New Cerebellar Lesion After Resolution of Cryptococcal Infection: Flare-up of Infection or Coincidental Finding?

초록

Background & Significance: Cryptococcal infection of the central nervous system (CNS) is manifested with meningitis, meningoencephalitis, ventriculitis or intracerebral mass lesions. Cryptococcal infections are typically associated with deficiencies in cell-mediated immunity. On magnetic resonance imaging (MRI) scans, there is high signal intensity on T2-weighted imaging and uniform or ring enhancement on T1-weighted enhancement image. The lesions occur most commonly in the cerebellum, brainstem, basal ganglia, and temporoparietal regions. We report a patient with acute lesion of cerebellum after resolution of Cryptococcal infection without accompanying abnormalities of cerebrospinal fluid (CSF). Case: A 74-yearold woman was admitted for evaluation of right hemifacial spasm. In 2006, meningoencephalitis developed after having had steroid therapy for nephrotic syndrome twice. Cryptococcus neoformans was detected on CSF and Cryptococcal antigen was elevated. The initial MRI showed no specific findings. One month later this patient had severe cerebellar dysfunction on neurological examination, and MRI revealed high signal intensities in the cerebellum on T2-weighted and diffusion weighted images, with strong enhancement of the posterior fossa, accompanied by severe hydrocephalus. Two years later right hemifacial spasm newly developed. We considered the possibility of a flare-up of Cryptococcal infection. However, the CSF study was normal and organisms were not detected. Brain MRI showed foci of acute lesions in the right cerebellum and persistent enhancement of posterior fossa, but decreased hydrocephalus compared to the past MRI. Interestingly, hypothyroidism and glucose intolerance were newly noted on laboratory findings. Conclusions or Commentes: This patient showed newly developed hemifacial spasm and acute lesions in the right cerebellum with negative results on CSF studies. Whether these findings were coincidental or an outcome of masking of laboratory results owing to changes in the patient`s immune system cannot be concluded. This report implies that Cryptococcal infection could show variable radiologic findings after resolution.