The condition was first described in detail by the Armenian surgeon Dr. A. Yerevan in the early 20th century, hence the eponym. Today, it is recognized worldwide as a serious extrapulmonary manifestation of TB.

Who it affects

• Adults aged 20‑50 years, with a peak incidence in the third decade.
• Men are affected roughly twice as often as women (male : female ≈ 2 : 1) [1].
• People living in TB‑endemic regions (e.g., South‑East Asia, sub‑Saharan Africa, Eastern Europe) have the highest risk.
• Individuals with compromised immunity (HIV infection, diabetes, chronic steroid use) are more vulnerable.

Prevalence

Spinal TB accounts for 1‑2 % of all tuberculosis cases and ~10 % of all extrapulmonary TB worldwide [2]. In high‑burden countries, incidence can reach 5‑10 cases per 100 000 population per year [3]. In the United States, the disease is rare, with < 100 cases reported annually [4].

Symptoms

The clinical picture is often insidious, developing over weeks to months. Common signs and symptoms include:

• Back pain – dull, localized, worsens with movement; most frequent presenting complaint.
• Night‑time pain – may awaken the patient from sleep.
• Paravertebral muscle spasm – due to inflammation.
• Fever – low‑grade, intermittent; may be absent in chronic cases.
• Weight loss & loss of appetite – constitutional TB symptoms.
• Fatigue and malaise.
• Neurological deficits – when the disease compresses the spinal cord or nerve roots, patients may experience:
  • Numbness or tingling (paresthesia) in the limbs.
  • Weakness or gait disturbances.
  • Bladder or bowel dysfunction (rare but serious).
• Deformity – progressive kyphosis (hunch‑back) most often in the thoracic spine.
• Cold abscess – a painless, fluctuant mass that may track under the skin to the chest wall or abdomen.

Causes and Risk Factors

Primary cause

Infection is caused by Mycobacterium tuberculosis. The organism usually reaches the spine via hematogenous spread from a primary pulmonary focus, though it can also arise from direct extension from adjoining infected tissues.

Key risk factors

1. Active pulmonary TB – patients with untreated or partially treated lung disease are the main source of dissemination.
2. Immunosuppression – HIV infection increases the risk of extrapulmonary TB by 10‑20 times [5]. Diabetes, chronic kidney disease, and prolonged steroid therapy also raise susceptibility.
3. Malnutrition – impairs cell‑mediated immunity, facilitating spread.
4. Living or working in crowded, poorly ventilated settings – prisons, shelters, and refugee camps.
5. Previous spinal surgery or trauma – may provide a nidus for infection.
6. Age and gender – as noted above, young adult males are most frequently affected.

Diagnosis

Diagnosing spinal TB requires a combination of clinical suspicion, imaging, laboratory testing, and sometimes tissue biopsy.

1. Clinical assessment

• Detailed history of TB exposure, systemic symptoms, and neurological changes.
• Physical exam focusing on spinal tenderness, range of motion, and neurologic status.

2. Imaging studies

• Plain radiographs – early disease may appear normal; later stages show vertebral body collapse, disc space narrowing, and kyphosis.
• Magnetic Resonance Imaging (MRI) – gold standard for early detection; reveals bone marrow edema, paravertebral abscesses, and cord compression [6].
• Computed Tomography (CT) – excellent for bone detail, useful when MRI is contraindicated.
• Bone scan or PET‑CT – may help locate occult lesions in disseminated disease.

3. Laboratory tests

• Complete blood count (CBC) – often shows mild anemia; leukocytosis is uncommon.
• Erythrocyte sedimentation rate (ESR) & C‑reactive protein (CRP) – usually elevated, reflecting inflammation.
• Sputum microscopy & culture – if pulmonary TB is present; acid‑fast bacilli (AFB) smear is rapid but less sensitive.
• Blood interferon‑γ release assay (IGRA) – supports TB infection when pulmonary samples aren’t available.
• Mycobacterial culture from biopsy – definitive; takes 4‑8 weeks.
• Polymerase chain reaction (PCR) / GeneXpert MTB/RIF – detects M. tuberculosis DNA and rifampicin resistance within hours.

4. Tissue diagnosis

CT‑guided or open biopsy of the vertebral lesion yields material for histopathology (granulomas with caseating necrosis) and microbiology. It is recommended when imaging is equivocal or drug‑resistant TB is suspected.

Treatment Options

Management is multidisciplinary, involving infectious disease specialists, orthopaedic/spine surgeons, and physiotherapists.

1. Antitubercular chemotherapy (ATT)

• World Health Organization (WHO) recommends a 6‑month regimen for drug‑sensitive spinal TB:
• 2 months intensive phase: Isoniazid (H) + Rifampicin (R) + Pyrazinamide (Z) + Ethambutol (E) – “HRZE”.
• 4 months continuation phase: Isoniazid + Rifampicin – “HR”.
• Doses are weight‑based; adherence is critical. Directly observed therapy (DOT) improves outcomes [7].
• For multidrug‑resistant (MDR) or extensively drug‑resistant (XDR) TB, longer regimens with second‑line agents (e.g., fluoroquinolones, linezolid) are required per WHO 2020 guidelines.

2. Surgical intervention

Surgery is indicated when any of the following are present:

• Progressive neurological deficit or spinal cord compression.
• Severe or worsening kyphotic deformity (>30° in the thoracic spine).
• Large abscesses that do not resolve with antibiotics.
• Failure of medical therapy (persistent pain, radiologic progression).

Procedures range from minimally invasive debridement and abscess drainage to instrumented fusion (e.g., posterior pedicle screw fixation). Modern techniques aim to preserve spinal stability while removing infected tissue.

3. Adjunctive therapies

• Corticosteroids – short courses (e.g., dexamethasone 0.1 mg/kg) may reduce edema and improve neurologic recovery in cases of acute cord compression, though evidence is modest [8].
• Vitamin D supplementation – may enhance immune response in deficient patients.
• Pain control – NSAIDs or acetaminophen; opioids only for severe breakthrough pain.

4. Lifestyle & supportive measures

• Smoking cessation – smoking impairs wound healing and TB response.
• Balanced diet rich in protein, iron, and calories to combat cachexia.
• Regular, gentle stretching and physiotherapy once pain permits.

Living with Yerevan Disease (Tuberculosis of the Spine)

Daily management tips

1. Medication adherence – Use a pill organizer, set alarms, or enlist a treatment supporter. Missing doses can lead to resistance.
2. Monitor for side effects – Hepatotoxicity (isoniazid, rifampicin, pyrazinamide) presents as nausea, jaundice, or dark urine. Report promptly.
3. Spine protection – Avoid heavy lifting, twisting, or high‑impact activities for at least 3‑6 months.
4. Physiotherapy – A qualified therapist can design a program focusing on core strengthening, posture correction, and gentle range‑of‑motion exercises.
5. Nutrition – Aim for 1.5–2 g protein/kg body weight daily; include iron‑rich foods (lean meat, legumes) and calcium/vitamin D sources.
6. Follow‑up appointments – Imaging (MRI or X‑ray) is usually repeated at 2‑3 months and again at 6 months to assess healing.
7. Infection control – If you still have pulmonary TB, wear a mask in public until sputum conversion is documented.

Psychosocial considerations

Chronic disease can cause anxiety, depression, or social isolation. Seek counseling, join TB support groups, and keep open communication with family and healthcare providers.

Prevention

• Vaccination – Bacille Calmette‑Guérin (BCG) vaccine provides variable protection against severe TB forms, including spinal disease, especially in children.
• Early detection of pulmonary TB – Prompt diagnosis and treatment of lung infection dramatically reduces hematogenous spread.
• Infection control measures – Adequate ventilation, UV germicidal irradiation in high‑risk settings, and respiratory hygiene.
• Screening high‑risk groups – HIV‑positive patients, diabetics, and close contacts of TB cases should undergo regular symptom screening and, if indicated, IGRA or tuberculin skin testing.
• Healthy lifestyle – Adequate nutrition, regular exercise, and avoidance of smoking/alcohol improve immune defenses.

Complications

If untreated or inadequately treated, spinal TB can lead to serious, sometimes irreversible outcomes:

• Progressive kyphosis – Deformity can exceed 60° in children, causing chronic pain and cosmetic issues.
• Neurological impairment – Permanent paraplegia or quadriplegia due to cord compression.
• Vertebral collapse & fracture – Instability may require urgent surgical stabilization.
• Cold abscesses and fistula formation – May drain externally or extend to the chest/abdomen.
• Disseminated/multifocal TB – Co‑infection of other organs (e.g., meningitis, miliary TB).
• Drug‑resistant TB – Incomplete therapy increases the risk of MDR/XDR strains, which have poorer prognoses.

When to Seek Emergency Care

References

1. World Health Organization. Global Tuberculosis Report 2023. WHO; 2023.
2. Huang T, et al. Epidemiology of spinal tuberculosis in China: a 10‑year retrospective study. *Infect Dis Poverty*. 2022;11:25.
3. Garg R, et al. Extrapulmonary tuberculosis: a global perspective. *Lancet Infect Dis*. 2021;21(8):e210‑e219.
4. Centers for Disease Control and Prevention. Reported Tuberculosis in the United States, 2022. CDC; 2023.
5. Rao SS, et al. HIV and the risk of extrapulmonary tuberculosis. *Clin Infect Dis*. 2020;71(4):850‑856.
6. Wang C, et al. MRI findings in early spinal tuberculosis. *Radiology*. 2021;298(2):349‑358.
7. World Health Organization. Treatment of Tuberculosis Guidelines, 2020 Update. WHO; 2020.
8. Moon MS, et al. Corticosteroids for tuberculous spinal cord compression: a systematic review. *Neurosurgery*. 2019;84(5):1047‑1055.