Brain MRI Findings in Cryptococcal Meningoencephalitis

Kazuhiro Usuda, Yasuo Katayama
2000 Journal of Nippon Medical School  
Cryptococcus neoformans is pathogenic in immunocompromised patients, such as acquired immune deficiency syndrome(AIDS)patients. Brain MRI findings in cryptococcal meningoencephalitis are described in this photogravure. Inhalation is the usual mode of infection, and hematogenous spread to the central nervous system(CNS)results in diffuse subacute meningitis. The dural and leptomeningeal involvement and associated inflammatory reaction are mild, so dural and leptomeningeal enhancement can hardly
more » ... e seen(Fig. 1A・B, 2A・B and 3A・B ). An Arachnoid cyst filled with a mucoid material produced by the fungus can be seen within the subarachnoid space. Spread of infection to the cortex and parenchyma occurs via Virchow-Robin (V-R) spaces. Dilated V-R spaces are perivascular spaces that become distended with the fungus and mucoid material, which promotes enlargement of the perivascular spaces. They are small punctate rounded lesions less than 3 mm in size, and are hyperintense on T2-weighted images and of low signal on T1-weighted images. They are most evident in the bilateral basal ganglia, and are often symmetric(Fig. 1A・B and 4A・B ) . Gadolinium enhancement is seldom seen in these lesions. The foci are not associated with edema or mass effect(Fig. 2A・B and 3A・B ) . With disease progression these V-R spaces increase in size, resulting in the development of cryptococcomas, which extend into the parenchyma. These cryptococcomas are composed of gelatinous masses of cryptococcal
doi:10.1272/jnms.67.226 pmid:10938589 fatcat:bqyh2e7nffg2jdtqvbtilf7wma