Cyclic Vomiting Syndrome

Cyclic vomiting syndrome (CVS) is relatively rare but highly incapacitating brain-gut disorder. Several potential pathophysiologic factors are considered; migraine, cellular energy deficits induced by mitochondrial DNA mutation and enzymopathies, stress response with corticotropin-releasing factor, and autonomic dysfunction due to altered brain stem regulation. Paroxysmal, especially severe, recurrent, stereotypical vomiting is hallmark clinical feature of CVS. The different diagnosis of CVS cuts a broad swath across neurologic, gastrointestinal, renal, metabolic, and endocrinologic disorders. Diagnostic investigations include diverse blood and urine screening, gastrointestinal contrast study, abdominal/renal USG/CT scan, cranial MRI, and gastrointestinal endoscopic evaluation. Treatment of CVS is divided between acute intervention, when a patient is actively and severe vomiting, and prophylactic treatment for patients in their interictal phase, the goal of which is reducing frequency and intensity of subsequent episodes.