Cauda Equina Syndrome Basics


Cauda Equina Syndrome Definition


Cauda Equina Syndrome- is collection of symptoms due to a spinal nerve root disorder caused by injury to the cauda equina located in the spinal canal of the lumbar and sacral spine. The cauda equina transmits signals to and from the spinal cord (part of the central nervous system); relaying signals to and from the lower extremities, genitalia, lower abdomen, bladder, and rectal sphincters back to the spinal cord.


The cauda equina is currently classified as part of the peripheral nervous system as it is made up of lower motor neurons and the spinal cord and brain are made up of upper motor neurons. This is the reason Cauda Equina Syndrome is NOT a spinal cord injury, even though it resides within the spinal canal, the meninges, and cerebral spinal fluid.


Cauda Equina Syndrome Stages


There are three stages of Cauda Equina Syndrome; Acute, Potential Recovery Stage, and Chronic Cauda Equina Syndrome. (Potential Recovery Stage is not a currently recognized stage of Cauda Equina Syndrome by medical literature, however, there is no name for the phase between initial diagnosis/acute and chronic Cauda Equina Syndrome.)


Acute Cauda Equina Syndrome- A series of symptoms that arise from acute injury of the cauda equina. This means that the injury has just happened or is currently happening. This stage requires immediate evaluation by emergency medical teams. If you think you have Red Flag Symptoms of Cauda Equina Syndrome, seek emergency evaluation at the nearest emergency room. With timely treatment, Acute Cauda Equina Symptoms can be reversed or worsening can be stopped. Treatment MUST occur in the first 48 hours from ONSET of symptoms for the best patient outcomes. It is important to note that not all causes of Cauda Equina Syndrome have a treatment at this time. 


Acute Cauda Equina Syndrome Symptoms

Symptoms of Acute Cauda Equina Syndrome Include:

  • bladder and/or bowel dysfunction (incontinence is a late sign and has the poorest prognosis)

  • paresthesia and/or anesthesia of the lower extremities, lower abdomen, perineum, and/or genitalia

  • sciatica, usually bilateral, but not always

  • severe lower back pain

  • lower extremity weakness

  • abnormal and/or absent reflexes

  • foot drop

  • hip drop

  • gait disturbances and/or inability to walk

  • abnormal proprioception

  • sexual dysfunction

Patients do not have to have all of these symptoms to be diagnosed with Cauda Equina Syndrome. Nor do the symptoms need to be bilateral, although that is the most common. Note that one side is usually affected more than the other, but not in all cases. Additionally, not all patients realize they have paresthesia until a health care provider touches them.

The most common reason for misdiagnosis of Cauda Equina Syndrome is the misconception that a patient must have incontinence and/or saddle anesthesia. THIS IS WRONG. While highly likely that there is bladder and/or bowel involvement in Acute Cauda Equina Syndrome, there are cases where individuals do not have any saddle anesthesia and/or bladder/bowel involvement. This is why MRI is so important to rule it out, if a patient has multiple RED Flag Symptoms, the only way to rule out CES is imaging; the gold standard being MRI. Click here to learn more about the symptoms of Acute Cauda Equina Syndrome.


Causes of Acute Cauda Equina Syndrome include: 

  • disk herniation (most common)

  • tumor

  • spinal stroke

  • blood clot

  • infections (including Tuberculosis)

  • meningitis 

  • traumas

  • lumbar surgery

  • epidural steroid injections (esi)

  • epidurals

  • childbirth

  • shearing (sudden stretching of the cauda equina)

  • tethered cord

  • hematomas

  • neuroinflammation

  • accidental injury during lumbar procedures 

  • Arachnoiditis

  • Adhesive Arachnoiditis

  • broken vertebrae

  • other unknown causes (given the limited amount of CES research, this list is still growing)

  • Cancer

  • Chemotherapy

  • Radiation


Potential Recovery Stage Cauda Equina Syndrome (PRS CES)- The stage after initial treatment expected recovery time when treatment is possible as not all causes of CES are treatable but before 24 months. This timeframe is the greatest chance of recovery of function and reversal of deficits. (This is not an official stage recognized by medical literature, but is a gray area without a name.)


Chronic Cauda Equina Syndrome- A patient that has been diagnosed with CES and has not made a full recovery in 24 months. These individuals will likely have the symptoms they are experiencing at 24 months for the rest of their lives with periods of flare-ups. These individuals can make small and slow recoveries over many years with proper therapy and treatments.


Chronic Cauda Equina Syndrome Symptoms


Common member reported symptoms of Chronic CES PLUS Neuroinflammation Symptoms and increased risks of other co-morbidities including:


  • Chronic and Chronic Intractable Pain

  • Electric Shocks

  • Tremors

  • Flare-ups of Neuroinflammation causing increase in symptoms

  • Chronic Pain

  • Intractable Pain

  • Lower Extremity Swelling and Poor Circulation (slowed healing of wounds)

  • Poor Temperature Regulation of the Lower Extremities

  • Falls and increased risks of fall-related injuries, subsequent hospital admissions, and subsequent surgeries to repair fall-related injuries

  • Mental Health Disorders including Depression, Anxiety, and PTSD

  • Musculoskeletal Pain from Compensatory Gait Imbalances

  • Higher risks of osteoporosis from medication side effects and lack of mobility and weight-bearing

  • Obesity and subsequent co-morbidities,

  • Higher risks of blood clots and associated risks, pulmonary embolism and stroke

  • Higher risks of heart disease

  • Higher risks of diabetes

  • Changes in bone structure due to joint instability

  • Shoulder disorders due to assistive walking devices and wheelchair use

  • Increased risks of pressure sores and associated infections

  • Chronic Urinary Tract Infections

  • Chronic Constipation

  • Restless Back Syndrome (Exactly like Restless Leg Syndrome except in the Back and not associated with Secondary Restless Leg Syndrome)

  • Pseudodementia “Brain Fog”

  • Fatigue

  • Sciatica (usually bilateral)

  • Radiculopathy

  • Neuropathy

  • Social Economical Devastation (due to decreased ability to work or complete inability to work)

  • Facet Arthropathy

  • Facet Hypertrophy

  • Spinal Instability

  • Failed Back Surgery Syndrome

  • Arachnoiditis

  • Bladder Dysfunction

  • Bowel dysfunction

  • Paresthesia and/or anesthesia of the lower extremities and genitalia

  • *Severe Lower Back Pain

  • Lower extremity weakness

  • Abnormal or absent reflexes

  • Foot drop (can be unilateral or bilateral)

  • Hip drop

  • Gait Disturbances,

  • Abnormal Proprioception

  • Sexual Dysfunction

  • Adhesive Arachnoiditis

  • Spasticity (Food for thought. CES is a peripheral nervous system injury, spasticity should not be possible, other than in the bladder. We know the cauda equina is not a central nervous system disorder, and therefore not a spinal cord injury because the cauda equina is made up of lower motor neurons. Does this mean that the cauda equina has its own characteristics different from peripheral nerves outside of the spinal column? We don’t know, research is needed.)



Not every Chronic Cauda Equina Syndrome patient has every symptom listed, however, this is a list of the most common symptoms reported by our members. Many have one side worse than the other, but usually have bilateral symptoms. Rarely will only one side be affected, but it is reported. We are currently involved in a Delphi Study to determine the most important patient outcomes to those with Cauda Equina Syndrome. 



Cauda Equina Syndrome Severity Classifications


In addition to  Acute, PRS, and Chronic Cauda Equina Syndrome, there are classifications of severity of Cauda Equina Syndrome, currently in literature Incomplete Cauda Equina Syndrome (CES-I) and Complete Cauda Equina Syndrome (CES-C). Some literature, particularly outside of the United States, classify CES-C as CES-R or retention, for the purpose of our education we will use CES-R for High-Risk Cauda Euqina Syndrome.


High-Risk Cauda Equina Syndrome 


High-Risk Cauda Equina Syndrome, CES-R, is a classification for individuals showing mild RED Flag Symptoms of Cauda Equina Syndrome but do not have evidence of emergent need for surgery or treatment on imaging, nor are they officially diagnosed with Cauda Equina Syndrome. These patient require close monitoring, education, and a treatment plan.


CES-R patients may have more conservative treatments including physical therapy, pain management, inflammation treatment, and very close monitoring. When the cause of CES-R is a mechanical reason, something that can be fixed surgically, some physicians will choose to proceed with surgical repair to prevent Cauda Equina Syndrome.  It is important to note that individuals that have CES-R can transition to Incomplete or Complete Cauda Equina Syndrome at any moment, depending on what is causing the symptoms. There have been patient reported cases of transitioning from CES-R to CES-I from sneezing, vacuuming, tripping, falling, and "waking up with it". Patient education is extremely important for patients that are on a conservative treatment plan, particularly when to return to the emergency department and activities to avoid.




23-hour observation, neurosurgery consult, pain management, fall precautions, spinal precautions, blood clot prevention, patient education, pressure sore prevention (remember these patients might have decreased mobility and sensation). The neurosurgeon will make further recommendations and more in-depth treatment plan. 


The definition of CES-I, in literature, is Cauda Equina Syndrome in which an individual is NOT incontinent. These individuals may or may not have bladder dysfunction, urinary retention, urinary leakage, and trouble initiating and maintaining flow, they may even need to catheterize at times, and have chronic urinary tract infections, however, they are NOT incontinent. Unfortunately, this same individual can have every other issue listed above in the Chronic CES list but because they are not incontinent they are not considered complete for severity scoring.


Complete CES is defined as individuals with CES that have incontinence. These individuals may also have every symptoms off of the Chronic CES list, however, even when they only have incontinence (as horrible as that is) they are not as severe as someone with CES-I that also has many symptoms on the Chronic CES list of symptoms. For this reason, Cauda Equina Foundation is working to develop a better scoring system. In some countries, the CES-I or CES-C classification determines eligibility for services and assistance and with the current scoring system, this is a major disservice to those individuals with catastrophic CES that are still considered incomplete.


Perhaps additional scoring will include catastrophic CES in which individuals that have “x” number of devastating symptoms are classified? Only research will tell.

Acute Cauda Equina Syndrome-



Acute Cauda Equina Syndrome (CES) is a medical emergency in which there is pathology currently causing damage to the cauda equina. Acute Cauda Equina Syndrome requires emergency evaluation, timely diagnosis, and emergent treatment to reverse and/or stop the worsening of the symptoms of Cauda Equina Syndrome. 

i. Red Flag symptoms include:
  1. Decreased or Different sensation in the Saddle area. This is also called Saddle Paraesthesia or Anesthesia. This is the area of the body that when sitting on a horse touches a saddle. Some individuals notice that they cannot feel when they go to the bathroom or wipe. The degree of numbness can vary, the more numbness the more severe. 

  2. Sciatica or Radiculopathy on one or both sides; most cases will be on both sides. One sided is rare.

  3. Severe Back Pain

  4. Weakness and/or pain in one or both legs; most cases this will be on both legs with one leg worse than the other. 

  5. Neurological Deficits (changes in sensation, coordination, proprioception, reflexes, clonus). The changes in sensation can be subtle to full numbness with one side of the body affected more than the other. The numbness can also be worse in different areas of the legs and better in others. This is dependent on which nerves are affected the most severely. Poor coordination can lead to falls, tripping, or inability to change directions or suddenly stop while walking. Proprioception is knowing where your appendages are in relation to your body. For instance, one example is if someone were to tell you to close your eyes and they move your toes and ask you, "Did I move your toe up or down? When an individual is not able to appropriately answer this question, it is because their proprioception is abnormal indicating neurological abnormalities. When the reflexes are diminished, hyper-reactive, or absent, this indicates neurological abnormalities. Reflexes can be worse in one leg than the other, or completely normal in one leg and not the other. Strength can be diminished when nerves are not adequately sending a signal into the muscles to contract. This again may be worse in one leg or the other. Clonus is abnormal muscle contractions and jerking motions that can be made worse with stimulus. This represents abnormal neurological function. If an individual has one or more neuro deficits with other Red Flag symptoms, an MRI to rule out cauda equina syndrome is warranted and recommended. 

  6. Bladder and/or Bowel disturbances including hesitancy and/or retention; incontinence is a late sign of Cauda Equina Syndrome and while it still requires emergency evaluation, it is considered a White Flag Symptom (poor prognosis). 

  7. Sexual Dysfunction (usually found in slow-onset Cauda Equina Syndrome). This can include vaginal dryness, vaginal prolapse, erectile dysfunction. Acute Cauda Equina Syndrome patients will typically not know if they have sexual dysfunction until after attempting sexual engagement post-diagnosis. This is due to the severe pain associated with Acute Cauda Equina Syndrome. Slow-Onset Cauda Equina Syndrome, individuals may have good days and bad days allowing them to engage sexually. These are the individuals that may be aware of sexual dysfunction. However, it is recommended to always ask the individual if they have noticed any changes in their sexual health. 


Other patient-reported symptoms to be aware of in assessing risks and likelihood of Cauda Equina Syndrome. Note: These symptoms are commonly reported by members of Cauda Equina Foundation but are not yet well studied or reported in patient outcomes. These symptoms have been reported by both Acute and Chronic Cauda Equina Syndrome patients. 

  1. Electrical shock pain in the legs, hips, buttocks, groin, rectum, genitalia, feet. This is sometimes described as "being poked with a cattle prod", or "stabbed with a hot poker".

  2. Patient description of feeling "like bugs are crawling over the skin".

  3. Painful pins and needles or tingling anywhere below the belly button.

  4. Severe muscle spasms, cramps, descriptions of clonus or spasticity.

  5. Changes in temperature of the lower extremities. Always cold or hot.

  6. Swelling of the lower extremities

  7. Decreased skin integrity, longer healing times for abrasions

  8. The feeling of constantly having a "wedgie"

  9. Rectal, genital, bladder spasms

  10. Dull deep aches in the legs

Initial Recovery After Acute Cauda Equina Syndrome:

This phase is post-treatment-diagnosis of Cauda Equina Syndrome. The initial recovery stage is where there is a need for the most support and education for the patient and their families. Cauda Equina Syndrome is a family diagnosis, and as such, can change family dynamics and social-economical status. Patients needs can include physical and occupational therapy evaluations and plans, pain management, assistive devices/technology assessments and education, functional wheelchair assessment and fittings, social work and services consults, possible home evaluations (ramps, widening of doorways), driving accommodations and evaluations, transportation accommodations, both patient and family counseling, and food assistance. It is imperative to send patients newly diagnosed with Cauda Equina Syndrome home with a plan for healing, recovery, and guidance to independence. 


Patients with newly diagnosed Cauda Equina Syndrome may need complete care initially. They will be limited in their ability and on physicians directions to not lift, bend, twist, or do most household chores nor strenuous activity. They may also not be cleared to return to work for several weeks to months. Depending on their occupation, they may need to change occupations. Some individuals are not able to return to working status due to the severity of their symptoms and lack of recovery.


It is important to understand that Cauda Equina Syndrome is a chronic illness, NOT a bad back. A syndrome is a collection of symptoms making up an illness. The surgery and initial treatments may prevent further damage, with the goal of completely reversing the damage in all patients. At the current time, many individuals do not fully recover physically. It is certainly okay to encourage individuals towards independence, however, it is equally important to understand that the individuals may need help in learning how to live and function again. They must have a support system that is able to help them with their limitations. Many individuals, even those with full recovery, are restricted from certain actions for the rest of their lives.  Such actions are repetitive movements, like sweeping and vaccuming, lifting over 10lbs, and high impact activites, such as running and jumping. The physician is the best person to talk to about any physical restrictions placed on an individual. They may have to adapt how they used to do things, such as laundry, grocery shopping, and cooking. Please understand that the families expectations of recovery must be realistic to aid healing of the individual. Expected recovery is explained below.  


Recovery is greatest in the first 18-24 months after initial diagnosis. However, small, slow improvements can still be made after the 24 months. The first several months following treatment for cauda equina syndrome are the most intense as far as individuals reliance on others for basic necessities in life, such as eating, bathing, and dressing. These are called activieties of daily living (ADL). Physical and occupational therapy can help individuals gain their independance in their ADL's, however, it is improtant to understand that not all individuals will recover full independence. Some individuals become fully independent with adaptations and accessible equipment, others cannot. Those that do not will need help with adapting ADL's to fit their limitations, and may need permanent caregivers to help them throughout their lives. 



Prognosis is almost impossible to determine before the first 18-24 months, due to the inflammatory process of healing. However, the prognosis is determinant on the severity of the injury, slow onset vs. sudden onset, classification of cauda equina syndrome at the time of diagnosis, surgical technique, time from onset of symptoms to treatment, and other factors not yet understood. Patients that do not have Complete Cauda Equina Syndrome, and have treatment in under 48 hours of onset of symptoms have the best prognosis for full recovery. Patient outcomes are currently under investigation. 



After the patient’s symptoms of cauda equina remain unchanged for a period of time or do not fully resolve after 24 months. They are then classified as having Chronic Cauda Equina Syndrome. 
It is important to note that not all patients end up with Chronic Cauda Equina Syndrome, but those that do are not expected to return to their pre-CES selves, though they can make slow improvements with proper care over time.

ii.Pathophysiology (What happens)

iii.Etiology (Causes)

a. Herniated disk (most common)
b. Tumors
c. Epidurals
d. Trauma- falls, accidents, gunshot wounds, stabbings
e. Shearing (sudden stretching of the cauda equina)
f. Tethered Cord
g. Infections of the cerebral spinal fluid
h. Spinal Stroke
i. Hematomas
j. Neuroinflammation
k. Epidural Steroid Injections
l. Accidental injury during procedures or surgeries of the lumbar spine
M. Arachnoiditis and Adhesive Arachnoiditis
N. Child Birth
O. Broken vertebrae 
P. Tuberculosis and other infections
Q. Infections of the cerebral spinal fluid
R. Spinal Taps
R. and other unknown causes



1. Magnetic Resonance Imaging (MRI)- is the “gold standard” of diagnosis of cauda equina syndrome

2. Computerized Tomography (CT)/Computerized Axial Tomography (CAT scan)- Can be used to rule out cases of cauda equina syndrome when MRI is not available. However, it is important to note that it is not diagnostically definitive as CT images can miss images of nerve compression or infraction.

3.Myelography- This procedure is used to detect spinal cord injury and to view the nerve roots under contrast. It is not recommended as the first diagnostic tool as it requires the induction of contrast into the spinal column and can cause cauda equina syndrome in rare cases.

4.X-ray- This is not recommended to rule out cauda equina syndrome as it will not show soft tissue damage or disk herniation. This procedure is recommended as an additional test to the MRI to view bone structures.

5. Time to decompression surgery is one of the most important factors to a positive prognosis, though there are other factors at play. Some studies suggest that the prognosis is determined by the severity of the injury within the first six hours of injury. Remember, the fastest way to a proper diagnosis is through a thorough physical exam, recognizing the Red Flag symptoms, and MRI, the gold standard to diagnosis. Remember not all causes of CES are fixed surgically, such as CES resulting from epidurals. In such cases where injury is not caused by an anatomical structure, such as herniated disk or tumor, injury may not show up on MRI and may require myelography to determine injury.

6.Nerve Conduction Study(NCS)- measures how fast and how efficient a nerve can carry a signal. This test is used to determine which nerves are affected, how severely, and their rate of healing over time. It is not recommended to use this test as a diagnostic tool to rule out CES as it is not specific to the cauda equina. However, it is useful post diagnosis and after corrective surgery to establish a baseline of nerve function.

7. Electromyogram (EMG)- measures the electrical activity of the muscles both at rest and during to contraction. This test determines how well the muscles are functioning and the severity of potential muscle weakness. It is not recommended to use this test as a diagnostic tool to rule out CES as it is not specific to the cauda equina. However, it is useful post diagnosis and after corrective surgery to establish a baseline of nerve function.




1.There are three recognized classifications of Cauda Equina Syndrome:

a.CES-R: Risk of Cauda Equina Syndrome, also referred to as pre-clinical. These patients may have radiculopathy, bi-lateral sciatica, and some changes in sensation in the saddle region and/or lower extremities, however, there are no bladder or bowel disturbances, sexual function is normal, and may not show any significant compression of the cauda equina. These individuals may have large herniations that are not yet completely compressing the cauda equina but are causing neuroinflammation of the arachnoid layer causing inflammation to the cauda equina. 
b.CES-I: Incomplete Cauda Equina Syndrome, which is classified as individuals with known or unknown insult/trauma to the cauda equina, but are not incontinent. They may have neurogenic bladder, or urinary hesitancy and/or leakage/accidents. There are further classifications of severity in Incomplete Cauda Equina Syndrome:
  1. Mild: Sensory or Motor deficits resulting from acute cauda equina syndrome without bladder, bowel, and sexual dysfunction.

  2. Moderate: Sensory and/or Motor deficits with some bladder and bowel control deficits such as, frequent constipation, and incomplete emptying of the bladder. Additionally, there are changes in sexual function, but the individual is still able to participate in sexual relationships.

  3. Severe: Sensory and Motor deficits with minimal bladder and bowel function, and minimal or no sexual function. CES-C is impending at this stage.

c.CES-C: Complete Cauda Equina Syndrome, which is classified as individuals with insult/trauma to the cauda equina with complete incontinence. 


1.Cauda Equina Syndrome caused by structural anomalies such as herniated disk, tumors, or fractures, require emergency surgery within 48 hours of onset of symptoms to decompress the cauda equina. Current literature suggests that the sooner the surgery the more likely

viii.Post Surgical Care

1.Physical Therapy

2.Occupational Therapy

3.Bladder Care

4.Bowel Care

5.Pain Management

ix.Post Surgical Home Care

1.Physical Therapy

2.Occupational Therapy

3.Bladder Care

4.Bowel Care

5.Pain Management

6.Caregiver Education




What are the symptoms?

Cauda Equina Foundation's vision is to eradicate the devastating neurological deficits caused by Cauda Equina Syndrome.




Who does it affect?


Cauda Equina Foundation's current strategic focus for 2016-2017:



Who does it affect?


How is it treated?






Education Initiatives:


  1. Continuing education programs for healthcare practitioners.

  2. Case study review for allied health practitioner students.

  3. CES information library for educational resources.

  4. Brochures for patients, caregivers, and the community.



Research Initiatives:


Epidemiology: Who is CES affecting and what are those effects? How prevalent is CES? What is the impact of CES on society?


Clinical Practice Guidelines: We are researching peer reviewed retrospective case studies of CES to make evidence based clinical practice guidelines for the timely diagnosis of CES. 





Healthcare Practitioners: We are educating the medical community to improve the quality of care CES individuals receive.


Community: We are educating the community on CES to improve awareness and empathy for individuals living with CES. 


Government: We are writting our local, state, and federal legislaters to educate them on the effects of CES, in hopes to streamline and improve the approval rates for disability payments. 




 © 2020 Cauda Equina Foundation

P.O. Box 381

Howey in the Hills, FL 34737