The Common Vein Copyright 2010
Definition
Cerebral aspergillosis is a rare condition, classically affecting immunocompromised patients, often in patients that received bone marrow transplantation.
Aspergillus spores typically enter the body through inhalation and colonize the lungs or sinuses, which can secondarily spread to other organs by hematogenous spread. The brain is a common site of spread.
Structurally, unlike other microorganisms, aspergillus produces filaments that are angio-invasive; the wall of the large cerebral arteries is destroyed, and the ostia for small perforating arteries are blocked, causing initially sterile areas of infarction. Later, these areas also get infected however.
Clinically, most patients have lethargy or drowsiness during the course of infection and 75% develop acute focal neurological signs.
Because of the clinical and microbiological diagnostic difficulty, brain imaging is crucial for the positive and differential diagnosis. In the CSF however, galactomannan antigen detection by latex or ELISA technique are useful and have high sensitivity and specificity, as well as DNA detection by PCR.
Radiologically, CT scan and MRI appearance is nonspecific, lesions of aspergillosis classically presenting as multiple images rounded, with or without a hemorrhagic component, with or without ring enhancement after injection of contrast. DWI can provide more accurate findings and help with early diagnosis.
The prognosis is very poor; the mortality rate is estimated between 85 and 100%. Treatment is done with Amphotericin B in the acute phase of disease, later continuing with Itraconazole as maintenance therapy.