Central nervous system (CNS) infections, including meningitis, encephalitis, and brain abscess, are rare but time-sensitive emergency department (ED) diagnoses. Patients with CNS infection can present to the ED with nonspecific signs and symptoms, including headache, fever, altered mental status, and behavioral changes. Neuroimaging and CSF fluid analysis can appear benign early in the course of disease. Delaying therapy negatively impacts outcomes, particularly with bacterial meningitis and herpes simplex virus encephalitis. Therefore, diagnosis of CNS infection requires vigilance and a high index of suspicion based on the history and physical examination, which must be confirmed with appropriate imaging and laboratory evaluation.
Key points
- •
The classic triad of fever, neck stiffness, and altered mental status is present in only a minority of patients with meningitis.
- •
Kernig’s and Brudzinski’s signs are poorly sensitive but relatively specific physical examination maneuvers for identifying meningitis.
- •
Imaging tests and lumbar puncture should not delay initiation of empiric antibiotic therapy in patients suspected to have bacterial meningitis.
- •
Although certain cerebrospinal fluid (CSF) profiles are highly suggestive of viral or bacterial meningitis infection, emergency physicians should not be not falsely reassured by a benign CSF fluid profile supporting a viral cause.
- •
Encephalitis should be considered in any patient presenting with new-onset seizure or focal neurologic deficit accompanied by fever, headache, altered mental status, or behavioral changes.
Related posts:
Full access? Get Clinical Tree
