Clinical Features of Seizures Related to Rickets in Breastfed Children

Kang, Ben; Jung, Sook Young; Kim, Soon Ki; Lee, Jee Eun; Son, Byong Kwan; Kwon, Young Se

Abstract

PURPOSE
This study was aimed to evaluate the clinical features of seizures in breastfed children with vitamin D deficient rickets.
METHODS
Seventeen children, breastfed and diagnosed as vitamin D deficient rickets at Inha University Hospital from January 2000 to July 2010, were retrospectively investigated. Subjects were divided into two groups according to the presence/absence of seizures. Demographic and biochemical results were compared and statistically analyzed between the two groups, and the relative risk for seizure occurrence was estimated. Clinical features of seizures were also analyzed.
RESULTS
Out of the 17 subjects, nine patients (53.0%) had seizures, while eight patients (47.0%) did not. The mean age for the two groups were 4.1+/-2.0 months and 9.3+/-2.7 months, respectively, which was statistically different between the two groups (P<0.0001). Serum calcium (Ca) and 25-hydroxyvitamin D3 (25-OHD3) levels were significantly lower in the 'seizure' group (5.7+/-1.0 vs. 9.5+/-0.9 mg/dL, P<0.0001; 5.7+/-0.8 vs. 15.3+/-4.2 IU/L, P<0.0001). The relative risk for seizure occurrence was 8 times higher in hypocalcemia and 17 times higher in 25-OHD3<8 ng/mL. Seizures occurred several times as generalized or focal types, but none of them developed epilepsy nor showed developmental abnormalities later on.
CONCLUSION
Seizures in breastfed children with vitamin D deficiency rickets are mainly due to hypocalcemia, which is affected by 25-OHD3 levels. Seizures may also occur more frequently in children in the stages of rapid growth. Although seizures occurred multiple times, future outcomes were favorable. Further large-scaled prospective studies are required in the future.