Bone mineral density in a population of children and adolescents with cerebral palsy and mental retardation with or without epilepsy.

Purpose: The present study aimed to assess bone mineral density (BMD) in a population of children and adolescents with cerebral palsy and mental retardation with or without epilepsy. Methods: One hundred and thirteen patients (63 male and 50 female) were recruited for evaluation. Patients were divided in three groups: 40 patients (group 1) were affected by cerebral palsy and mental retardation, 47 (group 2) by cerebral palsy, mental retardation and epilepsy, and 26 (group 3) by epilepsy. The control group consisted of 63 healthy children and adolescents. Patients underwent a dual-energy X-ray absorptiometry /DEXA) scan of the lumbar spine (L1-L4) and z-score was calculated for each patient; t-score was considered for patients 18 years of age and older. Key-findings: Abnormal BMD was found in 17 patients (42.5%) in group 1, in 33 (70.2%) in group 2, and in 3 (11.5%) in group 3. In group 1 and 2, tetraparesis and severe/profound mental retardation were related to a significantly abnormal BMD (p= 0.003); notably, severe mental retardation was even more significant in group 1 (p= 0.0003). The multivariate analysis of independent factors on BMD (z-score) revealed a significant correlation between BMD (z-score) and age (p=0.04), body mass index (BMI) (p=0.002), and severe/profound mental retardation (p=0.03). Significance: a significantly lower BMD z score value was found in patients with cerebral palsy, mental retardation and epilepsy compared with those without epilepsy. The epileptic disorder appears to be an aggravating factor on bone health when comorbid with cerebral palsy and mental retardation. These findings are determined by many factors, but long term use of AEDs seems relevant.