Abstracts

Rationale: It is well known that the risk of osteoporosis increases progressively with age. Osteopenia is reported in 15% US pre-menopausal women between ages of 30-40. Epilepsy is a debilitating chronic disease found in about 1% general population. In both men and women with epilepsy from teenage to elderly, the risk of skeletal fractures is 2-6 folds higher than general population. Chronic use of AEDs of older generation (both enzyme-inducers and inhibitors) is found at high risk of bone loss. Newer AEDs with relative less effect on P450 systems are expected having fewer adverse effects but their effects on bone health have not been well studied. Methods: We reviewed the results of DEXA scan (Dual Xray Absorptiometry) performed 4/2006-5/2007 patients with epilepsy followed at neurology clinic of Robert Wood University Medical Practice. Fifty-nine male and female patients aged of 19-77, All patients were taking ≥1 AED(s) at the time of DEXA studies. Past medical history, medications other than AEDs, statue, diagnosis of osteopenia/osteoporosis by WHO definition, duration and types of AED uses were reviewed. Results of T-scores and Z-scores of bone mineral densities of AP view L1-4 lumbar spine and left femoral neck are analyzed. Median T and Z scores are used for comparison. Results are grouped by history of AED types as Old (phenytoin, valproate, carbamazepine, ethosuximide, Phenobarbital); New (lamotrigine, levetiracetam, gabapentin, topiramate, oxcarbazepine, pregabalin and zonisamide) and combination of Old and New.Results: Thirty-one of 59 patients meet criteria of osteopenia or osteoporosis. About 75% (23/31) of them are under age 50 and 50% (16/31) are men. Surprisingly, high risk of bone mineral abnormality is noted in New group (9/14, 64.3%). This is similar or slightly more than the other two groups. Ten patients of the New Group were only oxcarbazepine therapy and 7 out of 10 were abnormal. However, those with abnormality in New Group are suspected with abnormality before AED treatment based on their statue and timing of DEXA scan after AED initiation. The results of combination group is worse compared to Old Group. Conclusions: 1. Patients with epilepsy are more common at risk of osteopenia and osteoporosis than general population as previously reported. 2. Baseline DEXA scan is strongly recommended. 3. Polytherapy may be associated with higher risk of abnormality of bone. 4. New AED may or may not have less adverse effect on bone density. Longer duration of well designed study is necessary for further evaluation.