Table 2.

Uniform Tuberculous Meningitis Research Case Definition Criteria[²]

Criteria
Clinical criteria (maximum category score = 6)
Symptom duration of >5 d	4
Systemic symptoms suggestive of TB (≥1): weight loss/(poor weight gain in children), night sweats, or persistent cough >2 wk	2
History of recent close contact with an individual with pulmonary TB or a positive TST/IGRA in a child aged <10 y	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/µL	1
Lymphocytic predominance (>50%)	1
Protein concentration >1 g/L	1
CSF to plasma glucose ratio of <50% or an absolute CSF glucose concentration <2.2 mmol/L	1
Cerebral imaging criteria (maximum category score = 6)
Hydrocephalus (CT and/or MRI)	1
Basal meningeal enhancement (CT and/or MRI)	2
Tuberculoma (CT and/or MRI)	2
Infarct (CT and/or MRI)	1
Precontrast basal hyperdensity (CT)	2
Evidence of tuberculosis elsewhere (maximum category score = 4)
Chest radiograph suggestive of active TB (excludes miliary TB)	2
Chest radiograph suggestive of miliary TB	4
CT/MRI/US evidence for TB outside the CNS	2
AFB identified or Mycobacterium tuberculosis cultured from another source (ie, sputum, lymph node, gastric washing, urine, blood culture)	4
Positive commercial M. tuberculosis NAAT from extraneural specimen	4
Exclusion of alternative diagnoses: An alternative diagnosis must be confirmed microbiologically, serologically, or histopathologically.
Definite TBM: AFB seen on CSF microscopy, positive CSF M. tuberculosis culture, or positive CSF M. tuberculosis commercial NAAT in the setting of symptoms/signs suggestive of meningitis; or AFB seen in the context of histological changes consistent with TB brain or spinal cord together with suggestive symptoms/signs and CSF changes, or visible meningitis (on autopsy).
Probable TBM: total score of ≥12 when neuroimaging available or total score of ≥10 when neuroimaging unavailable. At least 2 points should either come from CSF or cerebral imaging criteria.
Possible TBM: total score of 6–11 when neuroimaging available, or total score of 6–9 when neuroimaging unavailable.

Abbreviations: AFB, acid-fast bacilli; CNS, central nervous system; CSF, cerebrospinal fluid; CT, computed tomography; IGRA, interferon-γ release assay; MRI, magnetic resonance imaging; NAAT, nucleic acid amplification test; TB, tuberculosis; TBM, tuberculous meningitis; TST, tuberculin skin test; US, ultrasound.