A simple back pain can be spinal tuberculosis!

In recent years there has been a sharp increase in the incidence of non-pulmonary tuberculosis. The typical picture of spinal tuberculosis is of destruction of the disc space, vertebral body, sometimes with secondary involvement of the spinal cord. In a few instances, spinal cord also can be involved primarily with tuberculosis as manifested by epidural tuberclomas or intramedullary tuberculosis.

Spinal tuberculosis is one of the oldest diseases known to mankind and is popularly known as Pott's spine. As it was first described by Sir Percival Pottt in his monograph in 1779. The risk of developing tuberculosis is estimated to be 20-37 times greater in people co-infected with HIV than among those without HIV infection. The exact incidence and prevalence of spinal tuberculosis in most parts of the world are not known.

In countries with a high burden of pulmonary tuberculosis, the incidence is expected to be proportionately high. Approximately 10% of patients with extra pulmonary tuberculosis have skeletal involvement. The spine is the most common skeletal site affected, followed by the hip and knee. Spinal tuberculosis accounts for almost 50% cases of skeletal tuberculosis.

The progression of spinal tuberculosis is slow and insidious. The total duration of the illness varies from few months to few years, with average disease duration ranging from 4 to 11 months. Usually, patients seek advice only when there is severe pain, marked deformity or neurological symptoms.

Constitutional symptoms are present in approximately 20-30% of cases of osteoarticular tuberculosis. The classical constitutional features of tuberculosis indicating presence of an active disease are malaise, loss of weight and appetite, night sweats, evening rise in temperature, generalized body aches and fatigue. Back pain is the most frequent symptom of spinal tuberculosis.

The intensity of pain varies from constant mild dull aching to severe disabling. Pain is typically localized to the site of involvement and is most common in the thoracic region. The pain may be aggravated by spinal motion, coughing and weight bearing, because of advanced disc disruption, and spinal instability, nerve root compression, or pathological fracture. Chronic back pain as the only symptom was observed in 61% of cases of spinal tuberculosis.

Classical Pott's disease of the spine with involvement of two vertebral bodies, the intervening disc and often a paravertebral abscess, is readily recognised and treated. Spinal tuberculosis presents as visible or palpable spinal deformity, radiographic appearance of destruction of the intervertebral disc and the two adjoining vertebral bodies. Few patients present with compression of the spinal cord, with features ranging from paraesthesia, radiculopathy and increasing weakness, to paraplegia and loss of sphincter control.

Extrapulmonary tuberculosis is usually blood-borne. Batson (1940) and Henriques (1958) suggested that the haematogenous spread occurs via the venous pathway. Spinal tuberculosis is a destructive form of tuberculosis. It accounts for approximately half of all cases of musculoskeletal tuberculosis.

Though no age group is exceptional as we come across this problem in all age groups, it has predilection for paediatric and younger age group. Main future of spinal tuberculosis is destruction of the intervertebral disc space and the adjacent vertebral bodies, collapse of the spinal elements, anterior wedging leading to kyphosis and gibbus formation.

The thoracic spine is most often affected. Formation of a cold abscess around the lesion is one more characteristic future. MRI is essential and sensitive for spinal tuberculosis. Neuroimaging guided needle biopsy from the affected site is the gold standard technique for early histopathological diagnosis.

Spinal tuberculosis is often neglected till patient develops gibbus deformity

Treatment regimen and duration varies institute to institute depending on their protocol. But most of them involve Cap. Rifampicin, Tab. Isoniazid Tab. Ethambutol, Tab. Pyrazinamide along with Tab. Pyridoxine. Steriods play vital role in cases with neurological compromise in addition to back pain.

These patients need to follow by periodical imaging for spine and liver functions to be checked. Patient to be kept under strict bed rest for at least 3 months as spinal tuberculosis may lead to instability often needs stabilization or fixation surgery where the instable segments are being fixed with instruments.

Overall tuberculosis is a disease of good prognosis and dramatic improvement is not an exceptional rather norm if diagnosed or noticed in earlier stage get on to treatment at the earliest. Early diagnosis and prompt treatment is necessary to prevent permanent neurological disability and to minimize spinal deformity (Writer is Consultant Neuro & Spine Surgeon; Continental Hospitals)

By Dr Laxminadh Sivaraju