Hypercalciuria in children with febrile convulsions.

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.

Incidence of bacteremia, urinary tract infections, and unsuspected bacterial meningitis in children with febrile seizures.

PURPOSE: To determine the incidence of bacteremia, urinary tract infections, and unsuspected bacterial meningitis in a cohort of children diagnosed with febrile seizures. METHODS: We assembled a retrospective, consecutive case series of patients who presented to an urban tertiary care pediatric emergency department for evaluation of febrile seizures during a consecutive 12- month period. A febrile seizure was defined as a convulsion associated with a temperature > or = 38.0 degrees C occurring in a child < or = 6 years. Children with initial laboratory evidence of meningoencephalitis in the emergency department (>8 white blood cells per milliliter of cerebrospinal fluid), known seizure disorders, chronic neurologic disease, or documented immunodeficiencies were excluded. RESULTS: There were 243 eligible patient encounters among 218 patients during the study period. The mean age was 1.9+/-0.96 years (range 0.3-5.9, median 1.7), and 156 (64.2%) were male. Of the 243 encounters, 214 (88.1%) were for simple febrile seizures and 29 (11.9%) were for complex febrile seizures. Blood cultures were performed during 206/243 encounters (84.8%), and 6/206 (2.9%, 95%CI 0.6-5.2%) were positive, all for Streptococcus pneumoniae. All six positive cultures occurred among the 154 encounters in children 3 to 36 months with a temperature > or = 39.0 degrees C and no pretreatment with antibiotics (incidence 6/154 or 3.9%, 95% CI 0.9-6.9%). Urine cultures were performed during 130/243 encounters (53.5%), and 1/130 (0.7%, 95% CI 0.0-2.2%) yielded a bacterial pathogen. Cerebrospinal fluid analysis was performed during 66/243 encounters (27.2%), and 0/66 (0.0%, 95% CI 0.0-4.5%) yielded bacterial pathogens. CONCLUSIONS: Patients presenting for evaluation of febrile seizures are not at increased risk for bacteremia or urinary tract infections. Bacterial meningitis in the absence of initial laboratory evidence of meningoencephalitis is very uncommon in children diagnosed with febrile seizures.

Unsuspected bacterial infections in febrile convulsions.

In a 12-month prospective study in 1984, blood and urinary cultures were obtained as a routine from 307 children who presented with fever and convulsions to the Mater Misericordiae Children's Hospital, Brisbane, and the results were compared with data from 1981-1983 when cultures were not taken as a routine. In the prospective study, bacteraemia was found in 12 (4.3%) of 282 patients but was not suspected clinically in half of these; urinary-tract infection was found in seven (2.6%) of 272 patients and in six of these it was not suspected clinically. All 12 patients with unsuspected bacteraemia or urinary-tract infection had persistent fever; of these, nine patients suffered simple convulsions and all cases of urinary-tract infection occurred in female patients. Bacteraemia was significantly more common in patients of less than two years of age, in children who were selected for lumbar puncture and in the study period compared with the retrospective period, 1981-1983. Leukocytosis (white-cell count, more than 15.0 X 10(9)/L) was a sensitive (75%) diagnostic aid but was poorly specific (59%) for bacteraemia. Bacterial meningitis was not diagnosed initially in four of the nine cases which occurred among children who presented with fever and convulsions between 1981 and 1984; in all four children, the cerebrospinal fluid appeared normal at hospital admission. We conclude that bacteraemia and urinary-tract infections are detected more frequently in children who are admitted to hospital with febrile convulsions when cultures are performed as a routine. In the at-risk group (children of less than two years of age), the prevalence of urinary-tract infection is increased in female patients and the prevalence of bacteraemia is increased in those patients who are selected for lumbar puncture. The use of leukocytosis as a criterion to determine the need for blood cultures improves the diagnostic yield but would result in increased costs and additional venepuncture. Bacterial meningitis was rare in our case series and the performance of a lumbar puncture as a routine at admission to hospital would not have led to its earlier diagnosis.

Hydroxykynurenine/hydroxyanthranilic acid ratios and febrile convulsions.

Hydroxykynurenine/hydroxyanthranilic acid ratios were measured in children with febrile convulsions, afebrile fits, and fever, as well as in healthy controls. Increased ratios were found not only in the children who had fits but also in the children who were febrile and did not have fits. It is suggested that a raised hydroxykynurenine/hydroxyanthranilic acid ratio does not necessarily indicate vitamin B6 deficiency but may represent a nonspecific response of tryptophan metabolism to stress.