Cryptococcal meningoencephalitis presenting with an unusual magnetic resonance imaging appearance--case report

A 61-year-old female with a past history of gastric cancer presented with altered mental status, a few seizures, and low-grade fever. Lumbar puncture revealed elevated cerebrospinal fluid (CSF) pressure, lymphocytic pleocytosis, elevated protein level, remarkably decreased glucose level, and presence of cryptococcal antigen. Cryptococcus neoformans was identified by India ink staining and culture of CSF. The patient was given antifungal agents intravenously and intrathecally. CSF findings improved and C. neoformans could not be detected in CSF one month after the onset. Cerebral sulcal hyperintensity was identified in the bilateral frontal and parietal lobes on fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) imaging one month after the onset, but no leptomeningeal enhancement was detected in the affected sulci on T1-weighted MR imaging. The sulcal hyperintensity on FLAIR imaging developed in the bilateral temporal and occipital lobes 2 months after the onset. CSF findings obtained by lumbar puncture were within the normal range except for pressure. However, neurological deterioration and reconfirmation of C. neoformans in CSF indicated recurrent cryptococcal inflammation. The sulcal hyperintensity on FLAIR imaging may indicate a high CSF protein concentration in the subarachnoid space. Such cerebral sulcal hyperintensity is an unusual MR imaging finding of cryptococcal meningoencephalitis, and may be an early sign of procrastinating process or recurrent inflammation even if the findings of CSF obtained by lumbar puncture are normal.