2014 Volume 36 Issue 6 Pages 443-448
The patient was a 75-year-old female who developed disturbance of consciousness, right hemiplegia, aphasia, and a high fever and was transported to our hospital by ambulance. On MRI (DWI), high-intensity regions were diffusely present in the splenium of the corpus callosum, hippocampus, and deep white matter of the left temporal lobe. The patient was initially diagnosed with multiple cerebral infarction and treated with general drip infusion and oral drugs. Pneumonia was also present, and treated with antibiotics. After admission, fever was gradually resolved and right hemiparesis improved, but aphasia remained. On MRI, performed to follow the course, the lesions had disappeared on DWI and FLAIR, and no abnormality was noted on MRA. Based on the clinical course and imaging findings, clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) was strongly suspected. MERS should be included in the differential diagnosis even in elderly patients. Transcortical sensory aphasia and acalculia remained in this patient, unlike reported cases, for which we considered the possibility of reduced cerebral blood flow in the left temporal lobe due to the commissural fibers of the splenium of the corpus callosum.
