Background: The purpose of the present study was to investigate whether
idiopathic hypercalciuria may be implicated in the pathogenesis of
febrile convulsions.
Methods: We studied 38 children (22 boys) with febrile convulsions (mean
(+/-SD) age 3.25+/-1.09 years) and 45 healthy children (28 boys) of
similar age who served as controls. Twenty-four hour urine calcium and
phosphate, as well as serum calcium, phosphate, alkaline phosphatase and
intact parathyroid hormone (PTH) concentrations were determined.
Results: Hypercalciuria (urine Ca >4.0 mg/kg bodyweight per 24 h) was
found in nine children with febrile convulsions (23.7%) and in three
controls (6.7%). Hypercalciuric children excreted significantly more
phosphate in their urine (37.0+/-11.6 mg/kg bodyweight per 24 h) than
normocalciuric children (18.7+/-8.7 mg/kg bodyweight per 24 h) and
controls (20.2+/-7.6 mg/kg bodyweight per 24 h). They also had higher
serum intact PTH concentrations (49.87+/-15.36 pg/mL) than
normocalciuric (35.39+/-15.67 pg/mL) and control children (28.21+/-14.00
pg/mL). According to the calcium-loading test, eight of nine children
with hypercalciuria had the renal type of the disorder. Furthermore,
hypercalciuric children had significantly more convulsive episodes
(2.77+/-1.98) than normocalciuric children (1.86+/-1.24).
Conclusions: Our results suggest that renal hypercalciuria may be
implicated in the pathogenesis of febrile convulsions
