The thoracic spine surrounds and protects the spinal cord, the nerve roots that travel toward the chest and abdomen, and the dura, which is the protective covering around the spinal cord.
Please review the Thoracic spine anatomy section for more information.
Disorders involving these structures are less common than routine degenerative spine problems, but they can be especially important because even relatively small abnormalities may affect spinal cord function.
Some conditions develop within the spinal cord itself, while others arise around the spinal cord, from the nerve roots, or from the dura.
Some abnormalities are found incidentally on MRI before they cause symptoms.
Because several of these disorders can produce spinal cord compression or dysfunction, progressive weakness, walking difficulty, or bowel and bladder changes should be evaluated promptly.
Major Diagnosis Types
Below are the major types we see in our clinic. Click on available links to learn about our approach to the problems.
Arachnoid Cyst
A spinal arachnoid cyst is a fluid-filled sac involving the arachnoid membrane, one of the thin layers surrounding the spinal cord.
These cysts may occur inside or outside the dura and are commonly found in the thoracic spine.
Many arachnoid cysts cause no symptoms. Larger cysts can push against the spinal cord.
Possible symptoms include:
- Mid-back pain
- Leg weakness
- Numbness
- Difficulty walking
- Poor balance
- Leg stiffness
- Bowel or bladder dysfunction
Symptoms may develop gradually as the spinal cord becomes increasingly compressed.
Small asymptomatic cysts can often be observed.
Surgery may be considered when an arachnoid cyst causes significant spinal cord compression or progressive neurologic symptoms.
Minor Diagnosis Types
These terms are often encountered, but are either less often treated or described within one of the above diagnoses.
Dural Ectasia
Dural ectasia is enlargement or ballooning of the dural sac surrounding the spinal cord or nerve roots.
As the dura expands, it may gradually remodel or erode nearby bone.
Dural ectasia is sometimes associated with connective tissue disorders, although it can occur in other situations.
Many patients have no symptoms.
When symptoms occur, they may include:
- Back pain
- Radicular pain
- Numbness
- Headache
- Symptoms that change with position
Severe dural expansion may cause widening of the spinal canal or thinning of the surrounding vertebral structures.
Most cases do not require surgery.
Treatment depends on:
- Symptoms
- Degree of bone erosion
- Presence of spinal instability
- Associated neurologic problems
- Underlying condition
Surgery is generally reserved for unusual cases involving significant symptoms, instability, or other complications.
Intradural Tumors
Intradural tumors are tumors that develop inside the dura surrounding the spinal cord.
They are generally divided into two groups:
Intradural extramedullary tumors develop inside the dura but outside the spinal cord.
Intramedullary tumors develop within the spinal cord itself.
Common intradural extramedullary tumors include:
- Schwannomas
- Meningiomas
Common intramedullary tumors include:
- Ependymomas
- Astrocytomas
Many spinal intradural tumors are benign or slow-growing, but even benign tumors can cause significant neurologic problems if they compress the spinal cord.
Possible symptoms include:
- Back pain
- Radicular pain
- Numbness
- Leg weakness
- Difficulty walking
- Balance problems
- Progressive myelopathy
MRI with contrast is usually the most important imaging study.
Treatment depends on tumor type, location, growth, symptoms, and the patient’s overall condition.
Syringomyelia
Syringomyelia is a condition in which a fluid-filled cavity, called a syrinx, develops within the spinal cord.
A syrinx can occur anywhere in the spinal cord and may gradually enlarge over time.
Possible causes include:
- Chiari malformation
- Previous spinal cord injury
- Spinal cord tumors
- Arachnoid scarring
- Previous infection
- Previous surgery
- Abnormal cerebrospinal fluid flow
In some patients, no clear cause is identified.
Symptoms depend on the location and size of the syrinx and may include:
- Numbness or altered sensation
- Weakness
- Muscle wasting
- Pain
- Stiffness
- Difficulty walking
- Changes in temperature or pain sensation
Small, stable syrinxes may not require treatment.
Treatment is generally directed toward the underlying cause when one can be identified. Surgery may be considered when the syrinx is enlarging or causing progressive neurologic symptoms.