Spinal Canal Infections

Spinal canal infections Overview

• Adult patients often progress through the following clinical stages

  • Severe back pain with fever and local tenderness in the spinal column
  • Nerve root pain radiating from the infected area
  • Weakness of voluntary muscles and bowel/bladder dysfunction
  • Paralysis

  In children, the most overt symptoms are prolonged crying, obvious pain when the area is palpated, and hip tenderness.

• Surgical Treatment

  Nonsurgical treatment should be considered first when patients have minimal or no neurological deficits and the morbidity and mortality rate of surgical intervention is high. However, surgery may be indicated when any of the following situations are present:

  • Significant bone involvement
  • Neurological deficits
  • Sepsis with clinical toxicity caused by an abscess unresponsive to antibiotics
  • Failure of needle biopsy to obtain needed cultures
  • Failure of intravenous antibiotics alone to eradicate the infection

  The following questions, which are considerations in most spine surgeries, may present additional challenges in the presence of a spinal infection:

  • Will the approach be anterior or posterior?
  • Should fusion be performed?
  • Is instrumentation beneficial?

  The primary goals of surgery are to:

  • Debride (clean and remove) the infected tissue
  • Enable the infected tissue to receive adequate blood flow to help promote healing
  • Maintain or restore spinal stability
  • Limit the degree of neurological impairment

  Once it is determined that the patient requires surgery, imaging tools such as plain x-rays, CT scans or MRI can help further pinpoint the level at which to perform surgery.

  Current treatment protocols for spinal infections require treatment by a multidisciplinary team of physicians, including infectious disease experts, neuroradiologists, and spine surgeons. The team will be able to assess the best treatment approach on an individualized basis, whether it is surgical or nonsurgical.

• Adjacent soft-tissue infections

  In general, symptoms are usually nonspecific. If a paraspinal abscess is present, the patient may experience flank pain, abdominal pain, or a limp. If a psoas muscle abscess is present, the patient may feel pain radiating to the hip of thigh area.

• Diagnosis

  The biggest challenge is making an early diagnosis before serious morbidity occurs. Diagnosis typically takes an average of one month, but can take as long as six months, impeding effective and timely treatment. Many patients do not seek medical attention until their symptoms become severe or debilitating.

• Laboratory Tests

  Specific laboratory tests can be useful in helping to diagnose a spinal infection. It may be beneficial to get blood tests for acute-phase proteins, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels. Both ESR and CRP tests are often good indicators as to whether any inflammation is present in the body (the higher the level the more likely it is that inflammation is present). These tests alone however, are limited, and other diagnostic tools are usually required.

  Identification of the organism is essential, and this can be accomplished through computed tomography-guided biopsy sampling of the vertebra or disc space. Blood cultures, preferably taken during a fever spike, can also help identify the pathogen involved in the spinal infection.

• Nonsurgical Treatment

  Spinal infections often require long-term intravenous antibiotic or antifungal therapy and can equate to extended hospitalization time for the patient. Immobilization may be recommended when there is significant pain or the potential for spine instability. If the patient is neurologically and structurally stable, antibiotic treatment should be administered after the organism causing the infection is properly identified. Patients generally undergo antimicrobial therapy for a minimum of six to eight weeks. The type of medication is determined on a case-by-case basis depending on the patient’s specific circumstances, including his or her age.

• Imaging Tools

  Imaging studies are necessary to pinpoint the location and extent of a lesion. The choice of specific imaging techniques varies slightly depending on the location of the infection.

  Vertebral osteomyletis: The degree of bone destruction is best imaged by computed tomography scan (CT or CAT scan), whereas soft tissue involvement is best defined by magnetic resonance imaging (MRI).

  Intervertebral disc space infections: If childhood discitis is suspected, plain x-rays are ordered first, followed by MRI if the x-rays are negative. For postoperative disc space infection, MRI is the imaging tool of choice. Inflamed areas generally show up clearly when a contrast agent is employed.

  Spinal canal infections: MRI with Gd enhancement has become the gold standard, largely replacing myelography to provide high resolution images of neural structures. If the MRI comes back negative and infection is still suspected, imaging should be repeated.

  Adjacent soft-tissue infections: Both MRI and CT scan can accurately identify soft-tissue abscesses.