Comment on Gastrointestinal Symptoms Associated with Orthostatic Intolerance

Dear Editor, We read with interest the article by Sullivan et al. (1) entitled "Gastrointestinal Symptoms Associated with Orthostatic Intolerance." In this context, it is noteworthy that several studies have provided evidence of an association between orthostatic intolerance and the "nutcracker syndrome." Hilgard et al. (2) reported that the coexistence of this syndrome with severe gastrointestinal symptoms and paroxysmal tachycardia may be caused by congestion of the splanchnic veins consequent to obstruction of the left renal vein. Takemura et al. (3) reported 4 adolescents who complained of physical discomfort, including headache, abdominal pain, fainting and tachycardia thereby mimicking the clinical symptoms of an orthostatic disturbance, which resulted in absence from school. Three patients were found to have nutcracker syndrome, and Takemura et al postulated that a decreased venous blood flow back to the heart, caused by congestion of blood in the left renal vein, might have caused the tachycardia and palpitations in these patients. Takahashi et al. (4) also described 9 children with orthostatic dysregulation who were intermittently or persistently absent from school. Also, the patients complained of various combinations of symptoms, such as chronic fatigue, headache, lightheadedness, dizziness, abdominal pain, unrefreshing sleep, muscle pain, joint pain, sore throat, low-grade fever, afebrile chills in hot summer and depression, which were compatible with the criteria of a disease entity of chronic fatigue syndrome or idiopathic chronic fatigue. Takahashi et al. speculated that severe congestion in the adrenal medulla caused by left renal venous hypertension might derange a complex set of central neural connections that controls the sympathoadrenal system. Alternatively, they suggested that overproduction or night retention of catecholamines might be responsible for these symptoms. Takahashi et al. (5) reported the case of 13-year-old girl who had been monitored because of a school phobia associated with orthostatic hypotension, tachycardia and chronic fatigue syndrome. This patient was successfully treated with transluminal balloon angioplasty of the compressed left renal vein between the aorta and superior mesenteric artery. Chronic fatigue syndrome and autonomic dysfunction symptoms also improved after catheter manipulation, which suggests that there could be a link between nutcracker syndrome and these autonomic symptoms. In conclusion, orthostatic intolerance appears to be closely related with nutcracker syndrome. Further studies are necessary to elucidate the prevalence and hemodynamic or neuroendocrine effects of nutcracker syndrome in children with orthostatic intolerance and abdominal pain. Jae Il Shin, MD Jae Seung Lee, MD The Institute of Kidney Disease Department of Pediatrics Yonsei University College of Medicine Severance Hospital Seoul, Korea