Dementia with Lewy bodies (DLB) is characterized by Lewy pathology in the peripheral and central nervous systems. It often presents with various somatic complaints in addition to neuropsychiatric symptoms such as cognitive dysfunction. Recently, the early appearance of Lewy pathology in the peripheral nerves of the gastrointestinal tract, especially esophageal lesions, which may correlate with the spread of systemic Lewy pathology and autonomic neuropathy, has been considered as a candidate prognostic marker. Thus, digestive symptoms as early symptoms of DLB have attracted attention in clinical practice.
 Herein, we describe a case in which nausea preceding the diagnosis of DLB was considered an early symptom. The patient was a woman in her 60 s who had experienced nausea for two years, and she was initially diagnosed as having somatic symptom disorder after repeated detailed examinations. She then developed poor oral intake and significant weight loss, with a body mass index (BMI) in the 13 kg/m² range. She was admitted to the Department of Psychiatry at a general hospital. A close examination did not identify the cause of her nausea. However, probable DLB was diagnosed based on cognitive decline, extrapyramidal symptoms, decreased sense of smell, decreased accumulation of dopamine transporters in the striatum bilaterally, and decreased uptake on early and late metaiodobenzylguanidine myocardial scintigraphy. This case showed that it is necessary to consider the possibility of DLB in elderly persons with unexplained gastrointestinal symptoms. The case is reported along with a review of the literature.
 Authors' abstract