You are evaluating a 30-year-old previously healthy man for fever and confusion. His roommate tells you that he has complained of headache, nausea, vomiting, and photophobia. You suspect bacterial meningitis. Choose the correct statement regarding his diagnosis:
Kernig and Brudzinski signs are present in 95% of patients with bacterial meningitis.
+The culture of his cerebrospinal fluid (CSF) that is obtained promptly and prior to the administration of antimicrobials may yield the causative agent, as it does in at least 50% of cases.
+A CSF with numerous Gram-positive diplococci but a neutrophil count of only 18 cells/mL is a good prognostic sign.
+His appearance and level of mental function upon presentation indicate that this is most likely viral meningitis.
+If the Gram stain of his CSF reveals Gram-negative diplococci, suspect an underlying basilar skull fracture.
In a young, previously healthy adult, a diminished level of consciousness, the presence of seizures, and a low CSF cell count in the presence of a high bacterial load all are poor prognostic signs. It is critical to remember that empiric antibiotic treatment should be initiated as soon as possible during any workup for meningitis. The diagnostic results will not be affected by such treatment but morbidity and mortality will clearly be improved. Basilar skull fractures are associated with meningitis caused by Streptococcus pneumoniae and less commonly by Haemophilus influenzae.