We report the case of a patient with metastatic hormone refractory prostate cancer in whom “indirect” cauda equina syndrome developed concurrent with multilevel spinal cord compression (SCC). Three months after his first positive bone scan, a 65-year-old otherwise healthy man presented with severe back pain, bilateral lower extremity paresthesias, leg weakness and urinary retention. Magnetic resonance imaging (MRI) showed a dural-based mass causing SCC at the T9, T10 and T11 vertebrae, with a normal cauda equina. He received corticosteroids and palliative external beam radiotherapy, resulting in good pain control and gradual improvement in his neurological symptoms. He did well for 8 months, at which time his residual bilateral leg weakness abruptly worsened and he experienced numbness, paresthesias, urinary incontinence and constipation. Repeat MRI showed progression of epidural metastatic disease compressing the spinal cord or thecal sac at 7 thoracic vertebral levels. The cauda equina was also distorted and flattened without evidence of direct solid tumour impingement. We hypothesized that the etiology was increased intrathecal pressure due to disrupted cerebrospinal fluid flow resulting from multiple levels of upstream thecal sac compression. It is essential to image the entire spinal cord and cauda equina when patients with metastatic bone disease present with neurological symptoms to institute correct treatment and preserve function and mobility.
There is no validated gold-standard diagnostic support tool for LSS, and therefore an accurate diagnosis depends on clinical assessment. Assessment of the diagnostic value of the history of the patient requires an evaluation of the differences and overlap of symptoms of the radicular and cauda equina types; however, no tool is available for evaluation of the LSS category. We attempted to develop a self-administered, self-reported history questionnaire as a diagnostic support tool for LSS using a clinical epidemiological approach. The aim of the present study was to use this tool to assess the diagnostic value of the history of the patient for categorization of LSS.
The initial derivation study included 137 patients with LSS and 97 with lumbar disc herniation who successfully recovered following surgical treatment. The LSS patients were categorized into radicular and cauda equina types based on history, physical examinations, and MRI. Predictive factors for overlapping symptoms between the two types and for cauda equina symptoms in LSS were derived by univariate analysis. A self-administered, self-reported history questionnaire (SSHQ) was developed based on these findings. A prospective derivation study was then performed in a series of 115 patients with LSS who completed the SSHQ before surgery. All these patients recovered following surgical treatment. The sensitivity of the SSHQ was calculated and clinical prediction rules for LSS were developed. A validation study was subsequently performed on 250 outpatients who complained of lower back pain with or without leg symptoms. The sensitivity and specificity of the SSHQ were calculated, and the test-retest reliability over two weeks was investigated in 217 patients whose symptoms remained unchanged.
The key predictive factors for overlapping symptoms between the two categories of LSS were age > 50, lower-extremity pain or numbness, increased pain when walking, increased pain when standing, and relief of symptoms on bending forward (odds ratio ≥ 2, p < 0.05). The key predictive factors for cauda equina type symptoms were numbness around the buttocks, walking almost causes urination, a burning sensation around the buttocks, numbness in the soles of both feet, numbness in both legs, and numbness without pain (odds ratio ≥ 2, p < 0.05). The sensitivity and specificity of the SSHQ were 84% and 78%, respectively, in the validation data set. The area under the receiver operating characteristic curve was 0.797 in the derivation set and 0.782 in the validation data set. In the test-retest analysis, the intraclass correlation coefficient for the first and second tests was 85%.
A new self-administered, self-reported history questionnaire was developed successfully as a diagnostic support tool for LSS.
Although the most common aetiology of cauda equina lesions is lumbar intervertebral disc herniation, iatrogenic lesions may also be the cause. The aim of this study was to identify and present patients in whom cauda equina lesions occurred after spinal surgery. From the author’s series of patients with cauda equina lesions, those with the appearance of sacral symptoms after spinal surgery were identified. To demonstrate lesions more objectively, electrodiagnostic studies were performed in addition to history and clinical examination. Imaging studies were also reviewed. Of 69 patients from the series, 11 patients in whom a cauda equina lesion developed after spinal surgery were identified. The aetiology comprised surgery for herniated intervertebral disc in 5 (4 performed by a single surgeon), spinal stenosis surgery in 4, and postoperative lumbar epidural haematoma in 2 patients (each performed by a different surgeon). Proportion of spinal surgeries with this complication varied from 0 to 6.6‰ in different centres. Patients with iatrogenic cauda equina lesion were significantly older (p < 0.001), and reported more severe urinary, but similar bowel and sexual symptoms compared to other patients in the series. In conclusion the study identified spinal surgery as the cause of approximately 15% of cauda equina lesions. More than a third of lesions developed after procedures performed by a single surgeon. Most of the remaining lesions could probably be avoided by better surgical technique (e.g. the use of a high-speed drill instead of a Kerrison rongeur in patients with severe spinal stenosis), or prevented by closer postoperative monitoring (e.g. in patients with postoperative lumbar epidural haematoma).
Cauda equina; Disc herniation; Spinal stenosis; Spinal surgery; Sacral
This study is a prospective, clinical study assessing the efficacy of selective decompression of the level responsible in a two-level stenosis in accordance with the neurological findings defined by the gait load test with a treadmill.
To clarify the clinical features of multilevel lumbar spinal stenosis (LSS) regarding the neurological level responsible for the symptoms, neurogenic claudication, and outcomes of selective decompression.
Overview of Literature
Most spine surgeons have reported that multilevel compression of the cauda equina induces a more severe impairment of the nerve function than a single-level compression. However, the clinical effects of multilevel LSS on the cauda equine and nerve roots are unknown.
A total of 21 patients with lumbar spinal canal stenosis due to spondylosis and degenerative spondylolisthesis were selected. The level responsible for the symptoms in the two-level stenosis was determined from the neurological findings on the gait load test and functional diagnosis based on a selective nerve root block. All patients underwent a prospective, selective decompression at the level neurologically responsible only. The average follow-up period was 2.6 years (range, 1 to 6 years). The postsurgical outcome was defined using the Visual Analogue Scale (VAS) at the post-gait load test, 2 weeks after surgery, 3 months after surgery and at the last follow up.
Before surgery, the mean threshold distance and mean walking tolerance was 34.3 m and 113 m, respectively. All patients had neurogenic claudication and 19 of the patients had cauda equina syndrome, including hypesthesia in 11 cases, muscle weakness in 5 cases and radicular pain in 7 cases. Selective nerve blocks to determine the level responsible for the lumbosacral symptoms in 2 cases revealed a mean VAS score of 7.1, 2.61, 3.04, and 3.47 at the post-gait load test, 2 weeks after surgery, 3 months after surgery and at the last follow up, respectively. All subjects underwent surgery. After the operation, neurogenic claudication with or without cauda equna syndrome subsided in all patients.
The gait load test allows an objective and quantitative evaluation of the gait characteristics of patients with lumbar canal stenosis and is useful for determining the appropriate level for surgical treatment.
Gait load test; Neurogenic claudication; Lumbar canal stenosis
Spinal epidural hematoma is a well known complication of spinal surgery. Clinically insignificant small epidural hematomas develop in most spinal surgeries following laminectomy. However, the incidence of clinically significant postoperative spinal epidural hematomas that result in neurological deficits is extremely rare. In this report, we present a 33-year-old female patient whose spinal surgery resulted in postoperative spinal epidural hematoma. She was diagnosed with lumbar disc disease and underwent hemipartial lumbar laminectomy and discectomy. After twelve hours postoperation, her neurologic status deteriorated and cauda equina syndrome with acute spinal epidural hematoma was identified. She was immediately treated with surgical decompression and evacuation of the hematoma. The incidence of epidural hematoma after spinal surgery is rare, but very serious complication. Spinal epidural hematomas can cause significant spinal cord and cauda equina compression, requiring surgical intervention. Once diagnosed, the patient should immediately undergo emergency surgical exploration and evacuation of the hematoma.
Perineural cysts of the sacrum, or Tarlov cysts, are cerebrospinal fluid (CSF)-filled sacs that commonly occur at the intersection of the dorsal root ganglion and posterior nerve root in the lumbosacral spine. Although often asymptomatic, these cysts have the potential to produce significant symptoms, including pain, weakness, and/or bowel or bladder incontinence. We present a case in which the sacral roof is removed and reconstructed via plated laminoplasty and describe how this technique could be of potential use in maximizing outcomes.
We describe technical aspects of a sacral laminoplasty in conjunction with cyst fenestration for a symptomatic sacral perineural cyst in a 50-year-old female with severe sacral pain, lumbosacral radiculopathy, and progressive incontinence. This patient had magnetic resonance imaging (MRI) and computed tomography (CT)-myelographic evidence of a non-filling, 1.7 × 1.4 cm perineural cyst that was causing significant compression of the cauda equina and sacral nerve roots. This surgical technique was also employed in a total of 18 patients for symptomatic tarlov cysts with their radiographic and clinical results followed in a prospective fashion.
Intraoperative images, drawings, and video are presented to demonstrate both the technical aspects of this technique and the regional anatomy. Postoperative MRI scan demonstrated complete removal of the Tarlov cyst. The patient's symptoms improved dramatically and she regained normal bladder function. There was no evidence of radiographic recurrence at 12 months. At an average 16 month followup interval 10/18 patients had significant relief with mild or no residual complaints, 3/18 reported relief but had persistent coccydynia around the surgical area, 2/18 had primary relief but developed new low back pain and/or lumbar radiculopathy, 2/18 remained at their preoperative level of symptoms, and 1/18 had relief of their preoperative leg pain but developed new pain and neurological deficits.
Sacral laminoplasty and microscopic cystic fenestration is a feasible approach in the operative treatment of this difficult, and often controversial, spinal pathology. This technique may be used further and studied in an attempt to minimize potential surgical morbidity, including CSF leaks, cyst recurrence, and sacral insufficiency fractures.
Laminoplasty; perineural cyst; sacral; Tarlov cyst
Incidental or intentional durotomy causing cerebrospinal fluid (CSF) leakage, leading to the formation of a pseudomeningocele is a known complication in spinal surgery. Herniation of nerve roots into such a pseudomeningocele is very rare, but can occur up to years after initial durotomy and has been described to cause permanent neurologic deficit. However, cauda equina fiber herniation and entrapment into a pseudomeningocele has not been reported before. Here, we present a case of symptomatic transdural cauda equina herniation and incarceration into a pseudomeningocele, 3 months after extirpation of a lumbar Schwannoma. A 59-year-old man, who previously underwent intradural Schwannoma extirpation presented 3 months after surgery with back pain, sciatica and loss of bladder filling sensation caused by cauda equina fiber entrapment into a defect in the wall of a pseudomeningocele, diagnosed with magnetic resonance imaging. On re-operation, the pseudomeningocele was resected and the herniated and entrapped cauda fibers were released and replaced intradurally. The dura defect was closed and the patient recovered completely. In conclusion, CSF leakage can cause neurological deficit up to years after durotomy by transdural nerve root herniation and subsequent entrapment. Clinicians should be aware of the possibility of this potentially devastating complication. The present case also underlines the importance of meticulous dura closure in spinal surgery.
Pseudomeningocele; Dura defect; Nerve root entrapment
A case of cauda equina lesion as a result of recurrent adjacent segment degeneration (ASD) after multiple lumbar fusions is reported. ASD might be a consequence of biomechanical overload or simply a normal degenerative process. The reported clinical relevance of ASD is rather low. We describe an unusual case of cauda equina compression at L1–L2 in a patient who had undergone L2–L4 fusion 8 years previously and 2 decompression-fusion surgeries 16 years before.
Materials and methods
A 72-year-old man, who had two previous lumbar fusion–decompression procedures, underwent a third lumbar surgery in December 2000 to treat symptomatic spinal canal stenosis associated with L3–L4 pseudoarthrosis. After a symptom-free period of 8 years, the patient experienced low back pain radiating to both legs while standing, associated with saddle sensory disturbances and incontinence. Physical examination ruled out significant motor deficits. Plain radiographs showed solid fusion from L2 to L4, good spinal alignment, and low-grade L1–L2 retrolisthesis. Stainless steel pedicular instrumentation distorted magnetic resonance imaging, preventing adequate spinal canal evaluation. Electromyography demonstrated signs of cauda equina compression (bilateral L3–S2). CT myelography showed a stop at L1–L2, due to a severe spinal canal stenosis. L1–L2 decompression and fusion were performed.
After an uneventful surgery with no complications, the symptoms abated and incontinence recovered.
Even if the reported clinical relevance of ASD is very low, fused patients with a constitutional narrow spinal canal are at risk of developing severe neural compression at the level adjacent to the fusion.
Recurrent disease; Adjacent segment; Cauda equina; Degenerative changes; Narrow spinal canal
A 55-year-old obese man (body mass index, 31.6 kg/m2) presented radiating pain and motor weakness in the left leg. Magnetic resonance imaging showed an epidural mass posterior to the L5 vertebral body, which was isosignal to subcutaneous fat and it asymmetrically compressed the left side of the cauda equina and the exiting left L5 nerve root on the axial T1 weighted images. Severe arthritis of the left facet joint and edema of the bone marrow regarding the left pedicle were also found. As far as we know, there have been no reports concerning a solitary epidural lipoma combined with ipsilateral facet arthorsis causing lumbar radiculopathy. Solitary epidural lipoma with ipsilateral facet arthritis causing lumbar radiculopathy was removed after the failure of conservative treatment. After decompression, the neurologic deficit was relieved. At a 2 year follow-up, motor weakness had completely recovered and the patient was satisfied with the result. We recommend that a solitary epidural lipoma causing neurologic deficit should be excised at the time of diagnosis.
Solitary epidural lipoma; Posterior facet; Ipsilateral arthritis; Lumbar radiculopathy
Background and purpose
Cauda equina syndrome (CES) is a severe complication of lumbar spinal disorders; it results from compression of the nerve roots of the cauda equina. The purpose of this study was to evaluate the clinical usefulness of a classification scheme of CES based on factors including clinical symptoms, imaging signs, and electrophysiological findings.
The records of 39 patients with CES were divided into 4 groups based on clinical features as follows. Group 1 (preclinical): low back pain with only bulbocavernosus reflex and ischiocavernosus reflex abnormalities. Group 2 (early): saddle sensory disturbance and bilateral sciatica. Group 3 (middle): saddle sensory disturbance, bowel or bladder dysfunction, motor weakness of the lower extremity, and reduced sexual function. Group 4 (late): absence of saddle sensation and sexual function in addition to uncontrolled bowel function. The outcome including radiographic and electrophysiological findings was compared between groups.
The main clinical manifestations of CES included bilateral saddle sensory disturbance, and bowel, bladder, and sexual dysfunction. The clinical symptoms of patients with multiple-segment canal stenosis identified radiographically were more severe than those of patients with single-segment stenosis. BCR and ICR improved in groups 1 and 2 after surgery, but no change was noted for groups 3 and 4.
We conclude that bilateral radiculopathy or sciatica are early stages of CES and indicate a high risk of development of advanced CES. Electrophysiological abnormalities and reduced saddle sensation are indices of early diagnosis. Patients at the preclinical and early stages have better functional recovery than patients in later stages after surgical decompression.
Reduction of blood flow in compressed nerve roots is considered as one important mechanism of induction of neurogenic intermittent claudication in lumbar spinal canal stenosis. Vascular endothelial growth factor (VEGF) is a potent stimulator of angiogenesis, and is increased in expression in hypoxic conditions. The objective of this study was to examine if cauda equina compression affects motor function and induces expression of VEGF and angiogenesis. The cauda equina was compressed by placing a piece of silicone rubber into the L5 epidural space. Walking duration was examined by rota-rod testing. The compressed parts of the cauda equina and L5 dorsal root ganglion (DRG) were removed at 3, 7, 14, or 28 days after surgery, and processed for immunohistochemistry for VEGF and Factor VIII (marker for vascular endothelial cells). Numbers of VEGF-immunoreactive (IR) cells and vascular density were examined. Walking duration was decreased after induction of cauda equina compression. The number of VEGF-IR cells in the cauda equina and DRG was significantly increased at 3, 14, and 28 days after cauda equina compression, compared with sham-operated rats (P < 0.05). Vascular density in the cauda equina was not increased at any of the time points examined. Cauda equina compression decreased walking duration, and induced VEGF expression in nerve roots and DRG.
Cauda equina compression; Intermittent claudication; Vascular endothelial growth factor; Angiogenesis
Although postoperative spinal epidural hematoma (SEH) is not uncommon, hematomas that require surgery are rare. Cauda equina syndrome (CES) may be associated with postoperative SEH. In these cases, early recognition and emergency decompression can prevent further damage and better neurologic recovery.
A 41-year-old man underwent two-level discectomy with insertion of an interspinous spacer at L3-4 and L4-5 because of low back pain and radiculopathy. Eight hours after the operation, the patient developed CES. MRI revealed SEH compressing posteriorly at the L3-4 level. On emergency decompression and hematoma evacuation, the interspinous spacer had obstructed the laminotomy site at L3-4 completely, blocking drainage to the drain. The patient experienced complete neurologic recovery by 2 months followup.
Many studies report risk factors for SEH. However, postoperative SEH can also be encountered in patients without these risks. One study reported a critical ratio (preoperative versus postoperative cross-sectional area) correlated with postoperative symptoms, especially in those with CES. The propensity to develop CES is likely dependent on a number of patient-specific factors.
Surgeons should be aware that patients without risk factors may develop acute CES. Wider laminotomy (larger than half of the device size) may help to prevent this complication when one uses the compressible type of device, especially in patients with relatively small lamina.
We performed a retrospective analysis of all cases of lumbo-sacral or sacral metastases presenting with compression of the cauda equina who underwent urgent surgery at our institution. Our objective was to report our experience on the clinical presentation, management and finally the surgical outcome of this cohort of patients.
We reviewed medical notes and images of all patients with compression of the cauda equina as a result of lumbo-sacral or sacral metastases during the study period (2004–2011). The collected clinical data consisted of time of onset of symptoms, neurology (Frankel grade), ambulatory status and continence. Operative data analysed were details of surgical procedure and complications. Post-operatively, we reviewed neurological outcome, ambulation, continence, destination of discharge and survival.
During the 8-year study period, 20 patients [11 males, 9 females; mean age 61.8 years (29–87)] had received urgent surgery for metastatic spinal cauda compression caused by lumbo-sacral or sacral metastases. The majority of patients presented with symptoms of pain and neurological deterioration (n = 14) with onset of pain considerably longer than neurology symptoms [197 days (3–1,825) vs. 46 days (1–540)]; all patients were Frankel C (n = 2, both non-ambulatory), D (n = 13) or E (n = 5) at presentation and three patients were incontinent of urine. Operative procedures performed were posterior decompression with (out) fusion (n = 12), posterior decompression with sacroplasty (n = 1), decompression with lumbo-pelvic stabilisation with (out) kyphoplasty/sacroplasty (n = 7) and posterior decompression/reconstruction with anterior corpectomy/stabilisation (n = 2). Post-operatively, 5/20 (20 %) patients improved one Frankel grade, 1/20 (5 %) improved two grades, 13/20 (65 %) remained stable (8 D, 5 E) and 1/20 (5 %) deteriorated. All patients were ambulatory and 19/20 were continent on discharge. The mean length of stay was 7 days (4–22). There were 6/20 (30 %) complications: three major (PE, deep wound infection, implant failure) and three minor (superficial wound infection, incidental durotomy, chest infection). All patients returned back to their own home (n = 14/20, 70 %) or a nursing home (n = 6/20, 35 %). Thirteen patients are deceased (mean survival 367 days (120–603) and seven are still alive [mean survival 719 days (160–1,719)].
Surgical intervention for MSCC involving the lumbo-sacral junction or sacral spine has a high but acceptable complication rate (6/20, 30 %), and can be important in restoring/preserving neurological function, assisting with ambulatory function and allowing patients to return to their previous residence.
Sacral and lumbo-sacral metastasis; Spinal tumours; Cauda equina compression
Schwannoma is a relatively common benign spinal cord and/or cauda equina tumor; however, giant cauda equina schwannoma with extensive scalloping of the lumbar vertebral body is a rare pathology, and the treatment strategy, including the use of surgical procedures, is controversial. In this report, we present a rare case of a giant lumbar schwannoma of the cauda equina with extremely large scalloping of the vertebral body, and we discuss the surgical strategy we used to treat this pathology.
A 42-year-old Japanese man presented to our department with complaints of a gait disturbance and muscle weakness in the left lower limb. His muscle strength in the proximal part of the left lower limb was grade 2 or 3/5, and he exhibited a mild urinary disturbance on the first visit. X-ray and computed tomography myelography of the lumbar spine showed an extremely large erosive lesion at the L3 vertebral body. Magnetic resonance imaging of the lumbar spine showed a large soft-tissue mass in the spinal canal at L2-L3 and the vertebral body at L3. A one-stage complete tumor resection and instrumented circumferential fusion were performed via a posterior approach, and a good outcome was achieved after the surgery.
We performed one-stage posterior surgery in a patient with a giant cauda equina schwannoma with extensive scalloping of the vertebral body, and a good post-operative outcome was achieved.
Giant cauda equina tumor; Posterior surgery; Scalloping lesion; Schwannoma; Transdural approach
Objective To assess the efficacy of caudal epidural steroid or saline injection in chronic lumbar radiculopathy in the short (6 weeks), intermediate (12 weeks), and long term (52 weeks).
Design Multicentre, blinded, randomised controlled trial.
Setting Outpatient multidisciplinary back clinics of five Norwegian hospitals.
Participants Between October 2005 and February 2009, 461 patients assessed for inclusion (presenting with lumbar radiculopathy >12 weeks). 328 patients excluded for cauda equina syndrome, severe paresis, severe pain, previous spinal injection or surgery, deformity, pregnancy, ongoing breast feeding, warfarin therapy, ongoing treatment with non-steroidal anti-inflammatory drugs, body mass index >30, poorly controlled psychiatric conditions with possible secondary gain, and severe comorbidity.
Interventions Subcutaneous sham injections of 2 mL 0.9% saline, caudal epidural injections of 30 mL 0.9% saline, and caudal epidural injections of 40 mg triamcinolone acetonide in 29 mL 0.9% saline. Participants received two injections with a two week interval.
Main outcome measures Primary: Oswestry disability index scores. Secondary: European quality of life measure, visual analogue scale scores for low back pain and for leg pain.
Results Power calculations required the inclusion of 41 patients per group. We did not allocate 17 of 133 eligible patients because their symptoms improved before randomisation. All groups improved after the interventions, but we found no statistical or clinical differences between the groups over time. For the sham group (n=40), estimated change in the Oswestry disability index from the adjusted baseline value was −4.7 (95% confidence intervals −0.6 to −8.8) at 6 weeks, −11.4 (−6.3 to −14.5) at 12 weeks, and −14.3 (−10.0 to −18.7) at 52 weeks. For the epidural saline intervention group (n=39) compared with the sham group, differences in primary outcome were −0.5 (−6.3 to 5.4) at 6 weeks, 1.4 (−4.5 to 7.2) at 12 weeks, and −1.9 (−8.0 to 4.3) at 52 weeks; for the epidural steroid group (n=37), corresponding differences were −2.9 (−8.7 to 3.0), 4.0 (−1.9 to 9.9), and 1.9 (−4.2 to 8.0). Analysis adjusted for duration of leg pain, back pain, and sick leave did not change this trend.
Conclusions Caudal epidural steroid or saline injections are not recommended for chronic lumbar radiculopathy.
Trial registration Current Controlled Trials ISRCTN No 12574253.
Reduction of blood flow is important in the induction of neurogenic intermittent claudication (NIC) in lumbar spinal canal stenosis. PGE1 improves the mean walking distance in patients with NIC type cauda equina compression. PGE1 derivate might be effective in dilating blood vessels and improving blood flow in nerve roots with chronically compressed cauda equina. The aim of this study was to assess whether PGE1 derivate has vasodilatory effects on both arteries and veins in a canine model of chronic cauda equina compression.
Fourteen dogs were used in this study. A plastic balloon inflated to 10 mmHg was placed under the lamina of the 7th lumbar vertebra for 1 week. OP-1206-cyclodextrin clathrate (OP-1206-CD: prostaglandin E1 derivate) was administered orally. The blood vessels of the second or third sacral nerve root were identified using a specially designed surgical microscope equipped with a video camera. The diameter of the blood vessels was measured on video-recordings every 15 minutes until 90 minutes after the administration of the PGE1 derivate.
We observed seven arteries and seven veins. The diameter and blood flow of the arteries was significantly increased compared with the veins at both 60 and 75 minutes after administration of the PGE1 derivate (p < 0.05). Blood flow velocity did not change over 90 minutes in either the arteries or veins.
The PGE1 derivate improved blood flow in the arteries but did not induce blood stasis in the veins. Our results suggest that the PGE1 derivate might be a potential therapeutic agent, as it improved blood flow in the nerve roots in a canine model of chronic cauda equina compression.
Leg pain/numbness and gait disturbance, two major symptoms in the lower extremities of lumbar spinal stenosis (LSS), are generally expected to be alleviated by decompression surgery. However, the paucity of information available to patients before surgery about specific predictors has resulted in some of them being dissatisfied with the surgical outcome when the major symptoms remain after the procedure. This prospective, observational study sought to identify the predictors of the outcome of a decompression surgery: modified fenestration with restorative spinoplasty. Of 109 consecutive LSS patients who underwent the decompression surgery, 89 (56 males and 33 females) completed the 2 year follow-up. Both leg pain/numbness and gait disturbance determined by the Japanese Orthopedic Association scoring system were significantly improved at 2 years after surgery compared to those preoperative, regardless of potential predictors including gender, preoperative presence of resting numbness in the leg, drop foot, cauda equina syndrome, degenerative spinal deformity or myelographic filling defect, or the number of decompressed levels. However, 27 (30.3%) and 13 (14.6%) patients showed residual leg pain/numbness and gait disturbance, respectively. Among the variables examined, the preoperative resting numbness was associated with residual leg pain/numbness and gait disturbance, and the preoperative drop foot was associated with residual gait disturbance, which was confirmed by logistic regression analysis after adjustment for age and gender. This is the first study to identify specific predictors for these two remaining major symptoms of LSS after decompression surgery, and consideration could be given to including this in the informed consent.
Lumbar spinal stenosis; Decompression surgery; Outcome; Predictor
To determine the level of brain-derived neurotrophic factor (BDNF) in experimental dog model of severe acute cauda equina syndrome, which was induced by multiple cauda equina constrictions throughout the entire lumbar (L), sacral (S) and coccygeal (Co) spinal cord and their central processes of the dorsal root ganglia neurons. Adult male mongrel dogs were randomly divided into 2 groups. The experiment group (n=4) was subjected to multiple cauda equina constrictions. The control group (n=4) was subjected to cauda equina exposure without constrictions. Level of BDNF in the spinal cord and the dorsal root ganglion cells (L7, S1-S3) was assessed 48 hours after multiple constrictions by immunohistochemical and histopathological analyses. 48 hours after multiple constrictions of cauda equina, up-regulation of BDNF within lumbosacral (L7-S3) spinal cord and dorsal root ganglion was observed in experimental group as compared to control group. Our result suggests that BDNF might play a role in the inflammatory and neuropathic pain as a result of multiple cauda equina constrictions. Regulation of BDNF level could potentially provide a therapy for treating cauda equina syndrome.
Cauda equina syndrome (CES); dorsal root ganglion (DRG); brain-derived neurotrophic factor (BDNF); multiple cauda equina constrictions (MCEC); neurotrophic factors (NFs)
Acute low back pain is a common cause for presentation to the emergency department (ED). Since benign etiologies account for 95% of cases, red flags are used to identify sinister causes that require prompt management.
We assessed the effectiveness of red flag signs used in the ED to identify spinal cord and cauda equine compression.
Patients and Methods:
It was a retrospective cohort study of 206 patients with acute back pain admitted from the ED. The presence or absence of the red flag symptoms was assessed against evidence of spinal cord or cauda equina compression on magnetic resonance imaging (MRI).
Overall, 32 (15.5%) patients had compression on MRI. Profound lower limb neurologic examination did not demonstrate a statistically significant association with this finding. The likelihood ratio (LR) for bowel and bladder dysfunction (sensitivity of 0.65 and specificity of 0.73) was 2.45. Saddle sensory disturbance (sensitivity of 0.27 and specificity of 0.87) had a LR of 2.11. When both symptoms were taken together (sensitivity of 0.27 and specificity of 0.92), they gave a LR of 3.46.
The predictive value of the two statistically significant red flags only marginally raises the clinical suspicion of spinal cord or cauda equina compression. Effective risk stratification of patients presenting to the ED with acute back pain is crucial; however, this study did not support the use of these red flags in their current form.
Cauda Equina; Spinal Cord Compression; Low Back Pain
Extramedullary hematopoiesis (EMH) is occasionally reported in idiopathic myelofibrosis and is generally found in the liver, spleen, and lymph nodes several years after diagnosis. Myelofibrosis presenting as spinal cord compression, resulting from EMH tissue is very rare. A 39-yr-old man presented with back pain, subjective weakness and numbness in both legs. Sagittal magnetic resonance imaging showed multiple anterior epidural mass extending from L4 to S1 with compression of cauda equina and nerve root. The patient underwent gross total removal of the mass via L4, 5, and S1 laminectomy. Histological analysis showed islands of myelopoietic cells surrounded by fatty tissue, consistent with EMH, and bone marrow biopsy performed after surgery revealed hypercellular marrow and megakaryocytic hyperplasia and focal fibrosis. The final diagnosis was chronic idiopathic myelofibrosis leading to EMH in the lumbar spinal canal. Since there were no abnormal hematological findings except mild myelofibrosis, additional treatment such as radiothepary was not administered postoperatively for fear of radiotoxicity. On 6 month follow-up examination, the patient remained clinically stable without recurrence. This is the first case of chronic idiopathic myelofibrosis due to EMH tissue in the lumbar spinal canal in Korea.
Hematopoiesis, Extramedullary; Myelofibrosis; Spinal Canal
Giant spinal schwannoma of the cauda equine involving many nerve roots is rare, and ossification is usually not observed in the schwannoma. A 21-year-old man presented with a 12-month history of urinary dysfunction and numbness below the buttocks. Plain radiography showed scalloping of the posterior surface of the vertebral bodies from L4 to the sacrum, and magnetic resonance imaging and computed tomography revealed a giant cauda equina tumor with dystrophic calcification. The tumor was completely removed, with intraoperative neurophysiologic monitoring. Histopathologic examination showed that the tumor was a schwannoma. The patient's postoperative course was uneventful, with urinary function and numbness gradually improving. Although a giant schwannoma accompanied by dystrophic calcification is extremely rare, such a tumor can be removed safely and completely by meticulous dissection and careful neuromonitoring of the cauda equina spinal nerves involved in the tumor.
Giant schwannoma; Cauda equina; Complete excision; Calcification; Neuromonitoring
Cauda equina syndrome (CES) has been described in the literature as a clinical entity consisting of low back pain, bilateral leg pain with motor and sensory deficits, genitourinary dysfunction with overflow incontinence or retention, and faecal incontinence. CES has been recognised as a rare complication of spinal manipulative therapy, and is an absolute contraindication to this type of therapy. A case of CES that presented in an atypical manner is presented, highlighting the lack of leg symptomatology, but with the presence of painless urinary retention. A definition of CES as a condition presenting with bladder dysfunction and possible motor and/or sensory loss in the region of sacral and/or lumbar dermatomes is discussed. Evaluation of patients with lumbar disc pathology who are suspected of suffering from CES should include questioning regarding urinary difficulty and neurologic examination of the sacral plexus, including sensation; and may include advanced imaging such as contrast computerized tomography (CT) scan or magnetic resonance imaging (MRI). Immediate referral for consideration of decompression surgery is recommended for optimal recovery of neurologic function. Clinicians should be knowledgeable of the various forms CES can present in, and maintain a high index of suspicion for this condition in patients with suspected lumbar disc herniation or urinary dysfunction.
low back pain; disc herniation; cauda equina syndrome; cauda equina compression; bladder dysfunction
DuraSeal™ (Coviden, Waltham, MA, USA), a hydrogel sealant, is primarily used as an adjunct to a dural repair. Its use has also been described to seal off an annulotomy after a transforaminal lumbar interbody fusion when recombinant human bone morphogenetic protein-2 (rhBMP-2) is used. This aids in the reduction of postoperative radiculitis caused by rhBMP-2. However, as a result of its hydrophilic properties, DuraSeal™ has the potential to swell, which could lead to compression of the thecal sac.
We report a 57-year-old woman who developed cauda equina after a transforaminal lumbar 47 interbody fusion (TLIF) procedure in which the expansion of the DuraSeal™ was believed to be the causative factor. The patient developed urinary retention, bowel incontinence, and paresthesias in the saddle region on postoperative Day 3. She underwent emergent exploration and decompression of the thecal sac. The gel-like DuraSeal™ material was causing significant compression of the thecal sac.
Multiple reports have documented that DuraSeal™, used as an adjunct to dural repair, can swell leading to compression of the spinal cord and/or neural elements. Our case demonstrates the use of DuraSeal™ both over a site of a dural repair and over an annulotomy site, through which a TLIF was performed, is associated with the risk of developing postoperative cauda equina syndrome as a result of swelling of the DuraSeal™.
Those using DuraSeal™ to seal off the annulotomy after a TLIF procedure performed with rhBMP-2 should use the product with an understanding of the potential postoperative swelling of the product and resulting neurologic sequela, particularly if DuraSeal™ is used concomitantly at the site of dural repair.
The timing of surgery in cauda equina syndrome due to prolapsed intervertebral disc remains controversial. Assessment of these patients requires magnetic resonance imaging (MRI), which is of limited availability outside normal working hours in the UK.
PATIENTS AND METHODS
We reviewed radiological results in all patients undergoing emergency MRI within our unit for suspected cauda equina syndrome over a 2-year period, and all subjects undergoing emergency lumbar discectomy for cauda equina syndrome within the same period. Outcome measures were: proportion of positive findings in symptomatic patients and proportion of patients referred with diagnostic MRI scans undergoing emergency surgery. We also assessed outcomes of patients having surgery for cauda equina syndrome in terms of improvement of pain, sensory and sphincter disturbance.
A total of 76 patients were transferred for assessment and ‘on-call’ MRI; 27 were subsequently operated upon. Only 5 proceeded to emergency discectomy that night (prior to next scheduled list). This may be due to delays in timing – from referral to acceptance, to arrival in the department, to diagnostic scan and to theatre. With the second group of patients, 43 had emergency discectomy for cauda equina syndrome during the study period. Of these, 6 patients had an out-of-hours MRI at our hospital for assessment (one patient living locally). Most surgically treated patients experienced improvement in their pain syndrome, with approximately two-thirds experiencing improvement in sensory and sphincter disturbance.
These data support a policy of advising MRI scan for cauda equina syndrome at the earliest opportunity within the next 24 h in the referring hospital, rather than emergency transfer for diagnostic imaging which has a relatively low yield in terms of patients operated on as an emergency.
MRI scan; Cauda equina syndrome; Discectomy; Back pain
A retrospective study.
The aim of present study was to investigate imaging findings suggestive of cauda equina entrapment in thoracolumbar and lumbar burst fractures.
Overview of Literature
Burst fractures with cauda equina entrapment can cause neurologic deterioration during surgery. However, dural tears and cauda equina entrapment are very difficult to diagnose clinically or radiographically before surgery.
Twenty-three patients who underwent spinal surgery for thoracolumbar or lumbar burst fractures were enrolled in this study. In magnetic resonance imaging T2-weighted images of the transverse plane, we defined cauda equina notch sign (CENS) as a v-shaped image that entrapped cauda equina gathers between lamina fractures. We evaluated the fractured spine by using CENS and lamina fractures and the rate of available space for the spinal canal at the narrowest portion of the burst fracture level. We classified patients into entrapment group or non-entrapment group, based on whether cauda equina entrapment existed.
Lamina fractures were detected in 18 (78.3%) and CENS were detected in 6 (26.1%) of 23 burst-fracture patients. Cauda equina entrapment existed in all the patients with CENS. In addition, the rate of available space for the spinal canal increased according to logistic regression. The size of the retropulsed fragment in the spinal canal was the most reliable of all the factors, suggesting cauda equina entrapment.
CENS was the most predictable sign of cauda equina entrapment associated with burst fractures.
Burst fracture; Dural tear; Cauda equina entrapment; Lamina fracture; Magnetic resonance imaging