Validity of Meningeal Signs in Suspected Meningitis

Background: Meningitis, an inflammation of meninges, a common medical emergency. Meningeal signs like Kernig’s sign, Brudzinski’s sign and neck rigidity are used specifically to assess a patient’s with suspected meningitis. It has been proposed that in patients with meningitis, passive flexion of the neck stretches the nerve roots through the inflamed meninges, leading to pain and flexion movements of lower extremities. However, these signs are not pathognomonic for meningitis. The aim of study is to validate the meningeal signs in 75 adults with suspected meningitis.

Methods: Seventy-five patients admitted to our tertiary hospital with suspected meningitis were selected and divided into two groups: Patients with meningitis (n=62) and Patients without meningitis (n=13). Meningitis was considered to be present if the CSF WBC count was ? 6/cmm. The three meningeal signs Kernig’s sign, Brudzinski’s sign and nuchal rigidity noted in each patient prior to lumber puncture. The sensitivity, specificity and P-value calculated.

Results: Demography and clinical presentation of patients with meningitis (n=62) were similar to those without meningitis (n=13). Meningeal signs - Of the 62 patients with meningitis (WBCs/cmm of CSF ? 6) who were examined prior to lumbar puncture, neck rigidity in 46 (74.2%), Kernig’s sign in 37 (59.68%) and Brudzinski’s sign in 18 (29.03%) patients. None of the meningeal signs shown to have statistical significance (P<0.001). Kernig’s sign had a sensitivity of 60% and specificity, 85% whereas Brudzinski’s sign had 29% and 92% respectively. Sensitivity and specificity for nuchal rigidity were 74% and 77% respectively.

Conclusion: The study suggest that Kernig’s and Brudzinski’s signs are not sensitive for detecting meningitis and therefore, if not present, it can’t exclude the diagnosis of meningitis. Nuchal rigidity is the only meningeal sign with clinical usefulness. A larger number of patients need to be studied with standardization of clinical method for elicitation of meningeal signs.