Discitis – An uncommon cause of severe back pain in the elderly

Dr Sabari Girish
Consultant Ortho - Spine
Aster Medcity
Kochi

As we grow old, aches and pains are a part of daily life. Many things that we used to do easily cause some problems like sleeping on a soft mattress or lifting something moderately heavy. But while most aches and pains are minor, there are some that warrant attention, investigation and treatment, especially aches and pains related to the spine and back.

There can be many causes of back ache including muscle strain or spasm, arthritis, herniated disc, and even some tumors. But there is one cause of back pain that while uncommon is difficult to diagnose and requires early treatment to control it. This condition is known as ‘Discitis’.

Discitis is infection of the discs between the vertebrae, the bones of the back that make up the spinal column. It is usually a bacterial infection but may be viral or fungal in origin. What makes discitis a major problem is the relatively poor blood supply to the discs making it difficult for the body's immune cells and antibiotics to reach the infection. This makes it difficult to treat. Hence it is important to diagnose it early and start treatment.

While discitis is more likely to occur in the elderly, it may also occur in the young. Predisposing factors include diabetes, any immune deficiency, and vascular disease.

Discitis can result from a surgical or diagnostic procedure introducing infection. The more common form is "spontaneous" discitis that is caused by an infecting organism, either bacterial or viral that comes to the disc through the blood from the urinary tract (kidney or bladder), respiratory tract (nose, throat, lungs), intestine, gums (dental work), or any other entry into the body. There is usually high fever and chills occurring a week prior to the onset of severe back pain.

The most prominent symptom of discitis is severe, almost unbearable back pain. As back pain is common and can have many causes, discitis is often misdiagnosed. Inappropriate treatment leads to the pain continuing while looking for the cause. The pain of discitis is usually localized to the region of the infection and can shoot down the lower limbs or radiate to other regions like sciatica. The patient may have a history of fever. The patient may not have fever at present as the infection is now localised in the disc. Blood tests may indicate some infection in the body.xrays will be normal in early stages and will take atleast 2-6 wks before changes appear in plain radiographs. The final diagnosis can be confirmed by a MRI scan or leucocyte labelled bonescan which will show the infection in the disc. An aspiration under CT guidence can be done for a culture if the infection is not responding to treatment. Other disease processes like spinal tuberculosis are considered in the face of persistently negative cultures.

The good news is that once diagnosed, discitis is treatable. Antibiotic treatment must be tailored to the isolated organism. A long course of antibiotic therapy delivered intravenously usually controls the infection. Patients need to be educated about importance of completing the antibiotic course, as incomplete treatment can lead to resistance with devastating results.

Pain-killers give symptomatic relief and a brace is used to limit movement and reduce pain. Physiotherapy plays a part in keeping other parts of the body like the arms active to prevent overall weakness. Proper nutrition also needs to be taken to build immunity.

Surgery is an option only in cases of deformity, antibiotic toxicity, neurologic deficit or progression of the disease. Surgery is done to remove diseased tissue, relieve the compression on the neural structures and ensure stability of the spine. Vertebral fusion can also be done to allow early mobilization of the patient.

Once the treatment has been carried out, the patients need to be monitored. This includes checking blood indicators like ESR, and periodic x-rays for bony collapse or deformity. Patients should be educated on neurologic signs and told to return on the suspicion of the slightest deficit.

Discitis is treatable and timely treatment can help avoid pain and disability in old age.