Abstracts

Patients with epilepsy are predisposed to falls resulting in dislocations and fractures. Those with osteopenia and osteoporosis have an increased risk of fracture. Osteoporosis is a disorder characterized by decreased bone mineral density and deterioration of bone microarchitecture, leading to fragility. Several older antiepileptic drugs (AED) have been associated with osteopathies. Data was collected from two geographically diverse epilepsy centers. In evaluation 1, a 30-question survey was given to over 150 epileptic patients on AEDs at the University of Miami clinics. Questions addressed risk factors for bone loss, diagnosis of epilepsy and prior treatment with AEDs. In some of these patients, bone mineral density (BMD) at the femoral neck was evaluated by dual energy x-ray absorptiometry (DXA). In the second evaluation, determinations of serum 25-OH vitamin D (25-OHD) concentrations as well as DXA scans at the proximal femur were done in patients over 50 years of age, receiving monotherapy with an enzyme inducing AED. In both evaluations, osteopenia was defined as DXA T-scores between -1 and -2.4, and osteoporosis at T-score greater than -2.5. Optimal 25-OHD concentration was considered to be [ge] 30 ng/ml. Evaluation 1, mean age of those surveyed was 41.4 years with 44% being male. From the survey, indicators of potential bone disease were loss of height (10%), and fractures as an adult 27 (30%). Generalized or localized bone aching was reported in 43.3% of patients. Falls occurred in 40% with significant injuries reported in 22% during the prior year. DXA scans were obtained in patients taking phenytoin (47%), carbamazepine (34%), valproate (24%) and primidone (4%). DXA measured at the femur, in 21 patients (66% male, mean age: 65 years) revealed 42.8% with osteopenia and 28.6% with osteoporosis. A diagnosis of osteoporosis had previously been given to only 12.2%.
In Evaluation 2, a mean 25-OHD of 24.4 ng/ml was measured in 30 male patients (mean age: 76 years). 57% of these patients were receiving phenytoin (25-OHD=23.4 ng/ml), and 43% carbamazepine (25.6 ng/ml). 30% of patients had 25-OHD [lt] 20 ng/ml. DXA scans were performed in 23 patients. 39.1% had osteopenia and 17.4% had osteoporosis. None had previously been diagnosed with a bone disorder. These results indicate a high prevalence of decreased BMD in this population. These observations also suggest that many patients may have less than optimal 25-OHD concentrations. Importantly, our observations suggest that bone disorders may go unrecognized in many patients. These results emphasize the importance of proactive investigation of this potential disorder, particularly in those patients reporting previous fractures or perhaps bone pain.