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.

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.

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.

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.

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.

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.

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.

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.

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.

Strontium ranelate decreases the incidence of new caudal vertebral fractures in a growing mouse model with spontaneous fractures by improving bone microarchitecture.

UNLABELLED: Young mice over-expressing Runx2 fail to gain bone relative to wild type mice with growth and present spontaneous fractures. It allows, for the first time in rodents, direct assessment of anti-fracture efficacy of strontium ranelate which was able to decrease caudal vertebrae fracture incidence through an improvement of trabecular and cortical architecture. INTRODUCTION: The aim was to investigate whether strontium ranelate was able to decrease fracture incidence in mice over-expressing Runx2, model of severe developmental osteopenia associated with spontaneous vertebral fractures. METHODS: Transgenic mice and their wild type littermates were treated by oral route with strontium ranelate or vehicle for 9 weeks. Caudal fracture incidence was assessed by repeated X-rays, resistance to compressive loading by biochemical tests, and bone microarchitecture by histomorphometry. RESULTS: Transgenic mice receiving strontium ranelate had significantly fewer new fractures occurring during the 9 weeks of the study (-60%, p < 0.05). In lumbar vertebrae, strontium ranelate improves resistance to compressive loading (higher ultimate force to failure, +120%, p < 0.05) and trabecular microarchitecture (higher bone volume and trabecular number, lower trabecular separation, +60%, +50%, -39%, p < 0.05) as well as cortical thickness (+17%, p < 0.05). In tibiae, marrow cavity cross-section area and equivalent diameter were lower (-39%, -21%, p < 0.05). The strontium level in plasma and bone was in the same range as the values measured in treated postmenopausal women. CONCLUSIONS: This model allows, for the first time, direct assessment of anti-fracture efficacy of strontium ranelate treatment in rodents. In these transgenic mice, strontium ranelate was able to decrease caudal vertebral fracture incidence through an improvement of trabecular and cortical architecture.

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.

The clinical study of repairing cauda equina fibres with fibrin glue after lumbar fracture and dislocation.

STUDY DESIGN: A retrospective study. OBJECTIVES: To study the outcome of repair of cauda equina fibres with fibrin glue after lumbar fracture and/or dislocation. METHODS: Seven acute cases and one chronic case of L2 or L3 fracture and/or dislocation complicated with complete cauda equina injury were selected. Sural nerve or ventral roots of injured cauda equina were chosen to repair the motor cauda equina fibres with fibrin glue after open reduction and internal fixation of the unstable vertebrae. The functional recovery after surgery was observed. RESULTS: Recovery of the strength of thigh muscles (iliopsoas, quadriceps femoris, gluteus maximus, adductors) was observed in all seven acutely injured patients (t=3.74, P<0.05), but not in the chronic one. Neither recovery of leg muscles nor sensation of the lower extremities was observed in any case. CONCLUSIONS: The cauda equina ventral roots injured after lumbar fracture and/or dislocation can be repaired with fibrin glue and motor recovery is expected.

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.

Bayesian characterization of external anal sphincter muscles using quantitative electromyography.

OBJECTIVES: Based on the analysis of electromyographic (EMG) data muscles are often characterized as normal or affected by a neuromuscular disease process. The objective of this work was to compare the accuracy of Bayesian muscle characterization to conventional means and outlier analysis of motor unit potential (MUP) feature values. METHODS: Quantitative MUP data from the external anal sphincter muscles of control subjects and patients were used to compare the sensitivity, specificity, and accuracy of the methods under examination. RESULTS: The results demonstrated that Bayesian muscle characterization achieved similar accuracy to combined means and outlier analysis. Thickness and number of turns were the most discriminative MUP features for characterizing the external anal sphincter (EAS) muscles studied in this work. CONCLUSIONS: Although, Bayesian muscle characterization achieved similar accuracy to combined means and outlier analysis, Bayesian muscle characterization can facilitate the determination of "possible", "probable", or "definite" levels of pathology, whereas the conventional means and outlier methods can only provide a dichotomous "normal" or "abnormal" decision. Therefore, Bayesian muscle characterization can be directly used to support clinical decisions related to initial diagnosis as well as treatment and management over time. Decisions are based on facts and not impressions giving electromyography a more reliable role in the diagnosis, management, and treatment of neuromuscular disorders. SIGNIFICANCE: Bayesian muscle characterization can help make electrophysiological examinations more accurate and objective.

Clinical prognostic factors for bladder function recovery of patients with spinal cord and cauda equina lesions.

OBJECTIVE: To investigate the relationship between lesion severity and other clinical factors and bladder function recovery. PATIENTS AND METHODS: The charts of 269 patients with traumatic and non traumatic spinal cord lesion (SCL) were reviewed and the following information was recorded: lesion to admission time, injury variables, length of stay and neurological status. At five months, urological outcome was assessed by voiding modalities, and urodynamics according to International Continence Society. Logistic approach with univariate and multivariate analysis. RESULTS: Both ASIA impairment at admission and age were significantly correlated with bladder function outcome. None of the patients with ASIA A impairment at admission reached volitional voiding at five months. ASIA B patients had a 90% lower probability of achieving good bladder control and ASIA C ones a 65% lower than ASIA D patients (p < 0.05). Older patients had a significant lower probability (60%) of achieving volitional voiding than younger ones (p < 0.05). Of the 121 patients with ASIA D impairment at discharge only 78 voided spontaneously and showed a higher frequency of cervical lesions and a lower frequency of detrusor-external sphincter dyssynergia. DISCUSSION AND CONCLUSION: Bladder recovery in patients with complete SCL is limited. ASIA B patients showed a better neurological recovery and, concurrently, better bladder function recovery than ASIA A patients, thus demonstrating the importance of sensation preservation for recovery. Younger patients show better bladder recovery than older ones, probably because of different efficiency of spinal cord plasticity. Finally, patients with good neurological recovery may not achieve volitional voiding. Patients with bladder function recovery show a higher frequency of central cord and Brown-Sequard syndromes (with better prognosis) and a lower frequency of detrusor-sphincter dyssynergia.

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.

Functional reinnervation of the rat lower urinary tract after cauda equina injury and repair.

Conus medullaris and/or cauda equina forms of spinal cord injury commonly result in a permanent loss of bladder function. Here, we developed a cauda equina injury and repair rodent model to investigate whether surgical implantation of avulsed lumbosacral ventral roots into the spinal cord can promote functional recovery of the lower urinary tract. Adult female rats underwent sham surgery (n = 6), bilateral L5-S2 ventral root avulsion (VRA) injury (n = 5), or bilateral L5-S2 VRA followed by an acute implantation of the avulsed L6 and S1 ventral roots into the conus medullaris (n = 6). At 12 weeks after operation, the avulsed group demonstrated urinary retention, absence of bladder contractions and external urethral sphincter (EUS) electromyographic (EMG) activation during urodynamic recordings, increased bladder size, and retrograde death of autonomic and motoneurons in the spinal cord. In contrast, the implanted group showed reduced urinary retention, return of reflexive bladder voiding contractions coincident with EUS EMG activation, anatomical reinnervation of the EUS demonstrated by retrograde neuronal labeling, normalization of bladder size, and a significant neuroprotection of both autonomic and motoneurons. In addition, a positive correlation between motoneuronal survival and voiding efficiency was observed in the implanted group. Our results show that implantation of avulsed lumbosacral ventral roots into the spinal cord promotes reinnervation of the urinary tract and return of functional micturition reflexes, suggesting that this surgical repair strategy may also be of clinical interest after conus medullaris and cauda equina injuries.

Novel biomechanical quantification methodology for lumbar intraforaminal spinal nerve adhesion in a laminectomy and disc injury rat model.

Spinal nerve fibrosis following injury or surgical intervention may play an important role in the pathophysiology of chronic back pain. In this current study, we demonstrate the role of biomechanical quantification of lumbar intraforaminal spinal nerve adhesion and tethering in the analysis of the post-laminectomy condition and describe a direct methodology to make this measurement. Twenty age-matched Sprague-Dawley male rats were divided into operative and non-operative (control) groups. Operative animals underwent a bilateral L5-L6 laminectomy with right-side L5-6 disc injury, a post-laminectomy pain model previously published by this lab. At eight weeks, animals were sacrificed and the strength of adhesion of the L5 intraforaminal spinal nerve to surrounding structures was quantified using a novel biomechanical methodology. Operative animals were found to have a significantly greater load to displace the intact right L5 spinal nerve through the intervertebral foramen when compared to control animals. The findings show that the post-laminectomy condition creates quantifiable fibrosis of the spinal nerve to surrounding structures and supports the conclusion that this fibrosis may play a role in the post-laminectomy pain syndrome.

Cauda equina syndrome treated by surgical decompression: the influence of timing on surgical outcome.

A prospective longitudinal inception cohort study of 33 patients undergoing surgery for cauda equina syndrome (CES) due to a herniated lumbar disc. To determine what factors influence spine and urinary outcome measures at 3 months and 1 year in CES specifically with regard to the timing of onset of symptoms and the timing of surgical decompression. CES consists of signs and symptoms caused by compression of lumbar and sacral nerve roots. Controversy exists regarding the relative importance of timing of surgery as a prognostic factor influencing outcome. Post-operative outcome was assessed at 3 months and 1 year using the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS) scores for leg and back pain and an incontinence questionnaire. Statistical analysis was used to determine the association between pre-operative variables and these post-operative outcomes with a specific emphasis on the timing of surgery. Surgery was performed on 12 (36%) patients within 48 h of the onset of symptoms including seven patients (21%) who underwent surgery within 24 h. Follow up was achieved in 27 (82%) and 25 (76%) patients at 3 and 12 months, respectively. There was no statistically significant difference in outcome between three groups of patients with respect to length of time from symptom onset to surgery- <24, 24-48 and >48 h. A significantly better outcome was found in patients who were continent of urine at presentation compared with those who were incontinent. The duration of symptoms prior to surgery does not appear to influence the outcome. This finding has significant implications for the medico-legal sequelae of this condition. The data suggests that the severity of bladder dysfunction at the time of surgery is the dominant factor in recovery of bladder function.