Table 2 Lancet scoring system

Clinical criteria

Score (Maximum category score = 6)

 Symptom duration of more than 5 days

4

 Systemic symptoms suggestive of tuberculosis (one or more of the following): weight loss (or poor weight gain in children), night sweats, or persistent cough for more than 2 weeks

2

 History of recent (within past year) close contact with an individual with pulmonary tuberculosis or a positive TST or IGRA (only in children < 10 years of age)

2

 Focal neurological deficit (excluding cranial nerve palsies)

1

 Cranial nerve palsy

1

 Altered consciousness

1

CSF criteria

(Maximum category score = 4)

 Clear appearance

1

 Cells: 10–500 per μl

1

 Lymphocytic predominance (> 50%)

1

 Protein concentration greater than 1 g/L

1

 CSF to plasma glucose ratio of less than 50% or an absolute CSF glucose concentration less than 2·2 mmol/L

1

Cerebral imaging criteria

(Maximum category score = 6)

 Hydrocephalus

1

 Basal meningeal enhancement

2

 Tuberculoma

2

 Infarct

1

 Pre-contrast basal hyperdensity

2

Evidence of tuberculosis elsewhere

(Maximum category score = 4)

 Chest radiograph suggestive of active tuberculosis: signs of tuberculosis = 2; miliary tuberculosis = 4

2/4

 CT/ MRI/ ultrasound evidence for tuberculosis outside the CNS

2

 AFB identified or Mycobacterium tuberculosis cultured from another source—i.e., sputum lymph node, gastric washing, urine, blood culture

4

 Positive commercial M tuberculosis NAAT from extra-neural specimen

4