Lumbar puncture is the widely used diagnostic procedure for the meningitis and is performed whenever meningitis is even minimally suspected but it does involves some risk.
Although the value of the lumbar puncture in diagnosing meningitis is established and emphasize the importance of performing it in any child suspected of having meningitis,there is no data on the reliability of the signs commonly associated with the disease.
An analysis of the cerebrospinal fluid for 500 children subjected to lumbar puncture on the suspicion of meningitis for 5 years period was undertaken to determine the characteristics of patients with and without meningitis, and evaluate the precictive value of symptoms and signs of meningitis.
The following results were obtained.
The incidence of positive lumbar puncture was 42.4% and increased with patient´s age.
Vomiting irritability and headache showed high incidence of positive lumbar puncture. 56.0%, 63.8% and 78.4% respectively. The incidence of positive lumbar puncture was also higher in patients with nuchal rigidity and kernig´s sign and the higher incidence of these symptoms and signs observed among patients with meningitis. Fever, convulsion with or without fever, and lethargy were not specific.
ESR over 20mm/hr had higher incidence of posivive lumbar puncture and the incidence increased as ESR rises. Leukocytes and absolute granulocyte count in peripheral blood were not specific.
The most common conditions that mimic meningitis and led to lumbar puncture in this study were febrile convulsion, acute gastroenteritis, upper respiratory infection, pneumonia and acute pharyngotonsillitis in order.
The results of this study suggested that vomiting irritability headache nuchal rigidity and kernig´s sign proved to be more sensitive indicators of meningeal infection. Older age and elevated ESR also had high predictive value for lumbar puncture in patient suspected meningitis.
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