1. Department of Neurosurgery, Hoshi General Hospital, Koriyama, Fukushima, Japan;
2. Department of Neurosurgery, Fukushima Medical University, Fukushima, Fukushima, Japan;
3. Department of Surgery, Hoshi General Hospital, Koriyama, Fukushima, Japan;
4. Department of Gastroenterological Medicine, Hoshi General Hospital, Koriyama, Fukushima, Japan;
5. Department of Diagnostic Pathology, Fukushima Medical University, Fukushima, Fukushima, Japan