- A spinal epidural abscess typically causes local or radicular back pain, percussion tenderness, and fever; if the abscess compresses the spinal cord, neurologic deficits (leg paresis, saddle anesthesia, bladder and bowel dysfunction) develop.
- Because rapid treatment is necessary to prevent or minimize neurologic deficits, clinical suspicion of spinal epidural abscess should be high (eg, if patients have unexplained atraumatic back pain, particularly with focal percussion tenderness or risk factors); if it is suspected, MRI or, if unavailable, myelography followed by CT should be done immediately.
- If an abscess is causing neurologic deficits, immediately drain the abscess surgically; treat all abscesses with antibiotics that cover staphylococcus, anaerobes, and sometimes gram-negative bacteria.
Free Case Evaluation
SPINAL EPIDURAL ABSCESS
While rare, occurring in less than 3 patients per 10,000 hospital admissions, a Spinal Epidural Abscess (SEA) can cause devastating and permanent neurologic damage.
As shown in the illustration located below, a SEA is a collection of pus that is located between the dura (the outer covering of the spinal cord) and the bones of the spine (vertebrae). SEAs are most often located in the middle and lower areas of the spine. They are typically caused by a bacterial infection, such a Staphylococcus Aureus, that originates on the skin, in the throat or in the mouth.
Essentially, a SEA is an infection inside of the spine. While treatable if diagnosed early, if diagnosis is delayed, a SEA often will result in severe nerve damage and, in some cases, paralysis.
SEAs can develop at any age. However, the majority of people who develop a SEA are between ages 30 and 60. Men more than women have a higher statistical chance of developing a SEA. In addition to age and male gender, the other risk factors for SEAs are diabetes, MRSA infections, infection of nearby spinal bone structures and soft tissue, recent epidural injections, IV drug use, alcoholism, malignancy, and recent spinal trauma and surgery.
Because the early signs and symptoms of a SEA are similar to many less serious conditions, such as back pain and unexplained fever, delays in the diagnosis of a SEA are common. It is for this reason that SEAs must be considered in any patient who presents with the following classic signs, often referred to as the “Classic Triad,” associated with SEAs:
- Back pain (present in 2/3 cases).
- Fever (present in almost ½ of cases).
- Neurologic deficits, such as motor weakness (present in ½ of cases).
It is rare for patients to initialy present to an ER, UrgiCenter of physician office with all 3 of the “Classic Triad” of symptoms associated with SEAs.
When a patient complains of the sudden onset of back pain or motor weakness without trauma, SEAs need to be considered, especially since it can progress to cause devastating neurologic deficits.
MECHANISM OF NEUROLOGIC INJURY
Injury to the spinal cord from a SEA can occur when the pus collection blocks blood flow into and out of the spinal cord. Without proper blood flow, the spinal cord, like any other part of the body, is susceptible to damage. If the abscess becomes large enough, it can also compress the spinal cord or one of its nerve roots. When the spinal cord or one of its nerve roots is compressed, the portion of the body controlled by that area can become neurologically impaired.
FOUR STAGES OF A SPINAL EPIDURAL ABSCESS
The 4 common stages of an evolving SEA are:
- Back pain at the level where the infection is present, sometimes causing a fever.
- Nerve root pain from the area that is affected by the abscess.
- Motor weakness and sensory deficit by the areas affected by the abscess. During this stage, bowel and bladder dysfunction can develop.
- Paralysis with complete bowel and bladder loss.
DIAGNOSIS AND TREATMENT
Early diagnosis is critical to patient outcome. The longer period of time and the severity or extent of the compression on the patient’s spinal cord from an undiagnosed SEA has a direct relationship to the permanency of the patient’s neurologic deficits.
Although neurologic exams and blood tests for infection and inflammation, including white blood counts, Erythrocyte Sedimentation Rate and C-Reactive Protein, are potentially helpful, these tests are not diagnostic of a SEA. Many patients with SEAs will have normal lab results during the early stages of a SEA. Again, if a patient presents with sudden onset of severe back pain and/or fever without any obvious reason, SEA must be considered. An MRI is the so called “Gold Standard” for diagnosing a SEA. This is because an MRI will permit the identification of a SEA at an early stage when neurologic deficit is much more likely to be reversed.
Depending upon the patient’s neurologic status, high dose antibiotics, often administered via an IV, may prove sufficient to eliminate the SEA. This is especially true in those patients who are not experiencing motor loss or bowel and/or bladder dysfunction. However, when a SEA is treated by antibiotics, it is essential that the patient be monitored at regular intervals to determine if his or her neurologic condition is worsening. This is because neurologic symptoms of more than 72 hours without surgical evacuation of the SEA are associated with a poorer outcome. The chance for neurologic recovery decreases the longer the delay in evacuating the SEA. If the antibiotics fail to adequately treat the SEA and it continues to press on the spinal cord or its nerve roots, surgical evacuation of the SEA is required followed by 4-6 weeks of IV antibiotics. Once paralysis sets in, the only realistic chance for meaningful recovery is neurosurgical evacuation of the SEA within 24 hours.
If you or a loved one has suffered injury from a SEA that was not timely diagnosed or treated, call our knowledgeable and experienced team. We understand that a delay in diagnosing a SEA can cause life altering consequences.