Unusual Acute Pediatric Pyelonephritis Presenting With Cluster Convulsions by Possible Central Nervous System Lesion: A Case Report

Acute pyelonephritis is the leading cause of bacterial infection among children. It can be difficult to diagnose early in the disease course owing to non-specific symptoms and physical findings. Recently, some cases of pediatric acute pyelonephritis with mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) have been reported. We describe a case of a six-year-old boy who presented with a high fever and four episodes of cluster convulsions. Despite the absence of leukocyturia and hypo-inflammatory response in the blood, he was diagnosed with acute pyelonephritis by contrast-enhanced computed tomography seven days after onset. The convulsions were not simple febrile convulsions and suggested central nervous system (CNS) lesions, as the patient was older than the usual cut-off age of five years for febrile seizures. This case highlights an unusual presentation and clinical course of a case of pediatric acute pyelonephritis characterized by cluster convulsions and a poor inflammatory response. Furthermore, we strongly consider that the cause of the cluster convulsions may be related to MERS spectrum disorder and emphasize that pyelonephritis can be accompanied by CNS disturbances.