Symptoms of Meningitis
The most common symptoms of meningitis are fever, headache, neck stiffness, and altered mental status, but the classic triad of fever, neck stiffness, and altered mental status occurs in less than half of patients—meaning bacterial meningitis should never be ruled out based solely on the absence of these classic findings. 1
Core Clinical Features
The presenting symptoms and signs of meningitis include:
- Fever is present in 77-97% of cases, though it can be absent, particularly in elderly patients 1, 2
- Headache occurs in 58-87% of patients 1
- Neck stiffness is found in 65-83% of cases 1
- Altered mental status (confusion, lethargy, or decreased consciousness) appears in 30-69% of patients 1
- Nausea and vomiting occur in approximately 74% of cases 1
- Coma develops in 7-16% of patients at presentation 1
Critical Diagnostic Threshold
At least 95% of patients with bacterial meningitis present with two or more of these four symptoms: headache, fever, neck stiffness, or altered mental status. 3 This means:
- If a patient has none of these four symptoms, meningitis is effectively ruled out 4
- If any two or more are present, meningitis must be seriously considered and investigated 3
Specific Features by Meningitis Type
Meningococcal Disease
- Petechial or purpuric rash is the hallmark finding, occurring in 20-52% of meningococcal cases 1, 2
- When a rash is present in the context of meningitis, meningococcus is the causative organism in over 90% of cases 2
Bacterial Meningitis (General)
- Focal neurologic deficits occur in 11-34% of cases 1, 5
- Seizures occur in 10-56% of children and 19-25% overall 2
- The presence of confusion or altered mental status should raise suspicion for bacterial meningitis rather than simple viral meningitis 5
Tuberculous Meningitis
- Subacute onset of symptoms over days to weeks, rather than acute presentation 6
- Cranial nerve palsies, particularly the sixth cranial nerve, occur in more than one-third of patients—a distinctive feature 6
Common Pitfalls and Caveats
The Classic Triad is Unreliable
The classic triad of fever, neck stiffness, and altered mental status is present in only 41-51% of bacterial meningitis cases 1, 5, 7. Grade A recommendation: Bacterial meningitis should not be ruled out solely on the absence of classic symptoms. 1
Meningeal Signs Have Poor Sensitivity
- Neck stiffness has only 31% sensitivity in adults 1, 2
- Kernig's sign has 5-11% sensitivity 2, 5
- Brudzinski's sign has 5-9% sensitivity 1, 5
- These signs should never be used to rule out meningitis due to their very low sensitivity 1, 2, 5
Jolt Accentuation Test
Among patients with fever and headache, jolt accentuation of headache (worsening headache with horizontal head rotation) has 100% sensitivity but only 54% specificity for meningitis 4. This can be a useful adjunctive maneuver when present.
Clinical Decision-Making Algorithm
When evaluating a patient for possible meningitis:
If the patient has ≥2 of the following four symptoms (headache, fever, neck stiffness, altered mental status) → proceed with urgent evaluation including lumbar puncture 3
If a petechial or purpuric rash is present with any systemic symptoms → assume meningococcal disease and initiate immediate treatment 2
If altered consciousness or focal neurologic deficits are present → prioritize bacterial meningitis or encephalitis; obtain neuroimaging before lumbar puncture 5
If subacute onset with cranial nerve palsies → consider tuberculous meningitis 6
Never delay antibiotic therapy while awaiting diagnostic confirmation, as mortality remains high in untreated disease 2