Spinal Infections
Infection can affect any part of the spine including bone, intervertebral disc spaces, ligaments, muscles, spinal cord, and meninges.
Although spine infection is uncommon, but can lead to serious complications like paralysis or instability of the spine if untreated. The infection can be classified as acute or chronic depending on the severity and the onset of the clinical features. e disease is usually its ability to start anywhere in the body and spread to other regions through the bloodstream. Direct inoculation of the bacteria may happen as a complication of invasive spinal procedure. To certain extent, spine infections are more common in certain group of patients, whom are more susceptible to infection like diabetes, HIV AIDS, alcoholism, drug abuse etc. Tuberculosis of the spine is a special type of infection, which is increasing in numbers in the UK.
The most common types of spinal infections are
Symptoms
Symptoms may vary depending on the onset of the symptoms, area of the primary infection, Patients with spinal infections typically have severe pain in a localised area of the spine, which develops over a short time (days). The pain may radiate down the arm or leg if it effects nerve roots (radiculopathy). Most patients will also have fever and may feels generally unwell. If untreated, the infection may cause destruction of the spine tissues and bone leading to spinal mechanical instability. Infection may also lead to pus and granulation tissue collection within a confined spinal canal. In either case, this may cause compression of the spinal cord and/or nerves leading to a condition called myelopathy or cauda equina syndrome.
In chronic infections like tuberculosis (TB) of the spine, the symptoms are usually insidious and develop slower over weeks and sometimes months. Because of the slower progression, some patients are misdiagnosed by their doctors with musculoskeletal neck or back pain. Although some of the patients may show constitutional symptoms of infection like night sweats and unexplained weight loss, most of the patients are initially asymptomatic a part from spine pain.
Management
High index of suspicion is essential especially in chronic infection like Tuberculosis. Detailed clinical history, back ground and social history, nutrition history, travel history, family history of infection, medical history of any immune related condition, and drug abuse history. Clinical examination will establish signs of systemic infections or possible sources. It is important to assess the neurological function and pick up signs of myelopathy.
Blood tests are essential to pick up any systemic infection, however, an urgent MRI and CT scan will help to establish the diagnosis and show the extent of the infection.
If no organism has been grown from blood cultures a biopsy of the infection may be indicated. This, however, is negative in many cases and treatment should not be delayed as this might take a few days to organise in most hospitals.
Treatment
Antibiotic
Confirming the causative organism of spinal infection is the keystone in treating the infection with the appropriate antibiotics. Pyogenic infections (pus producing organisms like Staphylococcus aureus, groups of Streptococcus, E.coli and others) can be treated successfully with antibiotic alone in most cases. However,these kind of infections are usually progress rapidly and need aggressive treatment under supervision of Infectious Disease team (ID Team)! . The initial treatment is usually with broad spectrum antibiotics until the blood cultures or direct samples identify the organism and sensitivities to specific antibiotics. The treatment might then be changed according to the results. In cases where no organisms can be identified, these broad spectrum antibiotics are continued. The duration of the treatment depends on the severity and extent of the initial infection, improvement of inflammatory parameters (see above) and clinical response to the treatment. Initially, antibiotics are given intravenously but may be switched to tablets at a later stage. The antibiotic treatment of patients should be supervised by an infectious disease team or microbiologist.
Any patient with TB needs to be under the care of a specialist team (often infectious disease team or chest physicians) and attend a TB-clinic. Most patients need to take a combination of four drugs for a duration of one year. Because of the slower clinical progress, the need for immediate treatment (i.e. within a day or two) is not as important as in pyogenic infection. This is why in patients who are clinically well and stable and where the diagnosis could not be established otherwise a biopsy might be done before the start of the treatment.
Surgery
Surgical option may indicated if there is any mechanical stability issues due to destruction of spinal structures by infection, in these cases, spinal fixation with metal implants may indicated to achieve stability or to correct spinal deformities, especially in cases of chronic infections like Tuberculosis. The other indication of surgery, which is indicated in the majority of cases of infection when there is a significant compression of the spinal cord or the nerve roots resulted from pus formation in the spinal canal, Epidural or Subdural spinal abscesses. The last indication for surgical intervention is biopsy of the spinal tissues to isolate the causative organisms and this can be achieved either by CT guided biopsy by radiologist or open biopsy by Neurosurgeons.
Painkillers and analgesia
Infections of the spine are very painful and strong painkillers are often necessary in the beginning. Sometimes a brace is necessary to stabilise the spine and give a good relive of symptoms until the infection has healed. Severe pain may indicate spinal instability and this necessitate internal or external immobilisation.
Outcome and prognosis
Overall, the prognosis of spinal infections is good if treatment is started early. Spondylodiskitis (spread of the infection into the vertebral body) is a complication which often requires antibiotic treatment for three months. In many cases of spinal infections, the affected segment of the spine will fuse.