Abstracts

Rationale: Epilepsy affects 1% of the population across all age groups. Most of the patients are on one or more Anti Epileptic Drugs (AEDs). Epilepsy as well as its treatment with AEDs are well known to reduce Bone Mineral Density (BMD) and cause fractures. However the most effective way of managing this complication is unclear. The objective of this study was to compare the effects of different AEDs in their likelihood of contributing to bone loss and to determine the efficacy of bisphosphonate therapy in reversing AED-induced bone loss and bone fractures.Methods: We conducted retrospective chart review of the patients with epilepsy who are followed at the affiliated hospitals of the State University of NY at Buffalo. Information regarding history, and past and current medications were reviewed. Specific attention was paid to parameters such as the results of Dual Energy X-ray Absorptiometry (DEXA) scan, history of fractures, and use of Calcium, Vitamin D and Bisphosphonates. Comparison between groups with Normal bone density Vs. Osteopenia and Osteoporosis was made using Chi- Square analysis.Results: Of a total of 414 patients with epilepsy (age range 17-85) 130 underwent DEXA scan of which 45 (35%) were normal, 52 (41%) had osteopenia and 31 (24%) had osteoporosis. The combined number of patients with osteopenia and osteoporosis Vs normal was statistically significant (p <0.0008). In this subpopulation of 130 patients, 37.5% had medically refractory epilepsy and 56% carried a diagnosis of developmental delay (MRDD). Concurrent history of MRDD, previous use of Carbamazepine and current polypharmacy with two or more AEDs were predictors of bone loss (P values <0.0002, <0.013 and <0.011 respectively). A total of 40 Patients were put on Bisphosphonates after diagnosis of osteopenia or osteoporosis and all of them were put on Calcium and vitamin D (average 1200 mg + 800 IU daily). DEXA scan was repeated in 8 patients after 1-2 years of taking Bisphosphonates. Six Patients showed positive trends with mean improvement in T score of 0.59 over 1-2 years. One Patient with history of Multiple Sclerosis on monthly IV Solumedrol showed worsening of her bone density measure and one Patient showed no significant change. A total of 18 patients reported bone fractures (12 with osteoporosis, 4 with osteopenia and 2 with normal bone density), 13 of which were on bisphosphonates. The bone fracture in all but one patient occurred prior to the start of the bisphosphonate agent.Conclusions: Our review of 414 patients with epilepsy taking AEDs confirms the high prevalence of bone loss in this population of patients with risk factors including polypharmacy, history of MRDD and use of Carbamazepine in the past. We have found encouraging positive trends in potential reversibility of bone loss and likely prevention of bone fractures in this population of patients with the use of Bisphosphonates for 1-2 years. The rest of the patients on bisphosphonates are undergoing repeat DEXA scan and the results will be reported in the near future.