Differential Expression of Tubulin Acetylase and Deacetylase Between the Damaged Central and Peripheral Branch of Dorsal Root Ganglion Neurons.

BACKGROUND The differences between the peripheral and central branches of the dorsal root ganglion (DRG) have not been fully elucidated. This study aimed to explore the expression of tubulin post-translational modifications (acetylation and deacetylation) between damaged peripheral and central branches of DRG neurons. MATERIAL AND METHODS Fifty Sprague-Dawley rats were randomly assigned to five groups with 10 rats in each group. These five groups consisted of spinal nerve ligation (SNL) at 24 hour and 48 hour, and cauda equina compression (CEC) at 24 hour and 48 hour, and a sham group. SNL injury in rats was induced by ligating L5 and L6 spinal nerves with 1-0 silk thread outboard the DRGs. CEC injury in rats was induced by a piece of silicone (10×1×1 mm) placed under the laminae of the L5-6 vertebra. Sham-operated rats underwent a simple laminectomy in L4, but silicone was not implanted. The expression profile of acetylase and deacetylase was examined by real-time PCR, Western blotting, and immunohistochemistry. RESULTS In the experimental groups, rats presented increased expression of acetylase (NAT1 and MEC-17) and decreased expression of deacetylase (Sirt2 and HDAC6) levels. Additionally, the expression of NAT1 and MEC-17 was gradually increased in DRG neurons following peripheral axonal injury compared to central axonal injury in a time-dependent manner. Conversely, the expression of Sirt2 and HDAC6 was gradually decreased in DRG neurons following peripheral axonal injury compared to central axonal injury in a time-dependent manner. CONCLUSIONS Our study indicated that insufficiency of acetylase and upregulation of deacetylase in DRG neurons after central axonal injury may contribute to the pathogenesis of cauda equine syndrome.

Metabolomic Changes in Rat Model of Cauda Equina Injury.

BACKGROUND: To show the differences of metabolomic changes in a rat model of cauda equina injury (CEI) and find potent metabolic biomarkers of CEI. METHODS: A total of 28 Sprague-Dawley rats were used in this study. After the rats were given anesthesia and fixed in a prone position, a piece of silicone block was placed into the epidural space below the lamina. Behavior tests including the Basso, Beattie, and Bresnahan open field locomotor scale and an inclined plane test were conducted 1 day and 2 days after surgery. The cauda equina tissue was collected 12 hours, 1 day, and 2 days after surgery. Ultraperformance liquid chromatography coupled with quadruple time-of-flight mass spectrometry was used for a quantitative analysis of cauda equine metabolic changes in rats from different groups. The differences between the metabolic profiles of the rats in 4 groups were analyzed using partial least squares discriminant analysis. RESULTS: In behavior tests and histologic analyses given 2 days after surgery, the animals showed remarkable organ dysfunction and pathologic damage. Metabolic profiles showed remarkable differences between the control and model groups. Thirty-four potential CEI metabolite biomarkers were identified between the control group and different time-point model groups. These potential biomarkers appeared in 15 metabolic pathways. CONCLUSIONS: Our results may improve the cause of CEI and provide a basis for clinical diagnosis and locating biomarkers in the early stages of the pathologic process of CEI.

[P75 neurotrophin receptor mRNA sequential expression and significance after Cauda equina compression in rats].

OBJECTIVE: To observe the mRNA expression of p75NTR (p75 neurotrophin receptor) and the amount of neuronal cells apoptosis in lumbar-sacral spinal cord at different time points after the acute cauda equina compression in rats and to explore their correlation. METHODS: Sixty adult female Sprague Dawley(SD) rats were randomly divided into the normal control group and the compression groups. The acute cauda equine compression model was established as placing a silicon gel rubber at L(3,4) level of the vertebral canal which represented about 70% to 80% compression to the cross section. The whole L(1,2) level of spinal cords were harvested at 1, 3, 5, 7, 14, 28 d after operation in compression group. Tunel method was applied to observe cell apoptosis and RT-PCR was used to detect the p75NTR mRNA expression. SPSS 13.0 statistical software was adopted to help analysis. RESULTS: In the compression group, both the nerve cells apoptosis and the p75 mRNA expression existed the trend of low-high-low synchronally compared with the control group, there was a significant difference (P < 0.05) among comprssion groups at different time points,there was a significant difference in changes (P < 0.05). p75NTR of mRNA expression and lumbosacral nerve cells apoptosis was in a positive correlation. CONCLUSION: After acute cauda equina compression, p75NTR mRNA expression is closely related to the neuronal apoptosis, which plays an important role in the molecular mechanism of the CES.

Selective cauda equina hypertrophy with idiopathic inflammation.

A 20-year-old woman with selective cauda equina hypertrophy presented with muscle weakness and severe pain in the lower extremities. Serial immunotherapy was not effective. We performed biopsy of the cauda equina, and laminectomy and duraplasty of the thoracolumbar region. Biopsy revealed marked infiltration of small lymphocytes and foamy macrophages in the endoneurium. Three years after decompression surgery, her symptoms have improved slightly without progression or relapse. This is the first case of selective cauda equina hypertrophy with idiopathic inflammation. We propose that this is a new disease entity.

Inflammatory mediators in diabetic and non-diabetic lumbosacral radiculoplexus neuropathy.

Nerve microvasculitis and ischemic injury appear to be the primary and important pathogenic alterations in lumbosacral radiculoplexus neuropathy of patients with (DLRPN) and without (LRPN) diabetes mellitus (DM). Here, we examine the involvement of inflammatory mediators in DLRPN and LRPN. Paraffin sections of sural nerves from 19 patients with DLRPN, 13 patients with LRPN, and 20 disease control patients were immunostained for intercellular adhesion molecule-1 (ICAM-1), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and nuclear factor kappaB (NF-kappaB). The findings were correlated with histopathology. The pathologic and immunohistochemical alterations of DLRPN and LRPN nerves were indistinguishable. The nerves of both types of LRPN had a significantly greater number of ICAM-1 positive vessels than did the controls (P < 0.01). TNF-alpha expression was seen in Schwann cells and some macrophages of DLRPN and LRPN nerves, whereas IL-6 expression was minimal. There was greater NF-kappaB immunoreactivity in vessels and endoneurial cells of DLRPN and LRPN nerves than of the controls (P < 0.001). NF-kappaB expression correlated with the number of empty nerve strands (P < 0.01) and the frequency of axonal degeneration (P < 0.05), whereas TNF-alpha expression correlated inversely with the number of empty nerve strands of teased fibers (P < 0.05). Our findings suggest that up-regulation of inflammatory mediators target different cells at different disease stages and that these mediators may be sequentially involved in an immune-mediated inflammatory process that is shared by both DLRPN and LRPN. Up-regulated inflammatory mediators may be immunotherapeutic targets in these two conditions.

Cerebrospinal fluid dissecting into spinal epidural space after lumbar puncture causing cauda equina syndrome: review of literature and illustrative case.

OBJECTS: We report a case of epidural cerebrospinal fluid (CSF) leak after lumbar puncture caused by CSF dissecting into the spinal epidural space. The incidence of this phenomenon may be higher than suspected, although most cases may remain asymptomatic. MATERIALS AND METHODS: A 4-year-old girl with new-onset seizure underwent a diagnostic lumbar puncture, the results of which were normal; 3 h later, she began experiencing severe low-pressure headaches and lower back pain, bilateral lower extremity weakness, numbness, and pain, and urinary retention when upright. Spinal MRI demonstrated extensive epidural CSF collection posterior to the thecal sac extending from the cervicothoracic junction to the sacrum. After 48 h in the supine position and gradual mobilization, the patient had complete resolution of symptoms and no neurological sequelae. CONCLUSION: Patients usually recover without any neurological deficits after conservative treatment. Prone or lateral decubitus positioning immediately after lumbar puncture may decrease the incidence of this phenomenon.

Increases in COX II mRNA in the rat spinal cord induced by cauda equina traction.

This article investigated the time response of COX II induction by traction of the cauda equina assessed by a quantified RT-PCR method. Under deep GOI anesthesia, male Wistar rats were fixed in the prone position and a laminectomy of the dorsal part of the first and second sacral vertebrae was performed. Following, COX II-mRNA levels in the cervical, thoracic, lumbar, sacral, and caudal segments were measured at 2, 4, 6, and 24 h after traction by a quantified RT-PCR method. After cauda equina traction, significant levels of COX II mRNA were detected in all segments of the spinal cord examined. Maximum levels in each segment were determined 4 h after traction of the cauda equina. Particularly in the sacrocaudal segments significantly higher levels of COX II mRNA were measured 24 h after traction. These results indicate that significant induction of spinal COX II mRNA was caused by cauda equina traction and that such induction plays a regulatory role in the nociceptive pain pathway.

Autonomic and motor neuron death is progressive and parallel in a lumbosacral ventral root avulsion model of cauda equina injury.

Injuries to the cauda equina of the spinal cord result in autonomic and motor neuron dysfunction. We developed a rodent lumbosacral ventral root avulsion injury model of cauda equina injury to investigate the lesion effect in the spinal cord. We studied the retrograde effects of a unilateral L5-S2 ventral root avulsion on efferent preganglionic parasympathetic neurons (PPNs) and pelvic motoneurons in the L6 and S1 segments at 1, 2, 4, and 6 weeks postoperatively in the adult male rat. We used Fluoro-Gold-prelabeling techniques, immunohistochemistry, and quantitative stereologic analysis to show an injury-induced progressive and parallel death of PPNs and motoneurons. At 6 weeks after injury, only 22% of PPNs and 16% of motoneurons remained. Furthermore, of the neurons that survived at 6 weeks, the soma volume was reduced by 25% in PPNs and 50% in motoneurons. Choline acetyltransferase (ChAT) protein was expressed in only 30% of PPNs, but 80% of motoneurons remaining at 1 week postoperatively, suggesting early differential effects between these two neuronal types. However, all remaining PPNs and motoneurons were ChAT positive at 4 weeks postoperatively. Nuclear condensation and cleaved caspase-3 were detected in axotomized PPNs and motoneurons, suggesting apoptosis as a contributing mechanism of the neural death. We conclude that lumbosacral ventral root avulsions progressively deplete autonomic and motor neurons. The findings suggest that early neuroprotection will be an important consideration in future attempts of treating acute cauda equina injuries.

Fos protein expression in sacral spinal cord in relation to early phase of cauda equina syndrome in dogs.

1. The aim of the present study is to map the incipient phase of Fos expression in the sacral spinal cord neuronal pools of multiple cauda equina constrictions canine model. 2. Fos-positive neurons were found bilaterally in the lateral portion of superficial dorsal horn layers (Laminae I-III) and along the lateral edge of the dorsal horn accompanied by the lateral collateral pathway, fibers of Lissauer's tract, terminating at the sacral parasympathetic nucleus. Similarly, high Fos expression was detected in the ventral portion of the dorsal sacral commissure and in the dorsomedial portion of the anterior horns at S1-S3 segment level. Finally, a clearly expressed Fos-positivity was disclosed bilaterally in the neuropil of the nucleus Y in the anterior horn. 3. Data from the present study show that continuous stimulation of the central fibers of sacral dorsal root ganglia neurons, i.e., fibers of sacral primary afferents, unlike those using various stimulations of the peripheral fibres offers an unusual pattern of Fos-like immunoreactivity.

Incipient cauda equina syndrome as a model of somatovisceral pain in dogs: spinal cord structures involved as revealed by the expression of c-fos and NADPH diaphorase activity.

Segmental and laminar distribution of Fos-like immunoreactive, reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd)-exhibiting and double-labeled (Fos-like immunoreactive and NADPHd-exhibiting) neurons was examined in lower lumbar and sacral segments of the dog spinal cord using the model of multiple cauda equina constrictions. NADPHd histochemistry was used as marker of nitric oxide synthase-containing neurons. The appearance and the time-course of Fos-like immunoreactive, NADPHd and double-labeled neurons was studied at 2 h and 8 h postconstriction characterized as the incipient phase of cauda equina syndrome. The occurrence of Fos-like immunoreactive and NADPHd-exhibiting neurons in fully developed cauda equina syndrome was studied at five days postconstriction. An increase in Fos-like immunoreactivity in superficial laminae (I-II) and an enhanced NADPHd staining of lamina VIII neurons were found. A statistically significant increase in Fos-like immunoreactive neurons was found in laminae I-II and VIII-X 8 h postconstriction, and in contrast, a prominent decrease in Fos-like immunoreactive neurons was found in laminae I-II, accompanied by a statistically significant increase in Fos-like immunoreactive neurons in more ventrally located laminae VII-X at five days postconstriction. Quantitative analysis of laminar distribution of constriction-induced NADPHd-exhibiting neurons revealed a considerable increase in these neurons in laminae VIII-IX 8 h postconstriction and a statistically highly significant increase in NADPHd-exhibiting neurons in laminae VII-X five days postconstriction. Concurrently, the number of NADPHd-exhibiting neurons in laminae I-II was greatly reduced. While a low number of double-labeled neurons was found throughout the gray matter of lower lumbar and sacral segments at 2 h postconstriction, a statistically significant number of double-labeled neurons was found in lamina X 8 h and in laminae VII-X five days postconstriction. The course and distribution of anterograde degeneration resulting five days after multiple cauda equina constrictions are compared with segmental and laminar distribution of Fos-like immunoreactive and NADPHd-exhibiting neurons. Prominent involvement of the spinal cord neurons appearing in the lumbosacral segments at the early beginning and in fully developed cauda equina syndrome results in a Fos-like immunoreactivity and strongly enhanced NADPHd staining of some neuronal pools. Under such circumstances, an early cauda equina decompression surgery is advisable aimed at decreasing or preventing the derangement of the neural circuits in the lumbosacral segments.

The effect of epidural injection of betamethasone or bupivacaine in a rat model of lumbar radiculopathy.

STUDY DESIGN: The effect of epidural injection of betamethasone or bupivacaine was investigated in an animal model of lumbar radiculopathy. OBJECTIVE: To investigate the effects of an epidural steroid (betamethasone) or a local anesthetic (bupivacaine) in an animal model of radiculopathy produced by nerve root irritation. SUMMARY OF BACKGROUND DATA: Epidural injections are commonly used for the treatment of low back pain and sciatica. However, efficacy remains controversial, and there is a paucity of basic information to support clinical use or the injections. METHODS: Fifty-one rats were used. The left L4 and L5 nerve roots were loosely ligated with chromic gut, and either betamethasone, bupivacaine, betamethasone in combination with bupivacaine, or saline was injected using an epidurally placed catheter. The effects of epidural injection were evaluated using response to noxious stimuli and immunohistochemical methods. RESULTS: In betamethasone-treated rats (either alone or in combination with bupivacaine), thermal hyperalgesia was significantly less (P < 0.010 after surgery than that in saline- or bupivacaine-treated groups, in which the hyperalgesia was maximum at 2-3 postoperative weeks before resolving 5 weeks after surgery. Immunohistochemical analysis did not correlate with these results. CONCLUSIONS: Epidural steroid injection has a significant effect on the thermal hyperalgesia produced in a model of radiculopathy, which may provide clinical support for advocates of epidural steroids.

Localized CNS brucellosis: report of 7 cases.

Seven patients with brucellar infection localized in the central nervous system (CNS) are reported. This series represent 3.5% of all brucellosis cases in our hospital. There was a conspicuous absence of systemic signs and symptoms. The clinical course was characteristically protracted. Meningitis (acute, chronic, transient and recurrent) and progressive myeloradiculopathy were the 2 clinical patterns. Cranial nerve neuropathy was frequent, eight nerve involvement being present in 4 cases; transitory ischemic attacks and subarachnoid haemorrhage occurred in 2. Routine laboratory determinations were negative or non-specific. Cerebrospinal fluid (CSF) findings included hypoglycorrhachia, lymphocytic pleocytosis and hyperproteinorrhachia. There was also a remarkable increase in the gamma-globulin and IgG values with morphology of oligoclonal bands in CSF electrophoresis. Brucella agglutination titers were low or absent in serum and/or CSF. By contrast, Coombs tests were always positive and higher titers were found in serum and CSF. After treatment a persistent CSF positive Coombs test at low titers together with an isolated increase in CSF gamma-globulin and IgG values were detected in cured patients. Brucella blood cultures were negative, but CSF cultures were positive in four cases. Rifampin and doxycycline seems to be the treatment of choice. These agents must be maintained at least for 4 months in order to avoid relapses. Corticosteroids may be helpful at the beginning of treatment. Outcome is generally favourable in this disorder. We conclude that clinical and biological characteristics of localized CNS brucellosis are in accordance with those already described in other types of localized brucellosis.

Lymphocyte subpopulations in blood and cerebrospinal fluid from patients with acute Guillain-Barré syndrome.

The numbers of T and B lymphocytes were determined in blood and cerebrospinal fluid (CSF) from 25 patients with acute Guillain-Barré syndrome and from 30 controls. The relative and absolute number of T lymphocytes in blood was decreased in the patient group (mean 48 +/- 2% and 947 +/- 71/mm3 compared to 66 +/- 2% and 1,381 +/- 93/mm3 in controls). Correspondingly, the number of B lymphocytes was increased (mean 37 +/- 2% and 758 +/- 75/mm3 compared to 25 +/- 2% and 580 +/- 45/mm3 in controls). In the CSF the number of T lymphocytes was increased (85.0 +/- 2.2% compared to 76.9 +/- 2.4% in controls).

Hypertension and papilloedema in the Guillain-Barré syndrome.

Three patients with the Guillain-Barré Syndrome are described, one of whom was relapsing. Hypertension persisted for three to four months in two patients, associated with increased urinary excretion of catecholamines. Baroreceptor sensitivity, although depressed, did not explain the hypertension. It may be due to lesions affecting either central vasomotor control or peripheral sympathetic nerve activity. Two patients had papilloedema. This has been attributed in the literature to defective reabsorption of CSF due to high protein concentration. Normal reabsorption of isotope labelled albumin from the subrachnoid space argues against this explanation in our cases.