Spine University s Guide to Cauda Equina Syndrome
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Introduction Your spine is a very complicated part of your body. It s made up of the bones (vertebrae) that keep it aligned, nerves that channel down from your brain to the rest of your body, blood vessels to help provide nutrients, and fluid that moves up and down to bathe and protect the spinal cord, as well as muscles, blood vessels, and more. Because there are so many parts to the spine, a back injury can be caused by many things. All can cause a different effect because of where the injury may be, the extent of the injury, as well as what area of the spine is hurt. One problem that is not very common but can cause severe pain and other issues is called cauda equina syndrome (CES). Cauda equina syndrome is an emergency so this is something that must be treated as quickly as possible. What is Cauda Equina Syndrome? Cauda equina syndrome (CES) is not a particular injury or trauma. It is the term used to describe an extreme compression (pressure) or inflammation (swelling) of nerves at the end of the spinal cord. Cauda equina is Latin for horse's tail. It was given this name because the nerves at the end of the spinal cord do look like a horse s tail. It was first written about in English-language medical literature in 1934. Causes What causes cauda equina syndrome? Cauda equina syndrome is caused when the spinal canal is narrowed and this presses on the nerves that pass through. This narrowing can be caused by many spinal injuries, spinal defects, or traumas. These include: Herniated discs (also called slipped discs, bulging discs, and ruptured discs) Trauma or injury, such as from a car accident or lifting a heavy object Tumors in the spine cancerous or noncancerous Spinal stenosis Infection Diseases that cause inflammation Herniated Discs. Between one and 15 percent of patients with herniated discs may develop Cauda equina syndrome (CES). If so, the discs affected are most often in the lumbar area (lower back) or the sacral area (around the tail bone area). According to statistics, the majority of patients who develop CES from herniated discs are those who have chronic back pain. Only about 30 percent of patients with CES develop it as the first sign of disc trouble. The problem occurs because the disc material ruptures into the spinal canal taking up nearly all the space and crowding or putting pressure on the nerves. Trauma, Injury and Tumors. A fall or accident may cause the spine to compress, putting pressure on the nerves. Certain types of injuries could also cause blood to collect or pool in the area, also putting pressure on the nerves. This would include injury from surgery. Tumors also take up space and put pressure on the nerves. The tumors can be malignant (cancerous) or benign (noncancerous), but their presence pushes on the nerves. Spinal Stenosis. Spinal stenosis is a condition that causes the spinal canal to narrow. Some people are born with this problem, others develop it later on in life. Inflammation. Some diseases and conditions cause inflammation or swelling in the spine. This can cause narrowing in the spine, which also presses on the nerves. 3
Symptoms What are the symptoms of cauda equina syndrome (CES)? Cauda equina syndrome (CES) can cause pain, weakness or numbness in the lower part of the body. The most common symptoms include: Lower back pain Pain down one leg, starting in the buttocks and going down along the sciatic nerve, usually in the first stages of CES Pain down both legs, along the sciatic nerve, in the later stages Numbness in the groin or in the perineal area (the area between the urethra and rectum, for women, and between the base of the penis and the rectum for men) Numbness in the area that would make contact on a bike seat, for example. This is called saddle anesthesia Weakness in the leg muscles Loss of sensation below the waist Slowed or absent reflexes in the legs and feet Difficulty controlling bowel and/or bladder (being unable to urinate or move your bowels, or loss of control) If cauda equina syndrome (CES) is caused by surgery, usually, the signs begin to show within 24 hours of the operation, but can take as long as seven days in some cases. Bladder problems (neurogenic bladder), are the most common symptom of cauda equina syndrome (CES). Initially, the problem may not be that noticeable. You may have problems starting the flow of urine, but this then can move on to urinary retention (inability to let the urine go). This then leads to overflow incontinence (when the bladder gets so full the urine spills out involuntarily). Diagnosis Although there isn t a precise definition of cauda equina syndrome, most researchers believe that there should be some effect on the bladder for it to be diagnosed. In other words, if the bladder isn t affected, they don t believe that the patient can have cauda equina syndrome. There are possibly two types of cauda equina syndrome (CES) In 1986, a researcher, JP Kostiuk, and his colleagues, described two ways that patients with cauda equina syndrome may appear, or present. The first is the acute (sudden onset) cauda equina syndrome. These patients have severe low back pain and sciatica, and they can t empty their bladders to the extent that they need to be catheterized (have a tube inserted into the urethra) to allow the urine to empty. They also complain of having leg muscle weakness and perineal anesthesia. Acute cauda equina syndrome is most often caused by a herniated disc. The second type is insidious (which means it comes upon you slowly) with recurring bouts of back pain. These recurring bouts of pain can be over a few weeks or as long as over a few years. This then develops into muscle weakness, numbness, and bowel and bladder issues. The insidious type seems to be caused most often by spinal stenosis. Why is the effect on bladder an important feature in cauda equina syndrome? The bladder uses different types of nerves to function, so it can be affected in different ways. For example, one type of muscle, controlled by one type of nerve, helps you control when you empty your bladder, while another type of nerve tells you when your bladder is full. Yet another type of nerve keeps the urine in the bladder. If you have cauda equina syndrome, there is a good chance that some part of the bladder 4
is affected, which is why researchers feel that this should be one of the symptoms required for cauda equina syndrome to be diagnosed. What type of pain does cauda equina syndrome (CES) cause? The type of pain you would experience depends on what is causing the cauda equina syndrome. If the pain is in a localized area in the back, it s often felt as a local, deep, aching pain. If the pain is in the leg, it can feel like a sharp stabbing pain, as if a knife is piercing through the muscle. How is cauda equina syndrome (CES) diagnosed? Your doctor will need to do a physical examination and take a medical history by asking questions about your health and your back. Because of the importance of the bladder symptoms, you ll be asked about your bathroom habits as well. One of the causes of cauda equina syndrome is a pooling of blood pressing on the nerves so, if you re taking any blood thinners (anticoagulants) this is important information for your doctor. In fact, if you present with the symptoms listed previously and are taking anticoagulants, your doctor will likely consider cauda equina syndrome almost right away. During your physical exam, your doctor will need to understand where you have lost sensation, so your exam may include pinpricks on the legs, but also in the perineal area. A rectal exam is also important so the doctor can assess the strength of the rectal sphincter (the muscle that controls if you move your bowels or not). This assessment may also include pressing onto the head of the penis (the glans) or the clitoris, to see how the anal sphincter reacts. Some patients may be sent for a test to measure residual urine. This test measures how much urine is left in the bladder after you have urinated, although it's not a commonly done test for this problem. X-rays will be done of your lower back to see if or what kind of trauma there is in the area that is causing the pain. X-rays can pick up disc damage and arthritis, for example. However, if you are experiencing these problems right after having had spinal surgery, your doctor will likely skip the x-rays and go straight to treating your problem. After x-rays, the test of choice is usually magnetic resonance imaging (MRI), which allows your doctor to get a more detailed look at what is going on. An MRI gets its images using magnets rather than radiation and can be done with or without a dye. Dye is used to look more closely at certain features in the body part that is being examined. If for some reason you can t have an MRI, your doctor may choose to do a test called a lumbar myelography, which is an x-ray done after dye has been injected into the spinal area. This is then followed by a computed tomography (CT) scan. The important issue in testing for cauda equina syndrome (CES) is speed. Cauda equina syndrome is an emergency so testing needs to be done as quickly as possible. Unfortunately, if someone has long-standing or chronic back pain, a diagnosis of CES might not be thought of at first. How is cauda equina syndrome (CES) treated? Cauda equina syndrome (CES) is an emergency so this is something that must be treated as quickly as possible. This treatment is usually surgery. If cauda equina syndrome is the result of an infection, antibiotics should be ordered in the hope of reducing the pressure on the nerves once the infection has been treated. If the cause is a tumor, you may have to undergo chemotherapy or radiation to shrink it before surgery is performed. This would all depend on what type of tumor it is, its aggressiveness, as well as other factors. 5
Surgery for cauda equina syndrome is emergency decompression, where the surgeon removes the cause of the pressure on the nerves. Most researchers and surgeons believe that the decompression surgery should be done within 24 hours of the first symptoms, 24 to 48 hours at the most. This quick surgery reduces the risk of permanent damage to the nerves and provides the best hope for a full recovery. What is the prognosis for cauda equina syndrome (CES)? Because cauda equina syndrome can be caused by so many different problems and taking into account how long you may have had it and how long it took to be diagnosed, it s not really possible to say what the prognosis, or outcome, will be. The best prognosis happens with the quick surgery. That's not always possible. It's not always easy to diagnose cauda equina syndrome. The general thought is that a full recovery is rare, however. Some patients may continue to have some pain, others may have problems with their bladder and/or bowel. Men often have sexual problems that can range from a decreased sensation in the penis to erectile dysfunction, the inability to maintain an erection. Women may be incontinent of urine (let go of urine accidentally) during sexual intercourse and they may have decreased sensation. In general, patients with only one leg that has pain tend to do better than those who have both legs affected. Patients with perineal anesthesia also tend to have bladder problems lasting after surgery. As well, doctors are finding that the extent of groin numbness can help predict which patients may do better than others (the worse the numbness, the less likely for a full recovery). Spine University's Guide to Cauda Equina Syndrome 6
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