Częstość występowania i czynniki ryzyka kamicy nerkowej związanej z dietą ketogenną u dzieci z opornościową epilepsją: doświadczenia szpitala trzeciego stopnia

OBJECTIVES: Objectives: The ketogenic diet (KD) is a recognized non-pharmacological treatment option for children with drug-resistant epilepsy (DRE). However, concerns persist regarding metabolic and renal complications, including nephrolithiasis. This study aimed to describe the incidence, clinical characteristics, and factors associated with renal stones in pediatric patients treated with KD or modified Atkins diet (MAD), and to characterize stone management strategies and clinical outcomes. METHODS: This retrospective cohort study was conducted at the Pediatric Neurology Clinic of King Fahad Specialist Hospital-Dammam (KFSHD). A total of 112 children initiated dietary therapy (KD or MAD) during the study period; 80 patients with adequate follow-up and complete clinical, laboratory, and imaging data were included in the final analysis. Extracted variables included diet type, ketogenic ratio, duration of therapy, antiseizure medications, carbonic anhydrase inhibitor (CAI) use, metabolic parameters, and serial renal ultrasonography findings. The primary outcome was the development of nephrolithiasis or nephrocalcinosis. Clinical and treatment characteristics were compared between patients with and without renal stones. RESULTS: Renal stones or nephrocalcinosis were identified in 11 of 80 patients (13.8%), while 69 patients (86.2%) showed no evidence of renal stones during follow-up. Patients who developed renal stones were older at KD initiation (p = 0.025) and were more frequently treated with higher ketogenic ratios (≥3:1), although this difference did not reach statistical significance (p = 0.071). All patients who developed kidney stones were on KD and no children receiving MAD developed renal stones/nephrocalcinosis; however, this finding was interpreted descriptively only because of the small MAD sample size. Concomitant CAI use, etiology, mobility status, route of feeding, KD duration, and number of antiseizure medications were not significantly associated with stone development. Management was predominantly conservative, and four patients required interruption of KD, with no patients requiring surgical intervention. A clinically meaningful seizure reduction (>50%) was observed in 60% of the cohort. CONCLUSION: In this single-center cohort of children with DRE, KD was generally well tolerated and associated with meaningful seizure reduction. Renal stones occurred in a subset of patients, were frequently asymptomatic, and were managed conservatively. Older age at diet initiation was associated with stone formation. Higher ketogenic ratios showed a non-significant trend toward increased risk of renal stones. Regular metabolic surveillance and routine renal imaging may facilitate early detection and allow continued dietary therapy in most patients. These findings suggest that KD can be implemented with acceptable renal safety when appropriately monitored.