1Department of Anatomical Pathology, Shinshu University Hospital, Asahi, Matsumoto 2Departments of Internal Medicine, and 3Neurosurgery, Iida Municipal Hospital, Iida, Nagano 4Department of Parasitology, National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 5Department of Anatomic Pathology, Iida Municipal Hospital, Iida, Nagano, Japan.