Final answer:
Brain abscesses form when organisms infect brain tissue, usually via the bloodstream, direct extension, or trauma. Conditions like granulomatous amebic encephalitis, bacterial meningitis, and neurocysticercosis can lead to brain abscesses. Accurate diagnosis is essential for appropriate management and treatment.
Step-by-step explanation:
Brain abscesses are localized infections in the brain that can arise from bacteria, fungi, or parasites entering the brain tissue. The spread of infection to the brain can occur through the bloodstream, direct spread from an infection in nearby structures like the sinuses or middle ear, or by a penetrating head injury. Single or multiple brain abscesses can be a severe complication of conditions such as granulomatous amebic encephalitis (GAE), bacterial meningitis, or neurocysticercosis. Figure 26.23 illustrates brain damage from GAE caused by Balamuthia mandrillaris, showing necrosis in brain tissue. Similarly, Figure 26.5 depicts the effects of bacterial meningitis on the brain, another route through which bacteria can access the central nervous system (CNS). Figure 26.26 shows a brain with neurocysticercosis, a parasitic infection where cysts form in the brain due to Taenia solium. Lastly, Figure 11.44.2 highlights the bacteria responsible for bacterial meningitis, a condition with high mortality if not promptly treated.
Patients can be particularly susceptible to brain abscesses and bacterial meningitis through trauma, surgical procedures, or pre-existing conditions that compromise the CNS, such as cochlear implants or immune deficits. Therefore, understanding the pathways of infection is crucial for proper diagnosis and treatment. Brain abscesses get to the brain through hematogenous spread, local extension from an infection, or directly via trauma; the presence of single or multiple abscesses depends on the source and nature of the infection.