Table 1 Features distinguishing chronic meningitis (bacterial and non bacterial) compared with acute bacterial meningitis

Aetiology

Variable

Neisseria meningitides 13–56% [10,17, 39]

Streptococcus pneumoniae 24–37% [10,17]

Variable

TB- 40–60% [3,5]

Malignancy 8–13% [3,5]

Cryptococcus 7–11% [3,5]

Unknown 30–33% [3,5]

Clinical features

- Classic triad of fever, headache and neck stiffness

85% [9]

10% [4]

- Fever

78–91% [39]

44% [4]

- Headache

32–68% [39]

79% [4]

- Neck Stiffness

58–82% [39]

75% [5]

- Altered Mental state

52–82% [39]

41% [4]

- Focal neurology

23% [39]

32% [5]

- Papilloedema

<1–4% [9,10]

30% [5]

- Cranial Nerve Palsies

4% [10]

24% [5]

Mortality

Variable – aetiology dependent

19.7–25% overall [10,17]

37–44% ≥ 60 years old [1,10]

10–25% < 60 years old [10,16–20]

Variable – aetiology dependent

29%- overall [5]

Elevated WCC, CRP and ESR

Elevated

Normal or only mildly elevated [5]

Hyponatraemia

<10%

>90% [5]

Cerebrospinal fluid analysis

10% – lymphocytic [9,17]

90% – neutrophilic [9,17]

Gram stain positive 57–90% [9,10,17]

>90% lymphocytic [5]

<10% neutrophilic [5]

Gram stain positive <10% [5]

Abnormal CT

2.7 – 13% [10,40]

60% [5]