Factors affecting neurological outcome in traumatic conus medullaris and cauda equina injuries

Anterior approach for a stab wound with penetrating rebar injury causing incomplete cauda equina syndrome in lumbosacral spine lesion: a case report and literature review

PURPOSE

To report a unique case of incomplete CES following a rebar penetrating injury in perineal region with retro-pulsed fragment, which was treated with anterior approach and discuss suitable surgical approach.

METHODS

Incomplete cauda equina syndrome caused by non-missile penetrating injury is extremely rare. A 26-year-old male patient presented incomplete cauda equina syndrome due to a penetrating rebar wound from his perineal region to the lumbosacral spine. Computed tomography demonstrated a bony fragment broken from S1 body compressing into the spinal canal.

RESULTS

By anterior approach, we performed partial corpectomy of L5, decompression by retrieving the bony fragment and L5-S1 interbody fusion. The patient had a significant recovery, and no clinical complication was found after over 2-year follow-up.

CONCLUSION

It is challenging to determine the optimal strategy of surgical treatment for penetrating spinal injuries with retained foreign bodies, here we suggest an anterior approach situation that has the advantage of being able to effectively perform decompression and prevent iatrogenic damages of thecal sac and nerve rootlets.

High-Riding Conus Medullaris Syndrome: A Case Report and Literature Review-Its Comparison with Cauda Equina Syndrome

INTRODUCTION

Conus medullaris syndrome (CMS) is a distinctive spinal cord injury (SCI), which presents with varying degrees of upper motor neuron signs (UMNS) and lower motor neuron signs (LMNS). Herein, we present a case with a burst fracture injury at the proximal Conus Medullaris (CM).

CASE PRESENTATION

A 48-year-old Taiwanese male presenting with lower back pain and paraparesis was having difficulty standing independently after a traumatic fall. An Imaging survey showed an incomplete D burst fracture of the T12 vertebra. Posterior decompression surgery was subsequently performed. However, spasticity and back pain persisted for four months after surgical intervention. Follow-up imaging with single photon emission computed tomography (SPECT) and a whole body bone scan both showed an increased uptake in the T12 vertebra.

CONCLUSION

The high-riding injury site for CMS is related to a more exclusive clinical representation of UMNS. Our case's persistent UMNS and scintigraphy findings during follow-up showcase the prolonged recovery period of a UMN injury. In conclusion, our study provides a different perspective on approaching follow-up for CM injuries, namely using scientigraphy techniques to confirm localization of persistent injury during the course of post-operative rehabilitation. Furthermore, we also offered a new technique for analyzing the location of lumbosacral injuries, and that is to measure the location of the injury relative to the tip of the CM. This, along with clinical neurological examination, assesses the extent to which the UMN is involved in patients with CMS, and is possibly a notable predictive tool for clinicians for the regeneration time frame and functional outcome of patients with lumbosacral injuries in the future.

Bladder and Bowel Dysfunction due to a Spontaneous Spinal Epidural Hematoma Without Paraplegia: A Case Report

CASE

A 44-year-old man developed urinary retention due to a spontaneous spinal epidural hematoma (SSEH) at the cervicothoracic junction, without paraplegia. Symptoms improved with surgical treatment.

CONCLUSION

SSEH is rare and causes acute neck or back pain and progressive paralysis. Patients with advanced myelopathy due to spinal cord compression lesion including SSEH often present with bladder and bowel disorders after exacerbation of quadriplegia. However, SSEH can cause predominant bladder and bowel disorders without paraplegia or quadriplegia. Physicians should consider that there can be a manifestation of myelopathy with bladder and bowel dysfunction without quadriplegia.

Non-traumatic spinal cord infarction of the conus medullaris in a child: a case report

INTRODUCTION

The etiologies of pediatric spinal cord infarction are commonly cardiovascular problems resulting from hypotensive events from trauma and abdominal aortic surgery. Non-traumatic spinal cord infarction in children is rare and remains difficult to diagnose. We report a case of non-traumatic spinal cord infarction of the conus medullaris in a child who recovered after receiving only rehabilitative treatment.

CASE PRESENTATION

A 12-year-old female patient experienced sudden low back pain for 2 days, followed by weakness in the lower extremities and difficulties in micturition. On admission, magnetic resonance imaging indicated spinal cord infarction of the conus medullaris. After initial treatment with prednisone and mannitol, a few weeks of intensive rehabilitation was recommended. Physical therapy focused on improving lower limb strength. A plastic solid ankle-foot orthosis was used with Lofstrand crutches throughout the period of rehabilitation. After 2 months of rigorous therapy, she was able to walk independently.

DISCUSSION

Non-traumatic spinal cord infarction of the conus medullaris in children is extremely rare. The current case is unique because it involves a patient who presented with pediatric spinal cord infarction of the conus medullaris and showed remarkable neurological recovery after rehabilitation. The case describes a rare spinal cord infarction in a pediatric patient and emphasizes the importance of providing an accurate diagnosis and treatment.

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.

Surgical outcomes in thoracolumbar fractures with pure conus medullaris syndrome

Background

Pure conus medullaris syndrome is defined as a combination of signs and symptoms of bladder/bowel incontinence and impotence without the presence of lower limbs weakness. The purpose of the study is to assess the recovery of voiding, sexual, and sensory function in patients with isolated conus medullaris syndrome after surgical treatments.

Methods

From January 2005 to December 2012, patients with a single level burst fracture with pure conus medullaris syndrome were assessed. Level of injury, use of steroid, surgical time, surgical approach, preoperative radiographic parameters, and types of neurogenic bladder were recorded. Bladder function was evaluated using urodynamic study; sexual function was assessed by self-report questionnaire. The final outcomes were focused on the recovery of voiding, sexual, and sensory function.

Results

Eight patients met the criteria of pure conus medullaris syndrome with thoracolumbar burst fracture. The injury level were all located at L1 vertebra. There were 6 males and 2 females. Four patients had overactive neurogenic bladder, and the other 4 patients had underactive type. At final, five patients regained self-voiding function, and three required intermittent catheterization. Two male patients were sexually active, and four male patients had some sexual dysfunction. Two female patients could have normal sexual intercourse but the frequency decreased. One female patients had prolonged perineum numbness at final follow-up.

Conclusions

Although extremely rare, pure conus medullaris syndrome may occur with L1 burst fracture. Despite surgical treatment, only one half of the patients regained normal bladder and sexual function.

Heterogeneity among traumatic spinal cord injuries at the thoracolumbar junction: helping select patients for clinical trials

Study design

Retrospective analysis.

Setting

China Rehabilitation Research Center, Beijing, China.

Objective

A retrospective study that documents the modalities and clarifies the heterogeneity among spinal cord injuries (SCIs) caused by trauma to the thoracolumbar vertebral junction.

Methods

X-ray and MRI imaging, neurological records, and the urodynamics results of 190 patients were reviewed and used to categorize different SCI modalities. First, injuries were divided into complete and incomplete injuries using the International Standard for Neurological Classification of Spinal Cord Injury. Next, the complete injuries were further grouped using the neurological level of injury and Long T2 signal from mid-sagittal MRI images, whereas the bulboconvernosus reflexes were also used as a reference to detect injury to the sacral cord.

Results

The SCI modalities were classified into five categories: pure complete epiconus lesion with caudal cord intact (G1), complete epiconus injury with conus medullaris (CM) totally involved in the lesion (G2), CM syndrome, cauda equine syndrome without sacral sparing (G3 and G4), and incomplete injury (G5).

Conclusions

The heterogeneity of SCIs at the thoracolumbar junction was documented, a criterion we propose to be of great significance when selecting patients for clinical trials. In particular, the G2 group, which comprises nearly one third of the patients with epiconus lesions, is sometimes mistaken as G1, an observation that has thus far received insufficient attention.

Impact of bladder, bowel and sexual dysfunction on health status of people with thoracolumbar spinal cord injuries living in the community

OBJECTIVE

The disruption of autonomic function following a spinal cord injury (SCI) is common and can negatively affect quality of life. The objective of this study was to describe the prevalence of bladder/bowel incontinence and sexual dysfunction in community-dwelling individuals with a thoracolumbar SCI and examine the impact on general physical and mental health status.

METHODS

Participants who sustained a traumatic SCI to the thoracolumbar region of the spinal cord and classified as American Spinal Injury Association Impairment Scale (AIS) A to D were recruited. Demographic, injury data, MRI classification and neurological data were collected on admission. At follow-up, the neurological data, a questionnaire collecting participant-reported secondary health conditions (SHCs) (e.g. bladder incontinence, depression etc.) following SCI and health status measured by Short Form-36 were obtained. Regression models determined the association of health status with demographic/injury-related data, types and number of SHCs.

RESULTS

Of the 51 participants, 58.8% reported bladder incontinence, 54.0% bowel incontinence, 60.8% sexual dysfunction and 29.4% had all three. The regression models demonstrated that age at injury, bowel incontinence, sexual dysfunction, presence of pain, motor score at follow-up and the number of SHCs were significant predictors of health status. The number of SHCs was more predictive than all other demographic and injury variables for health status.

CONCLUSION

Results highlight the high prevalence of self-reported bowel/bladder incontinence and sexual dysfunction in the traumatic thoracolumbar SCI population and support the need for standardized assessments. Several demographic, injury-related and SHCs impacted health status and should be considered for the management of individuals living in the community.

Traumatic Conus Medullaris Syndrome: A Case Report and Review of the Literature

CASE

A twenty-six-year-old man was diagnosed with conus medullaris syndrome (CMS) after sustaining a traumatic L1 burst fracture. Surgical decompression and stabilization was performed within ninety-six hours of admission; postoperatively, normal bladder function rapidly returned.

CONCLUSION

CMS is difficult to diagnose because of the clinically variable presentation. There is no consensus regarding the natural history of conus medullaris injury or regarding the necessity, approach, or timing for decompression. Higher-level evidence is needed to guide treatment for acute traumatic CMS.

Can MRI Findings Help to Predict Neurological Recovery in Paraplegics With Thoracolumbar Fracture?

Objective

To evaluate the usefulness of various magnetic resonance imaging (MRI) findings in the prognosis of neurological recovery in paraplegics with thoracolumbar fracture using association analysis with clinical outcomes and electrodiagnostic features.

Methods

This retrospective study involved 30 patients treated for paraplegia following thoracolumbar fracture. On axial and sagittal T2-weighted MRI scans, nerve root sedimentation sign, root aggregation sign, and signal intensity changes in the conus medullaris were independently assessed by two raters. A positive sedimentation sign was defined as the absence of nerve root sedimentation. The root aggregation sign was defined as the presence of root aggregation in at least one axial MRI scan. Clinical outcomes including the American Spinal Injury Association impairment scale, ambulatory capacity, and electrodiagnostic features were used for association analysis.

Results

Inter-rater reliability of the nerve root sedimentation sign and the root aggregation sign were κ=0.67 (p=0.001) and κ=0.78 (p<0.001), respectively. A positive sedimentation sign was significantly associated with recovery of ambulatory capacity after a rehabilitation program (χ²=4.854, p=0.028). The presence of the root aggregation sign was associated with reduced compound muscle action potential amplitude of common peroneal and tibial nerves in nerve conduction studies (χ²=5.026, p=0.025).

Conclusion

A positive sedimentation sign was significantly associated with recovery of ambulatory capacity and not indicative of persistent paralysis. The root aggregation sign suggested the existence of significant cauda equina injuries.

Missed Cauda Equina Syndrome after Burst Fracture of the Lumbar Spine

Cauda equina syndrome (CES) is often defined as a complex of symptoms and signs consisting of low back pain, bilateral sciatica, lower extremity weakness, saddle anesthesia, and bowel and bladder dysfunction. CES is considered to be neurosurgical emergency. Delayed or missed diagnosis of CES can result in serious morbidity and neurological sequelae. However, the diagnosis of CES is often difficult when one or more of these symptoms are absent or when these symptoms develop asymmetrically or incompletely. We report a case of urinary retention and sphincter dysfunction without sciatica or motor weakness following an L3 burst fracture in a 52-year-old male and discuss the atypical presentation of CES and treatment of traumatic CES.

Innervation and function of rat tail muscles for modeling cauda equina injury and repair

INTRODUCTION

The rat tail exhibits functional impairment after cauda equina injury. Our goal was to better understand the innervation and roles of muscles that control the tail.

METHODS

Adult rats received either: (1) ventral root injury; (2) caudales nerve injury; or (3) mapping of sacrococcygeal myotomes. Activation of small muscles within the tail itself (intrinsics) was compared with that of larger lumbosacral muscles acting on the tail (extrinsics). Behavioral testing of tail movement was done 1 week later.

RESULTS

Rats that received ventral root injury exhibited multiple behavioral deficits, whereas rats with injury to caudales nerves maintained more fully preserved tail movement. Mapping studies revealed much broader overlap of myotomes for extrinsic muscles.

CONCLUSIONS

Extrinsic tail muscles play a greater role in tail movement in the rat than their intrinsic counterparts and are innervated by multiple neurological segments. These findings have major implications for future research on cauda equina injury.

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.

The relationship between the duration of acute cauda equina compression and functional outcomes in a rat model

STUDY DESIGN

Immunohistochemical and behavioral study using a rat model of acute cauda equina syndrome (CES).

OBJECTIVE

To determine the effect of duration of extradural cauda equina compression (CEC) on bladder, sensory, and motor functions.

SUMMARY OF BACKGROUND DATA

Cauda equina syndrome is a devastating injury treated with surgical decompression. Controversy exists regarding the optimal timing of surgery. Animal models of CES have focused on motor recovery but have not evaluated pain behavior or bladder function.

METHODS

A 4-mm balloon-tipped Fogarty catheter was inserted between the fifth and sixth lumbar lamina into the dorsal epidural space and inflated to compress the nerve roots at the L5 level. Maximal inflation was maintained at a constant balloon pressure of 304 Kpa for 1 or 4 hours. The catheter was inserted but not inflated in sham animals. During a 4-week period, pain behavior, bladder function, and locomotor function were assessed. Postmortem bladders and the lesion site were collected for analysis.

RESULTS

Mechanical allodynia was 2-fold greater in 1-hour CEC rats than 4-hour CEC (P=0.002) and sham-operated (P=0.001) rats at 4 weeks after injury. Hind limb locomotor function was not different between groups at 4 weeks after injury. Both the 1-hour and 4-hour CEC group rats retained greater volumes of urine than the sham-operated rats throughout the 4-week period (P<0.05). At 4 weeks, bladder weight and volume were 2-fold greater in the 4-hour CEC group than in the 1-hour CEC group (P=0.006 and P=0.01, respectively). Histology of the bladder wall revealed an overall thinning after 4-hour CEC. Histology of the lesion site revealed a greater overall severity of injury after 4-hour CEC than after 1-hour CEC (P=0.04) and sham operation (P=0.002).

CONCLUSION

Our data suggest that recovery of motor function is less affected by the timing of decompression compared with bladder function and pain behavior. Early decompression preserved bladder function but was associated with allodynia.

LEVEL OF EVIDENCE

N/A.

Implantation of cauda equina nerve roots through a biodegradable scaffold at the conus medullaris in rat

BACKGROUND CONTEXT

Traumatic injuries occurring at the conus medullaris of the spinal cord cause permanent damage both to the central nervous system and to the cauda equina nerve roots.

PURPOSE

This proof-of-concept study was to determine whether implanting the nerve roots into a biodegradable scaffold would improve regeneration after injury.

METHODS

All experimental works involving rats were performed according to the approved guidelines by the Mayo Clinic Institutional Animal Care and Use Committee. Surgical procedures were performed on 32 Sprague-Dawley rats. Four ventral cauda equina nerve roots were reimplanted either directly into the ventral cord stump or through a poly(lactic-co-glycolic acid) (PLGA) scaffold. These experimental groups were compared with a control group in which the nerves were inserted into a muscle fascia barrier that was placed between the spinal cord and the nerve roots. Animals were sacrificed at 4 weeks.

RESULTS

There was no difference in motor neuron counts in the spinal cord rostral to the injury in all treatment groups, implying equal potential for the regeneration into implanted nerve roots. One-way analysis of variance testing, with Tukey post hoc test, showed a statistically significant improvement in axon regeneration through the injury in the PLGA scaffold treatment group compared with the control (p<.05, scaffold n=11, control n=11).

CONCLUSIONS

This pilot study demonstrated that a PLGA scaffold improved regeneration of axons into peripheral nerve roots. However, the number of regenerating axons observed was limited and did not lead to functional recovery. Future experiments will employ a different scaffold material and possible growth factors or enzymes to increase axon populations.

Neurotraumatology

Neurotraumatology has its roots in ancient history, but its modern foundations are the physical examination, imaging to localize the pathology, and thoughtful medical and surgical decision making. The neurobiology of cranial and spinal injury is similar, with the main goal of therapies being to limit secondary injury. Brain injury treatment focuses on minimizing parenchymal swelling within the confined cranial vault. Spine injury treatment has the additional consideration of spinal coumn stability. Current guidelines for non-operative and operative management are reviewed in this chapter.

Improvement in chronic low back pain in an aviation crash survivor with adjacent segment disease following flexion distraction therapy: a case study

OBJECTIVE

The purpose of this case study is to describe the chiropractic management of chronic low back pain in a patient with adjacent segment disease.

CLINICAL FEATURES

The patient was a 30-year-old man with a 3-year history of chronic nonspecific low back pain following a lumbar disk herniation. Two years before this incident, he had severe lumbar fractures and cauda equina injury due to an aviation accident that required multilevel lumbar fusion surgery, vertebrectomy, and cage reconstruction.

INTERVENTION AND OUTCOME

The patient received chiropractic management using Cox Flexion Distraction over a 4-week period. A complete reduction of symptoms to 0/10 on a verbal numerical rating scale was achieved within 4 weeks. At 3 months, the patient was able to work 8 to 9 hours per day in his dental practice with no pain. At 9 months, the patient continued to report a complete reduction of symptoms.

CONCLUSIONS

This report describes the successful management of a patient with chronic low back pain associated with adjacent segment disease using Cox Flexion Distraction protocols.

Current management review of thoracolumbar cord syndromes

BACKGROUND CONTEXT

Injuries to the thoracolumbar spine may lead to a complex array of clinical syndromes that result from dysfunction of the anterior motor units, lumbosacral nerve roots, and/or spinal cord. Neurologic dysfunction may manifest in the lower extremities as loss of fine and gross motor function, touch, pain, temperature, and proprioceptive and vibratory sense deficits. Two clinical syndromes sometimes associated with these injuries are conus medullaris syndrome (CMS) and cauda equina syndrome (CES).

PURPOSE

To review the current management of thoracolumbar spinal cord injuries.

STUDY DESIGN

Literature review.

METHODS

Index Medicus was used to search the primary literature for articles on thoracolumbar injuries. An emphasis was placed on the current management, controversies, and newer treatment options.

RESULTS/CONCLUSIONS

After blunt trauma, these syndromes may reflect a continuum of dysfunction rather than a distinct clinical entity. The transitional anatomy at the thoracolumbar junction, where the conus medullaris is present, makes it less likely that a "pure" CMS or CES syndrome will occur and more likely that a "mixed" injury will. Surgical decompression is the mainstay of treatment for incomplete spinal cord injury (SCI) and incomplete CMS and CES. The value of timing of surgical intervention in the setting of incomplete SCI is unclear at this time. This review summarizes the recent information on epidemiology, pathophysiology, diagnosis, and controversies in the management of thoracolumbar neurologic injury syndromes.

Spine trauma

Spinal fractures represent 3% to 6% of all skeletal injuries. Spine trauma is a complex diagnostic area in which the radiological assessment is crucial. Plain radiography is often used as the initial diagnostic modality. However, stabilization of the acutely injured spine is a primary concern. In this respect, computed tomography (CT) is vastly superior to plain film in terms of speed and accuracy. In many trauma centers, CT has replaced plain film as the primary modality for evaluation of spinal trauma. Magnetic resonance imaging is not indicated for all cases of spinal trauma but provides detailed information about soft tissue structures including the intervertebral disc, the ligaments, the epidural space, the blood vessels, and the spinal cord. MR imaging provides information on these structures not obtained from other modalities. Patients with spinal cord injury may suffer devastating long-term neurologic deficits, so prompt and efficient spinal imaging guidelines are necessary in all trauma centers.

Cowherd's injury: Traumatic retrospondyloptosis of L1 over L2 in a 7-year-old child

Traumatic retrolisthesis of the first lumbar vertebra is a rare injury and only one case has been documented in the literature. We report a case of traumatic retrolisthesis of the first lumbar vertebra in a 7-year old child. He was injured after being dragged by a cow and presented with Frenkel grade A paraplegia. His plain radiographs revealed complete retrolisthesis of the first lumbar vertebra over the second. The patient was treated surgically with open reduction and sublaminar wire loop rectangle fixation. The patient showed Frankle grade D (Frankle grade) neurological recovery in the postoperative period over a period of 15 months. This case is reported in view of rarity and mechanism of injury is described.

Relationship of neural axis level of injury to motor recovery and health-related quality of life in patients with a thoracolumbar spinal injury

BACKGROUND

Outcomes following traumatic conus medullaris and cauda equina injuries are typically predicted on the basis of the vertebral level of injury. This may be misleading as it is based on the assumption that the conus medullaris terminates at L1 despite its variable location. Our primary objective was to determine whether the neural axis level of injury (the spinal cord, conus medullaris, or cauda equina) as determined with magnetic resonance imaging is better than the vertebral level of injury for prediction of motor improvement in patients with a neurological deficit secondary to a thoracolumbar spinal injury.

METHODS

Patients diagnosed with a motor deficit secondary to a thoracolumbar spinal injury, and who met the inclusion criteria, were contacted. Each patient had a magnetic resonance imaging scan that was reviewed by a spine surgeon and a neuroradiologist to determine the termination of the conus medullaris and the neural axis level of injury. Patient demographic data were collected prospectively at the time of admission. Admission and follow-up neurological assessments were performed by formally trained dedicated spine physiotherapists.

RESULTS

Fifty-one patients were evaluated at a median of 6.2 years (range, 2.7 to 12.3 years) postinjury. The final motor scores differed significantly according to whether the patient had a spinal cord injury (mean, 62.8 points; 95% confidence interval, 55.4 to 70.2), conus medullaris injury (mean, 78.6 points; 95% confidence interval, 70.3 to 86.9), or cauda equina injury (mean, 88.8 points; 95% confidence interval, 78.9 to 98.7) (p = 0.0007). A univariate analysis showed the improvement in the motor scores after the cauda equina injuries (mean, 17.1 points; 95% confidence interval, 8.3 to 25.9) to be significantly greater than that after the spinal cord injuries (mean, 7.7 points; 95% confidence interval, 3.1 to 12.3) (p = 0.03). A multivariate analysis showed that an absence of initial sacral sensation had a negative effect on motor recovery by a factor of 13.2 points (95% confidence interval, 4.2 to 22.1). When compared with classifying our patients on the basis of the neural axis level of injury, reclassifying them on the basis of the vertebral level of injury resulted in a misclassification rate of 33%.

CONCLUSIONS

The motor recovery of patients with a thoracolumbar spinal injury and a neurological deficit is affected by both the neural axis level of injury as well as the initial motor score. The results of this study can help the clinician to determine a prognosis for patients who sustain these common injuries provided that he or she evaluates the precise level of neural axis injury utilizing magnetic resonance imaging.

An atypical ballistic traumatic cauda equina syndrome with a positive outcome. Focus on prognostic factors

INTRODUCTION

Traumatic cauda equina syndromes due to projectile wounds often have a poor prognosis. We report on an unusual ballistic cauda equina traumatism with a good functional outcome.

CLINICAL CASE

A 44-year-old man was admitted to emergency room for an incomplete cauda equina syndrome after trying to kill himself by means of a pneumatic nail gun. The nail had gone right through the third lumbar vertebra. Because of the stability of the fracture, orthopaedic surgery was not indicated. Neurological recovery was progressive. At 6 months, there was still a partial L5-S1 motor deficit on the left side but the patient could walk without crutches, and within an unlimited walking distance.

DISCUSSION

Initial imaging displayed a projectile trajectory focused on the spinal canal on level L3, which could have been considered as bad prognosis. The positive analytic and functional outcome correlates with the limited neurological tissue damage, probably explained by the ballistic properties of the projectile.

CONCLUSION

Apart from the influence of a possible surgical act, the neurological and functional prognosis of a traumatic cauda equina syndrome caused by a projectile also depends on its physical characteristics.