Acute Encephalitis vs. Meningitis: Early Identification of CNS Infection in Patients with Fever and Neck Stiffness

Central nervous system (CNS) infections such as acute encephalitis and meningitis present significant diagnostic challenges due to their similar clinical presentations, yet they have different therapeutic and prognostic implications. Early and accurate identification of these conditions is crucial for improving clinical outcomes and reducing associated morbidity and mortality.
Diving into the Differential Diagnosis
Meningitis is characterized by the inflammation of the meninges, the membranes surrounding the brain and spinal cord. Classic symptoms include fever, neck stiffness, and altered mental status. Viral meningitis is commonly caused by enteroviruses, although in immunocompromised patients, other viruses may be responsible, leading to significant neurological complications [1].
On the other hand, encephalitis involves inflammation of the brain tissue and may present symptoms similar to meningitis, but with a higher incidence of focal neurological deficits and seizures. High-throughput sequencing has emerged as a valuable tool for identifying viral etiologies in cases of encephalitis and meningitis where conventional methods fail [2].
The analysis of cerebrospinal fluid (CSF) is fundamental in the differential diagnosis. The presence of lymphocytic pleocytosis and normal glucose levels in the CSF suggests a viral etiology, while neutrophilic pleocytosis and hypoglycorrhachia are more indicative of a bacterial infection. Fungal CNS infection should also be considered, especially in immunocompromised patients, where rapid identification of the etiological agent is crucial for appropriate treatment [3].
Conclusions
Early and accurate identification of acute encephalitis and meningitis is essential for guiding treatment and improving clinical outcomes. Advanced diagnostic tools, such as high-throughput sequencing and multiplex PCR panels, are revolutionizing our ability to rapidly and accurately identify pathogens in the CNS. However, clinical interpretation remains fundamental to differentiate between these conditions and optimize patient management.
Referencias
- [1] Viral meningitis
- [2] High-throughput sequencing for the aetiologic identification of viral encephalitis, meningoencephalitis, and meningitis
- [3] Neuroinfections caused by fungi
Created 6/1/2025