Questions & Answers

Mauffrey C, Randhawa K, Lewis C, Brewster M, Dabke H. Cauda equina syndrome: an anatomically driven review. Br J Hosp Med (Lond). 2008 Jun. 69(6):344-7. [Medline].
Rogers WK, Todd M. Acute spinal cord injury. Best Pract Res Clin Anaesthesiol. 2016 Mar. 30 (1):27-39. [Medline].
Olmarker K, Rydevik B, Hansson T, Holm S. Compression-induced changes of the nutritional supply to the porcine cauda equina. J Spinal Disord. 1990 Mar. 3(1):25-9. [Medline].
Delamarter RB, Sherman JE, Carr JB. 1991 Volvo Award in experimental studies. Cauda equina syndrome: neurologic recovery following immediate, early, or late decompression. Spine (Phila Pa 1976). 1991 Sep. 16(9):1022-9. [Medline].
Olmarker K, Rydevik B, Holm S. Edema formation in spinal nerve roots induced by experimental, graded compression. An experimental study on the pig cauda equina with special reference to differences in effects between rapid and slow onset of compression. Spine (Phila Pa 1976). 1989 Jun. 14(6):569-73. [Medline].
Olmarker K, Rydevik B, Holm S, Bagge U. Effects of experimental graded compression on blood flow in spinal nerve roots. A vital microscopic study on the porcine cauda equina. J Orthop Res. 1989. 7(6):817-23. [Medline].
Olmarker K, Holm S, Rydevik B. Importance of compression onset rate for the degree of impairment of impulse propagation in experimental compression injury of the porcine cauda equina. Spine (Phila Pa 1976). 1990 May. 15(5):416-9. [Medline].
Olmarker K, Holm S, Rosenqvist AL, Rydevik B. Experimental nerve root compression. A model of acute, graded compression of the porcine cauda equina and an analysis of neural and vascular anatomy. Spine (Phila Pa 1976). 1991 Jan. 16(1):61-9. [Medline].
Metser U, Lerman H, Blank A, Lievshitz G, Bokstein F, Even-Sapir E. Malignant involvement of the spine: assessment by 18F-FDG PET/CT. J Nucl Med. 2004 Feb. 45(2):279-84. [Medline].
Takahashi K, Olmarker K, Holm S, Porter RW, Rydevik B. Double-level cauda equina compression: an experimental study with continuous monitoring of intraneural blood flow in the porcine cauda equina. J Orthop Res. 1993 Jan. 11(1):104-9. [Medline].
Rydevik BL, Pedowitz RA, Hargens AR, Swenson MR, Myers RR, Garfin SR. Effects of acute, graded compression on spinal nerve root function and structure. An experimental study of the pig cauda equina. Spine (Phila Pa 1976). 1991 May. 16(5):487-93. [Medline].
Rydevik B. Neurophysiology of cauda equina compression. Acta Orthop Scand Suppl. 1993. 251:52-5. [Medline].
Pedowitz RA, Garfin SR, Massie JB, et al. Effects of magnitude and duration of compression on spinal nerve root conduction. Spine (Phila Pa 1976). 1992 Feb. 17(2):194-9. [Medline].
Todd NV. An algorithm for suspected cauda equina syndrome. Ann R Coll Surg Engl. 2009 May. 91(4):358-9; author reply 359-60. [Medline]. [Full Text].
Olivero WC, Wang H, Hanigan WC, et al. Cauda equina syndrome (CES) from lumbar disc herniations. J Spinal Disord Tech. 2009 May. 22(3):202-6. [Medline].
Kingwell SP, Curt A, Dvorak MF. Factors affecting neurological outcome in traumatic conus medullaris and cauda equina injuries. Neurosurgical Focus. 2008. 25(5):E7. [Medline].
Fujisawa H, Igarashi S, Koyama T. Acute cauda equina syndrome secondary to lumbar disc herniation mimicking pure conus medullaris syndrome--case report. Neurol Med Chir (Tokyo). 1998 Jul. 38(7):429-31. [Medline].
Raj D, Coleman N. Cauda equina syndrome secondary to lumbar disc herniation. Acta Orthop Belg. 2008 Aug. 74(4):522-7. [Medline].
Gleave JR, MacFarlane R. Prognosis for recovery of bladder function following lumbar central disc prolapse. Br J Neurosurg. 1990. 4(3):205-9. [Medline].
Gellido CL, Onesti S, Llena J. Spinal schistosomiasis. Neurology. 2000 Jan 25. 54(2):527. [Medline].
Waters JH, Watson TB, Ward MG. Conus medullaris injury following both tetracaine and lidocaine spinal anesthesia. J Clin Anesth. 1996 Dec. 8(8):656-8. [Medline].
Kothbauer K, Seiler RW. [Tethered spinal cord syndrome in adults]. Nervenarzt. 1997 Apr. 68(4):285-91. [Medline].
Widge AS, Tomycz ND, Kanter AS. Sacral preservation in cauda equina syndrome from inferior vena cava thrombosis. J Neurosurg Spine. 2009 Mar. 10(3):257-9. [Medline].
Rooney A, Statham PF, Stone J. Cauda equina syndrome with normal MR imaging. J Neurol. 2009 May. 256(5):721-5. [Medline].
Harrop JS, Hunt GE Jr, Vaccaro AR. Conus medullaris and cauda equina syndrome as a result of traumatic injuries: management principles. Neurosurg Focus. 2004 Jun 15. 16(6):e4. [Medline].
Fisher RG. Sacral fracture with compression of cauda equina: surgical treatment. J Trauma. 1988 Dec. 28(12):1678-80. [Medline].
Schizas C, Ballesteros C, Roy P. Cauda equina compression after trauma: an unusual presentation of spinal epidural lipoma. Spine (Phila Pa 1976). 2003 Apr 15. 28(8):E148-51. [Medline].
Thongtrangan I, Le H, Park J, Kim DH. Cauda equina syndrome in patients with low lumbar fractures. Neurosurg Focus. 2004 Jun 15. 16(6):e6. [Medline].
Haldeman S, Rubinstein SM. Cauda equina syndrome in patients undergoing manipulation of the lumbar spine. Spine (Phila Pa 1976). 1992 Dec. 17(12):1469-73. [Medline].
Muthukumar T, Butt SH, Cassar-Pullicino VN, McCall IW. Cauda equina syndrome presentation of sacral insufficiency fractures. Skeletal Radiol. 2007 Apr. 36(4):309-13. [Medline].
Kebaish KM, Awad JN. Spinal epidural hematoma causing acute cauda equina syndrome. Neurosurg Focus. 2004 Jun 15. 16(6):e1. [Medline].
Chen HJ, Liang CL, Lu K, Liliang PC, Tsai YD. Cauda equina syndrome caused by delayed traumatic spinal subdural haematoma. Injury. 2001 Jul. 32(6):505-7. [Medline].
Zuccarello M, Powers G, Tobler WD, Sawaya R, Hakim SZ. Chronic posttraumatic lumbar intradural arachnoid cyst with cauda equina compression: case report. Neurosurgery. 1987 Apr. 20(4):636-8. [Medline].
Raaf J. Removal of protruded lumbar intervertebral discs. J Neurosurg. 1970 May. 32(5):604-11. [Medline].
Kostuik JP, Harrington I, Alexander D, Rand W, Evans D. Cauda equina syndrome and lumbar disc herniation. J Bone Joint Surg Am. 1986 Mar. 68(3):386-91. [Medline].
Shapiro S. Cauda equina syndrome secondary to lumbar disc herniation. Neurosurgery. 1993 May. 32(5):743-6; discussion 746-7. [Medline].
Shapiro S. Medical realities of cauda equina syndrome secondary to lumbar disc herniation. Spine (Phila Pa 1976). 2000 Feb 1. 25(3):348-51; discussion 352. [Medline].
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 (Phila Pa 1976). 2000 Jun 15. 25(12):1515-22. [Medline].
Scott PJ. Bladder paralysis in cauda equina lesions from disc prolapse. J Bone Joint Surg. 1965. 47B:224-235.
Dinning TA, Schaeffer HR. Discogenic compression of the cauda equina: a surgical emergency. Aust N Z J Surg. 1993 Dec. 63(12):927-34. [Medline].
Shaw M, Birch N. Facet joint cysts causing cauda equina compression. J Spinal Disord Tech. 2004 Oct. 17(5):442-5. [Medline].
Ahn NU, Ahn UM, Nallamshetty L, et al. Cauda equina syndrome in ankylosing spondylitis (the CES-AS syndrome): meta-analysis of outcomes after medical and surgical treatments. J Spinal Disord. 2001 Oct. 14(5):427-33. [Medline].
Tullous MW, Skerhut HE, Story JL, et al. Cauda equina syndrome of long-standing ankylosing spondylitis. Case report and review of the literature. J Neurosurg. 1990 Sep. 73(3):441-7. [Medline].
Devlin GP, Sheppeard H. Cauda equina syndrome in ankylosing spondylitis diagnosed by computed tomography. N Z Med J. 1987 Oct 28. 100(834):651-2. [Medline].
Rubenstein DJ, Ghelman B. Case report 477: Cauda equina syndrome (CES) complicating long-standing ankylosing spondylitis (AS). Skeletal Radiol. 1988. 17(3):212-5. [Medline].
Indrieri RJ. Lumbosacral stenosis and injury of the cauda equina. Vet Clin North Am Small Anim Pract. 1988 May. 18(3):697-710. [Medline].
Baba H, Maezawa Y, Furusawa N, Imura S, Tomita K. The role of calcium deposition in the ligamentum flavum causing a cauda equina syndrome and lumbar radiculopathy. Paraplegia. 1995 Apr. 33(4):219-23. [Medline].
Schweitzer JS, Batzdorf U. Ependymoma of the cauda equina region: diagnosis, treatment, and outcome in 15 patients. Neurosurgery. 1992 Feb. 30(2):202-7. [Medline].
Anderson JR, Gullan RW. Paraganglioma of the cauda equina: a case report. J Neurol Neurosurg Psychiatry. 1987 Jan. 50(1):100-3. [Medline]. [Full Text].
Kagaya H, Abe E, Sato K, Shimada Y, Kimura A. Giant cauda equina schwannoma. A case report. Spine (Phila Pa 1976). 2000 Jan 15. 25(2):268-72. [Medline].
Bagley CA, Gokaslan ZL. Cauda equina syndrome caused by primary and metastatic neoplasms. Neurosurg Focus. 2004 Jun 15. 16(6):e3. [Medline].
Ampil FL, Mills GM, Burton GV. A retrospective study of metastatic lung cancer compression of the cauda equina. Chest. 2001 Nov. 120(5):1754-5. [Medline].
Saad F, Clarke N, Colombel M. Natural history and treatment of bone complications in prostate cancer. Eur Urol. 2006 Mar. 49(3):429-40. [Medline].
Natale M, Spennato P, Savarese L, Bocchetti A, Esposito S, Barbato R. Anaplastic oligodendroglioma presenting with drop metastases in the cauda equina. Clin Neurol Neurosurg. 2005 Aug. 107(5):417-20. [Medline].
den Boon J, Avezaat CJ, van der Gaast A, Koops W, Huikeshoven FJ. Conus-cauda syndrome as a presenting symptom of endodermal sinus tumor of the ovary. Gynecol Oncol. 1995 Apr. 57(1):121-5. [Medline].
Bourezgui M, Rafai MA, El Moutawakkil B, et al. [Cauda equina syndrome revealing neuroblastoma]. Rev Neurol (Paris). 2008 Dec. 164(12):1048-51. [Medline].
Lenehan B, Sullivan P, Street J, Dudeney S. Epidural abscess causing cauda equina syndrome. Ir J Med Sci. 2005 Jul-Sep. 174(3):88-91. [Medline].
Kapoor SK, Garg V, Dhaon BK, Jindal M. Tuberculosis of the posterior vertebral elements: a rare cause of compression of the cauda equina. A case report. J Bone Joint Surg Am. 2005 Feb. 87(2):391-4. [Medline].
Faraj A, Krishna M, Mehdian SM. Cauda equina syndrome secondary to lumbar spondylodiscitis caused by Streptococcus milleri. Eur Spine J. 1996. 5(2):134-6. [Medline].
Brecker SJ, Pugey CD. Nocardia asteroides infection of the cauda equina. J Neurol Neurosurg Psychiatry. 1988 Feb. 51(2):309-11. [Medline]. [Full Text].
Donovan DJ, Polly DW Jr, Ondra SL. The removal of a transdural pedicle screw placed for thoracolumbar spine fracture. Spine (Phila Pa 1976). 1996 Nov 1. 21(21):2495-8; discussion 2499. [Medline].
Rittmeister M, Leyendecker K, Kurth A, Schmitt E. Cauda equina compression due to a laminar hook: A late complication of posterior instrumentation in scoliosis surgery. Eur Spine J. 1999. 8(5):417-20. [Medline].
Mineiro J, Weinstein SL. Delayed postoperative paraparesis in scoliosis surgery. A case report. Spine (Phila Pa 1976). 1997 Jul 15. 22(14):1668-72. [Medline].
Ilias WK, Klimscha W, Skrbensky G, Weinstabl R, Widhalm A. Continuous microspinal anaesthesia: another perspective on mechanisms inducing cauda equina syndrome. Anaesthesia. 1998 Jul. 53(7):618-23. [Medline].
Wera GD, Dean CL, Nho S, et al. Cauda equina syndrome resulting from treatment of dural ectasia with fibrin glue injection. J Spinal Disord Tech. 2006 Apr. 19(2):148-50. [Medline].
Imran Y, Halim Y. Acute cauda equina syndrome secondary to free fat graft following spinal decompression. Singapore Med J. 2005 Jan. 46(1):25-7. [Medline].
Johnson ME. Potential neurotoxicity of spinal anesthesia with lidocaine. Mayo Clin Proc. 2000 Sep. 75(9):921-32. [Medline].
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 Apr. 43(4):371-9. [Medline].
Liu YC, Wu RS, Wong CS. Unexpected complication of attempted epidural anaesthesia: cauda equina syndrome. Anaesth Intensive Care. 2003 Aug. 31(4):461-4. [Medline].
Pouchot J, Si-Hassen C, Damade R, Bayeux MC, Mathieu A, Vinceneux P. Cauda equina compression by epidural lipomatosis in obesity. Effectiveness of weight reduction. J Rheumatol. 1995 Sep. 22(9):1771-5. [Medline].
Diaz JH. Permanent paraparesis and cauda equina syndrome after epidural blood patch for postdural puncture headache. Anesthesiology. 2002 Jun. 96(6):1515-7. [Medline].
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 Sep. 70(8):1256-8. [Medline].
Lambert DH. Bupivacaine spinal block cauda equina syndrome: why did it happen?. Anesthesiology. 2005 Jun. 102(6):1285-6; author reply 1287-8. [Medline].
Shaw A, Anwar H, Targett J, Lafferty K. Cauda equina syndrome versus saddle embolism. Ann R Coll Surg Engl. 2008 Sep. 90(6):W6-8. [Medline]. [Full Text].
O'Laughlin SJ, Kokosinski E. Cauda equina syndrome in a pregnant woman referred to physical therapy for low back pain. J Orthop Sports Phys Ther. 2008 Nov. 38(11):721. [Medline].
Bell DA, Collie D, Statham PF. Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning?. Br J Neurosurg. 2007 Apr. 21(2):201-3. [Medline].
Ma B, Wu H, Jia LS, Yuan W, Shi GD, Shi JG. Cauda equina syndrome: a review of clinical progress. Chin Med J (Engl). 2009 May 20. 122(10):1214-22. [Medline].
Bardin LD, King P, Maher CG. Diagnostic triage for low back pain: a practical approach for primary care. Med J Aust. 2017 Apr 3. 206 (6):268-273. [Medline].
Balzer JR, Rose RD, Welch WC, Sclabassi RJ. Simultaneous somatosensory evoked potential and electromyographic recordings during lumbosacral decompression and instrumentation. Neurosurgery. 1998 Jun. 42(6):1318-24; discussion 1324-5. [Medline].
Mathew P, Todd NV. Diagnosis of intradural conus and cauda equina tumours. Br J Hosp Med. 1993 Aug 18-31. 50(4):169-70, 172-4. [Medline].
Bell DA, Collie D, Statham PF. Cauda equina syndrome: what is the correlation between clinical assessment and MRI scanning?. Br J Neurosurg. 2007 Apr. 21(2):201-3. [Medline].
Coscia M, Leipzig T, Cooper D. Acute cauda equina syndrome. Diagnostic advantage of MRI. Spine. 1994 Feb 15. 19(4):475-8. [Medline].
Mailleux R, Redant C, Milbouw G. MR diagnosis of transdural disc herniation causing cauda equine syndrome. JBR-BTR. 2006 Nov-Dec. 89(6):303-5. [Medline].
Kikuchi M, Nagao K, Muraosa Y, Ohnuma S, Hoshino H. Cauda equina syndrome complicating pneumococcal meningitis. Pediatr Neurol. 1999 Feb. 20(2):152-4. [Medline].
Spencer TS, Campellone JV, Maldonado I, et al. Clinical and magnetic resonance imaging manifestations of neurosarcoidosis. Semin Arthritis Rheum. 2005. 34(4):649-661. [Medline].
Podnar S. Electromyography of the anal sphincter: which muscle to examine?. Muscle Nerve. 2003 Sep. 28(3):377-9. [Medline].
Joaquim AF, Powers A, Laufer I, Bilsky MH. An update in the management of spinal metastases. Arq Neuropsiquiatr. 2015 Sep. 73 (9):795-802. [Medline].
Gleave JR, Macfarlane R. Cauda equina syndrome: what is the relationship between timing of surgery and outcome?. Br J Neurosurg. 2002 Aug. 16(4):325-8. [Medline].
Hussain SA, Gullan RW, Chitnavis BP. Cauda equina syndrome: outcome and implications for management. Br J Neurosurg. 2003 Apr. 17(2):164-7. [Medline].
Institute for Clinical Systems Improvement (ICSI). Adult low back pain. Bloomington (MN): Institute for Clinical Systems Improvement (ICSI); 2008 Nov. [Full Text].
Michigan Quality Improvement Consortium. Management of acute low back pain. Southfield (MI): Michigan Quality Improvement Consortium; 2008 Mar. [Full Text].
Bussieres AE, Taylor JA, Peterson C. Diagnostic imaging practice guidelines for musculoskeletal complaints in adults-an evidence-based approach-part 3: spinal disorders. J Manipulative Physiol Ther. 2008 Jan. 31(1):33-88. [Medline]. [Full Text].
Herschorn S, Gajewski J, Ethans K, et al. Efficacy of botulinum toxin A injection for neurogenic detrusor overactivity and urinary incontinence: a randomized, double-blind trial. J Urol. 2011 Jun. 185(6):2229-35. [Medline].
Cruz F, Herschorn S, Aliotta P, et al. Efficacy and safety of onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity: a randomised, double-blind, placebo-controlled trial. Eur Urol. 2011 Oct. 60(4):742-50. [Medline].
Ginsberg D, et al. Phase 3 Efficacy and Safety Study of OnabotulinumtoxinA in Patients With Urinary Incontinence Due to Neurogenic Detrusor Overactivity. Presented at 107th Annual Meeting of the American Urological Association, Washington, DC. May, 2011.
McCarthy MJ, Aylott CE, Grevitt MP, Hegarty J. Cauda equina syndrome: factors affecting long-term functional and sphincteric outcome. Spine (Phila Pa 1976). 2007 Jan 15. 32(2):207-16. [Medline].
O'Laoire SA, Crockard HA, Thomas DG. Prognosis for sphincter recovery after operation for cauda equina compression owing to lumbar disc prolapse. Br Med J (Clin Res Ed). 1981 Jun 6. 282(6279):1852-4. [Medline]. [Full Text].
Weninger P, Schultz A, Hertz H. Conservative management of thoracolumbar and lumbar spine compression and burst fractures: functional and radiographic outcomes in 136 cases treated by closed reduction and casting. Arch Orthop Trauma Surg. 2009 Feb. 129(2):207-19. [Medline].
Sayegh FE, Kapetanos GA, Symeonides PP, Anogiannakis G, Madentzidis M. Functional outcome after experimental cauda equina compression. J Bone Joint Surg Br. 1997 Jul. 79(4):670-4. [Medline].
Goodman BP. Disorders of the Cauda Equina. Continuum (Minneap Minn). 2018 Apr. 24 (2, Spinal Cord Disorders):584-602. [Medline].

Media Gallery

Muscle groups, surface anatomy, peripheral sensory innervation, and dermatomes of the anterior lower limb. This image should be correlated with Tables 1 and 2 in the text. Image courtesy of Nicholas Y. Lorenzo, MD.
Muscle groups, surface anatomy, peripheral sensory innervation, and dermatomes of the posterior lower limb. This image should be correlated with Tables 1 and 2 in the text. Image courtesy of Nicholas Y. Lorenzo, MD.
Conus/epiconus infarction in the setting of sickle cell crisis. Image courtesy of Matthew J. Baker, MD.
Conus/epiconus infarction in the setting of sickle cell crisis in the same patient shown in the above image. Image courtesy of Matthew J. Baker, MD.
Conus/epiconus infarction in the setting of sickle cell crisis in the same patient shown in the images above. Image courtesy of Matthew J. Baker, MD.
Illustration demonstrating the relevant anatomy of the cauda equina region
Illustration demonstrating an example of cauda equina syndrome secondary to a spinal neoplasm
Sagittal MRI of a patient with cauda equina syndrome secondary to a large lumbar disk herniation
Epidural abscess with effacement of thecal sac in a 56-year-old man.

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Table 1. Symptoms and Signs of Conus Medullaris and Cauda Equina Syndromes

	Conus Medullaris Syndrome	Cauda Equina Syndrome
Presentation	Sudden and bilateral	Gradual and unilateral
Reflexes	Knee jerks preserved but ankle jerks affected	Both ankle and knee jerks affected
Radicular pain	Less severe	More severe
Low back pain	More	Less
Sensory symptoms and signs	Numbness tends to be more localized to perianal area; symmetrical and bilateral; sensory dissociation occurs	Numbness tends to be more localized to saddle area; asymmetrical, may be unilateral; no sensory dissociation; loss of sensation in specific dermatomes in lower extremities with numbness and paresthesia; possible numbness in pubic area, including glans penis or clitoris
Motor strength	Typically symmetric, hyperreflexic distal paresis of lower limbs that is less marked; fasciculations may be present	Asymmetric areflexic paraplegia that is more marked; fasciculations rare; atrophy more common
Impotence	Frequent	Less frequent; erectile dysfunction that includes inability to have erection, inability to maintain erection, lack of sensation in pubic area (including glans penis or clitoris), and inability to ejaculate
Sphincter dysfunction	Urinary retention and atonic anal sphincter cause overflow urinary incontinence and fecal incontinence; tend to present early in course of disease	Urinary retention; tends to present late in course of disease

Table 2. Pain and Deficits Associated with Specific Nerve Roots

Nerve Root	Pain	Sensory Deficit	Motor Deficit	Reflex Deficit
L2	Anterior medial thigh	Upper thigh	Slight quadriceps weakness; hip flexion; thigh adduction	Slightly diminished suprapatellar
L3	Anterior lateral thigh	Lower thigh	Quadriceps weakness; knee extension; thigh adduction	Patellar or suprapatellar
L4	Posterolateral thigh, anterior tibia	Medial leg	Knee and foot extension	Patellar
L5	Dorsum of foot	Dorsum of foot	Dorsiflexion of foot and toes	Hamstrings
S1-2	Lateral foot	Lateral foot	Plantar flexion of foot and toes	Achilles
S3-5	Perineum	Saddle	Sphincters	Bulbocavernosus; anal

Table 3. Root and Peripheral Nerve Innervation of the Lumbosacral Plexus

Muscle	Nerve	Root
Iliopsoas	Femoral	L2, 3, 4
Adductor longus	Obturator	L2, 3, 4
Gracilis	Obturator	L2, 3, 4
Quadriceps femoris	Femoral	L2, 3, 4
Anterior tibial	Deep peroneal	L4, 5
Extensor hallucis longus	Deep peroneal	L4, 5
Extensor digitorum longus	Deep peroneal	L4,5
Extensor digitorum brevis	Deep peroneal	L4, 5, S1
Peroneus longus	Superficial peroneal	L5, S1
Internal hamstrings	Sciatic	L4, 5, S1
External hamstrings	Sciatic	L5, S1
Gluteus medius	Superior gluteal	L4, 5, S1
Gluteus maximus	Inferior gluteal	L5, S1, 2
Posterior tibial	Tibial	L5, S1
Flexor digitorum longus	Tibial	L5, S1
Abductor hallucis brevis	Tibial (medial plantar)	L5, S1, 2
Abductor digiti quinti pedis	Tibial (lateral plantar)	S1, 2
Gastrocnemius lateral	Tibial	L5, S1, 2
Gastrocnemius medial	Tibial	S1, 2
Soleus	Tibial	S1, 2

Table 4. Cauda Equina Versus Conus Medullaris Syndrome

Features	Cauda Equina Syndrome	Conus Medullaris
Vertebral level	L2-sacrum	L1-L2
Spinal level	Injury to the lumbosacral nerve roots	Injury of the sacral cord segment (conus and epiconus) and roots
Severity of symptoms and signs	Usually severe	Usually not severe
Symmetry of symptoms and signs	Usually asymmetric	Usually symmetric
Pain	Prominent, asymmetric, and radicular	Usually bilateral and in the perineal area
Motor	Weakness to flaccid paralysis	Normal motor function to mild or moderate weakness
Sensory	Saddle anesthesia, may be asymmetric	Symmetric saddle distribution, sensory loss of pin prick, and temperature sensations (Tactile sensation is spared.)
Reflexes	Areflexic lower extremities; bulbocavernosus reflex is absent in low CE (sacral) lesions	Areflexic lower extremities (If the epiconus is involved, patellar reflex may be absent, whereas bulbocavernosus reflex may be spared.)
Sphincter and sexual function	Usually late and of lesser magnitude; lower sacral roots involvement can cause bladder, bowel, and sexual dysfunction	Early and severe bowel, bladder, and sexual dysfunction that results in a reflexic bowel and bladder with impaired erection in males
EMG	Multiple root level involvement; sphincters may also be involved	Mostly normal lower extremity with external anal sphincter involvement
Outcome	May be favorable compared with conus medullaris syndrome	The outcome may be less favorable than in patients with CES

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Author

Segun Toyin Dawodu, JD, MD, MS, MBA, LLM, FAAPMR, FAANEM Attending Interventional Physiatrist, Wellspan Health

Segun Toyin Dawodu, JD, MD, MS, MBA, LLM, FAAPMR, FAANEM is a member of the following medical societies: American College of Sports Medicine, American Academy of Physical Medicine and Rehabilitation, Royal College of Surgeons of England, American Association of Neuromuscular and Electrodiagnostic Medicine, American Medical Association, American Medical Informatics Association, Association of Academic Physiatrists, International Society of Physical and Rehabilitation Medicine

Disclosure: Nothing to disclose.

Coauthor(s)

Kirsten A Bechtel, MD Associate Professor of Pediatrics, Section of Pediatric Emergency Medicine, Yale University School of Medicine; Co-Director, Injury Free Coalition for Kids, Yale-New Haven Children's Hospital

Kirsten A Bechtel, MD is a member of the following medical societies: American Academy of Pediatrics

Disclosure: Nothing to disclose.

Michael S Beeson, MD, MBA, FACEP Professor of Emergency Medicine, Northeastern Ohio Universities College of Medicine and Pharmacy; Attending Faculty, Akron General Medical Center

Michael S Beeson, MD, MBA, FACEP is a member of the following medical societies: American College of Emergency Physicians, National Association of EMS Physicians, Council of Emergency Medicine Residency Directors, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Scott D Hodges, DO Consulting Surgeon, Department of Orthopedic Surgery, Center for Sports Medicine and Orthopedics

Scott D Hodges, DO is a member of the following medical societies: American Academy of Disability Evaluating Physicians, American Medical Association, American Osteopathic Association, American Spinal Injury Association, North American Spine Society, Southern Medical Association, Southern Orthopaedic Association, Tennessee Medical Association

Disclosure: Received royalty from Medtronic for consulting; Received royalty from Biomet Spine for consulting.

S Craig Humphreys, MD Orthopedic Spine Surgeon, Department of Orthopedic Surgery, Center for Sports Medicine and Orthopedics

S Craig Humphreys, MD is a member of the following medical societies: American Spinal Injury Association, Alpha Omega Alpha, American Academy of Orthopaedic Surgeons, American Medical Association, North American Spine Society, Southern Medical Association, Southern Orthopaedic Association, Tennessee Medical Association

Disclosure: Nothing to disclose.

James F Kellam, MD, FRCSC, FACS, FRCS(Ire) Professor, Department of Orthopedic Surgery, University of Texas Medical School at Houston

James F Kellam, MD, FRCSC, FACS, FRCS(Ire) is a member of the following medical societies: American Academy of Orthopaedic Surgeons, Orthopaedic Trauma Association, Royal College of Physicians and Surgeons of Canada

Disclosure: Nothing to disclose.

Specialty Editor Board

Francisco Talavera, PharmD, PhD Adjunct Assistant Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Received salary from Medscape for employment. for: Medscape.

J Stephen Huff, MD, FACEP Professor of Emergency Medicine and Neurology, Department of Emergency Medicine, University of Virginia School of Medicine

J Stephen Huff, MD, FACEP is a member of the following medical societies: American Academy of Neurology, American College of Emergency Physicians, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Chief Editor

Nicholas Lorenzo, MD, MHA, CPE Co-Founder and Former Chief Publishing Officer, eMedicine and eMedicine Health, Founding Editor-in-Chief, eMedicine Neurology; Founder and Former Chairman and CEO, Pearlsreview; Founder and CEO/CMO, PHLT Consultants; Chief Medical Officer, MeMD Inc

Nicholas Lorenzo, MD, MHA, CPE is a member of the following medical societies: Alpha Omega Alpha, American Academy of Neurology, American Association for Physician Leadership

Disclosure: Nothing to disclose.

Additional Contributors

Milind J Kothari, DO Professor, Department of Neurology, Pennsylvania State University College of Medicine; Consulting Staff, Department of Neurology, Penn State Milton S Hershey Medical Center

Milind J Kothari, DO is a member of the following medical societies: American Academy of Neurology, American Neurological Association, American Association of Neuromuscular and Electrodiagnostic Medicine

Disclosure: Nothing to disclose.

Acknowledgements

The authors and editors of Medscape Reference gratefully acknowledge the contributions of previous author Jason C Eck, DO, MS,to the development and writing of a source article.

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