What is the management of spinal cord compression secondary to Tuberculosis (TB)?

Management of Spinal Cord Compression Secondary to Tuberculosis

For spinal tuberculosis with cord compression, initiate standard 6-month anti-tuberculous chemotherapy (2 months of isoniazid, rifampicin, pyrazinamide, and ethambutol followed by 4 months of isoniazid and rifampicin) immediately, reserving surgery for patients with severe or progressive neurological deficits (Frankel grade C or worse), spinal instability, or failure to respond to medical therapy. 1

Initial Assessment and Diagnosis

Confirm diagnosis through image-guided aspiration biopsy to establish mycobacterial diagnosis and determine drug susceptibility patterns. 1 Consider holding antibiotics for 1-2 weeks prior to biopsy to increase diagnostic yield, except when neurological compromise or hemodynamic instability is present. 1

Obtain MRI of the entire spine to assess the extent of disease, degree of cord compression, presence of epidural abscess, and signal cord changes—which are predictive factors for neurological deterioration. 2

Medical Management (First-Line Treatment)

Standard chemotherapy regimen consists of:

• Initial phase (2 months): Isoniazid, rifampicin, pyrazinamide, and ethambutol (2HRZE) 3, 1
• Continuation phase (4 months): Isoniazid and rifampicin (4HR) 3, 1

Daily dosing is strongly recommended over intermittent regimens for optimal outcomes. 1 Fixed-dose combinations may provide more convenient administration. 1

If pyrazinamide cannot be tolerated, extend treatment duration to 9 months with rifampicin and isoniazid, supplemented with ethambutol for the initial 2 months. 3

Evidence Supporting Medical Management

Multiple Medical Research Council studies demonstrated that 24 of 30 patients (80%) and 74 of 85 patients (87%) achieved complete resolution of myelopathy or complete functional recovery with chemotherapy alone. 3 A more recent prospective study showed that 47 of 50 patients (94%) with radiological cord compression and early neurological signs responded completely to non-operative treatment when managed with systematic medical therapy. 4

Surgical Indications

Surgery is indicated for:

• Severe or progressive neurological deficit (Frankel grade C or worse—no useful motor function) 1, 4
• Spinal instability or significant kyphosis (Cobb angle >30°) 1, 2
• Large abscess formation requiring drainage 1
• Failure to respond to medical therapy with evidence of ongoing infection 3
• Bony retropulsion or bone fragments causing cord compression 3

Surgical Approach

For thoracic lesions: Anterior transthoracic approach for decompression, debridement of pus, granulation tissue, and sequestra, with internal splintage using bone grafts. 5

For cervical lesions: Anterior approach lateral to the carotid vessels. 5

Timing: Surgery should be performed urgently at the onset of neurological deterioration, as neurological involvement is relatively benign if urgent decompression is performed early. 6 However, radiological evidence of cord compression and early neurological signs (hyperreflexia without motor deficit) need not be an emergency surgical indication if systematic medical management is applied. 4

Surgical Outcomes

Prognosis is heavily dependent on pretreatment neurological status:

• Patients with Frankel grade D or E (useful motor function preserved) have excellent recovery rates 5
• Only 30% of non-ambulatory patients regain ability to walk 5
• Thoracic lesions with severe neurological deficits show the least improvement, while lumbar disease has the best outcome 5

Monitoring and Follow-Up

Clinical monitoring should include:

• Monthly weight recording and assessment of clinical response 3
• Monitoring for drug-related adverse effects, particularly hepatotoxicity (AST/ALT levels) and visual disturbances with ethambutol 3, 1
• Follow-up imaging to evaluate response to treatment and detect complications 1

Liver function monitoring protocol:

• Check baseline liver function before treatment 3
• If AST/ALT is 2× normal or greater, monitor weekly for 2 weeks, then biweekly until normal 3
• Stop rifampicin, isoniazid, and pyrazinamide if AST/ALT rises to 5× normal or bilirubin rises 3

Long-term follow-up is essential, particularly for children, as spinal growth can exaggerate deformities over time. 1

Adjunctive Therapies

Corticosteroids are NOT routinely recommended for spinal tuberculosis with cord compression. The evidence for corticosteroids is established only for tuberculous meningitis and pericarditis, not for spinal disease. 3

Supportive measures include:

• Nutritional support, especially for malnourished patients 1
• Physiotherapy and rehabilitation to improve function and prevent complications 1
• Orthotic devices to support the spine during healing 1
• Directly Observed Therapy (DOT) to ensure adherence 1

Special Populations

HIV co-infection: Initiate antiretroviral therapy within 2 weeks of starting TB treatment and monitor for immune reconstitution inflammatory syndrome (IRIS). 1

Diabetic patients: Require more frequent glucose monitoring as TB disease and some TB drugs can disrupt glycemic control. 1

Drug-Resistant Tuberculosis

For suspected or confirmed multidrug-resistant TB (MDR-TB): Treatment should be guided by drug susceptibility testing and managed by or in close consultation with TB experts. 3, 1 Empirical regimens may include a fluoroquinolone, an injectable agent, and additional oral agents such as cycloserine, ethionamide, or PAS. 1 Never add a single new drug to a failing regimen to prevent further acquired resistance. 1

Common Pitfalls

Misdiagnosis is common: In one series, 41% of patients were initially misdiagnosed, with unexpected operative findings including lymphoma, plasmacytoma, non-tuberculous granulation tissue, salmonella osteomyelitis, and tumor metastasis. 5, 7

Treatment failure is often due to:

• Poor adherence to medication regimens 1
• Inadequate duration of therapy (courses shorter than 6 months invariably associated with disease recurrence) 7
• Unrecognized drug resistance 1

Affected lymph nodes and vertebrae may enlarge or show radiographic changes during appropriate therapy without evidence of bacteriological relapse—this does not indicate treatment failure. 3, 1