The Most Impactful Articles On Cauda Equina Syndrome PDF

Open Access Review Article DOI: 10.7759/cureus.38069 The Most Impactful Articles on Cauda Equina Syndrome Review began 04/...

Open Access Review Article DOI: 10.7759/cureus.38069 The Most Impactful Articles on Cauda Equina Syndrome Review began 04/12/2023 Aasim Hawa 1 , Adwin Denasty 1 , Karim Elmobdy 1 , Addisu Mesfin 1 Review ended 04/22/2023 Published 04/24/2023 1. Orthopedics, University of Rochester Medical Center, Rochester, USA © Copyright 2023 Hawa et al. This is an open access article Corresponding author: Addisu Mesfin, [email protected] distributed under the terms of the Creative Commons Attribution License CC-BY 4.0., which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Abstract 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. Categories: Orthopedics Keywords: bibliometrics analysis, top cited, impactful articles, spine conditions, cauda equina syndrome Introduction And Background Cauda equina syndrome (CES) is a relatively rare condition affecting the nerve bundles towards the end of the spinal cord, and it requires urgent treatment to prevent rapid symptom progression. Symptoms characteristic of this condition include acute or chronic lower back pain, numbness, weakness, sciatic nerve pain, loss of lower motor function and bladder, bowel, and sexual dysfunction, depending upon the rate of onset [2,3]. The term cauda equina anatomically refers to the spinal nerves L2-L5, S1-S5, as well as the coccygeal nerve. Cauda equina syndrome is a result of the compression of some or all of these nerves. The most common cause of CES is lumbar disc herniation, with 45% of all cases attributed to this condition. Other causes include spinal stenosis, cysts, fractures, tumors, or any other lesions that can cause compression to the cauda equina. Diagnosis of CES involves imaging via MRI or CT. Decompressive surgery, ideally within 48 hours of symptom onset, is the most common treatment option [4,5]. Treatment must begin urgently to prevent permanent neurological damage and to reverse any existing symptoms [1,3]. Identification articles discussing CES can be beneficial in enhancing the treatment of this surgical emergency, improving the care of patients with CES, and assessing the medico-legal implications of this condition. Our objective was to identify the most impactful articles on CES and to analyze the characteristics of these articles. Review Methods In August 2021, we used the Web of Science Core Collection bibliographic database to query the key phrase “cauda equina syndrome.” Articles between 1900 and 2021 were included in the search, and non-English literature was excluded. Search categories included clinical neurology, surgery, orthopedics, and more. These articles were ranked based on the number of citations. We further sorted the results by excluding articles that did not solely focus on CES or were based on animal studies. Key information regarding each article was recorded, including title, first author, journal, year of publication, and the number of citations. Next, we listed the top 50 cited articles in rank order. The country of origin for each article was then recorded. In addition to these two lists, we sorted the articles by journal of publication, the decade of publication, the first author, the institution of origin, and the content of the article. How to cite this article Hawa A, Denasty A, Elmobdy K, et al. (April 24, 2023) The Most Impactful Articles on Cauda Equina Syndrome. Cureus 15(4): e38069. DOI 10.7759/cureus.38069  Results Top 50 Cited Publications A total of 2096 articles matched the search criteria. The top 50 most influential articles determined by the number of citations are listed in Table 1. These articles ranged from 43 to 439 in their number of citations, with a total number of 4406 citations among all papers. On average, each article had approximately 90 citations. Twelve publications had over 100 citations, with the most highly-cited article being Cauda equina syndrome after continuous spinal anesthesia by Rigler et al., published in 1991. The second-most cited paper was the work by Lambert et al. published in 1994, and the third in the number of citations was the article by Ahn et al. published in 2000 [7,8]. All articles on the list were published in English, with the year of publication ranging from 1938 to 2014. Number Year of Author Journal of Title of Article Publication Citations Rigler et al. 1991 Anesthesia and Analgesia 439 Cauda equina syndrome after continuous spinal anesthesia Irreversible conduction block in isolated nerve by high concentrations of Lambert et al. 1994 Anesthesiology 218 local anesthetics Cauda equina syndrome secondary to lumbar disc herniation: a meta- Ahn et al. 2000 Spine 206 analysis of surgical outcomes Assendelft et al. Complications of spinal manipulation: a comprehensive review of the 1996 Journal of Family Practice 174 literature Schildhauer et al. Journal of Orthopaedic Decompression and lumbopelvic fixation for sacral fracture-dislocations 2006 168 Trauma with spino-pelvic dissociation Intermittent claudication of the cauda equina: an unusual syndrome Blau et al. 1961 Lancet 155 resulting from central protrusion of a lumbar intervertebral disc The Journal of Bone and Kostuik et al. 1986 150 Cauda equina syndrome and lumbar disc herniation Joint Surgery British Journal of Cauda equina syndrome: what is the relationship between timing of Gleave et al. 2002 110 Neurosurgery surgery and outcome? Gardner et al. Cauda equina syndrome: a review of the current clinical and medico- 2011 European Spine Journal 106 legal position Bellabarba et al. Complications associated with surgical stabilization of high-grade sacral 2006 Spine 105 fracture dislocations with spino-pelvic instability Archives of Physical Cauda equina syndrome: a literature review of its definition and clinical Fraser et al. 2009 101 Medicine and Rehabilitation presentation Medical realities of cauda equina syndrome secondary to lumbar disc Shapiro 2000 Spine 101 herniation Drasner et al. Persistent sacral sensory deficit induced by intrathecal local anesthetic 1994 Anesthesiology 99 infusion in the rat Significance of the small lumbar spinal canal: cauda equina compression Ehni 1969 Journal of Neurosurgery 99 syndromes due to spondylosis (Part 1: Introduction) Shapiro 1993 Neurosurgery 99 Cauda equina syndrome secondary to lumbar disc herniation Local anesthetic distribution in a spinal model: a possible mechanism of Ross et al. 1992 Regional Anesthesia 96 neurologic injury after continuous spinal anesthesia Lambert et al. 1991 Anesthesia and Analgesia 93 Cauda equina syndrome and continuous spinal anesthesia Significance of the small lumbar spinal canal: cauda equina compression Wilson 1969 Journal of Neurosurgery 86 syndromes due to spondylosis (Part 3: Intermittent Claudication) Drasner et al. 1992 Anesthesiology 79 Cauda equina syndrome following intended epidural anesthesia 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 2 of 10  McCarthy et al. Cauda equina syndrome: factors affecting long-term functional and 2007 Spine 79 sphincteric outcome Journal of Neurosurgery: Timing of surgery in cauda equina syndrome with urinary retention: DeLong et al. 2008 77 Spine meta-analysis of observational studies Orendacova et 2001 Progress in Neurobiology 76 Cauda equina syndrome al. Hemorrhage into a lumbar synovial cyst causing an acute cauda equina Tatter et al. 1994 Journal of Neurosurgery 75 syndrome: case report Delamarter et al. 1991 Volvo Award in Experimental Studies – Cauda equina syndrome: 1991 Spine 72 neurologic recovery following immediate, early or late decompression Cauda equina syndrome treated by surgical decompression: the Qureshi et al. 2007 European Spine Journal 70 influence of timing on surgical outcome American Journal of Roentgenology Radium The effect of anatomic variations in lumbar vertebrae and spinal canal on Epstein et al. 1964 67 Therapy and Nuclear cauda equina and nerve root syndromes Medicine British Journal of Cauda equina syndrome: the timing of surgery probably does influence Todd 2005 66 Neurosurgery outcome Schoenecker et The Journal of Bone and Cauda equina syndrome after in situ arthrodesis for severe 1990 64 al. Joint Surgery spondylolisthesis at the lumbosacral junction British Journal of Cauda equina syndrome - What is the correlation between clinical Bell et al. 2007 63 Neurosurgery assessment and MRI scanning? Cauda equina syndrome following a single spinal administration of 5% Gerancher 1997 Anesthesiology 61 hyperbaric lidocaine through a 25-gauge Whitacre needle Balasubramanian British Journal of 2010 61 Reliability of clinical assessment in diagnosing cauda equina syndrome et al. Neurosurgery Kennedy et al. 1999 European Spine Journal 61 Predictors of outcome in cauda equina syndrome Diagnosis and prognosis of cauda equina syndrome produced by Shephard 1959 British Medical Journal 59 protrusion of lumbar disk Lavy et al. 2009 British Medical Journal 59 Cauda equina syndrome Time-dependent surgical outcomes Kohles et al. 2004 Spine 56 following cauda equina syndrome diagnosis: comments on a meta- analysis The Journal of Bone and Cauda equina syndrome as a complication of free epidural fat-grafting: a Prusick et al. 1988 53 Joint Surgery report of two cases and a review of the literature Bartleson et al. Cauda equina syndrome secondary to long-standing ankylosing 1983 Annals of Neurosurgery 53 spondylitis Russell et al. 1973 Annals of Internal Medicine 52 The cauda equina syndrome of ankylosing spondylitis Haldeman et al. Cauda equina syndrome in patients undergoing manipulation of the 1992 Spine 51 lumbar spine A urodynamic study of cauda equina syndrome due to lumbar disc Nielsen et al. 1980 Urologia Internationalis 51 herniation Ferguson et al. Paralysis of the bladder and associated neurological sequelae of spinal 1938 British Journal of Surgery 49 anaesthesia (cauda equina syndrome) Permanent paraparesis and cauda equina syndrome after epidural blood Diaz 2002 Anesthesiology 48 patch for postdural puncture headache Hellstrom et al. Late urodynamic findings after surgery for cauda equina syndrome 1986 Journal of Urology 48 caused by a prolapsed lumbar intervertebral disk Cauda equina syndrome secondary to idiopathic spinal epidural 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 3 of 10  Lisai et al. 2001 Spine 46 lipomatosis Cauda equina syndrome after spinal anaesthesia with hyperbaric 5% Acta Anaesthesiologica Loo et al. 1999 45 lignocaine: a review of six cases of cauda equina syndrome reported to Scandinavica the Swedish Pharmaceutical Insurance 1993-1997 Timing of surgical intervention in cauda equina syndrome: a systematic Chau et al. 2014 World Neurosurgery 45 critical review Journal of Spinal Disorders Olivero et al. 2009 45 Cauda equina syndrome (CES) from lumbar disc herniations & Techniques Journal of the American Spector et al. 2008 Academy of Orthopaedic 44 Cauda equina syndrome Surgeons Brown et al. 2001 Spine 44 Surgery for lumbar disc herniation during pregnancy Posterior epidural migration of a lumbar disc fragment Dosoglu et al. 2001 European Spine Journal 43 causing cauda equina syndrome: case report and review of the relevant literature TABLE 1: Top 50 cited publications listed as per rank order determined by the number of citations Countries of Origin Twelve countries were represented as countries of origin for these 50 articles (Table 2). The United States accounted for the greatest number of articles at 27. The United Kingdom produced 12, followed by Canada at two. The remaining represented countries produced one article each. Country Number of Articles United States of America 27 United Kingdom 12 Canada 2 Australia 1 Denmark 1 Finland 1 Ireland 1 Italy 1 Netherlands 1 Slovakia 1 Sweden 1 Turkey 1 TABLE 2: Countries of origin of the top 50 cited publications Top Journals of Publication Of all the journals represented in the top 50 list, Spine published the greatest number of articles with nine (Table 3). Anesthesiology accounted for the second-greatest number of publications at five. British Journal of Neurosurgery, European Spine Journal, and Journal of Neurosurgery published four articles each. Three more destination journals produced multiple publications. 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 4 of 10  Journal Number of Articles Spine 9 Anesthesiology 5 British Journal of Neurosurgery 4 European Spine Journal 4 Journal of Neurosurgery 4 The Journal of Bone and Joint Surgery 3 Anesthesia and Analgesia 2 British Medical Journal 2 TABLE 3: Most common journals that feature the top 50 cited articles Decades of Publication The 2000s was the most active decade in publishing articles on CES (20 articles), followed closely by the 1990s (15 papers published) as shown in Table 4. The oldest of the articles, Paralysis of the bladder and associated neurological sequelae of spinal anaesthesia (cauda equina syndrome) by Ferguson et al., was published in 1938. The most recent publication is the 2014 article by Chau et al. titled T iming of surgical intervention in cauda equina syndrome: a systematic critical review. Decade Number of Articles 2000s 20 1990s 15 1980s 5 1960s 4 2010s 3 TABLE 4: Most common decades of publication for the top 50 cited articles Top Authors Only two first authors produced multiple publications: Drasner [18,24], and Shapiro [17,20] (Table 5). Both of these authors published two articles each. The remaining 46 articles were published by unique first authors. First Author Number of Articles Drasner K 2 Shapiro S 2 TABLE 5: Authors with multiple first authorships in the top 50 cited publications Top Institutions of Publication A total of 42 institutions were affiliated with the top 50 articles (Table 6). Five institutions, four of which are located in the United States while one is located in the United Kingdom, accounted for multiple articles. The 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 5 of 10  University of California San Francisco contributed the greatest number of publications at four. The University of Washington followed with three publications. Each of the following institutions was credited with two publications: Brigham and Women’s Hospital, University Hospitals of Leicester, and Wishard Memorial Hospital. Institution Location Number of Articles University of California San Francisco San Francisco, California, USA 4 University of Washington Seattle, Washington, USA 3 Brigham and Women’s Hospital Boston, Massachusetts, USA 2 University Hospitals of Leicester Leicester, England, UK 2 Wishard Memorial Hospital Indianapolis, Indiana, USA 2 TABLE 6: Most common institutions of publication for the top 50 cited articles Paper Topics The top 50 cited articles were characterized into the following topics: disc herniations, anesthetic complications, the timing of surgical intervention, fractures/dislocations, and ankylosing spondylosis (Table 7). The most common topics were disc herniations and anesthetic complications, with 11 articles falling into each category. The next most-frequent topic was the timing of surgical interventions with six publications, followed by two each on fractures/dislocations and ankylosing spondylosis. Article Type Number of Articles Disc Herniations 11 Anesthetic Complications 11 Timing of Surgical Intervention 6 Fractures/Dislocations 2 Ankylosing Spondylosis 2 TABLE 7: Most common paper topics for the top 50 cited articles Discussion Cauda equina syndrome is a rare but serious condition resulting from the compression of specific sacral and lumbar nerve roots. Due to the relatively low incidence of this condition, the pathophysiology of CES remains unclear, and diagnosis remains challenging due to a lack of clarity in initial symptoms and their progression. It is estimated that clinical diagnosis of CES is associated with a false positive rate of 43%. No consensus for the exact symptoms of this condition has been reached, though CES commonly presents with sensory loss and bladder dysfunction, with the latter widely regarded as the most important factor to consider for diagnosis [55,56]. Additionally, symptoms such as back pain, bladder dysfunction, and weakness can often present under differing timelines, ranging from progressing rapidly over days to prolonged development over months. At its 2012 annual general meeting, the British Association of Spine Surgeons discussed the diagnosis and treatment of CES. The members agreed that clinical signals for CES are diverse with no predictive value of these signs on patient outcomes. The etiology of CES is also quite diverse, with causes ranging from disc degeneration to infection. The most common cause of CES is lumbar disc herniation. Additionally, CES can be induced operatively, through injury of the nerve roots during surgery. Complications associated with spinal manipulation therapies can also lead to CES, as discussed in the article by Assendelft et al. identified in this bibliometrics analysis. Further, it appears that CES following spinal anesthesia is an etiological factor of special consideration, as 11 of the 50 articles listed in this study discuss anesthetic-induced CES (Table 7). Treatment of CES most commonly involves surgical decompression, though some concerns about the 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 6 of 10  efficacy of surgical treatment have been raised. Additionally, the urgency of surgical decompression is controversial. It has generally been recommended that CES is treated with urgent surgery; though, some have argued that delays in surgery may be beneficial [57,58]. Due to the diversity in the development, presentation, and treatment of CES, an understanding of the top 50 cited articles discussing this condition can provide insights. The most highly cited article addressing CES is by Rigler et al. from 1991. This publication discusses four cases of CES in patients following continuous spinal anesthesia. Each patient was scheduled for a different operation, and various types and gauges of needles and catheters were utilized. Though there was diversity in the exact circumstances of each case, all involved the development of CES following spinal anesthetics. In all cases, a focal sensory block was indicated, suggesting maldistribution of the anesthetic. Additionally, a relatively high dose of the anesthetic was administered in all four patients. The authors propose a ceiling to local anesthetic dose as a potential solution for this complication. The publication with the second most citations is the 1994 article titled I rreversible conduction block in isolated nerve by high concentrations of local anesthetics , an immediate extension of the aforementioned most highly cited article. This publication aims to explain the development of CES in the four patients discussed previously. Specifically, this study explores the observed conduction blocks present following anesthesia. Desheathed frog sciatic nerves were isolated and exposed to varying concentrations and types of local anesthetics. It was observed that irreversible total conduction blockade was achieved in nerves exposed to 5% lidocaine or 0.5% tetracaine, whereas lower concentrations of these drugs only resulted in a partial block. The authors concluded that these local anesthetics were likely responsible for causing irreversible conduction block in the four cases of CES. The 2000 article by Ahn et al. has the third most citations. This study analyzes surgical outcomes of CES secondary to lumbar disc herniation, with a particular focus on clinical outcomes of patients with surgical decompression at varying lengths following the onset of symptoms. Forty-two citations met the inclusion criteria for this meta-analysis, translating to a total of 322 patient outcomes evaluated. There was no significant difference indicated in clinical outcome between patients treated with surgical intervention less than 24 hours post-CES onset, and those undergoing decompressive surgery between 24 and 48 hours following symptom onset. However, the study did find a significant difference in sensory, urinary, and rectal function in patients treated within 48 hours compared with those who were operated on following this 48- hour cutoff. The oldest of the top 50 articles titled Paralysis of the bladder and associated neurological sequelae of spinal anaesthesia (cauda equina syndrome), was published in 1938. This paper reports multiple cases in which patients developed symptoms consistent with CES following spinal anesthesia. Duracaine was specifically utilized as the anesthetic in all 14 of the cases, leading the authors to recommend the discontinuation of heavy use of this drug to achieve analgesia in patients. The most recently published article is the work by Chau et al.. This article, published in 2014, discusses the timing of surgical decompression in patients presenting with CES. Specifically, the relevance of the established time cutoff of 48 hours was assessed, and a temporal ceiling was also analyzed in the work by Ahn et al.. A literature review was conducted with five articles indicating analytical data relevant to this investigation. The authors found no evidence to support the merit of this highly-cited 48-hour cutoff; instead, they recommend surgical intervention “at the earliest practical opportunity.” The authors also conclude that many of the articles on this subject provide limited data and lack statistical significance to govern the treatment ideals of CES. Another article in the top 50 bearing particular magnitude is the work by Gleave et al.. This publication was one of the first to provide guidelines on categories of CES. The authors defined two subclasses of CES: incomplete cauda equina syndrome (CESI) and cauda equina syndrome with retention (CESR). Incomplete cauda equina syndrome is designated as CES with urinary complications, but in the absence of established urinary retention. On the other hand, CESR is defined as CES where the bladder is not under executive control, resulting in urinary retention and overflow incontinence. This highly-cited article presents definitions of the subcategories of CES. Lastly, some of the recurring topics in these articles need to be mentioned. One of the most commonly explored subjects within clinical studies, prompting the creation of a separate category in Table 7, is CES induced by anesthetic complications. Cauda equina syndrome secondary to ankylosing spondylitis is also a subject discussed in multiple articles (Table 7). The importance of the timing of surgical intervention is another topic of interest, likely due to its controversy. Within the top 50 cited articles, some conclude that patient outcome is time-dependent [8,26,32], while others establish no significant correlation between clinical success and the timing of the surgery [30,51]. It is evident that controversy regarding this issue continues to exist. Another significant topic within the top 50 cited articles is the potential for predictors of clinical outcomes, especially given the incertitude of the relevance of symptomatic signals discussed earlier. The article by McCarthy et al. was unable to find a correlation between various clinical factors and patient outcomes. Kennedy et al. similarly could not obtain a significant enough correlation to establish 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 7 of 10  definitive predictors of clinical success; though the authors did note that early diagnosis increased the probability of a positive outcome. The primary limitation of this study is the fluid nature of citations that could impact the order of the top 50 cited articles. The database was searched in August 2021, and it is likely that the citations may change at a future date. However, dramatic trend changes in the citations are unlikely. Another limitation is that only the English language was included in the search criteria, so highly-cited articles in other languages may have been excluded. Conclusions In conclusion, this study evaluated the most highly cited articles discussing CES. The United States produced the majority of these top 50 cited articles, with Spine publishing the greatest number of articles. Most of the articles were published in the 2000s, and a majority of the articles discussed CES in relation to disc herniations or anesthetic complications. The lack of clarity in pathophysiology, diagnosis, and treatment of this condition is evident upon analysis of the top cited articles on the syndrome. Controversy continues to exist regarding symptom presentation, clinical outcome predictors, and the efficacy of surgical intervention even among the most impactful articles on CES. Additional Information Disclosures Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work. References 1. Greenhalgh S, Finucane L, Mercer C, Selfe J: Assessment and management of cauda equina syndrome. Musculoskelet Sci Pract. 2018, 37:69-74. 10.1016/j.msksp.2018.06.002 2. Spector LR, Madigan L, Rhyne A, Darden B 2nd, Kim D: Cauda equina syndrome. J Am Acad Orthop Surg. 2008, 16:471-479. 10.5435/00124635-200808000-00006 3. Hoeritzauer I, Wood M, Copley PC, Demetriades AK, Woodfield J: What is the incidence of cauda equina syndrome? A systematic review. J Neurosurg Spine. 2020, 1-10. 10.3171/2019.12.SPINE19839 4. Kapetanakis S, Chaniotakis C, Kazakos C, Papathanasiou JV: Cauda equina syndrome due to lumbar disc herniation: a review of literature. Folia Med (Plovdiv). 2017, 59:377-386. 10.1515/folmed-2017-0038 5. Quaile A: Cauda equina syndrome—the questions. Int Orthop. 2019, 43:957-961. 10.1007/s00264-018-4208- 0 6. Rigler ML, Drasner K, Krejcie TC, Yelich SJ, Scholnick FT, DeFontes J, Bohner D: Cauda equina syndrome after continuous spinal anesthesia. Anesth Analg. 1991, 72:275-281. 10.1213/00000539-199103000-00001 7. Lambert LA, Lambert DH, Strichartz GR: Irreversible conduction block in isolated nerve by high concentrations of local anesthetics. Anesthesiology. 1994, 80:1082-1093. 10.1097/00000542-199405000- 00017 8. Ahn UM, Ahn NU, Buchowski JM, Garrett ES, Sieber AN, Kostuik JP: Cauda equina syndrome secondary to lumbar disc herniation: a meta-analysis of surgical outcomes. Spine. 2000, 25:1515-1522. 10.1097/00007632-200006150-00010 9. Assendelft WJ, Bouter LM, Knipschild PG: Complications of spinal manipulation: a comprehensive review of the literature. J Fam Pract. 1996, 42:475-480. 10. Schildhauer TA, Bellabarba C, Nork SE, Barei DP, Routt ML Jr, Chapman JR: Decompression and lumbopelvic fixation for sacral fracture-dislocations with spino-pelvic dissociation. J Orthop Trauma. 2006, 20:447-457. 10.1097/00005131-200608000-00001 11. Blau JN, Logue V: Intermittent Claudication of the cauda equina: an unusual syndrome resulting from central protrusion of a lumbar intervertebral disc. Lancet. 1961, 277:1081-1086. 10.1016/S0140- 6736(61)92310-8 12. Kostuik JP, Harrington I, Alexander D, Rand W, Evans D: Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am. 1986, 68:386-391. 13. Gleave JR, Macfarlane R: Cauda equina syndrome: what is the relationship between timing of surgery and outcome?. Br J Neurosurg. 2002, 16:325-328. 10.1080/0268869021000032887 14. Gardner A, Gardner E, Morley T: Cauda equina syndrome: a review of the current clinical and medico-legal position. Eur Spine J. 2011, 20:690-697. 10.1007/s00586-010-1668-3 15. Bellabarba C, Schildhauer TA, Vaccaro AR, Chapman JR: Complications associated with surgical stabilization of high-grade sacral fracture dislocations with spino-pelvic instability. Spine. 2006, 31:S80-S88. 10.1097/01.brs.0000217949.31762.be 16. Fraser S, Roberts L, Murphy E: Cauda equina syndrome: a literature review of its definition and clinical presentation. Arch Phys Med Rehabil. 2009, 90:1964-1968. 10.1016/j.apmr.2009.03.021 17. Shapiro S: Medical realities of cauda equina syndrome secondary to lumbar disc herniation. Spine. 2000, 25:348-352. 10.1097/00007632-200002010-00015 18. Drasner K, Sakura S, Chan VW, Bollen AW, Ciriales R: Persistent sacral sensory deficit induced by 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 8 of 10  intrathecal local anesthetic infusion in the rat. Anesthesiology. 1994, 80:847-852. 10.1097/00000542- 199404000-00018 19. Ehni G: Significance of the small lumbar spinal canal: cauda equina compression syndromes due to spondylosis. Part 1: introduction. J Neurosurg. 1969, 31:490-494. 10.3171/jns.1969.31.5.0490 20. Shapiro S: Cauda equina syndrome secondary to lumbar disc herniation. Neurosurgery. 1993, 32:743-747. 10.1227/00006123-199305000-00007 21. Ross BK, Coda B, Heath CH: Local anesthetic distribution in a spinal model: a possible mechanism of neurologic injury after continuous spinal anesthesia. Reg Anesth. 1992, 17:69-77. 22. Lambert DH, Hurley RJ: Cauda equina syndrome and continuous spinal anesthesia. Anesth Analg. 1991, 72:817-819. 10.1213/00000539-199106000-00018 23. Wilson CB: Significance of the small lumbar spinal canal: cauda equina compression syndromes due to spondylosis. Part 3: intermittent claudication. J Neurosurg. 1969, 31:499-506. 10.3171/jns.1969.31.5.0499 24. Drasner K, Rigler ML, Sessler DI, Stoller ML: Cauda equina syndrome following intended epidural anesthesia. Anesthesiology. 1992, 77:582-585. 10.1097/00000542-199209000-00025 25. McCarthy MJ, Aylott CE, Grevitt MP, Hegarty J: Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome. Spine. 2007, 32:207-216. 10.1097/01.brs.0000251750.20508.84 26. DeLong WB, Polissar N, Neradilek B: Timing of surgery in cauda equina syndrome with urinary retention: meta-analysis of observational studies. J Neurosurg Spine. 2008, 8:305-320. 10.3171/SPI/2008/8/4/305 27. Orendácová J, Cízková D, Kafka J, et al.: Cauda equina syndrome. Prog Neurobiol. 2001, 64:613-637. 10.1016/s0301-0082(00)00065-4 28. Tatter SB, Cosgrove GR: Hemorrhage into a lumbar synovial cyst causing an acute cauda equina syndrome. Case report. J Neurosurg. 1994, 81:449-452. 10.3171/jns.1994.81.3.0449 29. Delamarter RB, Sherman JE, Carr JB: 1991 Volvo Award in experimental studies. Cauda equina syndrome: neurologic recovery following immediate, early, or late decompression. Spine. 1991, 16:1022-1029. 30. Qureshi A, Sell P: Cauda equina syndrome treated by surgical decompression: the influence of timing on surgical outcome. Eur Spine J. 2007, 16:2143-2151. 10.1007/s00586-007-0491-y 31. Epstein BS, Epstein JA, Lavine L: The effect of anatomic variations in the lumbar vertebrae and spinal canal on cauda equina and nerve root syndromes. Am J Roentgenol Radium Ther Nucl Med. 1964, 91:1055-1063. 32. Todd NV: Cauda equina syndrome: the timing of surgery probably does influence outcome. Br J Neurosurg. 2005, 19:301-308. 10.1080/02688690500305324 33. Schoenecker PL, Cole HO, Herring JA, Capelli AM, Bradford DS: Cauda equina syndrome after in situ arthrodesis for severe spondylolisthesis at the lumbosacral junction. J Bone Joint Surg Am. 1990, 72:369- 377. 34. Bell DA, Collie D, Statham PF: Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning?. Br J Neurosurg. 2007, 21:201-203. 10.1080/02688690701317144 35. Gerancher JC: Cauda equina syndrome following a single spinal administration of 5% hyperbaric lidocaine through a 25-gauge Whitacre needle. Anesthesiology. 1997, 87:687-689. 10.1097/00000542-199709000- 00031 36. Balasubramanian K, Kalsi P, Greenough CG, Seetharam MPK: Reliability of clinical assessment in diagnosing cauda equina syndrome. Br J Neurosurg. 2010, 24:383-386. 10.3109/02688697.2010.505987 37. Kennedy JG, Soffe KE, McGrath A, Stephens MM, Walsh MG, McManus F: Predictors of outcome in cauda equina syndrome. Eur Spine J. 1999, 8:317-322. 10.1007/s005860050180 38. Shephard RH: Diagnosis and prognosis of cauda equina syndrome produced by protrusion of lumbar disk. Br Med J. 1959, 2:1434-1439. 10.1136/bmj.2.5164.1434 39. Lavy C, James A, Wilson-MacDonald J, Fairbank J: Cauda equina syndrome. BMJ. 2009, 338:b936. 10.1136/bmj.b936 40. Kohles SS, Kohles DA, Karp AP, Erlich VM, Polissar NL: Time-dependent surgical outcomes following cauda equina syndrome diagnosis: comments on a meta-analysis. Spine. 2004, 29:1281-1287. 10.1097/00007632- 200406010-00019 41. Prusick VR, Lint DS, Bruder WJ: Cauda equina syndrome as a complication of free epidural fat-grafting. A report of two cases and a review of the literature. J Bone Joint Surg Am. 1988, 70:1256-1258. 42. Bartleson JD, Cohen MD, Harrington TM, Goldstein NP, Ginsburg WW: Cauda equina syndrome secondary to long-standing ankylosing spondylitis. Ann Neurol. 1983, 14:662-669. 10.1002/ana.410140610 43. Russell ML, Gordon DA, Ogryzlo MA, McPhedran RS: The cauda equina syndrome of ankylosing spondylitis. Ann Intern Med. 1973, 78:551-554. 10.7326/0003-4819-78-4-551 44. Haldeman S, Rubinstein SM: Cauda equina syndrome in patients undergoing manipulation of the lumbar spine. Spine. 1992, 17:1469-1473. 10.1097/00007632-199212000-00005 45. Nielsen B, de Nully M, Schmidt K, Hansen RI: A urodynamic study of cauda equina syndrome due to lumbar disc herniation. Urol Int. 1980, 35:167-170. 10.1159/000280317 46. Ferguson FR, Watkins KH: Paralysis of the bladder and associated neurological sequelæ of spinal anæsthesia (cauda equina syndrome). Br J Surg. 1938, 25:735-752. 10.1002/bjs.18002510004 47. Diaz JH: Permanent paraparesis and cauda equina syndrome after epidural blood patch for postdural puncture headache. Anesthesiology. 2002, 96:1515-1517. 10.1097/00000542-200206000-00035 48. Hellström P, Kortelainen P, Kontturi M: Late urodynamic findings after surgery for cauda equina syndrome caused by a prolapsed lumbar intervertebral disk. J Urol. 1986, 135:308-312. 10.1016/s0022-5347(17)45621-7 49. Lisai P, Doria C, Crissantu L, Meloni GB, Conti M, Achene A: Cauda equina syndrome secondary to idiopathic spinal epidural lipomatosis. Spine. 2001, 26:307-309. 10.1097/00007632-200102010-00017 50. Loo CC, Irestedt L: Cauda equina syndrome after spinal anaesthesia with hyperbaric 5% lignocaine: a review of six cases of cauda equina syndrome reported to the Swedish Pharmaceutical Insurance 1993-1997. Acta Anaesthesiol Scand. 1999, 43:371-379. 10.1034/j.1399-6576.1999.430402.x 51. Chau AM, Xu LL, Pelzer NR, Gragnaniello C: Timing of surgical intervention in cauda equina syndrome: a systematic critical review. World Neurosurg. 2014, 81:640-650. 10.1016/j.wneu.2013.11.007 52. Olivero WC, Wang H, Hanigan WC, et al.: Cauda equina syndrome (CES) from lumbar disc herniations. J Spinal Disord Tech. 2009, 22:202-206. 10.1097/BSD.0b013e31817baad8 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 9 of 10  53. Brown MD, Levi AD: Surgery for lumbar disc herniation during pregnancy. Spine. 2001, 26:440-443. 10.1097/00007632-200102150-00022 54. Dösoğlu M, Is M, Gezen F, Ziyal MI: Posterior epidural migration of a lumbar disc fragment causing cauda equina syndrome: case report and review of the relevant literature. Eur Spine J. 2001, 10:348-351. 10.1007/s005860100300 55. Kuris EO, McDonald CL, Palumbo MA, Daniels AH: Evaluation and management of cauda equina syndrome. Am J Med. 2021, 134:1483-1489. 10.1016/j.amjmed.2021.07.021 56. Kostuik JP: Medicolegal consequences of cauda equina syndrome: an overview. Neurosurg Focus. 2004, 16:e8. 10.3171/foc.2004.16.6.7 57. Germon T, Ahuja S, Casey AT, Todd NV, Rai A: British Association of Spine Surgeons standards of care for cauda equina syndrome. Spine J. 2015, 15:S2-S4. 10.1016/j.spinee.2015.01.006 58. Todd NV: Cauda equina syndrome: is the current management of patients presenting to district general hospitals fit for purpose? A personal view based on a review of the literature and a medicolegal experience. Bone Joint J. 2015, 97-B:1390-1394. 10.1302/0301-620X.97B10.35922 2023 Hawa et al. Cureus 15(4): e38069. DOI 10.7759/cureus.38069 10 of 10