Epidemiology

Etiology

• Primary source of infection
  • Contiguous spread of an infection (most common cause)
    • Can be otogenic (e.g., otitis media, mastoiditis)
    • Sinus (e.g., sinusitis): most commonly seen in men and caused by Streptococcus milleri
    • Oral (e.g., dental infection)
    • Meningeal (e.g., meningitis)
  • Direct injection, e.g., head trauma, neurosurgery
  • Hematogenous spread, e.g., patients with cyanotic heart disease (least common cause): multiple abscesses located in the middle cerebral artery distribution at the gray-white junction
• Pathogens: brain abscesses are most commonly polymicrobial
  • Most common pathogens
    • Viridans streptococci (often secondary to sinusitis)
    • Staphylococcus aureus
    • Less common pathogens
  • Obligate anaerobes, e.g., Bacteroides species, (mainly due to dental infections)
  • In immunocompromised states: Toxoplasma, Aspergillus, Candida, Mucormycosis (also known as Zygomycosis), Cryptococcus

Pathophysiology

Clinical features

Diagnostics

Treatment