Bone Mineral Density of Epileptic Patients on Long-term Antiepileptic Drug Therapy: a Quantitative Digital Radiography Study

In order to assess the bone atrophy lesions of epileptic patients, the bone mineral densities (BMDs) of their lumbar spines and femoral necks were measured using quantitative digital radiography (QDR). The study groups were 44 patients on long-term medication for epilepsy and 62 healthy control subjects. We selected patients who had been taking phenytoin, barbiturates, and/or acetazolamide for at least 5 years. BMDs at both sites were significantly lower in the patient group than in the control group. No sex differences were found in BMDs. There were no significant correlations with the onset or the duration of illness and BMD. We compared BMD according to the type of epileptic drug being taken and theorized that phenytoin, barbiturates, and acetazolamide reduced BMD. BMDs of the 15 patients were measured again 7 years later, and were found to be significantly lower at both sites than in the previous examination. These results confirm the presence of bone atrophy lesions in epileptic patients on long-term antiepileptic drugs. Patients on antiepileptic therapy for long periods should have their BMDs checked, because they are prone to developing bone atrophy.