G04.3

Clinical Causes: Viral infections, especially influenza (flu) viruses Other respiratory viruses, such as paramyxoviruses and enteroviruses Immune system responses that lead to inflammation in the brain Potential genetic predispositions, although not well understood

Key Symptoms: Sudden onset of high fever Severe headache Altered consciousness or coma Seizures Nausea and vomiting Neurological deficits, such as weakness or paralysis on one side of the body Visual disturbances or difficulty speaking Rapid decline in mental state

Diagnosis Path: Neurological examination to assess mental status and neurological function Magnetic resonance imaging (MRI) scans of the brain to detect inflammation, hemorrhage, and tissue necrosis Computed tomography (CT) scans as an alternative imaging method Laboratory tests to identify viral infections, such as polymerase chain reaction (PCR) or serology Cerebrospinal fluid analysis to evaluate for signs of infection or inflammation

Treatment Protocols: Hospitalization in intensive care units for close monitoring Supportive therapies such as oxygen supplementation and mechanical ventilation if breathing is compromised Managing increased intracranial pressure with medications or surgical interventions Antiviral medications if a specific viral infection is identified Immunomodulatory treatments like corticosteroids to reduce inflammation Seizure control through anticonvulsant medications Rehabilitation services, including physical, occupational, and speech therapy, after stabilization