (TNF), interferon (IFN)γ, MMP-2, MMP-9, chemokine ligand (CCL)2, CCL3, and three housekeeping genes was determined in the collected epidural material by Panomics 2.0 QuantiGene Plex technology. Relative mRNA expression and fold changes were calculated. Relative mRNA expression was correlated statistically to clinical parameters. RESULTS: Fold changes of TNF, IL-1ß, IL-2, IL-4, IL-6, IL-10, IFNγ, and CCL3 were clearly downregulated in all stages of the disease. MMP-9 was downregulated in the acute stage and upregulated in the subacute and chronic phase. Interleukin-8 was upregulated in acute cases. MMP-2 showed mild and CCL2 strong upregulation over the whole course of the disease. In dogs with severe pain, CCL3 and IFNγ were significantly higher compared with dogs without pain (p=.017/.020). Dogs pretreated with nonsteroidal anti-inflammatory drugs revealed significantly lower mRNA expression of IL-8 (p=.017). CONCLUSIONS: The high CCL2 levels and upregulated MMPs combined with downregulated T-cell cytokines and suppressed pro-inflammatory genes in extruded canine disc material indicate that the epidural reaction is dominated by infiltrating monocytes differentiating into macrophages with tissue remodeling functions. These results will help to understand the pathogenic processes representing the basis for novel therapeutic approaches. The canine IVD disease model will be rewarding in this process.

Associations between cerebrospinal fluid biomarkers and long-term neurologic outcome in dogs with acute intervertebral disk herniation.

OBJECTIVE: To examine associations between CSF biomarkers, initial neurologic dysfunction, and long-term ambulatory outcome in dogs with acute intervertebral disk herniation (IVDH). DESIGN: Prospective clinical study. ANIMALS: 54 dogs with acute thoracolumbar IVDH and 16 clinically normal dogs. PROCEDURES: For each dog, variables, including CSF myelin basic protein (MBP), lactate, calcium, glucose, and total protein concentrations; nucleated cell count; and creatine kinase (CK) and aspartate aminotransferase activities, were measured. For dogs with thoracolumbar IVDH, initial neurologic function was characterized by use of a modified Frankel score (MFS; determined on a scale of 0 to 5, where 0 represented paraplegia with no deep nociception and 5 represented paraspinal hyperesthesia only). Long-term follow-up was assessed. RESULTS: Among dogs with thoracolumbar IVDH, those with CSF CK activity ≤ 38 U/L had a 35-fold increase in the odds of long-term ambulation, compared with the odds in dogs with CSF CK activity > 38 U/L, adjusting for neurologic functioning at the evaluation. The CSF lactate, calcium, and glucose concentrations and aspartate aminotransferase activity were not predictive of long-term ambulatory outcome. Data analysis revealed that long-term functional recovery was > 98% for affected dogs, regardless of their initial MFS, when CSF CK activity was ≤ 38 U/L and MBP concentration was ≤ 3 ng/mL. CONCLUSIONS AND CLINICAL RELEVANCE: In dogs with acute thoracolumbar IVDH, CSF CK activity and MBP concentration appeared to be prognostic indicators and, along with initial MFS, can be used to predict long-term ambulatory outcome.

Analysis of cartilage oligomeric matrix protein and matrix metalloproteinase-9 in cerebrospinal fluid of miniature dachshund with intervertebral disc herniation.

We evaluated whether the cerebrospinal fluid (CSF) concentration of cartilage oligomeric matrix protein (COMP) is related to disease severity, prognosis and matrix metalloproteinase (MMP)-9 activity of the CSF in miniature dachshund with intervertebral disc herniation. Samples were obtained from 23 patients and 6 normal dogs, and all patients received hemilaminectomy. Twenty dogs recovered successfully and 3 of 11 dogs without deep nociception had MMP-9 activity in the CSF and an unsuccessful outcome. The COMP levels from patients were significantly higher than those from normal dogs. MMP-9 activity and neurological severity were not related to the COMP levels. However, the COMP levels from 3 unsuccessful cases that had MMP-9 activity were significantly lower than those from all recovered cases and/or successful cases without deep nociception. Concerning severe cases, increased proteolytic activity might affect the COMP concentration and prognosis due to MMP-9 associated deleterious effects.

[The marker of discogenic diseases of the nervous system in the cerebrospinal fluid].

Using a novel diagnostic technology that allows to investigate the structure of a biological fluid formed during its phase transition into a dried film, we revealed a cause of mistaken results of protein concentrations in the cerebrospinal fluid of patients with discogenic radiculitis. The traditional laboratory study does not reveal the elevated content of protein in patients with discogenic radiculitis and hernia of invertebral discs due to its more active binding with salts with the following sedimentation during centrifugation. It can be explained by the involvement of salt crystals in the formation of the inert organic-mineral aggregate with protein molecules which structure was changed by dystrophy, ischemia, hypoxia, mechanic damage, tumor process. The aggregate is characterized by abnormally tight links. This phenomenon is known as biomineralization, the universal mechanism preventing the organism from toxic effects of products of degraded tissues.

Association of cerebrospinal fluid analysis findings with clinical signs and outcome in acute nonambulatory thoracolumbar disc disease in dogs.

BACKGROUND: Cerebrospinal fluid (CSF) pleocytosis recently was associated with the severity of neurologic signs in dogs with intervertebral disc disease (IVDD). HYPOTHESIS/OBJECTIVES: To look for an association among CSF cell counts, total protein concentration, and severity of neurologic signs at presentation with outcome in dogs with acute thoracolumbar IVDD. Our hypothesis was that CSF total nucleated cell count (TNCC) and percentage cell types would be associated with the severity of spinal cord damage and therefore with both the presenting clinical signs and the prognosis of affected dogs. ANIMALS: Fifty-four dogs with acute nonambulatory thoracolumbar IVDD were evaluated. METHODS: Retrospective study. Signalment, neurologic grade, CSF TNCC, protein concentration, red blood cells count and differential cell percentages, and short- and long-term outcomes were evaluated. RESULTS: CSF pleocytosis (>5 cells/µL) was present in 54% of dogs and was positively associated with neurologic grade at presentation and with postoperative time to regaining ambulation. Neutrophils were observed most frequently. The percentage of CSF macrophages and macrophage to monocyte ratio were higher (P = .001, for both) in dogs presented without deep pain sensation (DPS) that did not regain ambulation. Receiver operator characteristics curve analysis yielded a cut-off point of 13% macrophages with a sensitivity and specificity of 100 and 83%, respectively, for prediction of a negative outcome. CONCLUSIONS AND CLINICAL IMPORTANCE: CSF pleocytosis is positively associated with the severity of spinal cord damage in dogs with thoracolumbar IVDD. The percentage of CSF macrophages can be used as a prognostic indicator for regaining ambulation in dogs that have lost DPS.