Differential Diagnosis for Hypodensity of Stroke versus Cryptococcal
- Single most likely diagnosis
- Ischemic stroke: This is the most common cause of hypodensity on imaging, particularly in the acute setting, due to the interruption of blood flow to a part of the brain, leading to cell death and subsequent changes in brain tissue density.
- Other Likely diagnoses
- Cerebral vasculitis: Inflammation of the blood vessels in the brain can lead to ischemia or infarction, presenting with hypodensity on imaging.
- Encephalitis: Inflammation of the brain tissue, which can be caused by various pathogens, including viruses and bacteria, may present with areas of hypodensity due to edema or necrosis.
- Cryptococcal infection: Especially in immunocompromised patients, Cryptococcus neoformans can cause meningitis or brain parenchymal infection, leading to hypodense lesions on imaging due to the formation of cysts or gelatinous pseudocysts.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Brain abscess: A collection of pus in the brain, usually as a result of bacterial infection, which can present with hypodensity on imaging and requires prompt diagnosis and treatment to prevent severe complications or death.
- Cerebral venous sinus thrombosis: A blood clot in the venous sinuses of the brain, which can cause ischemia or infarction and present with hypodensity, often with a more subtle onset than arterial stroke.
- Malignant cerebral edema: Severe swelling of the brain, which can be life-threatening and requires immediate intervention, may present with hypodensity due to the increased water content in the brain tissue.
- Rare diagnoses
- Progressive multifocal leukoencephalopathy (PML): A rare and often fatal viral disease caused by the JC virus that affects the brain and leads to the destruction of the myelin sheath, presenting with hypodense lesions on imaging, primarily in immunocompromised individuals.
- Subacute sclerosing panencephalitis (SSPE): A rare chronic, progressive encephalitis that affects primarily children and young adults, caused by a persistent infection with the measles virus, which can present with hypodense lesions due to inflammation and necrosis of the brain tissue.