Which of the following is NOT a typical feature of headaches associated with viral meningitis?

Altered Level of Consciousness and Neurological Exam Abnormalities is NOT a Typical Feature of Viral Meningitis

The correct answer is "altered level of consciousness and neurological exam abnormalities" - these features are much more characteristic of bacterial meningitis or encephalitis rather than typical viral meningitis. 1, 2

Key Distinguishing Features

Typical Features of Viral Meningitis

• Fever and meningismus are common presenting symptoms in viral meningitis, occurring in the majority of cases 3
• Diffuse headache developing over several days is characteristic of viral meningitis, with a more gradual onset compared to bacterial meningitis 3
• Associated symptoms of fatigue and myalgias are typical constitutional symptoms that accompany viral meningitis 3
• Clear mental status is the norm in uncomplicated viral meningitis - patients typically remain alert and oriented 4

Features That Suggest Bacterial Meningitis or Encephalitis Instead

• Altered level of consciousness occurs in only 44-51% of bacterial meningitis cases but is distinctly uncommon in viral meningitis 1, 2
• Focal neurological abnormalities are present in 11-34% of bacterial meningitis cases but are not typical of viral meningitis 1, 2
• When confusion or altered mental status is present, this suggests either bacterial meningitis or viral encephalitis rather than simple viral meningitis 5, 4
• All patients with aseptic meningitis who were confused also showed EEG abnormalities, suggesting parenchymal involvement beyond simple meningeal inflammation 4

Clinical Decision-Making Algorithm

If a patient presents with meningitis symptoms:

1. Preserved mental status + gradual onset headache + fever + myalgias → Think viral meningitis 3

2. Altered consciousness + focal deficits + acute onset → Think bacterial meningitis or encephalitis, requiring immediate neuroimaging before lumbar puncture 1, 5

3. Early mental status changes are more common in HSV encephalitis than in meningitis, helping differentiate these conditions 5

Critical Pitfalls to Avoid

• Do not assume viral meningitis if neurological exam abnormalities are present - this warrants investigation for bacterial meningitis or encephalitis 1, 5
• The classic triad of fever, neck stiffness, and altered mental status appears in less than 50% of bacterial meningitis cases, so its absence does not exclude bacterial disease 1, 2
• Never rely on Kernig's or Brudzinski's signs - they have very low sensitivity (5-11%) and should not guide clinical decision-making 1, 6
• Clinical features alone cannot distinguish between viral and bacterial meningitis, so proceed with appropriate diagnostic workup including lumbar puncture when safe 1