Spinal tuberculosis (TB), also known as Pott’s disease, is a destructive form of tuberculosis that affects the spine. It accounts for approximately half of all cases of musculoskeletal tuberculosis. {JSmed2011} It is a type of extrapulmonary TB, which means it occurs outside the lungs. Spinal TB is caused by the bacteria Mycobacterium tuberculosis.
Spinal TB typically starts in the lungs and spreads to the spine through the bloodstream or lymphatic system. It mainly affects the thoracic spine, although any part of the spine can be involved. The infection can cause the vertebral bodies to become weak and collapse, resulting in a hunched or curved posture.
The symptoms of spinal TB can vary but often include constitutional symptoms, back pain, spinal tenderness, paraplegia, and spinal deformities. As the disease progresses, it can lead to neurological problems such as weakness, numbness, and paralysis in the limbs due to compression of the spinal cord or nerve roots.
Diagnosis of Spinal TB
Diagnosis of spinal TB involves a combination of clinical evaluation, imaging tests such as X-rays, CT scans, and MRI, and laboratory tests to detect the presence of the bacteria. For the diagnosis of spinal tuberculosis magnetic resonance imaging is more sensitive than x-rays and more specific than computed tomography.
Magnetic resonance imaging (MRI) frequently demonstrates involvement of vertebral bodies on either side of the disk, disk destruction, cold abscess, vertebral collapse, as well as presence of vertebral column deformities.
Neuroimaging-guided needle biopsy from the affected site in the center of the vertebral body is the gold standard technique for early histopathological diagnosis.
Early diagnosis and prompt treatment are crucial in managing spinal TB and preventing complications. With appropriate treatment, most patients with spinal TB can achieve significant improvements in symptoms and quality of life.
However, if left untreated, spinal TB can lead to severe deformities, neurological damage, and even death. Hence, it is important to seek medical attention if any symptoms suggestive of spinal TB are present.
Symptoms of Spinal TB
Symptoms of spinal tuberculosis (TB) may include:
1. Spinal Damage: Characteristically, there is destruction of the intervertebral disk space and the adjacent vertebral bodies, collapse of the spinal elements, and anterior wedging leading to kyphosis and gibbus formation. Multi-level noncontiguous vertebral tuberculosis can occur.
2. Cold Abscess: Formation of a ‘cold’ abscess around the spinal lesion (damage) as seen best with MRI is another characteristic feature.
3. Back pain: The pain is usually persistent, worsening over time, and may be severe, especially during movement or physical activity. The thoracic region of vertebral column is most frequently affected.
4. Stiffness: The spine may feel stiff, making it difficult to bend or twist. This can affect mobility and cause difficulty in performing daily activities.
5. Deformity: As the disease progresses, it can lead to abnormalities in the spine, causing curvature or hunching of the back.
6. Weakness: Spinal TB can weaken the back muscles and lead to difficulty in standing or walking.
7. Numbness or tingling: If the spinal cord is affected, it can result in numbness or tingling in the arms, legs, or other parts of the body.
8. Fatigue: General fatigue and weakness may be present, as the body’s immune system is fighting the infection.
9. Fever and night sweats: Some individuals may experience low-grade fever and night sweats, especially during the active phase of the disease.
10. Weight loss: Spinal TB can cause loss of appetite, resulting in unintentional weight loss.
11. Loss of bladder or bowel control: In severe cases where the spinal cord is compressed, there may be loss of bladder or bowel control.
It is important to note that these symptoms can be similar to other back conditions. Spinal TB should be diagnosed by a healthcare professional through a thorough medical examination, imaging tests, and microbiological tests.
Risk Factors for Spinal TB
There are several risk factors that can increase the chances of developing spinal tuberculosis (TB) or Pott’s disease. These include:
1. Weakened immune system: People with weakened immune systems, such as those with HIV/AIDS, malnutrition, or who are on immunosuppressive medications, have an increased risk of developing spinal TB.
2. Close contact with an infected individual: Spinal TB is caused by the bacteria Mycobacterium tuberculosis, which spreads through respiratory droplets. Having close contact with someone who has active TB increases the risk of infection.
3. Living in crowded or unsanitary conditions: Spinal TB is more common in overcrowded areas, where the risk of exposure to the bacteria is higher.
4. Age: Elderly individuals and young children have a higher risk of developing spinal TB due to their weaker immune systems.
5. History of TB infection: Individuals who have previously had TB, even if the infection was treated, have a higher risk of developing spinal TB.
6. Poor nutrition: Malnutrition weakens the immune system, making individuals more susceptible to infections like spinal TB.
7. Diabetes: People with diabetes are more susceptible to infections, including spinal TB.
8. Alcohol and drug abuse: Excessive alcohol consumption and drug abuse can weaken the immune system, making individuals more vulnerable to infectious diseases like spinal TB.
9. Chronic kidney disease: Individuals with chronic kidney disease have a compromised immune system and are at higher risk of developing spinal TB.
10. Genetics: Genetic susceptibility to spinal tuberculosis has been demonstrated.
11. Country: The incidence of spinal tuberculosis is increasing in developed nations.
While these factors increase the risk of developing spinal TB, it does not guarantee that an individual will get the disease. Taking preventive measures, such as practicing good hygiene, maintaining a healthy immune system, and seeking early treatment for TB infection, can help reduce the risk.
How Spinal or Bone TB is Spread
Treatment
Antituberculous treatment remains the cornerstone of treatment. Treatment for spinal TB typically involves a combination of anti-TB medications, such as isoniazid, rifampicin, pyrazinamide, and ethambutol, taken for at least six months or more. Surgery may also be required in some cases to stabilize the spine and alleviate pressure on the spinal cord. Surgery is appropriate in selected cases, e.g. large abscess formation, severe kyphosis, an evolving neurological deficit, or lack of response to medical treatment.
Prognosis
With early diagnosis and early treatment, prognosis is generally good.