As a disc degenerates, it can herniate (the inner core bulges) into the spinal canal, which is known as a disc herniation (or a herniated disc). The weak spot in a disc is directly under the nerve root, and a herniated disc in this area puts direct pressure on the nerve, which in turn can cause pain to radiate all the way down the patient’s leg to the foot.
Approximately 90% of disc herniations will occur at L4- L5 (lumbar segments 4 and 5) or L5- S1 (lumbar segment 5 and sacral segment1), which causes pain in the L5 nerve or S1 nerve, respectively.
- L5 nerve impingement from a herniated disc can cause weakness in extension of the big toe and potentially in the ankle (foot drop). Numbness and pain can be felt on top of the foot, and the pain may also radiate into the rear.
- S1 nerve impingement from a herniated disc may cause loss of the ankle reflex and/or weakness in ankle push off (e.g. patients cannot do toe rises). Numbness and pain can radiate down to the sole or outside of the foot.
The many definitions for spinal pain
Terms such as “herniated disc”, “pinched nerve”, and “bulging disc” are used differently by individual healthcare practitioners. There is no agreement in the healthcare field as to an exact definition of any of these terms. Often a patient hears his or her diagnosis referred to in these different terms from health care practitioners. This leads to confusion for patients about their diagnosis. The actual source of the a patient’s low back pain, leg pain, or other symptoms will lead to a better understanding of the precise diagnosis for the patient.
Some examples of terms used to describe spinal disc abnormalities include:
- Pinched nerve
- Sciatica
- Herniated disc (or herniated disk)
- Bulging disc
- Ruptured disc
- Torn disc (or disc tear)
- Slipped disc
- Collapsed disc
- Disc protrusion
- Disc degeneration
- Degenerative disc disease
- Disc disease
- Black disc
An individuals’ symptoms of disc injury or degeneration, and their relief from treatments, can vary tremendously. Patients are encouraged to provide complete and accurate descriptions of their symptoms as possible to their doctor. The actual source of the a patient’s low back pain, leg pain, or other symptoms will lead to a better understanding of the precise diagnosis for the patient.
Integrated findings form the medical diagnosis
A physician’s medical diagnosis focuses on determining the source of a patient’s pain. For this reason, the medical diagnosis of a patient’s low back pain, leg pain, or other symptoms is based on more than just the findings from a diagnostic test, such as an MRI scan or CT scan. The doctor evaluates all of the findings from tests, symptoms, medical history, trauma or injury, complete physical examination and sometimes the results of additional diagnostic tests.
- Medical history. The physician will take the patient’s medical history, such as a description of when the low back pain, sciatica or other symptoms occur, a description of how the pain feels, and what activities, positions or treatments make the pain feel better, when the pain or symptoms began, what conditions such as an injury or accident occurred that may have lead to the symptoms, and more.
- Physical exam. The physician will conduct a thorough physical exam of the patient. This may include testing nerve function and muscle strength in certain parts of the leg or arm. Testing for pain in certain positions and the activities causing the pain. Usually, this series of physical tests will give the doctor a good idea of the type of back problem or neck problem that the patient has.
Diagnostic tests
After the physician has a good idea of the source of the patient’s pain, a diagnostic test, such as a CT scan or an MRI scan, is often ordered to confirm the presence of a herniated disc or other lesions in the spine. The tests can give a detailed picture of the problem, such as the location of the herniated disc and impinged nerve roots. Your doctor may want more extensive diagnostic tests. One such test is a discogram to develop as much information as possible about the patient’s condition. This test is expensive and somewhat painful because it is a ‘provocative’ test (i.e., it is designed to provoke pain responses in the patient to locate the area of pain generation). For this reason many doctors will refrain from using discography unless necessary.
Although the findings on an imaging study (CT scan, MRI or X-Ray) and other diagnostic tests are important they are not in and of themselves diagnostic: Sometimes lesions present on an imaging study may not be symptomatic. Many people have some level of disc degeneration by the time they reach 60 years old. It is important to match the findings from a patient’s physical exam, symptoms, diagnostic test results, history of trauma or injury and medical history to arrive at an accurate medical diagnosis. This is especially important to create an effective treatment plan.
The medical diagnosis determines the pain generator
The key factor in a clinical diagnosis is to determine if the patient has a pinched nerve or if the disc space itself is generating the pain. These two common conditions produce a different type of pain.
- Pinched nerve: When a patient has a herniated disc, it is not the disc space itself that hurts, but rather the disc herniation is pinching a nerve in the spine. This produces pain that is called radicular pain (e.g., nerve root pain, or sciatica from a lumbar herniated disc, or arm pain from a cervical herniated disc).
- Disc pain: When a patient has a degenerated disc (one that causes low back pain or other symptoms), it is the disc space itself that is painful and is the source of pain. This type of pain is typically called axial pain.
While radiographic findings are important, they are not as meaningful in determining the source of the pain (the clinical diagnosis) as the patient’s specific symptoms and the doctor’s findings on physical exam.
An individuals’ symptoms of disc injury or degeneration, and their relief from treatments, can vary tremendously. Patients are encouraged to provide complete and accurate descriptions of their symptoms as possible to their doctor. The actual source of the a patient’s low back pain, leg pain, or other symptoms will lead to a better understanding of the precise diagnosis for the patient.
Conservative treatment for a lumbar herniated disc
In most cases, if a patient’s low back and/or leg pain is going to resolve after a lumbar herniated disc it will do so within about six weeks. While waiting to see if the disc will heal on its own, several conservative treatment options can help reduce the back pain, leg pain and discomfort caused by the herniated disc.
- Physical therapy
- Osteopathic/chiropractic manipulations
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- Oral steroids (e.g. prednisone or methyprednisolone)
- An epidural (cortisone) injection
Surgical treatment for a lumbar herniated disc
If the pain continues after six weeks, it is reasonable to consider microdiscectomy surgery as an option to alleviate the pain from the herniated disc. A microdiscectomy essentially acts as a microdecompression of the nerve root to provide the nerve with a better healing environment.
Surgical intervention can only treat anatomic anomalies that have been shown to generate pain; surgery is not appropriate in cases where disc degeneration—even severe disc degeneration – may not be the cause of a patient’s pain, or in situations where the patient has chronic pain but the exact source cannot be adequately identified.
Using microsurgical techniques
A small operation using a microscope to treat a lumbar herniated disc, a microdiscectomy can usually be done on an outpatient basis or with an overnight stay in the hospital, and most patients can return to work full duty in one to three weeks depending on their occupation.
With an experienced surgeon, the success rate of surgery for a lumbar herniated disc should be about 95%. Usually, only the small portion of the disc (5-8%) that is pushing against the nerve root needs to be excised, and the majority of the disc remains intact.