Recall the illustration of comparing an intervertebral disc to a jelly donut. The word “herniation” refers to some body part coming out of where it should be. Commonly, a herniated disc, which is also called a “ruptured” or “slipped” disc, occurs when part of the disc material (like the jelly) pops out of place (through the dough) and bulges into the spinal canal, sometimes placing pressure on the nerves.
In this MRI below, a very large herniation can be seen where the central material of the disc, like the jelly to use a jelly donut analogy, has squirted out and is pressing on the nerves causing leg and back pain.
Disc herniations can occur in a variety of settings.
Acute (Sudden): Discs can rupture suddenly because of excessive pressure. For example, in a fall,or with a strong sudden lifting force, the annulus (dough) can rupture causing some extrusion of the nucleus (jelly).
Chronic (Delayed, over time): Discs can also rupture from a
small amount of force due to repetitive weakening from accumulated stress over long periods of time, such as with people who have strenuous jobs that continue over many months and years. Repeated low level injuries add up over time. After a while, combined with the natural aging of the spine, an activity that might not have caused any injury years earlier can result in pain, dysfunction, and disability.
Thinking back to the idea of the jelly donut, disc problems can cause pain two major ways:
1) By the nucleus (jelly) leaking out, the result can be pressure on a nerve, and even local chemical irritation to that nerve (this irritation is made better by localized cortisone shots around the affected nerve), with symptoms affecting the involved nerve. Just like when you hit your funny bone in your elbow, with tingling in the small finger, the nerves in your back and neck have a certain area of the body where symptoms will occur.
The symptoms from the nerve root involvement can include
sensory changes: numbness, tingling
motor changes: weakness
reflex changes: would be noted by your doctor
Where these symptoms occur depends on which nerve(s) has been affected in the lumbar spine. Therefore, the location of the symptoms helps determine your diagnosis. Communicating the exact source of your pain assists your doctor in determining which disc has probably ruptured.
For large herniations, there can be loss of control of bowel or bladder function. If bowel or bladder dysfunction occurs, you need to contact your doctor right away, or report to the nearest Emergency Room!! For cervical spine herniations when the spinal cord is compressed, the symptoms might also include problems with balance as well. These problems also merit urgent attention!!
Here are some MRI pictures, cross sections, which show some normal anatomy first, and then some different locations of herniated discs.
The foramen is the hole through which the nerve exits. The spinal canal is where all the nerves are, and above the L1 vertebra, where the spinal cord resides.
In this example, the herniation is right in the middle, not off to one side.
Paracentral Herniation (off to one side)
As illustrated here, the herniation is compressing the nerves only on one side.
Far Lateral Herniation
This type of herniation can affect the nerve after it has already left the spinal canal and the foramen.
Making the diagnosis of a herniated disc begins with a complete history of the problem and a physical examination.
The main questions your doctor will be interested in are:
Did you have an injury?
Where is the pain and when did it start?
Do you have any numbness? Where?
Do you have any weakness? Where?
Have you had this problem or something like it before?
Have you had any weight loss, fevers, or illnesses recently?
Remember, as noted above, problems with losing control of bowel or bladder function could indicate a possible surgical emergency
The evaluation may include taking X-rays of your back. Regular X-rays will not show a herniated disc, but they will give your doctor an idea of how much wear and tear is present in the spine and may show other causes of your problem.
If there is suspicion that surgery will be needed, MRI or CT-Myelogram will be required.
To better understand the anatomy and function of the spine, click here.