Spinal stenosis results when the bony canal through which the spinal cord courses becomes narrowed and compresses the spinal cord. Although spinal stenosis most commonly occurs in the neck and lower back regions, it uncommonly involves the thoracic spine in the upper and middle back. According to a 1987 article in the "Journal of Neurosurgery," thoracic spinal stenosis is usually only seen in people with underlying diseases that cause abnormal bone growth.
Pain is one of the most common symptoms of thoracic stenosis. For some people, this pain is described as a burning sensation in the thighs or calves, a 1987 article in the "Journal of Neurosurgery" notes. In other cases, the pain of thoracic stenosis is described as a dull ache in the lower back. The pain from thoracic spinal stenosis may get worse with movement. One feature of thoracic spinal stenosis is that any pain in the back will not radiate down the legs, which helps distinguish the condition from sciatica. Instead, the pain will usually be contained to one area.
People with thoracic spinal stenosis may also have altered sensation, particularly in the lower body. Sensation problems are often limited to areas that are supplied by a specific region of the spinal cord, known as a dermatome. The higher the part of the thoracic spine affected by spinal stenosis, the higher the area of diminished sensation. For example, stenosis of the upper areas of the thoracic spine can cause problems with sensation around the upper chest and the area around the shoulder blades. On the other hand, injuries near the bottom of the thoracic spine can cause problems with sensation around the lower portions of the back and abdomen. A pins-and-needles sensation may also be felt in both lower legs.
Muscle weakness is common in thoracic spinal stenosis, particularly in the legs. Some people with this problem can have problems walking and keeping their balance while standing. The leg muscles can also become unusually stiff and rigid.
Positional Changes and Diagnosis
Some people with thoracic spinal stenosis find sitting or straightening the upper back helps alleviate their symptoms. Deep tendon reflexes -- which are tested by striking the knee and other regions of the body with a reflex hammer -- may also be heightened or diminished. Imaging studies, such as an MRI, can help identify the cause and severity of spinal stenosis. If you are concerned you may be experiencing symptoms of thoracic spinal stenosis, make an appointment with your doctor to determine the cause and appropriate treatment for your symptoms.