The meningeal signs fail.
Kernig, Brudzinski, and nuchal rigidity have likelihood ratios near 1. The exam cannot rule out meningitis; do the LP.
Reviewed July 2026 · verify against current guidelines
Bedside Evidence · Mythbuster
The meningeal signs fail.
Kernig and Brudzinski are taught as the classic signs of meningitis. Tested prospectively, they are close to useless.
What the signs actually do
| Finding | Sensitivity | LR+ |
|---|---|---|
| Kernig's sign | 5% | 0.97 |
| Brudzinski's sign | 5% | 0.97 |
| Nuchal rigidity | 30% | 0.94 |
| Jolt accentuation | 21% to 97% | 1.2 to 2.4 |
Thomas 2002, 297 adults with suspected meningitis. Jolt accentuation swings from 97% sensitivity (Uchihara 1991) to 21% (Nakao 2014), so it cannot be trusted to rule out.
What to do instead
- The exam cannot rule out meningitis. If you are considering it, do the LP.
- 95% have at least two of four: headache, fever, neck stiffness, altered mental status.
- The classic triad appears in only 44%. Waiting for it means missing most cases.
An LR near 1 changes nothing. These signs are ritual. The lumbar puncture is the test.
LR+ positive likelihood ratioLP lumbar puncture
Sources
Verify against current guidelines and local protocol before acting.
- Thomas Clin Infect Dis 2002 · van de Beek NEJM 2004 · Uchihara 1991 / Nakao 2014
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