How to diagnose and treat thoracic spinal disorders

The thoracic spine is not a common site for symptomatic degenerative nerve root compression or degenerative spinal cord compression. However, it should be kept in mind when dealing with disorders of the spine.

Although less common than in the cervical spine, thoracic spine compression can cause radiculopathy or myelopathy. Note that multilevel spondylotic stenosis is unusual in the thoracic spine; most of the degenerative pathologies are centered on one disc space.

Degenerative thoracic pathology can be overdiagnosed and overtreated when predicated on imaging findings—rather than clinical presentation. In other words, don’t base your diagnosis on imaging alone!

Asymptomatic degenerative findings (such as disc herniation, osteophyte formation, and mild stenosis) are common on thoracic magnetic resonance imaging (MRI). Therefore, when approaching suspected symptomatic thoracic spondylosis, it is important to combine the clinical findings and the radiographic findings before drawing any conclusions.

A thoracic radiculopathy diagnosis will be predominately made from the patient's history, which usually includes intense unilateral pain radiating from the back and around the chest. Clinical findings for thoracic radiculopathy are often very limited.

Symptoms

There are no motor or reflex findings to look for with thoracic radiculopathy. A sensory exam may or may not show a unilateral loss of pinprick or light touch sensation in a dermatomal pattern around the chest on the affected side. This would not be a sensory level per se, but a band of sensory loss along a rib with preserved sensation above the band.

Although uncommon, complaints may involve pain and paresthesia that radiate unilaterally around the rib cage. The symptoms can be quite severe. If you suspect thoracic radiculopathy, ask about this kind of radiating pain. Axial pain alone, even in the face of a disc herniation, will seldom respond to surgery.

Differential diagnosis

When evaluating the thoracic spine, look out for red flags, which are indicators of serious spinal disease. The thoracic spine is a common location for many other pathologies:

• Metastatic cancer
• Infection
• Traumatic injury
• Vascular malformation
• Spinal cord syrinx

Metastatic tumors and infectious abscesses are not uncommon in the thoracic spine and can result in devastating spinal cord compression. Because these may present with dysfunction in the legs, it is not uncommon for thoracic spine pathologies to be misdiagnosed as lumbar problems, which results in delays in diagnosis.

Could the patient’s symptoms be chest pain from a cardiac, rib, or lung pathology? It’s even possible to see a pulmonary embolus misdiagnosed as thoracic radiculopathy.

Tips for teasing out a diagnosis of thoracic radiculopathy

When evaluating for thoracic radiculopathy, first evaluate for myelopathy. If this is negative, proceed to evaluate the patient for radiculopathy. Remember, thoracic radiculopathy is an uncommon disorder.

Ask your patient about myelopathic symptoms, including their duration and progression. Thoracic myelopathy will present very similarly to cervical myelopathy, but without upper extremity involvement.

When a patient presents with leg weakness, always consider thoracic myelopathy. Although some lumbar pathologies can cause leg weakness, it is uncommon with lumbar degenerative diseases.

Next, focus on the myelopathy exam. Are the legs truly weak? Is there a sensory level? Any rigidity? Hyperreflexia? Loss of proprioception? Romberg sign? Clonus? Spasticity? With any of these findings, be suspicious of a spinal cord disease above the lumbar spine.

If the patient has a radicular pattern of pain and no evidence of myelopathy, consider other pathologies. Thoracic radiculopathy is uncommon, so other pathologies are far more likely.

Check for 12 upper motor neuron signs, which would be present in thoracic myelopathy but not in thoracic radiculopathy:

1. Hyperreflexia
2. Clonus
3. Babinski sign
4. Crossed adductor sign
5. Increased muscle tone
6. Spasticity
7. Loss of proprioception
8. Dermatomal sensory level
9. Romberg sign
10. Loss of balance
11. Spastic gait
12. Unsteady gait

Perform a neurological exam

Go through a standard neurologic exam with the patient. Seven assessments should be included in your exam:

1. Brain
2. Cranial nerves
3. Motor nerves
4. Sensory nerves
5. Deep tendon reflexes
6. Coordination
7. Gait

Order additional testing

Because disc pathology is common in thoracic imaging studies, its presence doesn’t rule out other regional pathologies, and doesn’t necessarily confirm symptomatic nerve root compression. Consider chest x-ray or chest computed tomography (CT) for severe, persistent pain.

If you are concerned about a progressive or severe thoracic myelopathy, the patient will need urgent imaging and an early referral to a spinal specialist. Ideally, you should obtain a non-contrast MRI of the thoracic spine.

If the patient has definitive myelopathy, and an MRI of the thoracic spine is negative, order an MRI of the cervical spine. Remember, cervical myelopathy may present with findings predominantly in the lower extremities and sensory levels in the thoracic dermatomes. Often, suspected thoracic myelopathies turn out to be cervical spinal cord pathologies instead.

If an MRI cannot be obtained, order a CT myelogram. A myelogram is not as sensitive as MRI, but it will help to rule out most compressive pathologies.

Consider surgery

Thoracic spinal stenosis without myelopathy does not require surgery, but the patient should be followed up clinically every 6–12 months. Thoracic degenerative stenosis with progressive myelopathy, on the other hand, should precipitate an urgent consultation with a spinal surgeon. However, this condition is not common.

With the persistence of intense radicular-like pain, obtain a non-contrast MRI of the thoracic spine. There may be disc pathology, but ask yourself if this finding correlates with the region of the patient’s pain. For example, T4­–T5 nerve root compression should not cause T9 radiating dermatomal pain and sensory loss.

Also, consider obtaining a non-contrast CT of the region. Often, thoracic discs are heavily calcified and show up better on CT. Look for regions of severe spinal cord compression with degenerative changes. Compression will usually be in the T8–T10 region, but look up and down the spine for both compressive and intrinsic lesions.

Conservative treatment

If a diagnosis of radiculopathy is still being considered, try a 4–7 day course of oral corticosteroids followed by 2–6 weeks of nonsteroidal anti-inflammatories and physical therapy.

With thoracic radiculopathy, there is no at-risk motor function and prolonged conservative management is very reasonable. After all, thoracic spine surgery is not risk-free! There can be significant complications such as blood loss and pulmonary complications.

Invasive treatment

If intense radicular-like pain persists and the MRI or CT raises suspicion, ask a specialist to try a series of epidural steroids or nerve blocks on the affected region. These are similar processes, but not exactly the same. The first method involves placing the steroids in a general space (e.g., the epidural space of the region), whereas the nerve block involves placing the steroids directly on the nerve root.

If radicular symptoms persist, other pathologies have been ruled out, and there are relevant correlative imaging studies, consult a spine surgeon to see if the patient is a candidate for surgery.

Persistent generalized thoracic spine pain without radicular symptoms or myelopathic findings should be treated conservatively. Most cases will be self-limited. Consider a 2–4 week course of nonsteroidal anti-inflammatory medicines and physical therapy.

If the pain persists or intensifies, it will eventually require imaging and possibly a referral to a spinal specialist.

Don’t be shocked if you are pursuing the diagnosis of symptomatic thoracic spondylosis and you turn up a more serious pathology—such as a metastatic lesion or an epidural abscess in the region. This is particularly true if you find myelopathic signs on the exam. Obviously, such cases need to be promptly referred to a neurosurgeon.

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