Thoracic Disc Herniation: The Stealth Spinal Disorder

Thoracic disc herniation has seemingly flown off the radar screen of the spine community. Indeed, hardly a day passes in which we don’t hear news about the illustrious cervical and lumbar regions. So I say to the obscure thoracic region: “Emerge and show thyself!” It is time to examine why thoracic disc herniation is spine’s “stealth disorder.”

A thoracic disc herniation is not unlike the equivalent cervical or lumbar rupture. It is generally caused by a herniated nucleus pulposus. However, it is one of the more difficult spinal disorders to diagnose. A thoracic disc herniation is often asymptomatic, meaning that no pain or other symptoms accompany the condition. For the patient, perhaps ignorance is bliss, but for the doctor, it can become a diagnostic nightmare. In an article entitled Thoracic Disk Herniation—Anatomy and Pathophysiology, Diagnosis, Treatment, by Dr. Thomas Wilson and Dr. Charles Branch at Wake Forest University, the authors state that “Thoracic disk herniations … are rare, and their often subtle and varied modes of presentation frequently result in delayed diagnosis, with potentially devastating neurologic sequelae.”

This view is also echoed in an article by Dr. David DeWitt of Spine-health.com. The study found that out of 90 patients, 37% had thoracic herniated discs. After following the patients for 26 months, researchers found that none of them showed symptoms of thoracic disc herniation. Stealthy indeed! What then, are the symptoms of a thoracic disc rupture?

As it turns out, the symptoms themselves are part of the problem and are a “critical part of the thoracic region’s “stealth arsenal.” The symptoms of thoracic disc herniation are common to many conditions. Perhaps the most common symptom is simply pain in the upper back. However, the challenge for physicians, and the confusion for patients, lies in the symptoms accompanying that pain. These include pain in the chest and belly and numbness below the area of herniation. If myelopathy is present, bladder dysfunction or dizziness may accompany the upper back pain. It is obvious that this range of symptoms could lead to a myriad of diagnoses. In fact, the manner and order in which these symptoms are expressed to the physician could add to the confusion.

Thoracic disc herniation often is diagnosed incidentally. This implies that it is commonly discovered in the course of treating another disorder. This idea is echoed in the PearlDiver Patient Cost and Utilization database (PCU). Thoracic disc herniation without myelopathy (ICD-9 code 722.11) was a secondary diagnosis 60% of the time. Interestingly, over 37% of the primary diagnoses that led to diagnoses of thoracic disc herniation were located in the cervical and lumbar regions. It can also be seen that neuritis, cervicalgia (neck pain), and radiculopathy are common symptoms that lead to the primary diagnosis (see Table 1). In an article entitled The Pathophysiology of Thoracic Disc Disease, by Dr. James McInerney and Dr. Perry Ball, the authors relate that “Radicular pain, back pain, long track signs, spacity, and bowel or bladder dysfunction are all common manifestations of thoracic disc disease.”

Table 1: PearlDiver Patient Cost and Utilization Database

An additional challenge to getting the correct diagnosis is simply that of rarity. As a consequence, it is not often diagnosed. In the PearlDiver Patient Cost and Utilization Database, thoracic disc herniations represent about 1.3% of the top 20 diagnoses in spine (see Table 2).

Table 2: PearlDiver Patient Cost and Utilization Database*

*Percentages are of the top 20 diagnoses

Thus far, we have found three reasons why thoracic disc herniation is so difficult to pick up on the physician’s radar:

1. It can be asymptomatic, so that patients do not even know they have it!
2. The patient presents with a range of symptoms that suggest many possible ailments, few of them directly linked to the spine
3. As seen from an analysis of the database, the rarity of the diagnosis itself is an impediment to correct diagnosis

With respect to treatment, conservative approaches such as non-steroidal anti-inflammitory drugs and exercises are administered first. The most frequent outpatient response to the diagnosis, other than exercise treatments, is injections, the most common being an epidural injection of antispasmodic or steroidal substances (CPT code 62310). Extensive use of MRI and discography is also ordered in an effort to find the affected area. Pain stemming from the thoracic region tends to be the most difficult to isolate.  

From an analysis of the inpatient side of the PearlDiver PCU, it appears that \surgical treatments revolve around dorsal fusion and discectomy. Dorsal fusion and discectomy make up a combined 78.9% of inpatient operations performed in response to the diagnosis. Discectomy is often performed as part of a spinal fusion. This is followed by decompression procedures such as laminectomy or laminotomy (see Table 3).

Table 3 PearlDiver Patient Cost and Utilization Database

However, traditional surgical treatments have met with mixed results. This, in combination with the anatomical challenges of operating in the thoracic region, has the industry looking for alternatives to surgery. Innovation to the rescue! Minimally invasive surgery (MIS) is at the center of forward-looking spine technology. Video-assisted thoracic surgery (VATS) is a sibling of laparoscopic surgery that can be used for thoracic discectomy. A small incision is made in the chest, and a small fiber-optic camera (called a thorascope) is inserted. Currently, research is being conducted with respect to VATS versus open thoracotomy.