What is the initial management for a 37-year-old patient with headache, fever, and regression?

Initial Management of a 37-Year-Old Patient with Headache, Fever, and Regression

Immediate Priority: Rule Out Life-Threatening Causes

This patient requires urgent evaluation for bacterial meningitis or viral encephalitis given the triad of headache, fever, and neurological regression, with immediate lumbar puncture and empiric antimicrobial therapy if meningitis is suspected. 1

The combination of headache, fever, and "regression" (interpreted as altered mental status, confusion, or neurological deterioration) represents a medical emergency requiring immediate action rather than outpatient management.

Critical Red Flags Present

This patient exhibits multiple red flags that mandate urgent investigation:

• Fever with headache suggests central nervous system infection (meningitis or encephalitis) 1, 2
• Neurological regression (altered mental status, confusion, or cognitive decline) indicates potential CNS involvement 1
• Age 37 years places the patient in the typical age range for viral encephalitis, particularly HSV-2 meningitis (median age 25 years for NMDA receptor antibody encephalitis) or bacterial meningitis 1

Immediate Diagnostic Workup

Cerebrospinal Fluid Analysis

• Perform lumbar puncture immediately to evaluate for meningitis or encephalitis, checking cell count with differential, protein, glucose, Gram stain, bacterial cultures, and HSV PCR 1, 3
• HSV-2 meningitis characteristically shows lymphocytic pleocytosis with mildly elevated protein and normal glucose 1
• Bacterial meningitis shows elevated white count, increased protein, and decreased glucose 3

Neuroimaging Before LP

• Obtain CT head emergently before lumbar puncture if any of the following are present: focal neurological signs, decreased level of consciousness, or papilledema 1, 3
• MRI brain with contrast is preferred when available and patient is stable, as it can identify characteristic findings in viral encephalitis (hippocampal high signal in 60% of VGKC-complex antibody cases) 1

Additional Laboratory Studies

• Blood cultures, complete blood count, comprehensive metabolic panel, and serum sodium (hyponatremia occurs in 60% of VGKC-complex antibody encephalitis) 1
• Serum VGKC-complex antibodies and NMDA receptor antibodies if encephalitis is suspected 1

Empiric Treatment Protocol

If Bacterial Meningitis Suspected

• Do not delay antibiotics for imaging or lumbar puncture if bacterial meningitis is strongly suspected based on clinical presentation 1
• Empiric therapy should include coverage for common pathogens based on age and risk factors 1

If HSV Meningitis/Encephalitis Suspected

• Initiate IV acyclovir 10 mg/kg every 8 hours immediately for suspected HSV encephalitis, as mortality is 59% with vidarabine versus 25% with acyclovir 1, 4
• For HSV-2 meningitis specifically: acyclovir 10 mg/kg IV every 8 hours until resolution of fever and headache, followed by valacyclovir 1g three times daily to complete 14-day course 1
• Critical distinction: HSV encephalitis requires 14-21 days of IV acyclovir due to high neurologic morbidity and mortality, while HSV-2 meningitis can transition to oral therapy 1

If Autoimmune Encephalitis Suspected

• For VGKC-complex antibody encephalitis: high-dose oral steroids (0.5 mg/kg/day) with IVIg (0.4 g/kg/day) or plasma exchange if acutely unwell 1
• For NMDA receptor antibody encephalitis: corticosteroids combined with either plasma exchange or IVIg, with consideration of rituximab or cyclophosphamide for non-responders 1

Common Pitfalls to Avoid

• Do not assume this is primary headache (migraine or tension-type) given the presence of fever and neurological symptoms 2, 5, 6
• Do not delay lumbar puncture for imaging unless contraindications exist (focal signs, decreased consciousness, papilledema) 3
• Do not withhold empiric antibiotics while awaiting diagnostic studies if bacterial meningitis is suspected, as delay increases mortality 1
• Do not miss HSV encephalitis, which requires immediate IV acyclovir, as patients under 30 years with least severe neurologic involvement have best outcomes when treated early 4

Disposition

• Immediate hospital admission is required for any patient with headache, fever, and altered mental status 1, 3
• Patients require monitoring in a setting capable of managing potential neurological deterioration, seizures, or respiratory compromise 1
• Neurology consultation should be obtained urgently for suspected encephalitis or atypical presentations 1, 5