What is Lumbar Spinal Stenosis
Lumbar spinal stenosis (LSS) is a low back pathology that describes the narrowing of either the spinal canal or the neuroforamina the lower extremity nerves pass through. To better understand this pathology, we first need to discuss the basic anatomy and cover a couple definitions.
Stenosis: An abnormal narrowing of a passage in the body.
Foramen, Foramina, Neuroforamen: An opening or hole especially in bone. When “neuro” is put in front of the word, we are specifically describing a passageway that a nerve will travel through.
Our vertebral column is made up of 24 bones. In addition to providing a skeletal structure to our organs and muscles also houses our spinal cord. The spinal cord runs directly down the middle of our vertebral bones from the base of the skull all the way to the pelvis. It travels through the spinal canal. At each vertebral level the spinal cord will have nerve roots that branch off and provide nerve supply to the extremities. There are always two nerve roots per level and each supply their respective sides of the body. Picture the spinal cord as a tree trunk and each nerve root is a branch extending off the trunk. To exit the spinal canal, the nerve roots will pass through a neuroforamina (or a passageway) before they extend to the rest of the body.
As previously described, stenosis is a narrowing of a passageway in the body. In LSS we are referring to two specific areas that can become narrowed. The neuroforamina where the nerve roots exit the spine is one location and the spinal canal itself is the other. When the neuroforamina is obstructed, we typically present with single sided symptoms. These are commonly due to disc herniations and often described in laymen’s terms as a “pinched nerve.” We discuss standard disc herniations in more detail here. Today we will be focusing on a narrowing of the spinal canal which may be more specifically termed “Central Spinal Canal Stenosis” There are numerous causes for the narrowing of these passageways, including severe disc herniations, chronic degenerative changes to the bone, traumas, or infections to name a few. In all of these examples, there is some change to either the soft tissue or bone that has led to the narrowing of the spinal canal. In an acute lumbar spinal stenosis, the patient may have sustained a trauma causing a severe lumbar disc herniation that can protrude into the spinal canal and impinge the spinal cord. Although acute traumatic cases occur, we see chronic cases of LSS far more frequently. Chronic cases are almost exclusively present in patients over the age of 50 and most prevalent in the 6th or 7th decades of life.
In the chronic LSS, the changes in your anatomy that may lead to stenosis are more likely to be degenerative changes of the spine such as bone spurs. In many cases “spinal degeneration” is a normal part of aging, often compared to wrinkles of the skin. Often, these “wrinkles” will have no symptomatic significance, but in more severe cases these bony growths can actually begin to narrow or cause “stenosis” where the nerves pass through. When these passages become too narrow, the nerves that pass through them can be impacted. This may lead to numbness, tingling, radiating pain or in more serious cases loss of muscular strength.
What are the symptoms of central lumbar spinal stenosis?
Lumbar spinal stenosis can present with many different symptoms varying from low back pain to pain in the lower extremities. The pain from the back may travel inferiorly, down through the buttocks, glutes and finally into the legs. In a central spinal stenosis patient, the spinal cord itself is impacted, therefore the symptoms are often found in both legs. Along with the radiating pain, a patient may also describe numbness, tingling and heaviness of their legs.
Another differentiating factor that can indicate LSS, is when the symptoms occur. Most general low back pain is worse with sitting for extended periods of time and improves with walking. In patients with LSS, it is often the opposite. Standing or walking for extended periods of time will increase leg symptoms and patients often only get relief once they sit down for several minutes. Patients may even find that their symptoms improve with walking uphill and get worse when they are walking downhill. This is because LSS is aggravated when the back is in an extended (arched) position and is relieved in a flexed (arched) position. We tend to extend our backs as we walk down hill and tend to have a more flexed posture when walking up hill.
In more advanced cases of LSS patients may begin to have trouble walking or find themselves tripping over their feet. There are many other conditions that can cause abnormal gait (walking patterns) or tripping but in advanced cases LSS can cause weakness in some of the lower extremity muscles making walking more difficult.
How is it evaluated and diagnosed?
Central lumbar spinal stenosis is evaluated and diagnosed with a combination of MRI imaging along with a correlating physical exam. A thorough medical history, health history and physical exam can provide guidance to a clinician in determining whether the patient is suffering from LSS or a different pathology that has led to their symptoms.
An MRI may also be performed to determine how stenotic the foramen are however research indicates that the degree of stenosis visualized on an MRI image does not correlate well with the severity of symptoms.
How is Lumbar Spinal Stenosis Treated
At Health Fit Chiropractic in Boca Raton, we treat patients suffering from Lumbar Spinal Stenosis every day. Without surgical intervention we cannot remove any of the bone or soft tissue that may be crowding the foramen that the nerves pass through, but we can help the patient build strength and mobility to create a more patent foramen for the nerve to pass through.
This is the main focus of our treatment techniques. We use a variety of chiropractic manipulation, flexion distraction, Active Release Technique and muscle stretching to help improve the mobility of the spine and surrounding structures. This can help improve neural mobility and allow the nerve to move more freely through the foramen. We also help our patients identify relieving positions for their symptoms. For example, in the majority of cases patients with LSS will have relief when they are in a forward flexed position. If we identify that in a patient, we can teach them to use these positions of relief to help calm their symptoms during an acute flare up or exacerbation.
We will follow up any manual therapy that we provide with a detailed exercise plan that is personalized and targeted to improve strength, mobility and neural mobility in the patient. These exercises are performed in the office and then provided to the patient to continue their program at home in between appointments.