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.

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.

Lumbopelvic fixation for multiplanar sacral fractures with spinopelvic instability

Sacral fractures with both transverse and bilateral vertical fracture components are by definition multiplanar fractures, and often present with spinopelvic instability and cauda equina deficits. The treatment is challenging. Between 2006 and 2009, we treated nine such patients at our trauma centre. There were six men and three women, with a mean age of 32.2 years. Preoperative neurologic deficits were noted in seven patients; four patients had complete cauda equina paralysis, and three patients had incomplete cauda equina syndrome. All patients were treated using lumbopelvic instrumented fixation without other devices for their multiplanar sacral fractures. Six patients who had neurological deficits and sacral canal compression underwent decompression laminectomy. The mean postoperative follow-up time was 21.7 months (range, 14-32 months). All fractures went on to union without loss of reduction or hardware failure. The mean Gibbons score improved from 3.5 preoperatively to 2.3 postoperatively among the patients who underwent decompression laminectomy. Eight out of nine patients had fair or better results based on radiographic criteria and the Majeed pelvic fracture outcome score. Our experience suggests lumbopelvic fixation can be used for the treatment of multiplanar sacral fractures with spinopelvic instability with a low rate of complications. Neurologic improvement can be expected, but whether surgical decompression results in substantially better neurologic recovery than conservative treatment remains uncertain.

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

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.

[Clinical effect of methylprednisolone sodium succinate and mouse nerve growth factor for injection in treating acute spinal cord injury and cauda equina injury]

OBJECTIVE

To investigate the effect of methylprednisolone sodium succinate (MP) and mouse nerve growth factor (mNGF) for injection in treating acute spinal cord injury (ASCI) and cauda equina injury.

METHODS

Between December 2004 and December 2007, 43 patients with ASCI and cauda equina injury were treated, including 33 males and 10 females with an average age of 43 years (range, 32-66 years). Injured vertebral columns were C2 in 1 case, C4 in 5 cases, C5 in 7 cases, C6 in 3 cases, T8 in 1 case, T10 in 1 case, T11 in 2 cases, T12 in 3 cases, L1 in 9 cases, L2 in 5 cases, L3 in 3 cases, L4 in 1 case, and L5 in 2 cases. All the patients had sensory disturbance and motor dysfunction at admission. The Frankel scale was used for assessment of nerve function, 5 cases were rated as Grade A, 12 as Grade B, 22 as Grade C, and 4 as Grade D before operation. In 43 patients, 23 cases were treated with MP and mNGF (group A), 20 cases with MP only (group B). There was no significant difference in general data between 2 groups (P > 0.05). All the patients were admitted, received drug treatment within 8 hours of injury, and were given spinal canal decompression, bone transplantation, and internal fixation within 48 hours. The neurological function score systems of American Spinal Injury Association (ASIA) were used for neurological scores before treatment, at 1 week and 2 years after treatment. The scores of the activity of daily living (ADL) were evaluated and compared.

RESULTS

All the patients achieved healing of incision by first intention. Forty-three cases were followed up 24-61 months with an average of 30 months. Bone graft fusion was achieved after 6-17 months, 11 months on average with stable fixation. No death and complications of osteonecrosis and central obesity occurred. There was no significant difference in neurological function scores and ADL scores between 2 groups before treatment (P > 0.05); however, the neurological function scores and ADL scores at 1 week and 2 years after treatment were higher than those before treatment (P < 0.01) in 2 groups. Group A had higher neurological function scores and ADL scores than group B (P < 0.01). At 1 week and 2 years after treatment, the improvement rates of neurological function of group A (47.8%, 11/23 and 91.3%, 21/23) were significantly higher (P < 0.01) than those of group B (30.0%, 6/20 and 70.0%, 14/20).

CONCLUSION

MP and mNGF play an important role in improving the neurological function in patients with ASCI and cauda equina injury.

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.

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.

Dramatic neurological recovery with delayed correction of traumatic lumbar spondyloptosis

✓The authors describe a 36-year-old woman with traumatic lateral spondyloptosis at L-2 and complete cauda equina injury who experienced a remarkable recovery after delayed treatment. To the authors' knowledge, this is the first case of traumatic spondyloptosis at L2–3 described in the English literature. A review of previous cases of lumbar spondyloptosis suggests that the degree of anatomical injury found at surgery is a better predictor of patient outcome than fracture severity assessed radiologically. Concomitant multisystem injury is common with spine disruptions of this magnitude and may mask clinical neurological function. Even when delayed, operative decompression of these severe lesions should be considered because dramatic neurological recovery is possible.

Contralateral radiculopathy after transforaminal lumbar interbody fusion

Transforaminal lumbar interbody fusion (TLIF) is an effective treatment for patients with degenerative spondylolisthesis and degenerative disc disease. Opposite side radiculopathy after the TLIF procedure has been recognized in this institution but has not been addressed in the literature. We present a case of opposite side radiculopathy after the TLIF procedure. We believe that this complication is related to asymptomatic stenosis on the contralateral side that is unmasked by the increased lordosis of the TLIF. The authors recommend increasing both disc height and foraminal height when choosing an interbody graft, and possibly decompressing the opposite foramen when preoperative MRI demonstrates foraminal stenosis.

The bullet in the dural sac. How to catch it? A report of two cases

OBJECTIVE

The purpose of this article is to present two cases of penetrating gunshot injuries to the lumbar spine with migration of the bullets within the dural sac and to describe the method of removal of the bullet from the dural sac.

MATERIAL AND METHODS

Two cases of penetrating gunshot injuries to the lumbar spine with migration of the bullets within the dural sac are presented. Clinical course, diagnostic tools, and management of two patients who suffered from these injuries are illustrated. The method of removal of the bullet from the dural sac is described too.

RESULTS

The wounds in these two cases healed without infection. The neurological status of our patients improved gradually. Radiographs taken 2 years after the injury did not demonstrate the postoperative instability of the lumbar spine.

CONCLUSIONS

The bullet in the dural sac at the level of the cauda equina must be removed. The method proposed by us can facilitate this procedure.

Epidemiology of cauda equina and conus medullaris lesions

The epidemiology of cauda equina and conus medullaris lesions is not well known, and this study aimed to provide further information on this topic. In the period 1996-2004, patients fulfilling the clinical, electrodiagnostic, and radiological criteria for such lesions were identified. For cauda equina/conus medullaris lesions an annual incidence rate of 3.4/1.5 per million, and period prevalence of 8.9/4.5 per 100,000 population were calculated. The values obtained are probably valid estimates of the incidence and prevalence of these lesions in developed countries.

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.

Decompression and lumbopelvic fixation for sacral fracture-dislocations with spino-pelvic dissociation

PURPOSE

To report results of sacral decompression and lumbopelvic fixation in neurologically impaired patients with highly displaced, comminuted sacral fracture-dislocations resulting in spino-pelvic dissociation.

DESIGN

Retrospective clinical study.

SETTING

Regional level one trauma center.

PATIENTS

Nineteen patients with highly displaced, comminuted, irreducible Roy-Camille type 2-4 sacral fractures with spino-pelvic instability patterns and cauda equina deficits were identified over a 6-year period, 18 of which met the 12-month minimum follow-up criterion.

INTERVENTION

All were treated with open reduction, sacral decompression, and lumbopelvic fixation. Radiographic and clinical results were evaluated. Neurological outcome was measured by Gibbons' criteria.

MAIN OUTCOME MEASUREMENTS

Radiographic evaluation with computed tomography scan and antero-posterior, lateral, and oblique views of the pelvis to assess alignment, hardware position and decompression. Clinical evaluation emphasizing neurological outcome as described by Gibbons' criteria.

RESULTS

Sacral fractures healed in all 18 patients without loss of reduction. Average sacral kyphosis improved from 43 to 21 degrees. Fifteen patients (83%) had full or partial recovery of bowel and bladder deficits, although only 10 patients (56%) had improved Gibbons scores. Average Gibbons score improved from 4 to 2.8 at 31-month average follow-up (range: 12 to 57 mo). Wound infection (16%) was the most common complication. Complete recovery of cauda equina function was more likely in patients with continuity of all sacral roots (86% vs. 0%, P = 0.00037) and incomplete deficits (100% vs. 20%, P = 0.024). Although not statistically significant, recovery of bowel and bladder function specifically was more closely associated with absence of any sacral root discontinuity (86% vs. 36%, P = 0.066) than on completeness of the injury (100% vs. 47%, P = 0.21).

CONCLUSIONS

Lumbopelvic fixation provided reliable fracture stability and allowed consistent fracture union without loss of alignment. Neurological outcome was, in part, influenced by completeness of injury and presence of sacral root disruption.

Cauda equina-penetrating injury in a child. Case report

The authors report the case of a 10-year-old boy who sustained an injury to the cauda equina as a result of the accidental penetration of a wooden pencil into the spinal canal. After neuroimaging evaluation to exclude visceral and vascular lesions, the foreign body was removed and the wound was repaired. This is the first report of a cauda equina injury caused by a pencil.

Cord and cauda equina injury complicating elective orthopedic surgery

STUDY DESIGN

Presented is a case series of 3 patients, all of whom developed neurologic deficits due to cord or cauda equina compression during elective extremity surgery.

OBJECTIVES

To identify characteristics of presentation that may differentiate cord or cauda equina injury from peripheral nerve palsy following extremity surgery and to establish the value of early decompression in patients with intraoperative injury.

SUMMARY OF BACKGROUND DATA

Intraoperative neural injury has been described in association with epidural and spinal anesthesia, with cervical or spinal manipulation in the face of instability, and with ischemic injury suffered during extensive vascular repair. However, it has not been described after uncomplicated elective extremity surgery.

METHODS

Retrospective review of a case series.

RESULTS

In 1 patient, intraoperative paraplegia occurred after routine shoulder arthroscopy. A second patient underwent elective bilateral total hip replacement and awoke with neurologic deficits in both lower extremities, then went on to develop an acute cauda equina syndrome. The third patient developed a central cord syndrome following an otherwise uncomplicated total hip replacement. Two patients were initially misdiagnosed as peripheral nerve palsies. All 3 patients had preexisting spinal stenosis at the level of neural injury. All underwent routine positioning and anesthetic care but were recognized as having a neural injury early in the recovery period. In only 1 case was the diagnosis of a cord level injury made immediately. All 3 patients were treated with urgent surgical decompression once diagnosed. Following surgery, neurologic symptoms improved in each of the 3 patients allowing early mobilization.

CONCLUSIONS

Spontaneous neural injury is rare but can occur to the anesthetized patient. Neurologic examination should be routinely performed in the recovery room; and if significant neurologic deficits are seen, investigative workup should not be delayed. If an intraspinal lesion is identified, immediate decompression may offer favorable results. Neurologic deficits should not be dismissed as peripheral palsies without careful evaluation.

Surgical Decision Making for Unstable Thoracolumbar Spine Injuries

OBJECTIVES

The optimal surgical approach and treatment of unstable thoracolumbar spine injuries are poorly defined owing to a lack of widely accepted level I clinical literature. This lack of evidence-based standards has led to varied practice patterns based on individual surgeon preferences. The purpose of this study was to survey the leaders in the field of spine trauma to define the major characteristics of thoracolumbar injuries that influence their surgical decision making. In the absence of good scientific data, expert consensus opinions may provide surgeons with a practical framework to guide therapy and to conduct future research.

METHODS

A panel of 22 leading spinal surgeons from 20 level I trauma centers in seven countries met to discuss the indications for surgical approach selection in unstable thoracolumbar injuries. Injuries were presented to the surgeons in a case scenario survey format. Preferred surgical approaches to the clinical scenarios were tabulated and comments weighed.

RESULTS

All members of the panel agreed that three independent characteristics of thoracolumbar injuries carry primary importance in surgical decision making: the injury morphology, the neurologic status of the patient, and the integrity of the posterior ligaments. Six clinical scenarios based on the neurologic status of the patient (intact, incomplete, or complete) and on the status of the posterior ligamentous complex (intact or disrupted) were created, and consensus treatment approaches were described. Additional circumstances capable of altering the treatments were acknowledged.

CONCLUSIONS

Decision making for the surgical treatment of thoracolumbar injuries is largely dependent on three patient characteristics: injury morphology, neurologic status, and posterior ligament integrity. A logical and practical decision-making process based on these characteristics may guide treatment even for the most complicated fracture patterns.

Entrapped spinal nerve roots in a pseudomeningocoele as a complication of previous spinal surgery

Pseudomeningocele is a rare but well recognised complication of lumbar surgery (microdiscectomy and laminectomy). Most of the patients tolerate the presence of the cyst well, however some present with back pain and spinal claudication, presumably due to neural compression. We report a case who presented following three operations (microdiscectomy, laminectomy and excision of a pseudomeningocele) with symptoms of spinal claudication and bilateral radicular pain. The cause of her pain was evident only at operation and was due to herniation of nerve roots through the dural defect.

Extradural spinal arachnoid cysts associated with spina bifida occulta

INTRODUCTION

Spinal extradural arachnoid cysts are an uncommon cause of neural compression in children. Even more uncommon is the association of such cysts with spina bifida occulta.

MATERIAL

Two girls, 12 and 8-years-old, presented with left leg pain, deteriorating gait, clinical signs of left L5 and S1 root compression, without bladder or bowel symptoms. The first patient had left foot drop. The second patient had muscle wasting and smaller left foot with pes cavus. Radiographs showed spina bifida occulta of S1 in both. MRI revealed an extradural cyst at the S1 level, indenting the thecal sac and the L5 and S1 roots. At operation in both patients a large arachnoid cyst arising from a small dural defect in the axilla of the left S1 root was compressing and displacing it and the dural sac. It was removed and the defect was repaired. The first patient improved with complete recovery of the foot drop. An MRI at 12 months showed no cyst recurrence. The second patient made good recovery initially, but at 10 months developed recurrent symptoms. An MRI scan showed recurrence of the cyst with root compression. On repeat exploration a different dural defect was identified in a more anterior position and was repaired.

DISCUSSION

The coexistence of extradural arachnoid cyst and corresponding bifid spinal segment has not been described previously. It raises the suspicion that the dural defect giving rise to the arachnoid cyst may be due to segmental dural dysgenesis in the context of the dysrhaphic neuroectodermal malformation.

Lap-belt injury with complete avulsion of the spinal cord and cauda equina

The authors report a child who was involved in an automobile accident. The patient was restrained by a rear seat lap belt. Radiological examination revealed an L4 Chance-type fracture and ligamentous disruption at the L4-L5 interval. During superficial dissection of the paraspinal muscles for a spinal fusion procedure, the cauda equina and the lower spinal cord (several centimeters) were visible, completely transected and herniated into the extraspinal space through a disrupted thoracolumbar fascia. The clinician should be aware of the potentially devastating results following a lap-belt injury in which a Chance fracture is produced.

Glial reactions in a rodent cauda equina injury and repair model

In the adult rat, an avulsion injury of lumbosacral ventral roots results in a progressive and pronounced loss of the axotomized motoneurons. A subsequent acute implantation of an avulsed ventral root into the spinal cord has neuroprotective effects. However, it has not been known whether a surgical implantation of an avulsed ventral root into the spinal cord for neural repair purposes affects intramedullary glial and microglial reactions. Here, adult female Sprague-Dawley rats underwent a unilateral L5-S2 ventral root avulsion injury with or without acute implantation of the L6 ventral root into the spinal cord. At 4 weeks postoperatively, immunohistochemistry using primary antibodies to GFAP (astrocytes), Ox-42 (microglia), and ED-1 (macrophages) was performed at the L6 spinal cord segment, and quantified using densitometry. Our results show that a lumbosacral ventral root avulsion injury induces an activation of astrocytes, microglia, and macrophages in the ventral horn. Interestingly, an acute implantation of an avulsed root into the white matter does not significantly affect the activation of glial cells or macrophages in the ventral horn. We speculate that neuroprotective and axonal growth promoting benefits of the combined glial and microglial/ macrophage responses may outweigh their potential negative effects, as previous studies have shown that implantation of avulsed roots is a successful strategy in promoting reinnervation of peripheral targets.

[Possibility of cauda equina nerve root damage from lumbar punctures performed with 25-gauge Quincke and Whitacre needles]

OBJECTIVE

To assess the possibility of puncturing nerve roots in the cauda equina with spinal needles with different point designs and to quantify the number of axons affected.

MATERIAL AND METHODS

We performed in vitro punctures of human nerve roots taken from 3 fresh cadavers. Twenty punctures were performed with 25-gauge Whitacre needles and 40 with 25-gauge Quincke needles; half the Quincke needle punctures were carried out with the point perpendicular to the root and the other half with the point parallel to it. The samples were studied by optical and scanning electron microscopy. The possibility of finding the needle orifece inserted inside the nerve was assessed. On a photographic montage, we counted the number of axons during a hypothetical nerve puncture.

RESULTS

Nerve roots used in this study were between 1 and 2.3 mm thick, allowing the needle to penetrate the root in the 52 samples studied. The needle orifice was never fully located inside the nerve in any of the samples. The numbers of myelinized axons affected during nerve punctures 0.2 mm deep were 95, 154, and 81 for Whitacre needles, Quincke needles with the point held perpendicular, or the same needle type held parallel, respectively. During punctures 0.5 mm deep, 472, 602, and 279 were affected for each puncture group, respectively. The differences in all cases were statistically significant.

CONCLUSIONS

It is possible to achieve intraneural puncture with 25-gauge needles. However, full intraneural placement of the orifice of the needle is unlikely. In case of nerve trauma, the damage could be greater if puncture is carried out with a Quincke needle with the point inserted perpendicular to the nerve root.

Multisegmental open sacral fracture due to impalement: a case report

We report on an unusual impalement injury to the sacrum in a 15-year-old adolescent patient. This open pelvic fracture resulted in a shattered sacrum with neurologic impairment including clinically absent anal sphincter tone and perineal sensation. Early debridement, wound revision, neural decompression, fracture reduction, and stable fixation using lumbopelvic fixation according to the principles of triangular osteosynthesis resulted in a favorable outcome with primary wound healing, return of bowel and bladder control, as well as immediate patient mobilization.

Experimental cauda equina compression induces HSP70 synthesis in dog

The heat shock protein 70 (HSP70) is a key component of the stress response induced by various noxious conditions such as heat, oxygen stress, trauma and infection. In present study we have assessed the consequences of the compression of lower lumbar and sacral nerve roots caused by a multiple cauda equina constrictions (MCEC) on HSP70 immunoreactivity (HSP70-IR) in the dog. Our data indicate that constriction of central processes evokes HSP70 up-regulation in the spinal cord (L7, S1-Co3) as well as in the corresponding dorsal root ganglion cells (DRGs) (L7-S1) two days following injury. A limited number of bipolar or triangular HSP-IR neurons were found in the lateral collateral pathway (LCP) as well as in the pericentral region (lamina X) of the spinal cord. In contrast, a high number of HSP70 exhibiting motoneurons with fine processes appeared in the ventral horn (laminae VIII-IX) of lumbosacral segments. Concomitantly, close to them a few lightly HSP70-positive neuronal somata or cell bodies lacking the HSP70-IR occurred. In the DRGs, HSP70 expression was mildly up-regulated in small and medium-sized neurons and in satellite cells. On the contrary, DRGs from intact or sham-operated dogs did not reveal HSP70 specific neuronal staining. In conclusion, we have demonstrated that the MCEC in dogs mimicking the cauda equina syndrome in clinical settings evokes expression of HSP70 synthesis in specific neurons of the lumbo-sacro-coccygeal spinal cord segments and in small and medium sized neurons of corresponding DRGs. This suggests that HSP70 may play an active role in neuroprotective processes partly by maintaining intracellular protein integrity and preventing the neuronal degeneration in this experimental paradigm.

Caudal spinal cord ischemia after lumbar vertebral manipulation

Neurological complications after lumbar spine manipulation are uncommon. The cause is usually a herniated disk or displaced bony structure. We report a case of paraplegia that developed a few hours after manipulation of the lumbar spine. Magnetic resonance imaging was consistent with ischemia of the caudal spinal cord. No disk fragment or bony structure impinging on the spinal cord was seen. Spinal cord ischemia may deserve to be added to the list of possible adverse events after lumbar spine manipulation.

Use of topiramate for spinal cord injury-related pain

BACKGROUND

Pain following spinal cord injury (SCI) has proved difficult to treat. Although the use of antiepileptic drugs to treat SCI-related pain has been studied previously, topiramate has not been investigated in this population. Our recent experience suggests that topiramate may be efficacious in the treatment of SCI-related pain.

METHOD

Case Studies Findings: This report presents the clinical histories of two people with pain following SCI who reported beneficial effects of treatment with the new antiepileptic drug topiramate, even after failing treatment with standard analgesic medications. Topiramate was well tolerated in these patients.

CONCLUSION

For post-SCI pain, topiramate appears to be an effective treatment in some patients. Based on the present anecdotal findings, larger controlled studies comparing topiramate with standard treatment for SCI-related pain are warranted.

Conus medullaris and cauda equina syndrome as a result of traumatic injuries: management principles

Conus medullaris syndrome (CMS) and cauda equina syndrome (CES) are complex neurological disorders that can be manifested through a variety of symptoms. Patients may present with back pain, unilateral or bilateral leg pain, paresthesias and weakness, perineum or saddle anesthesia, and rectal and/or urinary incontinence or dysfunction. Although patients typically present with acute disc herniations, traumatic injuries at the thoracolumbar junction at the terminal portion of the spinal cord and cauda equina are also common. Unfortunately, a precise understanding of the pathophysiology and optimal treatments, including the best timing of surgery, has yet to be elucidated for either traumatic CES or CMS. In this paper the authors review the current literature on traumatic conus medullaris and cauda equina injuries and available treatment options.

Standardization of anal sphincter electromyography: quantification of continuous activity during relaxation

AIM

Sphincter motor units (MUs) are continuously firing during relaxation. The quantification of this activity is a potentially useful electromyographic (EMG) parameter related to the number of MUs innervating the muscle and the level of motor neuron excitation. The aim of the present study was to develop a reliable, quantitative measure of continuous sphincter muscle activity during relaxation.

METHODS

EMG activity was analyzed during relaxation, 1 minute after insertion of the concentric needle electrode into four sites in the external anal sphincter (EAS) muscle. In 10 control subjects, 8 interference pattern samples were obtained by "turn/amplitude" analysis. In 35 control subjects, a multi-MUP count of continuously firing motor unit potentials (MUPs) was used, quadruplets with scores of 0-6 obtained, and the lower reference limits (95th percentile) calculated. This approach was then evaluated in 57 patients (182 muscles) with cauda equina or conus medullaris lesion (CECML) and 7 patients (13 muscles) with "idiopathic fecal incontinence."

RESULTS

The lower reference ("outlier") limits for MUP count were 0 0 6 6 and 0 1 2 2 for the subcutaneous, and 0 0 0 6 and 0 0 1 1 for the deeper EAS muscles. Both patient groups had a significantly diminished number of continuously firing MUPs, which was below the reference range in 43% of the EAS muscles from CECM patients and in 85% of muscles from patients with idiopathic fecal incontinence. In patients with CECML, the decrease in MUP count correlated with the severity of the lesion, as defined by the sensory deficit.

CONCLUSIONS

MUP count in sphincter muscles during relaxation is technically feasible, and it is a promising tool, particularly in patients with idiopathic fecal incontinence.

Primary spinal extradural hydatid cyst in a child: case report and review of the literature

Spinal hydatid cyst is a rare but serious condition. An 8-year-old boy presented with back pain, progressive weakness and numbness in both legs. Magnetic resonance imaging (MRI) of the lumbar region showed a cystic lesion with regular contour located in extradural space. There was cerebrospinal fluid- (CSF-) like signal intensity on T1- and T2-weighted images. The lesion had excessively compressed the dural sac and caudal roots, and expanded to the L3 and L4 neural foramina. The case was explored with L2, L3, L4 laminectomy and the hydatid cyst was removed totally. The clinical presentation, diagnosis and surgical treatment of this rare case of spinal hydatid disease is discussed, and all available cases of primary extradural hydatid cyst reported in the literature are presented.

Predictive power of motor unit potential parameters in anal sphincter electromyography

The diagnostic utility of motor unit potential (MUP) parameters is usually based exclusively on their diagnostic sensitivity, disregarding specificity. In the present study, advanced statistical methods were used to determine MUP parameters with the highest predictive power for the separation of neuropathic and normal external anal sphincter (EAS) muscles. Using multi-MUP analysis, 3,720 MUPs from 138 muscles of 52 patients with cauda equina lesion and 2,526 from 112 muscles of 64 controls were obtained. Only two principal components (PCs), which put weight on the MUP area and amplitude, were needed to explain all the data variability. On logistic and probit regression analyses, MUP area, duration, and number of turns gave results identical to all MUP parameters. Our results suggest that only these three MUP parameters are needed, and that they are as effective as PCs, in MUP analysis of chronic neuropathic EAS muscles. Reduced number of MUP parameters is expected to simplify MUP analysis and increase its specificity.

Efficacy of methylprednisolone in acute experimental cauda equina injury

In this experimental study the efficacy of methylprednisolone was investigated by neurophysiological and histopathological evaluation in a rabbit cauda equina model where injury was produced with an aneurysm clip (closed pressure 192 gr). High dose methylprednisolone (kg/30 mg) was administered by intravenous infusion in the 8th, 16th and 24th hours after injury followed by infusion of the same dosage every 6 hours for 24 hours. Nerve conduction velocity was measured before and early after trauma and 3 weeks after injury. Both neurophysiological and histopathological investigations demonstrated the neuroprotective effectiveness of methylprednisolone if it was given in the 8th hour after trauma. Although recovery was observed its efficacy was less pronounced when it was given in the 16th and 24th hours.

Inadvertent sacral bar transfixation of the cauda equina

We present a case of inadvertent sacral bar transfixation of the cauda equina as a complication of posterior pelvic internal fixation. The "safe zone" for sacral bar placement is narrow, especially in the presence of fracture displacement. This complication can be avoided by achieving fracture reduction before internal fixation. Intraoperative fluoroscopy, including inlet and lateral sacral views, should be used in addition to tactile guidance to confirm the reduction. Even after prolonged compression, hardware removal under direct visualization can alleviate radicular symptoms with less effect on motor deficit.

Comparison of quantitative techniques in anal sphincter electromyography

Data comparing results and utility of different quantitative electromyographic (EMG) techniques are limited. In the present study, we analyzed the EMG signal from the external anal sphincter (EAS) muscle using three techniques of motor unit potential (MUP) analysis, and a technique of interference pattern (IP) analysis. We examined 56 patients with damage to the cauda equina or conus medullaris, and 64 control subjects. Using manual-MUP and multi-MUP analysis about 20 MUPs, using a single-MUP technique about 10 MUPs, and using turn/amplitude (T/A) analysis about 20 IP samples were obtained. The sensitivities of these techniques in distinguishing neuropathic from control muscles were calculated. The single-MUP technique detected 63%, manual-MUP 57%, and multi-MUP analysis 62% of neuropathic muscles, and MUP parameters obtained by each of these differed significantly from the other. The sensitivity of T/A analysis of IP was 29%. Our results confirm the need for separate MUP normative data for each of the MUP analysis techniques, and favor them over the IP analysis technique. The normative data presented for the EAS muscle should improve and promote quantitative EMG in patients.

Postoperative radicular neuroma. Case report

Lumbar discectomy is the most common surgical procedure performed in neurosurgery clinics. Such a large number of procedures underscore not only the prevalence of conditions such as intervertebral disc herniation, but also the strong belief of surgeons that the operation does provide benefits to patients suffering from sciatica. In spite of this belief, sciatic pain may continue after the surgery. The recurrence of sciatic and/or back pain after primary discectomy is called the "failed back surgery syndrome." The rate of the complications involved in standard lumbar discectomy ranges from 5.4 to 14%. One of the complications of the lumbar disc surgery is nerve root injury. The complication rate of this injury ranges from 0.7 to 2.2%. Postoperative radicular neuroma must be considered in differential diagnosis for the patient who has failed back surgery syndrome. In this study the authors evaluate a patient who had undergone surgery for lumbar disc herniation and suffered intractable pain. A traumatic radicular neuroma is demonstrated and the pertinent literature is presented.

Post-traumatic lumbar nerve root avulsion

Lumbar nerve root avulsion is a rarely seen clinical entity that may complicate major trauma. The majority of previously reported cases have associated pelvic or lumbar vertebral fractures. Two cases of traumatic pseudomeningoceles at the lumbar level with associated avulsions of the lumbar nerve roots are presented. Both patients were involved in high velocity motor vehicle accidents. Case 1 had associated pelvic fractures but no spinal fractures and, interestingly, case 2 had no fractures of the spine or pelvis. The value of MRI in making the diagnosis is demonstrated.

Postoperative magnetic resonance imaging of lumbar disc herniation: comparison of microendoscopic discectomy and Love's method

STUDY DESIGN

We performed a study to compare the magnetic resonance imaging findings up to 24 weeks after microendoscopic discectomy or surgery using Love's method in patients with lumbar disc herniation.

OBJECTIVES

The objective was to determine whether or not microendoscopic discectomy was minimally invasive with respect to the nerve roots, cauda equina, and paravertebral muscles by comparing the postoperative magnetic resonance imaging findings in patients treated by microendoscopic discectomy and the conventional Love's method.

SUMMARY OF BACKGROUND DATA

We introduced microendoscopic discectomy as a minimally invasive surgical procedure for lumbar disc herniation in September 1998 and have obtained good results. Microendoscopic discectomy is superior to the conventional Love's method in that it reduces postoperative pain, shortens the duration of hospitalization, and allows earlier resumption of normal activities. However, the effect of microendoscopic discectomy on the nerves and paravertebral muscles has not been evaluated objectively.

METHODS

Enhancement of the nerve roots and paravertebral muscles, as well as the configuration of the cauda equina at the level of herniation, was assessed on axial magnetic resonance images obtained with contrast enhancement using gadolinium-diethylenetriamine penta-acetic acid before surgery and 1, 4, 8, 12, and 24 weeks after surgery in 25 patients who underwent microendoscopic discectomy and 15 patients who were treated using Love's method.

RESULTS

Increased enhancement of the nerve roots was seen in 50.0% of the microendoscopic discectomy group and 46.2% of the Love group at 1 week after surgery. Enhancement of the paravertebral muscles at the surgical site tended to persist for longer in the microendoscopic discectomy group than in the Love group. However, muscle enhancement was widespread in some patients from the Love group. Abnormalities of the cauda equina attributed to surgical invasion were seen in 12.5% of the microscopic discectomy group and 15.4% of the Love group at 1 week after surgery.

CONCLUSIONS

Microendoscopic discectomy had an effect on the nerve roots and cauda equina that was comparable with that of Love's method. The magnetic resonance images of the route of entry failed to show that microendoscopic discectomy is appreciably less invasive with respect to the paravertebral muscles.

Acute cauda equina syndrome caused by a gas-containing prolapsed intervertebral disk

Gas production as a part of disk degeneration can occur, but it rarely causes clinical nerve compression syndromes. A rare case of gaseous degeneration in a prolapsed lumbar intervertebral disk causing acute cauda equina syndrome is described. Radiologic features and intraoperative findings are reported. A 78-year-old woman with severe lumbar canal stenosis had acute cauda equina syndrome. Magnetic resonance imaging revealed a large disk protrusion, and she underwent an urgent operation for this. Surgery confirmed the severe lumbar canal stenosis, but the disk prolapse contained gas that had caused the nerve compression.

Age, outcome, and rehabilitation costs after paraplegia caused by traumatic injury of the thoracic spinal cord, conus medullaris, and cauda equina

The object of this study was to investigate the relationships of age on neurologic and functional outcome, hospitalization length of stay (LOS), and hospital charges after spinal cord injury (SCI). At 20 medical centers, 2,169 consecutive adult patients with paraplegia SCI were assessed in acute care and inpatient rehabilitation. Outcome and treatment measures included the ASIA motor index score, functional independence measure, discharge to community ratio, LOS, and hospital charges. Age differences were examined by separating the sample into 11 age categories and conducting one-way analyses of variance on treatment, medical expense, and outcome measures that included the Functional Independence Measure (FIM) and ASIA motor index scores. Cramer's statistic was used to derive a chi-square value that indicated whether variables differed significantly in terms of age. Post-hoc Tukey tests were also performed. Age-related differences were found with multiple demographic variables. Significant differences between age categories were found with regard to the following treatment measures: ASIA motor index scores at acute-care admission and at discharge, rehabilitation LOS, inpatient rehabilitation hospitalization charges, total LOS, total hospitalization charges, FIM scores at inpatient rehabilitation admission and discharge, FIM change, and FIM efficiency. In conclusion, in patients with paraplegia, age appears to adversely affect functional outcome, rehabilitation LOS, and hospital costs. However, neurologic recovery as defined by the ASIA motor scores does not appear to be related to age.

MR imaging of the traumatized lumbar spine

MR imaging is the imaging modality of choice for evaluation of the traumatized lumbar spine, providing critical information for determination of appropriate therapy. It is superior to other modalities for evaluating the supporting ligaments, disc, spinal cord, and the cauda equina. Major fracture patterns are readily discernable. Canal compromise caused by osseous fragments, epidural hemorrhage, or disc fragments is well visualized.

Current use and timing of spinal surgery for management of acute spinal surgery for management of acute spinal cord injury in North America: results of a retrospective multicenter study

OBJECT

A multicenter retrospective study was performed in 36 North American centers to examine the use and timing of surgery in patients who have sustained acute spinal cord injury (SCI). The study was performed to obtain information required for the planning of a randomized controlled trial in which early and late decompressive surgery are compared.

METHODS

The records of all patients aged 16 to 75 years with acute SCI admitted to 36 centers within 24 hours of injury over a 9-month period in 1994 and 1995 were examined to obtain data on admission variables, methods of diagnosis, use of traction, and surgical variables including type and timing of surgery. A total of 585 patients with acute SCI or cauda equina injury were admitted to participating centers, although approximately half were ultimately excluded because they did not meet inclusion criteria. Common causes for exclusion were late admission, age, gunshot wound, and absence of signs of compression on imaging studies. Thus, only approximately 50% of patients with acute SCI would be eligible for inclusion in a study of acute decompressive surgery. Although all patients underwent computerized tomography (CT) scanning, only 54% underwent magnetic resonance imaging, and CT myelography was performed in only 6%. Complete neurological injuries (American Spinal Injury Association Grade A) were present in 57.8%. Traction was applied in only 47% of patients who sustained cervical injury, in whom decompressive traction was successful in only 42% of cases. Neurological deterioration occurred in 8.1% of cases after traction. Surgery was performed in 65.4% of patients. The timing of surgery varied widely: less than 24 hours postinjury in 23.5%, between 25 and 48 hours postinjury in 15.8%, between 48 and 96 hours in 19%, and more than 5 days postinjury in 41.7% of patients.

CONCLUSIONS

These data indicate that although surgery is commonly performed in patients with acute SCI, one third of cases are managed nonoperatively, and there is very little agreement on the optimum timing of surgical treatment. The results of this study confirm the need for a randomized controlled trial to assess the optimum timing of decompressive surgery in SCI.

Neurological complications in insufficiency fractures of the sacrum. Three case-reports

Three cases of nerve root compromise in elderly women with insufficiency fractures of the sacrum are reported. Neurological compromise is generally felt to be exceedingly rare in this setting. A review of 493 cases of sacral insufficiency fractures reported in the literature suggested an incidence of about 2%. The true incidence is probably higher since many case-reports provided only scant information on symptoms; furthermore, sphincter dysfunction and lower limb paresthesia were the most common symptoms and can readily be overlooked or misinterpreted in elderly patients with multiple health problems. The neurological manifestations were delayed in some cases. A full recovery was the rule. The characteristics of the sacral fracture were not consistently related with the risk of neurological compromise. In most cases there was no displacement and in many the foramina were not involved. The pathophysiology of the neurological manifestations remains unclear. We suggest that patients with sacral insufficiency fractures should be carefully monitored for neurological manifestations.