Cauda equina syndrome—the questions

Comparison of capsule and posterior lumbar interbody fusion in cauda equina syndrome with retention: a 24-month follow-up study

BACKGROUND AND OBJECTIVES

Cauda equina syndrome with retention (CESR) is a severe lumbar condition characterized by painless urine retention due to cauda equina nerve injury. The standard treatment, posterior lumbar interbody fusion (PLIF), often yields suboptimal results. This study aims to compare the clinical safety and efficacy of a novel technique, capsule lumbar interbody fusion (CLIF), with PLIF in CESR patients, hypothesizing that CLIF can enhance neurological recovery by reducing nerve tension.

METHODS

A single-center, retrospective study was conducted on 83 patients with CESR due to lumbar disc herniation, who underwent either PLIF (n = 44) or CLIF (n = 39). Patients were assessed preoperatively and at 3, 12, and 24 months postoperatively using the Oswestry Disability Index (ODI), Visual Analogue Scale (VAS), International Consultation on Incontinence Questionnaire Short Form (ICI-Q-SF), and Rintala score. Urodynamic studies and nerve tension measurements were also performed. Statistical analysis included t tests, Mann-Whitney U tests, and Spearman's correlation.

RESULTS

Both groups showed significant postoperative improvements, but the CLIF group had superior outcomes. At 12 months, the CLIF group had lower VAS scores (1.15 ± 0.84 vs. 1.68 ± 0.60, p = 0.001) and ODI scores (23.31 ± 7.51 vs. 28.30 ± 8.26, p = 0.005). At 24 months, the CLIF group continued to show better results with ODI scores (15.97 ± 6.43 vs. 22.11 ± 6.41, p < 0.001) and higher ODI recovery rates (60.41 ± 17.6% vs. 44.71 ± 18.99%, p < 0.001). The CLIF group also had better ICI-Q-SF scores (2.13 ± 1.23 vs. 3.02 ± 1.45, p = 0.004) and Rintala scores (17.97 ± 1.43 vs. 16.59 ± 1.54, p < 0.001). Lower postoperative nerve tension in the CLIF group correlated with these improved outcomes.

CONCLUSIONS

CLIF demonstrated superior efficacy over PLIF in treating CESR, with significant improvements in pain relief, functional recovery, and bladder and bowel function. This study highlights the potential of CLIF as a more effective surgical option for CESR, emphasizing its importance in improving patient outcomes and reducing the burden of CESR on patients and society.

Discectomy versus sequestrectomy in the treatment of lumbar disc herniation: a systematic review and meta-analysis

BACKGROUND CONTEXT

Lumbar disc herniation (LDH) is a leading cause of low back pain (LBP) and leg pain and may require surgical treatment in case of persistent pain and/or neurological deficits. Conventional discectomy involves removing the herniated fragment and additional material from the disc space, potentially accelerating disc degeneration and contributing to chronic LBP. Conversely, by resecting the herniated fragment only, sequestrectomy may reduce postoperative LBP while increasing the risk of LDH recurrence.

PURPOSE

To compare discectomy versus sequestrectomy in terms of risk of reherniation, reoperation rate, complications, pain, satisfaction, and perioperative outcomes (operative time, blood loss, length of stay [LOS]).

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

A systematic search of PubMed/MEDLINE and Scopus databases was performed through May 1, 2024 for both randomized and nonrandomized studies. The search was conducted according to PRISMA guidelines. The RoB-2 and MINORS tools were utilized to assess the risk of bias in included studies. The quality of the evidence was evaluated according to the GRADE approach. Relevant outcomes were pooled for meta-analysis.

RESULTS

A total of 16 articles (1 randomized controlled trial with 2 follow-up studies, 6 prospective studies, and 7 retrospective studies) published between 1991 and 2020 involving 2009 patients were included for analysis. No significant differences were noted between discectomy versus sequestrectomy in terms of risk of reherniation (OR: 0.85, 95% CI: 0.57 to 1.26, p=.42), reoperation rate (OR: 0.95, 95% CI: 0.64 to 1.40, p=.78), and complications (OR: 1.03, 95% CI: 0.50 to 2.11, p=.94). Although LBP (MD: -0.06, 95% CI: -0.39 to 0.28, p=.74) and leg pain intensity (MD: 0.11, 95% CI: -0.21 to 0.42, p=.50) were similar postoperatively, significantly better outcomes were reported by patients treated with sequestrectomy at 1 year (leg pain: MD: 0.37, 95% CI: 0.19 to 0.54, p<.0001) and 2 years (LBP: MD: 0.19, 95% CI: 0.03 to 0.34, p=.02; leg pain: MD: 0.20, 95% CI: 0.09 to 0.31, p=.0005). Sequestrectomy also resulted in a higher patient satisfaction (OR: 0.60, 95% CI: 0.40 to 0.90, p=.01) and shorter operative time (MD: 8.71, 95% CI: 1.66 to 15.75, p=.02), while blood loss (MD: 0.18, 95% CI: -2.31 to 2.67, p=.89) and LOS (MD: 0.02 days, 95% CI: -0.07 to 0.12, p=.60) did not significantly differ compared to discectomy.

CONCLUSIONS

Based on the current evidence, discectomy and sequestrectomy do not significantly differ in terms of risk of reherniation, reoperation rate, and postoperative complications. Patients treated with sequestrectomy may benefit from a marginally higher pain improvement, better satisfaction outcomes, and a shorter operative time, although the clinical relevance of these differences needs to be validated in larger, prospective, randomized studies.

Post-traumatic cauda equina concussion: Definition and description of the injury mechanism

Despite being a prevalent clinical condition, cauda equina concussion has not been thoroughly elucidated in the literature. The aim of this study is to delineate the etiology and pathogenesis of cauda equina concussion and its associated clinical manifestations. Patients exhibiting clinical manifestations indicative of spinal cord injury and transient neurological deficits after spinal trauma were evaluated retrospectively. The pathogenesis was elucidated through correlating clinical presentations with radiological findings. Neurological deficits were categorized into two principal groups, symmetrical and asymmetrical. Non-penetrating fractures were classified to ascertain the relationship between the type of trauma and the ensuing neurological deficits. A cohort of 82 patients was diagnosed with cauda equina concussion. Among these, 58 had experienced vertical trauma resulting from falls, while 24 had encountered axial trauma in vehicular accidents. Stable spinal fractures were identified in 52 patients across multiple levels, whereas single-level fractures were observed in 30. Asymmetrical neurological deficits were detected in 51 (62.19%) patients, with a notably higher incidence among those subjected to vertical trauma (p < 0.014). The mean recovery time was 14.25 ± 15.16 h for sensory deficits and 11.25 ± 13.36 h for motor deficits in those patients. Notably, motor deficits resolved more expeditiously than sensory deficits in all cases presenting with both. Cauda equina concussion emerges as a frequently encountered clinical phenomenon attributable to the impact of high-energy vertical forces. Neurological deficits commonly manifest asymmetrically. The rapid resolution of neurological deficits presents challenges for the diagnostic process.

Understanding metastatic involvement of the conus medullaris: a systematic review of clinical presentations, diagnostic approaches, treatment options, and patient outcomes

INTRODUCTION

Metastasis to the conus medullaris (CM) is a rare but devastating condition. This systematic review aimed to evaluate the clinical presentation, diagnostic workup, treatment options, and outcomes of patients with CM metastasis. By synthesizing the available evidence, this study seeks to improve our understanding of this condition and inform clinical practice.

MATERIALS AND METHODS

A systematic review adhering to PRISMA guidelines analyzed literature on CM metastasis from 1997 to January 2024. Human studies in English were included, focusing on primary research articles. Screening criteria ensured a homogeneous study population, with data analyzed using SPSS 26 and assessed for quality using the JBI checklist.

RESULTS

The study analyzed 88 patients with conus medullaris metastasis. Common symptoms included back pain (49.3%), sensory impairment (75%), and bladder dysfunction (60.3%). MRI was the primary diagnostic tool, revealing lesions above L1 (37%) or between L1 and L2 (29%). Treatment involved surgery with laminectomy, and combined therapy (surgery plus radiotherapy) in 81.3%. Postoperative outcomes showed improved motor function in 59.6% of patients, while combined therapy yielded better sensory and bowel/bladder function recovery. Median survival was 100 days.

CONCLUSION

Metastasis to the conus medullaris is rare but significant. Surgical resection can improve motor function, while combined therapy (surgery plus radiotherapy) is effective in improving sensory manifestations and bowel/bladder functions. Despite these treatments, the median survival remains around 100 days, which is shorter compared to other types of intramedullary spinal cord metastases.

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.

Cauda equina, conus medullaris and syndromes mimicking sciatic pain: WFNS spine committee recommendations

Introduction

Cauda equina syndrome (CES), conus medullaris syndrome (CMS), and sciatica-like syndromes or "sciatica mimics" (SM) may present as diagnostic and/or therapeutic dilemmas for the practicing spine surgeon. There is considerable controversy regarding the appropriate definition and diagnosis of these entities, as well as indications for and timing of surgery. Our goal is to formulate the most current, evidence-based recommendations for the definition, diagnosis, and management of CES, CMS, and SM syndromes.

Methods

We performed a systematic literature search in PubMed from 2012 to 2022 using the keywords "cauda equina syndrome", "conus medullaris syndrome", "sciatica", and "sciatica mimics". Standardized screening criteria yielded a total of 43 manuscripts, whose data was summarized and presented at two international consensus meetings of the World Federation of Neurosurgical Societies (WFNS) Spine Committee. Utilizing the Delphi method, we generated seven final consensus statements.

Results and conclusion

s: We provide standardized definitions of cauda equina, cauda equina syndrome, conus medullaris, and conus medullaris syndrome. We advocate for the use of the Lavy et al classification system to categorize different types of CES, and recommend urgent MRI in all patients with suspected CES (CESS), considering the low sensitivity of clinical examination in excluding CES. Surgical decompression for CES and CMS is recommended within 48 h, preferably within less than 24 h. There is no data regarding the role of steroids in acute CES or CMS. The treating physician should be cognizant of a variety of other pathologies that may mimic sciatica, including piriformis syndrome, and how to manage these.

Cauda equina syndrome from intradural metastasis of a non-neural tumor: case report and review of literature

BACKGROUND

Cauda equina syndrome (CES) is a challenging condition and it can be caused by variable entities. Leptomeningeal carcinomatosis (LC) is a multifocal seeding of the leptomeninges by malignant cells and it is observed in 1-8% of patients with solid tumors. Diagnosis of intradural metastases of the cauda equina is often delayed due to the non-specific characteristics of this condition but also to the delay of presentation of many patients. Cauda equina metastases usually occur in advanced cancers, but rarely can be the first presentation of disease.

CASE DESCRIPTION

A 63-year-old man presented with 6 months history of low back pain and 20 d history of bilateral sciatica, hypoesthesia of the legs and the saddle, flaccid paraparesis and bowel incontinence determine by multiple nodular small lesions on the entire cauda equina with contrast-enhancement. Total-body CT showed a millimetric lesion at the lung. The patient underwent L2-L5 laminectomy and subtotal removal and histological examination showed a small cell lung carcinoma metastasis.

CONCLUSIONS

In the literature, 54 cases of CES from non-CNS tumor metastasis are described. The diagnosis is challenging, back pain, with or without irradiation to the lower limbs, is the most frequently reported disturbance. In about 30% of patients there is no known malignancy and CES is the first clinical presentation. Treatment of choice is surgery, followed by radiotherapy and less frequently adjuvant chemotherapy. The surgical removal is almost always incomplete and functional outcome is often not satisfactory. Prognosis is poor.

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.

The Most Impactful Articles on Cauda Equina Syndrome

Cauda equina syndrome (CES) is an uncommon condition that can lead to permanent neurological deficits if not diagnosed and addressed promptly. Varying prognoses, including retropulsed fracture fragments, disc herniations, and epidural abscesses, can result in CES. Our objective was to identify the top 50 most impactful articles on CES and analyze the characteristics of these publications. In August of 2021, we used the Web of Science Core Collection bibliographic database to query the phrase "cauda equina syndrome." Articles between 1900 and 2021 were included in the search, and these articles were ranked based on the number of citations. The following variables were recorded: title, first author, journal, year of publication, number of citations, country of origin, the institution of publication, and topic of the paper. A total of 2096 articles matched the search criteria. The top 50 most impactful articles ranged from 43 to 439 in their number of citations. All articles on the list were published in English, with the year of publication ranging from 1938 to 2014. The United States accounted for the greatest number of articles published at 27. The medical journal Spine accounted for the greatest number of publications at nine. And the 2000s was the decade with the most cited articles. It is generally acknowledged that the clinical signals for CES are diverse with no predictive value on patient outcomes. Similar uncertainty exists in the etiology of the condition, though CES induced by spinal anesthesia is a factor of particular interest. Additionally, it is generally recognized that delayed diagnosis of the condition often results in permanent neurological deficits. Identification of the most impactful articles on CES is critical in drawing attention to this significant condition.

Minimally invasive decompression alone versus fusion surgery for acute lumbar disk herniation combined incomplete cauda equina syndrome

STUDY DESIGN

Retrospective single center study.

BACKGROUND

Cauda equine syndrome (CES), which caused by acute lumbar disc herniation (LDH), often requires urgent surgical treatment. Currently, there is no standard defining the type of surgery, and approaches to the treatment of patients are based on the experience of the surgeon.

PURPOSE

to compare the clinical efficacy of minimally invasive decompression alone (Decompression alone group) and transforaminal lumbar interbody fusion (Fusion group) in the treatment of the incomplete CES, caused by acute LDH.

PATIENTS AND METHODS

89 patients with acute incomplete CES associated with LDH either underwent decompression alone and fusion surgery from January 2005 to January 2020 in single-center, and data were collected and retrospectively analyzed. The patients were divided into 2 groups according to the operation technics: the Decompression alone group (n = 46) and the Fusion group (n = 43). The perioperative clinical data (neurological deficit, control of the urinary bladder sphincter, ODI scale, SF-36) was used to assess the efficacy of the respective surgical methods before operation and with a minimum follow-up 24 months.

RESULTS

Verified statistical significance more bleeding, longer surgery time and hospital stay, in the Fusion group than in the Decompression alone group. The postoperative clinical data dramatic improved after Decompression alone and Fusion surgery. At early postoperative period registered better clinical outcomes according to ODI, SF-36 after Decompression alone surgery, but at minimum follow-up 24 months verified better in the Fusion group. The number of revision interventions in the Decompression alone group was 28.3% (n = 13), in Fusion group - 9.3% (n = 4) (p = 0.02).

CONCLUSIONS

The prevalence of acute incomplete CES due to LDH in our series was registered in 1.02% of patients (124 of 12087). In the Fusion group, in the long-term period, there were better clinical outcomes and fewer revision surgical interventions compared with Decompression alone.

Natural products can modulate inflammation in intervertebral disc degeneration

Intervertebral discs (IVDs) play a crucial role in maintaining normal vertebral anatomy as well as mobile function. Intervertebral disc degeneration (IDD) is a common clinical symptom and is an important cause of low back pain (LBP). IDD is initially considered to be associated with aging and abnormal mechanical loads. However, over recent years, researchers have discovered that IDD is caused by a variety of mechanisms, including persistent inflammation, functional cell loss, accelerated extracellular matrix decomposition, the imbalance of functional components, and genetic metabolic disorders. Of these, inflammation is thought to interact with other mechanisms and is closely associated with the production of pain. Considering the key role of inflammation in IDD, the modulation of inflammation provides us with new options for mitigating the progression of degeneration and may even cause reversal. Many natural substances possess anti-inflammatory functions. Due to the wide availability of such substances, it is important that we screen and identify natural agents that are capable of regulating IVD inflammation. In fact, many studies have demonstrated the potential clinical application of natural substances for the regulation of inflammation in IDD; some of these have been proven to have excellent biosafety. In this review, we summarize the mechanisms and interactions that are responsible for inflammation in IDD and review the application of natural products for the modulation of degenerative disc inflammation.

Rates of Future Lumbar Fusion in Patients with Cauda Equina Syndrome Treated With Decompression

INTRODUCTION

The long-term risk of conversion to lumbar fusion is ill-defined for patients with cauda equina syndrome (CES) treated with decompression. This study aimed to identify the rates of fusion in patients with CES and compare those rates with a matched lumbar spinal stenosis (LSS) group.

METHODS

Patients with CES who underwent decompression were identified in a national database and matched to control patients with LSS. The rates of conversion to fusion were identified and compared. Multivariate logistic regression analysis identified independently associated risk factors. A subanalysis was conducted after stratifying by timing between CES diagnosis and decompression.

RESULTS

The rate of lumbar fusion in the CES cohort was 3.6% after 1 year, 6.7% after 3 years, and 7.8% after 5 years, significantly higher than the LSS control group at all time points (1 year: 1.6%, P = 0.001; 3 years: 3.0%, P &lt; 0.001; 5 years: 3.8%, P &lt; 0.001). CES was independently associated with increased risk of conversion to fusion (odds ratio: 2.13; 95% confidence interval: 1.56 to 2.97; P &lt; 0.001). Surgical timing was not associated with risk of conversion to fusion.

CONCLUSIONS

After 5 years, 7.8% of patients with CES underwent fusion, a markedly higher rate compared with patients with LSS. Counseling patients with CES on this increased risk of future surgery is important for patient education and satisfaction.

Pudendal tumor mimicking cauda equina syndrome and acute radiculopathy: case report

INTRODUCTION

Cauda equina syndrome (CES) is most caused by lumbar disc herniation, and the associated treatment involves prompt surgical decompression. Rarer causes of CES include perineural (Tarlov) cysts.

CLINICAL PRESENTATION

A 62-year-old female with history of rheumatoid arthritis, hip and knee replacements, and chronic low back pain presented with worsening back pain, left leg weakness and pain for 6 weeks, and bowel/bladder incontinence with diminished sensation in the perianal region for 24 h prior to presentation. MRI demonstrated severe spinal stenosis at L4-S1, central disc herniation at L5-S1, and compression of the cauda equina, consistent with CES. A lumbar decompression was performed. Patient did well at 2-week follow up, but presented 5 weeks post-discharge with increased left leg pain/weakness and genitalia anesthesia. Imaging was unremarkable. Two months later, the patient presented with diminished sensation in the buttocks and bilateral lower extremities and bowel/bladder incontinence. Imaging demonstrated a large cystic presacral mass with involvement of the left sciatic foramen and S3 neural foramen. A team of plastic, orthopedic, and neurological surgeons performed an S3 sacral laminectomy, foraminotomy, partial sacrectomy, and S3 rhizotomy, and excision of the large left hemorrhagic pudendal mass. Final pathology demonstrated a perineural cyst with organizing hemorrhage. On follow-up, the patient's pain and weakness improved.

CONCLUSION

CES-like symptoms were initially attributed to a herniated disk. However, lumbar decompression did not resolve symptoms, prompting further radiographic evaluation at two separate presentations. This represents the first reported case of a pudendal tumor causing symptoms initially attributed to a herniated disc.

Cauda Equina Syndrome

Cauda equina syndrome (CES) involves compression of some or all of the lumbar and sacral peripheral nerve roots. However, there is a lack of consensus in the literature regarding the exact diagnosis criteria in this patient population. Much of the pathophysiology has been studied regarding the onset of this condition; however, the long-term effects are not able to be accurately predicted at this time. Recent literature has associated timing to surgical decompression, severity of symptoms at time of onset, and involvement of bladder dysfunction as prognostic indicators of CES.

To be, or not to be… Guillain-Barré Syndrome

Guillain-Barré Syndrome (GBS) is currently the most frequent cause of acute flaccid paralysis on a global scale, being an autoimmune disorder wherein demyelination of the peripheral nerves occurs. Its main clinical features are a symmetrical ascending muscle weakness with reduced osteotendinous reflexes and variable sensory involvement. GBS most commonly occurs after an infection, especially viral (including COVID-19), but may also transpire after immunization with certain vaccines or in the development of specific malignancies. Immunoglobulins, plasmapheresis, and glucocorticoids represent the principal treatment modalities, however patients with severe disease progression may require supportive therapy in an intensive care unit. Due to its symptomology, which overlaps with numerous neurological and infectious illnesses, the diagnosis of GBS may often be misattributed to pathologies that are essentially different from this syndrome. Moreover, many of these require specific treatment methods distinct to those recommended for GBS, in lack of which the prognosis of the patient is drastically affected. Such diseases include exposure to toxins either environmental or foodborne, central nervous system infections, metabolic or serum ion alterations, demyelinating pathologies, or even conditions amenable to neurosurgical intervention. This extensive narrative review aims to systematically and comprehensively tackle the most notable and challenging differential diagnoses of GBS, emphasizing on the clinical discrepancies between the diseases, the appropriate paraclinical investigations, and suitable management indications.

Cauda Equina Syndrome Secondary to Diffuse Infiltration of the Cauda Equina by Acute Myeloid Leukemia: Case Report and Literature Review

BACKGROUND

Cauda equina syndrome (CES) results from the dysfunction of the lumbar, sacral, and coccygeal rootlets composing the cauda equina. The underlying etiology is most commonly compression secondary to a large herniated lumbosacral disk; however, any pathology affecting the rootlets can result in the syndrome.

METHODS

We present a rare case of CES secondary to neoplastic polyradiculitis in a patient with acute myelogenous leukemia (AML) and review the pertinent literature. A 72-year-old male with a medical history of AML presented with 2 weeks of difficulty ambulating, followed by acute-onset low back pain radiating to the buttocks bilaterally.

RESULTS

Imaging of the lumbar spine demonstrated diffuse enhancement and thickening of the cauda equina rootlets. Lumbar puncture showed numerous blasts with monocytoid features consistent with AML, and the patient was diagnosed with polyradiculopathy of the cauda equina secondary to diffuse metastatic infiltration.

CONCLUSIONS

Central nervous system involvement of leukemia is poorly understood, even though such lesions are not uncommon in advanced disease. As treatment has improved, many types of leukemia, such as AML, are believed to be curable, and patients with the disease are living longer. With improved survival, it is reasonable to suspect that such involvement by AML may become more common. Our patient is a classic presentation of CES secondary to diffuse infiltration by AML and serves as an example of this rare manifestation of hematologic malignancy.