2023 Volume 32 Issue 4 Pages 261-267
This report describes a case of granulomatous amebic encephalitis (GAE) that was detected early and treated.
We report the case of a 43-year-old man. He was taken by ambulance to his previous hospital with the left hemiplegia. Cranial magnetic resonance imaging (MRI) revealed sporadic multiple mass lesions in the bilateral cerebral hemispheres and widespread cerebral edema in the right frontal lobe. Subsequently, the patient was referred to our hospital. Diffusion-weighted imaging (DWI) of MRI showed high signals in the lesions. Contrast-enhanced computed tomography revealed a ring-like enhancement. Susceptibility-weighted imaging (SWI) of MRI revealed microhemorrhage within the lesions. Craniotomy was performed to collect biopsy samples. Periodic acid-Schiff staining suggested amebic encephalitis. Medication therapy was initiated at an early postoperative stage, and the patient was temporarily in remission. However, because some of the lesions grew in size, craniotomy was performed again to remove them. Based on the results of the scrutiny at the National Institute of Infectious Diseases, the GAE caused by Balamuthia mandrillaris or other free-living amoebas was diagnosed. As of 1 year after the initial examination, we are continuing pathological investigation while treating the patient on an ambulatory basis.
Although amebic encephalitis has a high fatality rate, there have been reports of survival that was achieved by the combination of medical and surgical treatments. The key is to obtain a diagnosis at an early stage. This case also suggested the effectiveness of SWI in understanding hemorrhagic changes in lesions.
