[A geriatric case of hyperosmolar hyperglycemic state with osmotic demyelination syndrome that manifested with dysphagia].

The patient was an 84-year-old man who had been on insulin therapy for type 2 diabetes mellitus for 55 years. He had undergone bile duct stenting to avoid obstruction due to adenocarcinoma of the bile duct. The patient had suffered from fever and anorexia for two weeks, and had subsequently stopped insulin therapy. Since he showed signs of impaired consciousness, he was taken to the emergency room, and was diagnosed with a hyperosmotic hyperglycemic state (HHS) based on the following laboratory findings: blood glucose, 632 mg/dL; plasma osmolality, 391 mOsm/kg·HO; and serum Na, 163 mEq/L, with urine ketone bodies±and sepsis (Klebsiella pneumoniae). He was therefore admitted to the hospital. His blood glucose and serum Na levels slowly improved following the administration of fluids, insulin, and antibiotics. The patient's consciousness disturbance also improved. However, on the third day after admission, dysphagia was newly observed when the patient resumed eating, and swallowing endoscopy revealed a delayed gag reflex and pharyngeal retention of saliva. Cranial magnetic resonance imaging showed a high-intensity area in the central pontine, which was considered to be caused by osmotic demyelination syndrome (ODS). The patient's oral intake ability recovered with swallowing rehabilitation. ODS is a rare complication of HHS. We report a case of HHS with ODS, in which the patient's chief complaint was dysphagia, which should be distinguished from other diseases.