Thoracic stenosis is the narrowing of the spinal canal in the middle region of the back. The thoracic spine consists of 12 vertebrae connected to the ribs. This section of the spine is more stable than the neck or lower back, making stenosis in this area less common. When narrowing occurs, it can put pressure on the spinal cord and nerves, leading to various symptoms.
Causes of Thoracic Stenosis
The primary cause of thoracic stenosis is degenerative change from aging. Over time, wear and tear on the spine can lead to osteoarthritis, which breaks down the protective cartilage of the joints. In response, the body may form bony growths known as bone spurs, or osteophytes, that can protrude into the spinal canal.
Another factor is the thickening of spinal ligaments, such as the ligamentum flavum, which can harden and expand, constricting the canal. In some cases, intervertebral discs can herniate or bulge, pushing into the spinal cord’s space. Less frequently, thoracic stenosis can be caused by traumatic injuries or a congenitally narrow spinal canal.
Recognizing the Symptoms
A common initial sign is pain in the mid-back, which can sometimes wrap around the chest wall or into the abdomen. This pain is often a persistent, aching sensation. Difficulty or limitations in rotating the torso may also be present.
As compression worsens, neurological symptoms can develop. Individuals may experience numbness, tingling, or weakness that primarily affects the legs. This can lead to problems with balance and coordination, causing an unsteady walking pattern known as gait disturbance. A person might feel as though their foot slaps the ground when they walk.
In advanced cases, severe pressure on the spinal cord can cause myelopathy. Symptoms of myelopathy include significant leg weakness and, in some instances, a loss of bowel or bladder control. The appearance of these symptoms requires prompt medical evaluation.
How Doctors Diagnose the Condition
Diagnosis begins with a review of a patient’s medical history and symptoms, followed by a physical examination. The exam assesses muscle strength, sensation, reflexes, and balance. A doctor will also evaluate movements that may trigger pain to better understand the compression.
Imaging studies are necessary to confirm the diagnosis. Magnetic resonance imaging (MRI) is the preferred method, as it provides detailed pictures of the spinal cord, nerves, and surrounding soft tissues. An MRI can clearly show the narrowing of the spinal canal and the extent of nerve compression.
If an MRI cannot be performed, a computed tomography (CT) scan may be used to visualize the spine’s bony structures and identify bone spurs. A CT myelogram, which involves injecting contrast dye into the spinal fluid, can also be ordered. This makes the spinal cord and nerves more visible on the scan, highlighting areas of compression.
Available Treatment Options
Treatment for thoracic stenosis is tailored to the severity of a patient’s symptoms and includes non-surgical and surgical approaches. For mild to moderate symptoms, conservative methods are the first line of defense.
Non-Surgical Treatments
Physical therapy is often used to strengthen the muscles that support the spine, improving flexibility and stability. To manage pain and inflammation, doctors may prescribe nonsteroidal anti-inflammatory drugs (NSAIDs). Another option is an epidural steroid injection, where medication is injected around the compressed nerves to reduce swelling and pain. These treatments can manage symptoms but do not correct the underlying narrowing.
Surgical Treatments
Surgery is reserved for patients with significant neurological symptoms, like progressive leg weakness or loss of bowel and bladder control, or when pain does not improve with conservative care. The goal of surgery is decompression, which means creating more space for the spinal cord and nerves. The most common procedure is a laminectomy, where a surgeon removes a portion of the vertebral bone (the lamina) to relieve pressure. A spinal fusion may also be performed to ensure the spine’s stability.