Spinal Infections

Spinal infections can occur in the spinal canal, in the soft tissues that surround it, in the disc spaces between the vertebrae or in the vertebral column. The source of spinal infections can be a fungus or a bacterial organism. Sometimes infections happen after a surgical procedure. Most post-surgical infections occur sometime between three days and three months following surgery.

The most common type of spinal infections is Osteomyelitis of the spine. This can occur from a trauma that provides open access to the spinal area, from bacteria located somewhere else in the body which travels to the vertebra or from an infection in the surrounding tissues.

Spinal infections that occur between vertebrae, in the intervertebral disc space can be separated into three different sub-types: postoperative, childhood, also known as discitis, and adult (hematogenous), also known as spontaneous.

One type of spinal infections is an abscess of the spinal epidural tissues. This infection that occurs in the tissues surrounding the spinal cord itself and the nerve root, which is called the dura. If spinal infections affect the area separating the dura and the arachnoid, which is the thin tissue of the spinal cord between the pia mater and the dura mater, it is called a subdural abscess. These spinal infections rarely occur. The primary tissue of the spinal cord is called the parenchyma. Infections here are called intramedullary abscesses.

Infections which occur in tissues surrounding the spinal cord include lumbar psoas muscle abscesses and thoracic and cervical paraspinal lesions. These types of spinal infections do not typically occur in the elderly; they usually affect younger patients.

Prevalence

• Osteomyelitis, a spinal infection of the vertebrae, occurs in approximately 26,000 to 64,000 people each year.
• The occurrence of an epidural abscess is not common. It affects only 0.2 to 2 cases per every 10,000 hospital admissions. But, up to 18% of patients with disc space infections or with vertebral Osteomyelitis that has been caused by an infection in a surrounding tissue will go on to develop an epidural abscess.
• The occurrence of spinal infections is increasing according to available research. This may be due to the increased rise in the abuse of intravenous recreational drugs, and it may also be because of the increased use of medical instrumentation such as vascular devices.
• Of the patients who develop vertebral Osteomyelitis, up to 70% of them have no obvious prior infection.
• The epidural abscess occurs most frequently in people who are 50 years of age and older, but it can happen to people of any age.
• Despite the tremendous advancements made in treating spinal infections over the recent years, the death rate from these conditions is still estimated to be at around 20%.

Risk factors

There are certain conditions that place you at higher risk for developing spinal infections. These risk factors include conditions that lower your body’s natural immunity, such as:

• Your age
• Your use of intravenous drugs increases your risk of spinal infections
• Human immunodeficiency virus (HIV) infection
• Long-term use of systemic steroid medications
• Having Diabetes mellitus increases your risk of spinal infections
• Having had an organ transplantation
• Malnutrition
• Cancer increases the risk of spinal infections

Your surgical history can also place you at increased risk of developing spinal infections. If you have an operation that requires a long time to complete and involves a significant blood loss, and use of instrumentation, such as implants or prosthetics, you may be at increased risk. Also, if multiple surgeries are required at the same site to perform revisions, your chance of spinal infections increases. Spine infections occur in about 1 to 4 percent of all operations, despite all the steps that are taken to prevent complications.

Reasons

Spinal infections can be caused by organisms that are causing an infection in another part of the body and are carried in the bloodstream to the spine. These infection-causing organisms are either bacteria or fungi. The most common cause of spine infections is Staphylococcus Aureus, and the second most common cause is Escherichia Coli. Both of these organisms are bacteria.

Spinal infections sometimes appear following a urological procedure. This is because the blood vessels in the lower portion of the spine enter into the pelvis. The area of the spine most affected is the lower back or the lumbar region. People who abuse intravenous drugs are more likely to have spinal infections affecting the cervical or upper area of the spine.

Infections of the intervertebral disc space most likely begin in one of the nearby plates and the infection in the disc is a secondary infection. In children, it is not known exactly where these infections originate. When cultures and biopsies are performed on children, most are negative. this leads experts to believe that discitis that occurs in childhood may be brought on by the growth area of a bone (called the epiphysis) becoming partially dislocated because of an injury caused by flexion.

Spinal Infection Symptoms

Spinal infection symptoms vary and depend on what type of infection is present. Generally, localized pain in the area of the infection occurs. If the spine infection occurs following a surgical procedure, additional spinal infection symptoms may occur such as:

• Drainage from the surgical incision or wound
• Swelling, redness or tenderness near the incision

Vertebral Osteomyelitis

The spinal infection symptoms of Vertebral Osteomyelitis commonly include:

• Intense back pain
• Chills
• Fever is a symptom of spine infection
• Muscle spasms
• Weight loss is a spinal infection symptom of this type of spine infection
• Neurological deficiencies can be a symptom of this type of spine infection
• Painful or difficult urination

Intervertebral disc space infections

When spine infections occur in the intervertebral discs space, few spinal infection symptoms may occur at the onset of the illness. Eventually, severe back pain develops. Most often in young children who have not yet started to talk, pain and fever do not occur, but the children will refuse to flex their back. Back pain is the primary symptom in children between the ages of 3 to 9 years old. Spine infections in the disc space can occur after surgery. Its onset is usually one month postoperatively. The pain caused by the spine infection is usually relieved by immobilization and bed rest and increases with any movement. The pain gets more and more severe if not treated and eventually will not respond to even prescription-strength analgesics.

Spinal canal infections

This spinal infection usually progresses through the following stages in adult patients:

• Localized tenderness in the spinal column and fever with severe back pain
• Nerve root pain which radiates from the area of infection
• Weakness of voluntary muscles and disturbances of bowel and bladder functions
• Paralysis can sometimes result from these spine infections

In children, the most obvious spinal infection symptoms are inconsolable crying, pain when the area is touched, and tenderness in the hip.

Adjacent soft-tissue infections

The spinal infection symptoms that have developed in the soft tissues next to or lying near the spinal canal are usually vague and nonspecific. In the case of a paraspinal abscess, abdominal or flank pain or a limp pain may develop. If an abscess develops in the psoas muscle, radiating pain may occur to the hip or thigh.

Diagnostic procedures

The biggest barrier to the treatment of spine infections is being able to make an accurate diagnosis before serious complications occur. Most often a diagnosis can be a within an average of one month, but it can take as long as up to six months. This has a tremendous impact on the effective treatment of spine infections. Add to that the fact that many patients do not seek medical help until their spinal infection symptoms have already progressed to a severe or debilitating state.

Laboratory Tests

Laboratory blood tests that are very specific can help in the diagnosing of spine infections. It is often helpful to obtain acute-phase proteins, C-reactive protein (CRP) levels, and erythrocyte sedimentation rate (ESR). The CRP and ESR tests can many times indicate if any inflammation is present in the body. In addition to these tests, other diagnostic tests are typically needed to diagnose spine infections.

Determining what organism is responsible for the spine infection is critically important. This can be completed by taking blood cultures, which are best obtained during an episode of an elevated fever. Another way to identify the organism is through a computed tomography-guided biopsy to obtain a sample of the disc space or vertebra.

Imaging Tools

In order to find out exactly where the spine infection, abscess or lesion is located, paraspinal imaging studies are used. Depending on where the infection is located, different techniques may be used.

Vertebral osteomyelitis: In order to detect the amount of bone destruction being caused by the spine infection, computed tomography(CT or CAT) scans are used. To view the involvement of soft tissues, magnetic resonance imaging (MRI) produces the best images.

Intervertebral disc space infections: Plain x-rays can sometimes detect spine An epidural in the intervertebral disc space, so these are usually ordered first. If the x-rays are negative, they will be followed by an MRI. The MRI is most often the diagnostic standard when looking for postoperative disc space spine infections. Inflammation is clearly obvious when contrast is used with the MRI.

Spinal canal infections: To diagnose spinal canal spine infections, the MRI with Gd enhancement has mostly replaced myelography to provide the needed images to diagnose these infections. If negative results are obtained but spinal infection symptoms are still present, the imaging test should be repeated.

Adjacent soft-tissue infections: These spine infections can be accurately identified by either an MRI or a CT scan.

Spinal Infection Treatment

Spinal infection treatments incorporate a blend of intravenous antimicrobial drugs, propping, and rest. Vertebral discs don’t have a decent blood supply so when microorganisms are available, the body’s invulnerable cells and also anti-toxin prescriptions experience issues achieving the contamination site. IV anti-microbial spinal infection treatment is typically required for six weeks to two months. A brace might be prescribed to enhance the stability of the spine while the infection heals.

Surgical spinal infection treatment is important if the contamination can’t be controlled with anti-toxins and supporting drugs or if there is nerve pressure. Surgery is utilized as a spinal infection treatment and decrease pain, counteract intensifying of spinal deformation and alleviate any neurologic pressure. A spinal infection treatment advances, blood tests, and x-rays are required to check the contamination is reacting to spinal infection treatment. All patients with the suspected spinal disease should look for treatment.

Nonsurgical Treatment

Treatment for spine infections often includes the long-term administration of intravenous antifungal or antibiotic medications. This can sometimes mean extended hospital stays.If the patient is experiencing significant pain or the potential exists for spinal instability related to the spine infection, immobilization may become necessary. If there are no side effects to treatment, antibiotic therapy should be started as soon as the causative organism is identified. The course of antibiotic therapy usually lasts for a minimum of six weeks in spine infections.

The objective while recommending pharmaceuticals ought to be the optimal decrease of pain and uneasiness with minimal danger of abuse of the prescriptions and maintaining a strategic distance from reactions.

Non-steroidal calming medicines (NSAIDs) incorporate basic over-the-counter medications, for example, headache medicine, ibuprofen, and naproxen among others. These medications are powerful long-haul pain reducers that work without worries of reliance.

Opioid treatment to control incessant back pain is not ideal as a result of potential lethality to the body and physical and mental reliance. Treatment by this class of medications ought to by and large be a transient choice when patients don’t react to choices.

Pain can frequently be lessened using muscle relaxants, hostile to seizure pain solutions, for example, Neurontin, Topamax, and Lyrica, antidepressants, and oral steroids.

Surgical Treatment

Conservative measures and nonsurgical treatment should always be considered first if the patient has no neurological or even minimal neurological deficits and if surgery presents a greater risk. However, surgery may be indicated in the presence of any of the following situations related to spine infections:

• If there is a significant amount of bone involved in the spine infection
• In the presence of more than minimal neurological deficits
• If the spine infection causes sepsis due to an abscess that is not responding to antibiotic therapy
• Failure of biopsy to obtain the needed cultures
• Failure of intravenous antibiotics to eliminate the spine infection

When a spine infection is present, the following considerations, which are questions in most spinal surgical procedures, present even more critical challenges:

• Will the surgery be performed using an anterior or posterior approach?
• Should spinal fusion be performed?
• Would instrumentation be beneficial due to the spine infection?

The primary goals of surgery are to:

• Clean out and remove (debride) the infected or damaged, nonviable tissue
• Increase blood flow to the affected tissues which will help promote healing of the spine infection.
• Restore or maintain the stability of the spine.
• Limit the amount of neurological damage.

Once it has been decided that surgery is required, specialized tools such as x-rays, MRI or CT scans can help determine exactly at which level surgery needs to be performed.

Treatment of spine infections requires a multidisciplinary team made up of specialists including neuro-radiologists, spinal surgeons, infectious disease specialists, and neurologists. Working together, the team will be able to assess the patient’s condition and decide on the best treatment approach for the spine infection on an individualized basis.