Uniform Tuberculosis Meningitis Research Case Definition Criteria of Marais et al

Marais et al reported uniform criteria for the diagnosis of tuberculous meningitis.

Parameters:

(1) subscore for clinical criteria (maximum score 6)

(2) subscore for CSF criteria (maximum score 4)

(3) subscore for imaging criteria (maximum score 6)

(4) subscore for evidence of tuberculosis elsewhere (maximum score 4)

Parameter	Finding	Points
clinical criteria	symptom duration > 5 days	4
	systemic symptoms suggestive of tuberculosis	2
	history of recent close contact	2
	focal neurological deficit, excluding cranial nerve palsy	1
	cranial nerve palsy	1
	altered level of consciousness	1
CSF criteria	clear fluid	1
	cell count 10 to 500 per µL	1
	> 50% lymphocytes	1
	protein concentration > 1 g/L	1
	CSF/plasma glucose ratio less than 50% OR CSF glucose concentration less than 2.2 mmol/L	1
imaging criteria	hydrocephalus	1
	basal menigneal enhancement	2
	tuberculoma	2
	infarct	1
	preconstrast basal hyperdensity	2
tuberculosis elsewhere	chest X-ray suggests active TB	2
	chest X-ray suggests miliary TB	4
	imaging evidence of TB outside CNS	2
	AFB identified or cultured	4
	positive NAAT test from specimen collected outside CNS	4

where:

• Systemic symptoms suggestive of tuberculosis include: weight loss, night sweats, persistent cough for > 2 weeks.

total score =

= SUM(points for all of the subscores)

Interpretation:

• minimum total score: 0

• maximum total score: 20

• The diagnosis of tuberculosis can be excluded if there is no evidence of tuberculosis and if there is a confirmed alternative diagnosis.

Diagnosis	Findings
definite TB meningitis	AFB seen in CSF; positive TB culture from CSF; positive NAAT with signs of meningitis; AFB seen with histologic changes consistent with TB AND evidence of meningitis (clinical or meningeal appearance)
probable TB meningitis	total score >= 12 if neuroimaging available or >= 10 if neuroimaging not available, with at least 2 points coming from CSF or cerebral imaging criteria
possible TB meningitis	total score 6 to 11 if neuroimaging available; 6 to 9 if neuroimaging not available

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