How are Spinal Infections Diagnosed?


The spine is a very sensitive area and spinal infections usually don’t get timely diagnosis as they are initially put off as pain management issues. Infections can be secondary to invasive medical procedures or occur spontaneously as bacterial, fungal or viral infections. They are classified according to the locations they affect.

  • Osteomyelitis, when they affect the vertebral column
  • Infections of the inter-vertebral disc spaces known as discitis
  • Infections of the spinal canal presenting as abscesses
  • Infection of the meninges, called meningitis
  • Spread of infection from other sites in the body

Some of the predisposing factors include advancing age, malnourishment, obesity, arthritis, diabetes, drug addiction and immunosuppression due to HIV, cancer treatment, organ transplantation, prolonged use of oral steroids, etc. Urological procedures or spinal trauma can also be classified among the possible culprits.

Infections generally spread to the vertebral discs in the spine through the bloodstream and as the infection progresses, it weakens the discs and moves on to cause osteomyelitis, bone crumbling or deformity and even neurological symptoms as it progresses into the spinal canal.

Symptoms

Symptoms of spinal infections vary and are dependent on the location of infection. There could be localized pain, headaches, fevers and chills, neck stiffness, red swelling at the incision site, wound drainage, unexplained weight loss, limited movement and neurological complications. Symptoms often start with tenderness in the back or neck, with pain worsening upon movement. Initially, pain can be managed with rest and pain meds, but it gets worse over time. The onset of symptoms is usually slow, and it might take a few weeks or months, before a correct diagnosis is made.

Diagnosis

Laboratory evaluation can sometimes be misleading as the WBC counts may appear normal, the ESR (Erythrocyte Sedimentation Rate) and the CRP (C – reactive protein) on the other hand will throw up evidence of inflammation or infection. Diagnostics usually start with an x-ray; however, x-rays often don’t show any abnormalities for the first 2-4 weeks after onset of symptoms and bone density scans become positive only after a while too. An MRI (Magnetic Resonance Imaging) with enhancement by the gadolinium dye is a better option in confirming diagnosis here as it allows the visualization of neurologic structures that may be afflicted.

Further doubts in diagnosis or for enhancing treatment, a computer tomography – assisted fine needle biopsy from the vertebra or the disc space can be collected to identify the organism and its drug sensitivity pattern. Additionally, blood cultures can also help indentifying the causative organism, with samples collected during spikes in fever being more effective in producing the culprit. It must be mentioned here, that in about half the cases however, blood cultures come back negative.

There are however, some bad cases where open surgery may be required to obtain culture samples of the offending organism to enable proper diagnosis and initiation of therapy.

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