RESUMO
A 74-year-old man presented with positional vertigo and prandial dizziness and syncope. He had experienced episodes of frequent dizziness and loss of consciousness for several months. He underwent total gastrectomy with esophagojejunostomy and brown anastomosis 30 years ago. Thirteen years ago, subtotal colectomy with ileo-descending colostomy was done due to colon cancer. And he also had mitral valve replacement and maze operation due to severe mitral valve stenosis and atrial fibrillation. After cardiac operation, he has suffered from sudden dizziness with diaphoresis and chalky face, which usually occurs especially within 30 minutes from the onset of eating. Sometimes, this event was followed by several seconds of loss of consciousness, which caused recurrent events of falling. Neurological examination showed positional nystagmus compatible with benign paroxysmal positional vertigo arising from posterior semicircular canal of the right ear. The positional vertigo disappeared immediately after canalith repositioning maneuver. We tried to monitor vital signs and serum level of glucose during eating. Hyperglycemia (range, 210–466 mg/dL) was noted during eating, which was accompanied by postprandial and prandial hypotension, up to 60/40 mmHg. The patient was prescribed 100 mg of the alfa-glucosidase, acarbose to be taken half an hour before each meal. Eventually, the treatment with acarbose ameliorated the prandial dizziness and hypotension associated with hyperglycemia. Our patient suggests the acarbose could prevent postprandial dizziness and hypotension.