1. Department of Neurosurgery, Memfys Hospital for Neurosurgery, Onitsha Expressway, Enugu, Nigeria,
2. Department of Neurosurgery, Shinshu University School of Medicine, Asahi, Matsumoto, Nagano, Japan.
3. Department of Laboratory Medicine, Shinshu University School of Medicine, Asahi, Matsumoto, Nagano, Japan.