[Clinical course and serial brain MRI findings in a patient with Lissauer form of general paresis].

A 60-year-old man presented with progressive dementia and generalized convulsions. An initial MRI revealed a widespread high-intensity area with a mass effect in the right frontal and temporal lobes on T2-weighted images. Findings on digital subtraction angiography were normal. Serum and CSF tests showed high titers of antibodies to Treponema pallidum, which helped to distinguish neurosyphilis from glioma. He was initially treated with penicillin injection; however, it caused liver dysfunction and penicillin was switched to erythromycin. Even after antibiotic therapy for 2 months, his dementia did not improve. He underwent brain MRI four times during the treatment course, and they showed steady progression of brain atrophy in the right hemisphere. Taking these findings together, we diagnosed Lissauer form of general paresis. To the best of our knowledge, this is the first case of Lissauer form of paretic neurosyphilis, in which the progression of brain atrophy was clearly demonstrated on MRI.