Abstracts

Rationale: Osteopenia and osteoporosis are typically defined in women using bone mineral density T-scores of -1.0 and -2.5, respectively. Low bone density is an independent risk factor for fracture and prior reports state vertebral fracture in men may be associated with reduced bone mineral density. However, bone mineral density testing has not been validated to evaluate bone health in epileptic males. We describe bone mineral density findings and symptomatic bone pathology in a series of young epileptic males. Methods: We reviewed medical records from males aged 18-50 years undergoing inpatient video EEG monitoring at Mayo Clinic Arizona from 2004-2007. The records of patients with a final diagnosis of epilepsy were reviewed for reports of bone mineral density testing, symptomatic and silent fractures, length of AED exposure, seizure frequency, and seizure description. Results: One hundred eight men with epilepsy were identified from 170 admissions. Of these, 13 (12%) had bone mineral density testing. Three patients had osteoporosis, and all of whom had at least one generalized tonic-clonic seizure per month without report of symptomatic or silent fracture. Median duration of AED exposure was 20 years. Three patients had osteopenia, one of whom had symptomatic vertebral and lumbar compression fractures after a generalized tonic-clonic seizure. Median duration of AED exposure was 7 years, and all patients had generalized tonic-clonic seizures. Four additional patients were identified who suffered symptomatic thoracic vertebral compression fractures in the setting of generalized tonic-clonic seizures and non-osteopenic bone mineral density. Seizure frequency ranged from once per week to once per year (median once per week), and median length of AED exposure was 19 years. None of the thirteen patients with bone mineral density testing had symptomatic extra-vertebral fractures, or silent fractures seen on radiographs done for other indications. Seven patients without bone mineral density testing reported extra-vertebral bone fracture in the setting of generalized tonic-clonic seizure, with median length of AED exposure 11 years and median seizure frequency of once per month. Ten of the twelve patients with fracture were exposed to hepatic enzyme-inducing AEDs. Conclusions: This series demonstrates that young men with epilepsy are at risk for seizure-related fracture, which may not correlate with osteopenic or osteoporotic bone mineral density, seizure frequency, or length of AED exposure. Furthermore, when fractures occur, they are symptomatic and the vertebral bodies may be particularly susceptible. These findings suggest that further study of the pathogenesis of fracture in young male epilepsy patients is needed to define and manage bone disease in this population.