Renal stone associated with the ketogenic diet in a 5-year old girl with intractable epilepsy

In this paper, we report on a 5-year-old girl who developed a renal stone while following the ketogenic diet to treat refractory seizure disorder. Three months after initiating the ketogenic diet, she developed severe abdominal pain and vomiting. The spot urine calcium-to-creatinine (Ca/Cr) ratio and 24-hour urine evaluation showed hypercalciuria. Computed tomography (CT) imaging revealed a stone in the right ureteropelvic junction, resulting in hydronephrosis of the right kidney. The renal stone disappeared 5 days after conservative treatment; the patient's microscopic hematuria resolved concurrently. In light of this case report, we recommend regularly monitoring the urine Ca/Cr ratio with ultrasonography for further development of renal stones in patients following the ketogenic diet. If these patients exhibit evidence of symptomatic hypercalciuria or cyristalluria, liberalization of fluid restriction and urine alkalization using oral potassium citrate should be considered.