Valproic acid ameliorates cauda equina injury by suppressing HDAC2-mediated ferroptosis.

INTRODUCTION: Persistent neuroinflammatory response after cauda equina injury (CEI) lowers nociceptor firing thresholds, accompanied by pathological pain and decreasing extremity dysfunction. Histone deacetylation has been considered a key regulator of immunity, inflammation, and neurological dysfunction. Our previous study suggested that valproic acid (VPA), a histone deacetylase inhibitor, exhibited neuroprotective effects in rat models of CEI, although the underlying mechanism remains elusive. METHODS: The cauda equina compression surgery was performed to establish the CEI model. The Basso, Beattie, Bresnahan score, and the von Frey filament test were carried out to measure the animal behavior. Immunofluorescence staining of myelin basic protein and GPX4 was carried out. In addition, transmission electron microscope analysis was used to assess the effect of VPA on the morphological changes of mitochondria. RNA-sequencing was conducted to clarify the underlying mechanism of VPA on CEI protection. RESULTS: In this current study, we revealed that the expression level of HDAC1 and HDAC2 was elevated after cauda equina compression model but was reversed by VPA treatment. Meanwhile, HDAC2 knockdown resulted in the improvement of motor functions and pathologic pain, similar to treatment with VPA. Histology analysis also showed that knockdown of histone deacetylase (HDAC)-2, but not HDAC1, remarkably alleviated cauda equina injury and demyelinating lesions. The potential mechanism may be related to lowering oxidative stress and inflammatory response in the injured region. Notably, the transcriptome sequencing indicated that the therapeutic effect of VPA may depend on HDAC2-mediated ferroptosis. Ferroptosis-related genes were analyzed in vivo and DRG cells further validated the reliability of RNA-sequencing results, suggesting HDAC2-H4K12ac axis participated in epigenetic modulation of ferroptosis-related genes. CONCLUSION: HDAC2 is critically involved in the ferroptosis and neuroinflammation in cauda equina injury, and VPA ameliorated cauda equina injury by suppressing HDAC2-mediated ferroptosis.

Neurological Analysis Based on the Terminal End of the Spinal Cord and the Narrowest Level of Injured Spine in Thoracolumbar Spinal Injuries.

This study aimed to clarify neurological differences among the epiconus, conus medullaris, and cauda equina syndromes. Eighty-seven patients who underwent surgery for acute thoracolumbar spinal injuries were assessed. We defined the epiconus as the region from the terminal end of the spinal cord to the proximal 1.0 to 2.25 vertebral bodies, the conus medullaris as the region proximal to < 1.0 vertebral bodies, and the cauda equina as the distal part of the nerve roots originating from the spinal cord. On the basis of the distance from the terminal end of the spinal cord to the narrowest level of the spinal canal, the narrowest levels were ordered as follows: the epiconus followed by the conus medullaris and cauda equina. The narrowest levels were the epiconus in 22 patients, conus medullaris in 37 patients, and cauda equina in 25 patients. On admission, significantly more patients had a narrowed epiconus of Frankel grades A-C than a narrowed cauda equina. At the final follow-up, there were no significant differences in neurological recovery among those with epiconus, conus medullaris, or cauda equina syndrome. Anatomically classifying the narrowest lesion is useful for clarifying the differences and similarities among these three syndromes.

Gangliocytic Paraganglioma of the Filum Terminale. A Rare Entity

Paragangliomas are rare, benign and slow-growing neuroendocrine tumors that can arise from the adrenal medulla (85­90%) or from the extra-adrenal paraganglia. In the central nervous system (CNS), they can be found at several sites, but more often at the cauda equina and filum terminale region, where they account for between 2.5 and 3.8% of total tumor cases of that region. There are only 8 cases described in the literature that mention the presence of the gangliocytic variant of this entity at the filum terminale. We present the case of a 41-year-old man with chronic lumbar pain refractory to medical treatment, without any associated neurological deficits. Magnetic resonance imaging (MRI) revealed an intradural, extramedullar oval lesion with regular contours and homogeneous caption of contrast at L1 level. He was submitted to surgical treatment, with complete resection of the lesion. The histological analysis revealed a gangliocytic paraganglioma of the filum terminale. At 5 years of follow-up, he remains asymptomatic and without any signs of relapse. These are lesions with an overall good prognosis with gross total resection. Although the recurrence rate is extremely low, prolonged observation is recommended due to the slow-growing nature of the tumor, being estimated that between 1 and 4% can recur even after gross total removal.

Factors Associated with Recovery in Motor Strength, Walking Ability, and Bowel and Bladder Function after Traumatic Cauda Equina Injury.

Traumatic cauda equina injury (TCEI) is usually caused by spine injury at or below L1 and can result in motor and/or sensory impairments and/or neurogenic bowel and bladder. We examined factors associated with recovery in motor strength, walking ability, and bowel and bladder function to aid in prognosis and establishing rehabilitation goals. The analysis cohort was comprised of persons with acute TCEI enrolled in the Rick Hansen Spinal Cord Injury Registry. Multi-variable regression analysis was used to determine predictors for lower-extremity motor score (LEMS) at discharge, walking ability at discharge as assessed by the walking subscores of either the Functional Independence Measure (FIM) or Spinal Cord Independence Measure (SCIM), and improvement in bowel and bladder function as assessed by FIM-relevant subscores. Age, sex, neurological level and severity of injury, time from injury to surgery, rehabilitation onset, and length of stay were examined as potential confounders. The cohort included 214 participants. Median improvement in LEMS was 4 points. Fifty-two percent of participants were able to walk, and >20% recovered bowel and bladder function by rehabilitation discharge. Multi-variable analyses revealed that shorter time from injury to rehabilitation admission (onset) was a significant predictor for both improvement in walking ability and bowel function. Longer rehabilitation stay and being an older female were associated with improved bladder function. Our results suggest that persons with TCEI have a reasonable chance of recovery in walking ability and bowel and bladder function. This study provides important information for rehabilitation goals setting and communication with patients and their families regarding prognosis.

Expression of Nogo-A in dorsal root ganglion in rats with cauda equina injury.

OBJECTIVE: To investigate the expression of Nogo-A in dorsal root ganglion (DRG) in rats with cauda equina injury and the therapeutic effects of blocking Nogo-A and its receptor. METHODS AND MATERIALS: Fifty-eight male Sprague-Dawley rats were divided randomly into either the sham operation group (n = 24) or the cauda equina compression (CEC) control group (n = 34). Behavioral, histological, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) analyses were conducted to assess the establishment of the model. The dynamic expression change of Nogo-A was evaluated using real time-qPCR. Immunofluorescence was used to evaluate the expression of Nogo-A in the DRG and cauda equina. Furthermore, 20 male Sprague-Dawley rats were equally divided into 4 groups, including the sham group, the CEC group, the NEP1-40 (the NgR antagonist peptide) treatment group, and the JTE-013 (the S1PR2 antagonist) treatment group. Behavioral assessments and western blotting were used to evaluate the therapeutic effect of cauda equina injury via blocking Nogo-A and its receptor. RESULTS: Tactile allodynia and heat hyperalgesia in the CEC model developed as soon as 1 day after surgery and recovered to normal at 7 days, which was followed by the downregulation of Nogo-A in DRG neurons. However, the locomotor function impairment in the CEC model showed a different prognosis from the sensory function, which was consistent with the expression change of Nogo-A in the spinal cord. Immunofluorescence results also demonstrated that Nogo A-positive/NF200-negative neurons and axons increased in the DRG and cauda equina 7 days after surgery. Surprisingly, Schwann cells, which myelinate axons in the PNS, also expressed considerable amounts of Nogo-A. Then, after blocking the Nogo-A/NgR signaling pathway by NEP1-40, significant improvement of mechanical allodynia was identified in the first 2 days after the surgery. Western blotting suggested the NEP1-40 treatment group had lower expression of cleaved caspase-3 than the CEC and JTE-013 treatment group. CONCLUSION: Neuronal Nogo-A in the DRG may be involved in regeneration and play a protective role in the CEC model. Whereas Nogo-A, released from the injured axons or expressed by Schwann cells, may act as an inhibiting factor in the process of CEC repairment. Thus, blocking the Nogo-A/NgR signaling pathway can alleviate mechanical allodynia by apoptosis inhibition.

Metabolic Changes in Serum in the Rat Model of Cauda Equina Injury.

OBJECTIVE: To identify the potent metabolic biomarkers of cauda equina injury (CEI). METHODS: A total of 50 Sprague-Dawley rats were used to establish the CEI model in this study. The serum was collected at 12 hours, 1 day, 2 days, and 7 days after surgery. Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was performed to analyze metabolic changes in the serum of the CEI rats from different groups. The differences between the metabolic profiles of the rats in 5 groups were analyzed using partial least squares discriminant analysis (PLS-DA). RESULTS: Metabolic profiling revealed significant differences between the sham operated and other groups. A total of 57 potential CEI metabolite biomarkers were identified between the sham operated group and the model groups at the different time points. Principal component analysis and PLS-DA analyses revealed clear segregation between CEI versus sham operation group. These potential biomarkers appear in 15 metabolic pathways. CONCLUSIONS: Using metabolomic analysis, we were able to identify the novel serum biomarkers of CEI that may be relevant to the diagnosis and prognosis of CEI. In addition, our pathway analysis provides important insights into the etiology of CEI and a basis for clinical diagnosis, locating biomarkers in the early stages of the pathological process.

A case series of penetrating spinal trauma: comparisons to blunt trauma, surgical indications, and outcomes.

OBJECTIVEWhile blunt spinal trauma accounts for the majority of spine trauma, penetrating injuries affect a substantial number of patients. The goal of this study was to examine the epidemiology of penetrating spine injuries compared with blunt injuries and review the operative interventions and outcomes in the penetrating spine injury group.METHODSThe prospectively maintained trauma database was queried for spinal fractures from 2012 to 2018. Charts from patients with penetrating spine trauma were reviewed.RESULTSA total of 1130 patients were evaluated for traumatic spinal fractures; 154 injuries (13.6%) were secondary to penetrating injuries. Patients with penetrating injuries were significantly younger (29.2 years vs 44.1 years, p < 0.001), more likely male (87.7% vs 69.2%, p < 0.001), and more commonly African American (80.5% vs 33.3%, p < 0.05). When comparing primary insurers, the penetrating group had a significantly higher percentage of patients covered by Medicaid (60.4% vs 32.6%, p < 0.05) or prison (3.9% vs 0.1%, p < 0.05) or being uninsured (17.5% vs 10.3%, p < 0.05). The penetrating group had a higher Injury Severity Score on admission (20.2 vs 15.6, p < 0.001) and longer hospital length of stay (20.1 days vs 10.3 days, p < 0.001) and were less likely to be discharged home (51.3% vs 65.1%, p < 0.05). Of the penetrating injuries, 142 (92.2%) were due to firearms. Sixty-three patients (40.9%) with penetrating injuries had a concomitant spinal cord or cauda equina injury. Of those, 44 (69.8%) had an American Spinal Injury Association Impairment Scale (AIS) grade of A. Ten patients (15.9%) improved at least 1 AIS grade, while 2 patients (3.2%) declined at least 1 AIS grade. Nine patients with penetrating injuries underwent neurosurgical intervention: 5 for spinal instability, 4 for compressive lesions with declining neurological examination results, and 2 for infectious concerns, with some patients having multiple indications. Patients undergoing neurosurgical intervention did not show a significantly greater change in AIS grade than those who did not. No patient experienced a complication directly related to neurosurgical intervention.CONCLUSIONSPenetrating spinal trauma affects a younger, more publicly funded cohort than blunt spinal trauma. These patients utilize more healthcare resources and are more severely injured. Surgery is undertaken for limiting progression of neurological deficit, stabilization, or infection control.

Central Nervous System Bleeding After a Lumbar Puncture: Still an Ongoing Complication.

BACKGROUND A lumbar puncture is a procedure performed to uncover the state of the central nervous system by analysis of the cerebrospinal fluid. It is done also to infuse medications in the subdural space. A lumbar puncture should not cause central nervous system bleeding, but this complication is still occurring in certain cases. CASE REPORT We present 2 cases where a lumbar puncture was performed in the emergency department. The first patient had severe inflammatory lower back pain and received epidural steroids through a lumbar puncture and the second case presented with the clinical picture of meningitis and a lumbar puncture was performed for diagnostic purposes. In both cases, major complications arose secondary to bleeding in the cerebrospinal fluid. The first case developed a bleeding tendency because the patient had acute renal failure and was on low molecular weight heparin. The second case had low platelet count because of myelodysplasia. Both cases bled into the subarachnoid space and subdural space resulting in compression of the cauda equine and paralysis. The bleeding eventually flowed into the posterior fossa resulting in vasospasm of the posterior circulation and infarction of the posterior cerebral arteries. CONCLUSIONS We concluded that both patients sustained complications from the lumbar puncture because of a bleeding tendency secondary to systemic illnesses and multiple drugs and their side effects. We recommend that patients' medical condition be well evaluated, and proper blood studies be performed prior to lumbar punctures to avoid major morbidities.

Cauda equina repair in the rat: Part 3. Axonal regeneration across Schwann cell-Seeded collagen foam.

INTRODUCTION: Treatments for patients with cauda equina injury are limited. METHODS: In this study, we first used retrograde labeling to determine the relative contributions of cauda equina motor neurons to intrinsic and extrinsic rat tail muscles. Next, we transected cauda equina ventral roots and proceeded to bridge the proximal and distal stumps with either a type I collagen scaffold coated in laminin (CL) or a collagen-laminin scaffold that was also seeded with Schwann cells (CLSC). Regeneration was assessed by way of serial retrograde labeling. RESULTS: After accounting for the axonal contributions to intrinsic vs. extrinsic tail muscles, we noted a higher degree of double labeling in the CLSC group (58.0 ± 39.6%) as compared with the CL group (27.8 ± 16.0%; P = 0.02), but not the control group (33.5 ± 18.2%; P = 0.10). DISCUSSION: Our findings demonstrate the feasibility of using CLSCs in cauda equina injury repair. Muscle Nerve 57: E78-E84, 2018.

Neuroprotective Effects of Valproic Acid in a Rat Model of Cauda Equina Injury.

BACKGROUND: Histone deacetylase inhibitors, including valproic acid (VPA), are promising therapeutic interventions in neurological disorders and play an important role in synaptic activity and neuronal function. METHODS: A total of 30 rats were randomly allocated to 3 groups: sham, control, and VPA. The rats in the VPA and control groups received laminectomy at the L4 level of the vertebrae and silicone gel implantation into the epidural spaces L5 and L6. Rats in the sham group only received laminectomy at the L4 level of vertebrae without any implantation. VPA (300 mg/kg in saline) was administered 2 hours before the surgery. After the surgery, the VPA group received further VPA injections at 300 mg/kg twice a day for 1 week. The same volume of saline was injected in the control group. Neurobehavioral tests using the Basso, Beattie, Bresnahan scale and the oblique board test were performed for 1 week starting at 2 hours before surgery up to day 7 after surgery. At day 7 after surgery, tissues from the compressed cauda equina (L5-L6) were subjected to hematoxylin and eosin, luxol fast blue, or immunofluorescence staining, whereas the terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end label assay staining was performed on the tissue from the dorsal root ganglions and the lumbar segment of the spinal cord proximal to the compressed cauda equina (L5-L6). RESULTS: The behavioral results suggested a significant improvement in the lower limb motor function in the VPA group compared with controls (P < 0.05). Furthermore, histologic assessment revealed a significant reduction in nerve fibers showing Wallerian degeneration and demyelinating lesions in the VPA group, in addition to an increased myelination compared with the control group (P < 0.05). The terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end label assay staining revealed a significant decrease in the number of apoptotic neurons in the spinal cord anterior horn and dorsal root ganglions in the VPA group compared with controls (P < 0.05). CONCLUSIONS: Our data demonstrated that VPA could alleviate cauda equina injury, reduce apoptotic cells, and improve motor recovery, suggesting a neuroprotective effect in acute cauda equina syndrome.

Filum Terminale Needle Placement During Caudal Epidural Steroid Injection.

OBJECTIVE: Caudal epidural steroid injections (ESIs) are commonly used to treat lumbar radicular pain. Touhy needles are placed under live fluoroscopic guidance to ensure epidural administration of medication. This is a case report of direct needle and catheter placements into and through the filum terminale during a caudal approach to the epidural space. DESIGN: Single case report. SETTING: Beth Israel Deaconess Medical Center. PATIENT: A 69-year-old woman who suffered from chronic low back and leg pain from lumbosacral radiculopathy, failed back surgery syndrome, and lumbar facet arthropathy. INTERVENTIONS: Caudal epidural steroid injection. OUTCOME MEASURES: Patient safety. RESULTS: The needle and catheter placement were confirmed via intrathecal contrast spread to be in the filum terminale, which prompted abortion of the procedure. CONCLUSIONS: Although caudal ESI is a relatively safe and routine intervention, care must be taken to ensure proper placement of needle, catheter, and injectate. While contrast is injected to ensure appropriate epidural spread, it serves also to reveal unexpected and unwanted spread. We present the first report of a needle being inserted directly into the filum terminale during a caudal ESI.

Recovery from muscle weakness by exercise and FES: lessons from Masters, active or sedentary seniors and SCI patients.

Many factors contribute to the decline of skeletal muscle that occurs as we age. This is a reality that we may combat, but not prevent because it is written into our genome. The series of records from World Master Athletes reveals that skeletal muscle power begins to decline at the age of 30 years and continues, almost linearly, to zero at the age of 110 years. Here we discuss evidence that denervation contributes to the atrophy and slowness of aged muscle. We compared muscle from lifelong active seniors to that of sedentary elderly people and found that the sportsmen have more muscle bulk and slow fiber type groupings, providing evidence that physical activity maintains slow motoneurons which reinnervate muscle fibers. Further, accelerated muscle atrophy/degeneration occurs with irreversible Conus and Cauda Equina syndrome, a spinal cord injury in which the human leg muscles may be permanently disconnected from the nervous system with complete loss of muscle fibers within 5-8 years. We used histological morphometry and Muscle Color Computed Tomography to evaluate muscle from these peculiar persons and reveal that contraction produced by home-based Functional Electrical Stimulation (h-bFES) recovers muscle size and function which is reversed if h-bFES is discontinued. FES also reverses muscle atrophy in sedentary seniors and modulates mitochondria in horse muscles. All together these observations indicate that FES modifies muscle fibers by increasing contractions per day. Thus, FES should be considered in critical care units, rehabilitation centers and nursing facilities when patients are unable or reluctant to exercise.

[ESTABLISHING AN ANIMAL MODEL OF DEFECATION RECONSTRUCTION AFTER SPINAL CORD INJURY IN RATS BY MECHANICAL POLISHING METHOD].

OBJECTIVE: To study the feasibility and advantages of preparing an animal model of defecation reconstruction after spinal cord injury in rats by mechanical polishing method. METHODS: Forty adult female Sprague Dawley rats (weighing, 250-300 g) were randomly divided into 2 groups (n=20). The lamina was opened by mechanical polishing method to expose the cauda equina in experimental group, then bilateral L5 and S1 nerve roots end-to-end anastomosis was done under 10 times microscope, and finally cauda equina between the L5 and L6 (except S1) was cut. The lamina was opened by traditional bites method in control group, and the other treatment methods were in agreement with the experimental group. The operative time, intra-operative blood loss, and situation of rats at postoperative 3 days were recorded. RESULTS: The operative time of experimental group[(93.05±7.60) minutes] was significantly shorter than that in control group[(131.30±11.68) minutes] (t=12.279, P=0.000); intra-operative blood loss in experimental group[(4.33±0.46) mL] was significantly lower than that in control group[(7.36±0.58) mL] (t=18.293, P=0.000). At 3 days after operation, 18 rats (90%) survived in experimental group, and 12 rats (60%) survived in control group; difference was significant in the survival rate between 2 groups (χ2=4.800, P=0.028). CONCLUSIONS: To establish an animal model of defecation reconstruction after spinal cord injury in rats by mechanical polishing method is feasible, and it has shorter operative time, less blood loss, and lower postoperative mortality than the traditional bites method. But there is a certain learning curve and requirement to master microsurgical techniques.

Does an intraoperative finding of an intact dural sac help to prognosticate neurological recovery in cauda equinal and epiconal injuries in thoracolumbar fractures? An analysis of 31 patients.

OBJECTIVE: To evaluate the effect of integrity of dural sac in determining motor neurological recovery in patients with cauda equinal and epiconal injuries in vertebral fractures at thoracolumbar junction. METHODS: Thirty-one patients with single-level vertebra fracture over T12-L2 with cauda equinal or epiconal injuries that underwent posterior spinal decompression and stabilization were evaluated in the period between 2006 and 2012. All patients included had motor incomplete ASIA C in neurology and were either Type B or C (AO/Magerl classification) of fracture morphology. Radiologist opinion to confirm the level of conus in MRI was done preoperatively. Intraoperative findings with respect to intactness of dura was noted. All MRI images were postoperatively evaluated by an independent, blinded radiologist for evidence of dural breach caused by the trauma. All participants provided basic demographic data, ambulatory status, and current neurology and received neurologic examination at intervals. The differences in neurologic injury sites and functional walkers in patients with different levels of vertebral injury were analyzed. Receiver operating characteristic curve analysis was used to define the cut-off value of lower extremities motor score (LEMS) in functional walkers and non-walkers. All patients were seen at a postoperative follow-up of minimum 18 months. RESULTS: Data of the 31 patients were analyzed. Seventeen patients (55%) had epiconus and lumbar roots lesions and 14 (45%) had cauda equina lesions. The injury was at the T12 vertebra in 9 patients (29%), L1 in 12 (39%) and in L2 in 10 patients (32%). Mean LEMS for patients with T12, L1, and L2 fractures were calculated. Fourteen patients had intraoperative findings of intact dura as against 17 patients with dural breach. MRI images when revisited by an independent radiologist by keeping him blind about the intraoperative surgeons findings showed statistically very good interobserver agreement (κ = 0.618) with regard to integrity of the dural sac. Postoperative neurological assessment at minimum 18 months follow-up showed that four out of the 14 patients with intact dura were walkers (28%) whereas of the 17 patients with dural breach, 13 were walkers (82%). CONCLUSION: Neurological recovery in cauda equinal and epiconal injuries in thoracolumbar fractures is significantly less likely in an intact dural sac, probably because the dural breach prevents the roots to take as much impact as compared to an intact dural sac.

Neuroprotective effect of hydrogen sulfide on acute cauda equina injury in rats.

BACKGROUND: Hydrogen sulfide (H2S), as a novel gaseous messenger molecule, plays an important role in signal transduction and biological modulation. PURPOSE: In the present study the effect of H2S after compression injury of cauda equina was studied. STUDY DESIGN: The setting of this study is the laboratory investigation. METHODS: A total of 162 rats were randomly allocated into three groups: sham group, compression group, and H2S group. Cauda equina compression (CEC) injury in rats was induced by implanting silicone gels (10×1×1 mm) into the epidural spaces L5 and L6; laminectomy was performed at the L4 level of the vertebra in the sham-operated group. The experimental group was treated with sodium hydrosulfide intraperitoneally (20 µmol/kg body weight), whereas the compression and sham groups received equal volumes of physiological saline. Levels of malonaldehyde (MDA) and glutathione (GSH) were determined immediately before CEC surgery, 12 h, 24 h, 48 h, and 72 h after CEC surgery. Furthermore, hematoxylin and eosin (H&E) staining and terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling (TUNEL) assay were performed 48 h after CEC. RESULTS: Hematoxylin and eosin staining showed that myelin sheath and the cauda equina fibers in the compression group were less compact and highly degenerated compared with the sham group, and that H2S treatment could improve the status. Terminal deoxynucleotidyl transferase-mediated biotinylated UTP nick-end labeling staining exhibited that decreased number of TUNEL positive cells was found in the H2S group than in the compression group. The level of MDA was increased in the sham and H2S groups compared with the compression group (p<.05, p<.01), whereas the level of GSH was decreased (p<.05, p<.01). CONCLUSIONS: With the above data, we conclude that H2S could reduce the oxidative stress and has neuroprotective effect in acute cauda equina syndrome.

Factors associated with outcome of spinopelvic dissociation treated with lumbopelvic fixation.

Spinopelvic dissociation is a rare high-energy injury, which is frequently associated with lumbosacral plexus and cauda equina deficits. During an 18-year period, 36 consecutive patients with a H-type sacral fracture and spinopelvic dissociation were treated using lumbopelvic fixation with a minimum follow-up of 18 months. We evaluated factors prognostic of outcome after standardised surgical fixation and neural decompression. Neurological recovery was assessed by Gibbons' criteria. Pelvis Outcome Scale (POS clinical score) was used to evaluate the clinical outcome. Despite excellent or good radiological results in the vertical components of the sacral fractures having been achieved in all patients, 15 patients (42%) had a poor clinical outcome. The degree of initial translational displacement in the transverse sacral fracture was significantly associated with neurological recovery (as defined by a change in Gibbons score) (p = 0.038) and final POS clinical score (p < 0.001). Both neurological recovery and clinical outcome were worse in patients with completely displaced fractures than in patients with a partially displaced sacral fracture. The degree of residual translational displacement and kyphosis in the transverse sacral fracture were also associated with clinical outcome (POS clinical score) (p = 0.011 and p = 0,018, respectively). However, Roy-Camille classification (type 2 vs. type 3), age, gender, ISS, timing of surgery, and sacral laminectomy did not have a statistically significant association with the outcome. Based on the results, Roy-Camille sacral fracture classification (type 2 vs. type 3) was not prognostic of neurological impairment. Thus further categorisation of the transverse sacral fractures as partially displaced or completely displaced could be used to predict the rate of neurological recovery following lumbopelvic fixation. Accurate reduction of all sacral fracture components seems to be associated with better clinical outcome.

Microsurgical reconstruction of the cauda equina after traumatic transecting injury.

INTRODUCTION: The microsurgical reconstruction of the cauda equina nerve roots (MRCER) after traumatic injury is a highly controversial procedure with very few reports in the literature. METHODS: We report on four patients who had a penetrating traumatic injury in the lumbosacral area and underwent primary MRCER at our institution during the last decade. RESULTS: All four patients presented complete distal sensory and motor palsy affecting the lower lumbosacral roots. Primary microsuture was feasible in three patients harboring stab wounds, whereas autologous nerve graft interposition was necessary in the patient who had a gunshot wound. At the 5-year follow-up, we observed a marked improvement in motor function in two patients, but no sensory recovery.

Long-term effects of a lumbosacral ventral root avulsion injury on axotomized motor neurons and avulsed ventral roots in a non-human primate model of cauda equina injury.

Here, we have translated from the rat to the non-human primate a unilateral lumbosacral injury as a model for cauda equina injury. In this morphological study, we have investigated retrograde effects of a unilateral L6-S2 ventral root avulsion (VRA) injury as well as the long-term effects of Wallerian degeneration on avulsed ventral roots at 6-10 months post-operatively in four adult male rhesus monkeys. Immunohistochemistry for choline acetyl transferase and glial fibrillary acidic protein demonstrated a significant loss of the majority of the axotomized motoneurons in the affected L6-S2 segments and signs of an associated astrocytic glial response within the ventral horn of the L6 and S1 spinal cord segments. Quantitative analysis of the avulsed ventral roots showed that they exhibited normal size and were populated by a normal number of myelinated axons. However, the myelinated axons in the avulsed ventral roots were markedly smaller in caliber compared to the fibers of the intact contralateral ventral roots, which served as controls. Ultrastructural studies confirmed the presence of small myelinated axons and a population of unmyelinated axons within the avulsed roots. In addition, collagen fibers were readily identified within the endoneurium of the avulsed roots. In summary, a lumbosacral VRA injury resulted in retrograde motoneuron loss and astrocytic glial activation in the ventral horn. Surprisingly, the Wallerian degeneration of motor axons in the avulsed ventral roots was followed by a repopulation of the avulsed roots by small myelinated and unmyelinated fibers. We speculate that the small axons may represent sprouting or axonal regeneration by primary afferents or autonomic fibers.

Afferent pathways arising from the lower urinary tract after complete spinal cord injury or cauda equina lesion: clinical observations with neurophysiological implications.

BACKGROUND: Afferents from the urinary tract transmit bladder sensations to the central nervous system. Spinal cord injury (SCI) may affect both efferent motor and afferent sensory pathways. Presence/absence of bladder sensations in patients with complete spinal cord, conus or cauda equina lesions was compared with neurologically unimpaired patients. METHODS: During urodynamics, bladder sensations were studied and compared in 59 patients: 21 patients with complete SCI below T6 and above Th12, 7 patients with a complete lesion of the conus medullaris, 11 patients with a complete lesion of the cauda equina, and 20 patients without neurological deficit. RESULTS: Two of 7 patients with complete conus lesion had a preserved filling sensation. Ten of 11 patients with complete lesion of the cauda equina reported a bladder filling sensation. Sensations are perceived at a similar pressure threshold but at a higher volume threshold. CONCLUSIONS: In patients with a complete cauda or a lower conus lesion, a sensory input from the bladder is preserved. These findings imply that the preserved bladder filling sensation in complete cauda or lower conus lesions is possibly transferred through the intact hypogastric plexus to the thoracolumbar segments of the spinal cord.